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IIIIIIII X*VII US EPA Contract No. 68-W9-0024 FINAL ENDANGERMENT ASSESSMENT TUTU WELLS SITE ST. THOMAS, VIRGIN ISLANDS VOLUME I OF IV REMEDIAL PLANNING ACTIVITIES AT SELECTED UNCONTROLLED HAZARDOUS SUBSTANCE DISPOSAL SITES WITHIN EPA REGION II (NY, NJ, PR, VI) CDM Federal Programs Corporation TUT OO& 2175 *64940* 64940 FINAL ENDANGERMENT ASSESSMENT TUTU WELLS SITE ST. THOMAS, VIRGIN ISLANDS VOLUME I OF IV Prepared for U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Waste Programs Enforcement Washington, DC 20460 EPA Work Assignment No. EPA Region Site No. Contract No. Document Control No. Prepared by Work Assignment Project Manager Telephone Number EPA Work Assignment Manager Telephone Number Date Prepared 073-2PID II VID982272569 68-W9-0024 7720:073-RA-CFKJ CDM Federal Programs Corporation Sally Odland (212) 393-9634 Caroline Kwan (212) 637-4275 March 24, 1995 TUT 006 2176 TABLE OF CONTENTS Section Page VOLUME I: EXECUTIVE SUMMARY BASELINE HUMAN HEALTH RISK ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . 1 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.2 Site Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.2.1 Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.3 Scope of the Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . 10 1.4 Organization of the Risk Assessment . . . . . . . . . . . . . . . . . . . 13 2.0 DATA COLLECTION AND EVALUATION . . . . . . . . . . . . . . . . . . 19 2.1 Summary of Sampling and Analysis Activities . . . . . . . . . . . . . 22 2.1.1 Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.1.2 Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.1.3 Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2.2 Summary of Sampling and Analysis Results . . . . . . . . . . . . . . . 32 2.2.1 Data Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2.2.2 Chemicals Detected in Soil . . . . . . . . . . . . . . . . . . . . 34 2.2.3 Chemicals Detected in Groundwater . . . . . . . . . . . . . . . 68 2.3 Criteria for the Selection of Chemicals of Potential Concern . . . . . 74 2.3.1 Blank Concentrations . . . . . . . . . . . . . . . . . . . . . . . 103 TUT 006 2177 TABLE OF CONTENTS (Cont'd) Page 2.3.2 Background Concentrations . . . . . . . . . . . . . . . . . . . 105 2.3.3 Physical and Chemical Properties . . . . . . . . . . . . . . . . 116 2.4 Evaluation of Tentatively Identified Compounds (TICs) . . . . . . . 119 2.5 Selected Chemicals of Potential Concern . . . . . . . . . . . . . . . . 120 3.0 EXPOSURE ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 3.1 Potential Release and Transport Mechanisms . . . . . . . . . . . . . 124 3.2 Identification of Exposure Pathways . . . . . . . . . . . . . . . . . . 124 3.2.1 Present-Use Scenarios . . . . . . . . . . . . . . . . . . . . . . . 127 3.2.2 Future-Use Scenarios . . . . . . . . . . . . . . . . . . . . . . . 136 3.3 Exposure Point Concentrations . . . . . . . . . . . . . . . . . . . . . . 141 3.3.1 Exposure Point Concentration Modeling . . . . . . . . . . . 143 3.4 Calculation of Chronic and Subchronic Daily Intakes . . . . . . . . 146 3.5 Exposure Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 3.5.1 Surface Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 3.5.2 Subsurface Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 3.5.3 Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 4.0 TOXICITY ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 4.1 Health Effects Criteria for Carcinogens . . . . . . . . . . . . . . . . 170 4.2 Health Effects Criteria for Noncarcinogens . . . . . . . . . . . . . . 178 TUT OO6 2178 TABLE OF CONTENTS (Cont'd) 4.2.1 Toxicity Endpoints/Target Organs for Noncarcinogenic Chemicals of Potential Concern Quantitatively Evaluated in the Risk Assessment . . . . . . . . . . . . . . . . . . . . . . 181 4.3 Qualitative Discussion of Chemicals Not Quantitatively Evaluated in the Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . 185 5.0 RISK CHARACTERIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . 190 5.1 Carcinogenic Risk Characterization . . . . . . . . . . . . . . . . . . . 190 5.2 Noncarcinogenic Effects Characterization . . . . . . . . . . . . . . . 191 5.3 Quantitative Results of Carcinogenic Risk and Noncarcinogenic Effects Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 5.3.1 Surface Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 5.3.2 Subsurface Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 5.3.3 Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 5.4 Combining Cancer Risks and Noncancer Hazard Index Values Across Exposure Pathways . . . . . . . . . . . . . . . . . . . . . . . . 209 5.5 Applicable or Relevant and Appropriate Requirements (ARARs) . 216 6.0 UNCERTAINTIES IN RISK ASSESSMENT . . . . . . . . . . . . . . . . . 220 6.1 Central Tendency Calculations . . . . . . . . . . . . . . . . . . . . . . 223 6.1.1 Surface Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 6.1.2 Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 TUT OO6 217<? TABLE OF CONTENTS (Cont'd) Page 7.0 PRELIMINARY REMEDIATION GOALS . . . . . . . . . . . . . . . . . . 229 7.1 Residential Land Use: Soil Ingestion and Inhalation . . . . . . . . 230 7.1.1 Noncarcinogens . . . . . . . . . . . . . . . . . . . . . . . . . . 232 7.2 Commercial/Industrial Land Use: Soil Ingestion and Inhalation . 235 7.2.1 Noncarcinogens . . . . . . . . . . . . . . . . . . . . . . . . . . 235 7.3 Residential Land Use: Groundwater Ingestion and Inhalation . . . 237 7.3.1 Noncarcinogens . . . . . . . . . . . . . . . . . . . . . . . . . . 238 8.0 SUMMARY OF THE BASELINE RISK ASSESSMENT . . . . . . . . . . 242 VOLUME II: Baseline Risk Assessment Appendices APPENDIX A: 95 Percent Upper Confidence Limit Calculations APPENDIX B: Toxicological Profiles APPENDIX C: Spreadsheet Calculations APPENDIX D: Central Tendency Calculations APPENDIX E: Site Data VOLUME III: Baseline Risk Assessment Appendices (Cont'd) APPENDIX E (Cont'd): Site Data TUT 006 2180 VOLUME IV: ECOLOGICAL ASSESSMENT Ecological Assessment Appendices APPENDIX A: Contacts made for Ecological Information on the Site APPENDIX B: Threatened and Endangered Species/Significant Habitats APPENDIX C: Ecological Exposure and Toxicity TUT 006 2181 LIST OF TABLES Table 2-1 Groundwater Monitoring Program (February 1991 - March/April 1993) Table 2-2 Summary of Chemicals in Surface Soil - Tillett Gardens and Art Center Table 2-3 Summary of Chemicals in Surface Soil - Fire Department/Texaco Gas Station/ Antilles Auto Parts/Ramsay Motor Company Table 2-4 Summary of Chemicals in Surface Soil - Curriculum Center Building (Present) Table 2-5 Summary of Chemicals in Surface Soil - Curriculum Center Building (Future) Table 2-6 Summary of Chemicals in Surface Soil - O'Henry Dry Cleaners and Liquor Barn Table 2-7 Summary of Chemicals in Subsurface Soil - Tillett Gardens and Art Center Table 2-8 Summary of Chemicals in Subsurface Soil - Fire Department/Texaco Gas Station/ Antilles Auto Parts/Ramsay Motor Company Table 2-9 Summary of Chemicals in Subsurface Soil - Curriculum Center Building Table 2-10 Summary of Chemicals in Subsurface Soil - Esso Gas Station and Splash and Dash Car Wash Table 2-11 Summary of Chemicals in Subsurface Soil - O'Henry Dry Cleaners and Liquor Barn Table 2-12 Summary of Chemicals in Groundwater (Site-Wide) Table 2- 13 Chemical Concentration - Toxicity Screen for Surface Soil - Tillett Gardens and Art Center Table 2-14 Chemical Concentration - Toxicity Screen for Surface Soil - Fire Department/Texaco Gas Station/ Antilles Auto Parts/Ramsay Motor Company Table 2-15 Chemical Concentration - Toxicity Screen for Surface Soil - Curriculum Center Building (Present) Table 2-16 Chemical Concentration - Toxicity Screen for Surface Soil - Curriculum Center Building (Future) Table 2-17 Chemical Concentration - Toxicity Screen for Surface Soil - O'Henry Dry Cleaners and Liquor Barn TUT 006 2182 LIST OF TABLES (Cont'd) Table 2-18 Chemical Concentration - Toxicity Screen for Subsurface Soil - Tillett Gardens and Art Center Table 2-19 Chemical Concentration - Toxicity Screen for Subsurface Soil - Fire Department/Texaco Gas Station/Antilles Auto Parts/Ramsay Motor Company Table 2-20 Chemical Concentration - Toxicity Screen for Subsurface Soil - Curriculum Center Building (Future) Table 2-21 Chemical Concentration - Toxicity Screen for Subsurface Soil - Esso Gas Station and Splash and Dash Car Wash Table 2-22 Chemical Concentration - Toxicity Screen for Subsurface Soil - O'Henry Dry Cleaners and Liquor Barn Table 2-23 Chemical Concentration - Toxicity Screen for Groundwater (Site-Wide) Table 2-24 Polycyclic Aromatic Hydrocarbon Compound Classification Table 2-25 Soil Background Samples: Analytical Data - Detections Only Table 2-26 Chemical Concentrations in Site Surface Soil versus Surface Soil Background Concentrations Table 2-27 Chemical Concentrations in Site Subsurface Soil versus Subsurface Soil Background Concentrations Table 2-28 Summary of Chemicals of Potential Concern in Site Matrices by Area of Concern Table 3-1 Potential Exposure Pathways Table 3-2 Inhalation of Airborne Chemicals (Shower Scenario) Table 3-3 Ingestion of Chemicals in Soil Table 3-4 Dermal Contact with Chemicals in Soil Table 3-5 Inhalation of Indoor and Outdoor Particulates Table 3-6 Inhalation of VOCs from Surface Soil Table 3-7 Ingestion of Chemicals in Drinking Water TUT 006 2183 LIST OF TABLES (Cont'd) Table 3-8 Dermal Contact with Chemicals in Groundwater While Showering Table 3-9 Variables Used for Chronic and Subchronic Daily Intake Calculations Table 4-1 Toxicity Values for Potential Carcinogenic Health Effects - Dose - Response Relationship Table 4-2 Chronic Toxicity Values for Potential Noncarcinogenic Health Effects - Dose - Response Relationship Table 4-3 Subchronic Toxicity Values for Potential Noncarcinogenic Health Effects - Dose - Response Relationship Table 4-4 Toxicity Endpoints/Target Organs for Noncarcinogenic Chemicals of Potential Concern Quantitatively Evaluated in the Risk Assessment Table 5-1 Combining Carcinogenic Risks Across Pathways Table 5-2 Combining Noncarcinogenic Hazard Index Values Across Pathways Table 5-3 Detected Concentrations versus Maximum Contaminant Levels (MCLs) for Chemicals of Potential Concern in Groundwater Table 6-1 Variables Used for Chronic and Subchronic Daily Intake Calculations for Central Tendency Evaluation (50* Percentile) Table 7-1 Soil Risk-Based Preliminary Remediation Goals (PRGs) for Noncarcinogens - Residential and Commercial/Industrial Ingestion and Inhalation Table 7-2 Groundwater Risk-Based Preliminary Remediation Goals (PRGs) for Noncarcinogens - Residential Ingestion 006 2184 LIST OF FIGURES Figure 1-1 Site Location Map 2-1 Site Map (Areas of Concern) TUT OO6 21SS LIST OF ABBREVIATIONS ABS AF ARARs ARCS AT BW CA GDI CERCLA CF CS CW CAG CDM Federal CLP CRAVE DPNR ED EF ET FI FS HEAST IR IRIS LOAEL MCL MF NCP NOAEL NPL PAH PC PCB PRG PRP RAGS-HHEM RAS RCRA Absorption Factor Soil-to-Skin Adherence Factor Applicable or Relevant and Appropriate Requirements Alternative Remedial Contracting Strategy Averaging Time Body Weight Chemical Concentration in Air Chronic Daily Intake Comprehensive Environmental Response, Compensation, and Liability Act Conversion Factor Chemical Concentration in Soil Chemical Concentration in Water Carcinogen Assessment Group CDM Federal Programs Corporation Contract Laboratory Program Carcinogen Risk Assessment Verification Endeavor Department of Planning and Natural Resources Exposure Duration Exposure Frequency Exposure Time Fraction Ingested Feasibility Study Health Effects Assessment Summary Tables Ingestion Rate; Inhalation Rate Integrated Risk Information System Organic Carbon Partitioning Coefficient Octanol-Water Partition Coefficient . Lowest-Observed-Adverse-Effect-Level Maximum Contaminant Level Modifying Factor National Oil and Hazardous Substances Pollution Contingency Plan No-Observed-Adverse-Effect-Level National Priority List Polycyclic Aromatic Hydrocarbon Chemical-Specific Dermal Permeability Constant Polychlorinated Biphenyl Preliminary Remediation Goal Potentially Responsible Party Risk Assessment Guidance for Superfund - Human Health Evaluation Manual Routine Analytical Services Resource Conservation and Recovery Act TUT OO6 2186 LIST OF ABBREVIATIONS (Cont'd) RF RfC RfD RME RI ROD RPM SA SF SQL SSC SVOC TAL TBC TCL TES TIC TPH UCL UF USEPA VF VIHA VOC WA WAPA Respirable Fraction Reference Concentration Reference Dose Reasonable Maximum Exposure Remedial Investigation Record of Decision Remedial Project Manager Skin Surface Area Slope Factor Sample Quantitation Limit Suspended Soil Concentration Semivolatile Organic Compound Target Analyte List To Be Considered Target Compound List Technical Enforcement Support Tentatively Identified Compound Total Petroleum Hydrocarbon Upper Confidence Limit Uncertainty Factor United States Environmental Protection Agency Soil-to-Air Volatilization Factor Virgin Islands Housing Authority Volatile Organic Compound Work Assignment Water and Power Authority TUT 006 2187 EXECUTIVE SUMMARY BASELINE HUMAN HEALTH RISK ASSESSMENT The Tutu Wells site is located on the eastern end of St. Thomas, U.S. Virgin Islands, at the Anna's Retreat Section (Figure 1-1). Many commercial businesses as well as private residences and the Virgin Islands Housing Authority (VIHA) multiple family units are located along the main road (Route 38) running through the site. Numerous water supply wells located at and in the vicinity of the site are utilized for a public drinking water supply. In July 1987, the Department of Planning and Natural Resources (DPNR) received a report of an odor emanating from a well on private property located at Anna's Retreat. The DPNR contacted the USEPA which determined, based on sampling, that drinking water wells at Tutu were contaminated with hazardous chemicals and petroleum products coming from two gas stations in the Tutu area. As a result, four wells were closed down by the DPNR due to high volatile organic compound (VOC) contamination. Under USEPA direction, cisterns served by the contaminated wells were disinfected, home plumbing was modified, contaminated wells were disconnected, and a local water hauler was contracted to deliver uncontaminated drinking water. A water sampling program to monitor the wells was also established by the USEPA. The USEPA issued a Unilateral Administrative Order to Esso Standard Oil Company, Texaco Caribbean, Inc., and O'Henry dry cleaners in March 1990 to conduct groundwater monitoring of the drinking water wells in the Tutu aquifer, and to provide water to affected homes until the respondents connected to the water main. Esso and Texaco entered into a RCRA 7003/9003 Order of Consent with the USEPA to conduct a Remedial Investigation/Feasibility Study (RI/FS) 1 TUT 006 2188 18*17 GERAGHTY & MILLER, INC. Environmental Services SCALE: SHOWN SITE LOCATION TUTU SERVICE STATION INVESTIGATION ST. THOMAS, U.S. VIRGIN ISLANDS FIGURE 1-1 Source: Technical Memorandum II - Results of the Field Program - Tutu Service Station Investigation by Geraghty & Miller (May 1993). at the site in February 1992. The site was proposed for the NPL in February 1992. This baseline human health risk assessment document for the Tutu Wells site provides quantitative estimates, in accordance with current USEPA policy and guidance, of the carcinogenic risks and noncarcinogenic health effects from human exposure to chemical contaminants in site environmental matrices in the absence of any site remediation and assuming no further institutional controls are put into place. This risk assessment process included data evaluation, exposure assessment, toxicity assessment, risk characterization, and uncertainty evaluation. The data used in this report were obtained from: • Geraghty & Miller's Draft Phase II RI Report (October 1994). Seven quarterly groundwater sampling reports produced by Geraghty & Miller (February 1991 through March/April 1993). • Technical Memorandum II - Results of the Field Program Tutu Service Station Investigation produced by Geraghty & Miller (May 1993). • CDM Federal Programs Corporation (COM Federal's) 1993 Data Comparison and Evaluation Report for Groundwater and Soil Split Samples of the Tutu Wells Site (June 1993). • CDM Federal's CLP Sample Analysis Data Summary of the 104(e) Letter Response Sampling Tutu Wellfield Area (September 8 through 15, 1988). • CDM Federal's Final CLP Sample Analysis Data Summary of Soils and Waters Sampled in 1989, Tutu Wellfield Site, St. Thomas, U.S. Virgin Islands (June 5 through 10, 1989). »06 2190 • Five groundwater samples collected from four monitoring wells at O'Henry dry cleaners by the O'Henry PRP in March 1993. Chemicals of potential concern were selected for each sampled matrix for quantitative evaluation in the risk assessment. The selected chemicals are expected to be most representative of site conditions and the greatest contributors to potential human health impacts. The chemicals of potential concern selected for each sampled matrix are presented in Table 2-28. Exposure scenarios (i.e., receptor groups and routes of exposure) were developed for both present and future land uses, as appropriate. The exposure point concentration for each chemical to which a person may be exposed was estimated by using the 95 percent Upper Confidence Limit (UCL) on the mean calculation as defined by USEPA guidance. Potential chemical intakes were then calculated using 95 percent UCL concentrations and reasonable maximum exposure (RME) variables. The toxicity assessment presents general lexicological properties and identifies health effects criteria of selected chemicals of potential concern using the most current lexicological human health effects data. Chemicals with insufficient lexicological data were qualitatively addressed. Carcinogenic risks and noncarcinogenic health effecls were then characterized by integrating these exposure and toxicily assessmenis inlo quantitative expressions of carcinogenic risk and noncarcinogenic hazard index values. The quantitative results of this risk assessment should not be construed as absolute values, but instead as estimates of potential human health impacts. By TUT 006 2191 /••^ using RME variables, conservative estimates of health risks/effects within the range of possible exposures were obtained. These estimates were then compared to the acceptable USEPA target risk range of KF'to 10"6 for carcinogens and target level of one for noncarcinogens. The 10"4 to 10"6 target risk range may be interpreted as meaning carcinogenic risks should not be greater than approximately 1 in 10,000 to 1 in 1,000,000. Based on consultation with the USEPA, a carcinogenic risk greater than 1 in 10,000 or 1 .OE-04 is considered in exceedance of the target risk range. Carcinogenic risks for present and potential future residential (adult and child) exposure to surface soil in the Tillett Gardens and Art Center via ingestion and dermal contact, and to groundwater via ingestion (adults and children), were in exceedance of the upper-bound of the /*\ USEPA's target risk range of 104 to 10"6 (i.e., greater than .1.OE-04). Present and potential future site worker (employee) exposure to groundwater via ingestion also showed a carcinogenic risk which was in exceedance of the upper-bound of the target risk range. While soil exceedances were due mainly to Aroclor 1242, groundwater exceedances were due mainly to the combined tetrachloroethene and vinyl chloride risks. Hazard index values for present and potential future residential (child only) exposure to surface soil in the Tillett Gardens and Art Center via ingestion and inhalation of particulates, as well as present and potential future resident (adult and child), site worker (employee), and construction worker (future-use only) exposures to groundwater via ingestion, were in exceedance of the USEPA's target level of one. The soil exceedances were due mainly to manganese while the I"UT OO6 groundwater exceedances were due mainly to 1,2-dichloroethene (total), tetrachloroethene, antimony, manganese, and vanadium. The range of detections for the chemicals of potential concern selected in groundwater were compared to Applicable or Relevant and Appropriate Requirements (ARARs), which include federal maximum contaminant levels (MCLs). In accordance with standard risk assessment practice, uncertainty in risk assessment is evaluated both qualitatively and quantitatively. A quantitative evaluation, involving the calculation of central tendencies, was performed for those exposure scenarios showing carcinogenic risks or noncarcinogenic hazard index values above the USEPA target levels. Risk-based preliminary remediation goals (PRGs), as defined by USEPA guidance, were developed for the residential groundwater exposure scenario for chemicals not having established MCLs. Soil PRGs were developed for manganese for residential and commercial/industrial combined ingestion and inhalation exposures (1,360 mg/kg and 9,900 mg/kg, respectively). These PRGs are presented in Table 7-1. Groundwater PRGs of 0.33 mg/1 and 0.18 mg/1 were developed for the noncarcinogens 1,2-dichloroethene (total) and manganese and are presented in Table 7-2. Available MCLs for chemicals of potential concern in groundwater are presented in Table 5-3. Finally, a summary of the results of the quantitative evaluation of potential carcinogenic risks and noncarcinogenic health effects was presented, with special note given to those results in TUT QO6 2193 exceedance of the USEPA target levels. Risks and hazards are discussed in detail in Section 5.0 and are summarized in Table 5-1 and 5-2. TUT OO6 2194 1.0 INTRODUCTION 1.1 Overview CDM Federal Programs Corporation (CDM Federal) originally received Work Assignment (WA) No. C02116 from the U.S. Environmental Protection Agency (USEPA) under the Technical Enforcement Support (TES) V Contract which expired on April 30, 1994. When the WA was transferred and reactivated as WA 073-2P1D under the Alternative Remedial Contracting Strategy (ARCS II) contract, CDM Federal completed the endangerment assessment. The purpose of this WA is for CDM Federal to provide technical assistance by conducting an endangerment assessment relating to the Remedial Investigation/Feasibility Study (RI/FS) currently being performed for the Tutu Wells site in St. Thomas, Virgin Islands. The specific objectives of this risk assessment are to evaluate appropriate site environmental matrices for potential human exposure routes to determine if adverse human health impacts are occurring at present and/or may occur in the future. This risk assessment was performed under the assumption that no additional corrective action will occur in the future. Presently, an order exists which states that site groundwater should not be used for drinking or bathing, but may be used for secondary purposes such as lawn watering and clothes laundering. TUT OO6 2195 This report was prepared in accordance with USEPA Region II and federal guidance documents and the on-line data base listed below. Additional references are listed in the reference section at the end of the report. Risk Assessment Guidance for Superfund: Human Health Evaluation Manual (USEPA, 1989a). Exposure Factors Handbook (USEPA, 1989b). Guidance for Data Useability in Risk Assessment (USEPA, 1992a). Dermal Exposure Assessment: Principles and Applications - Interim Report (USEPA, 1992c). Human Health Evaluation Manual, Supplemental Guidance: Standard Default Exposure Factors (USEPA, 1991a). Health Effects Assessment Summary Tables FY 1994-Annual (USEPA, 1994). Integrated Risk Information System On-line Data Base of Toxicity Measures (IRIS, 1994). 1.2 Site Background 1.2.1 Site Description The Tutu Wells site is located near the eastern end of St. Thomas, an island covering 32 square miles. As reported by Geraghty & Miller (1993a), the site is located within the Turpentine Run surface drainage basin which covers approximately 3.4 square miles. Turpentine Run is an intermittent stream which flows from northwest to southeast. The Turpentine Run basin is TUT OO6 2196 separated into upper and lower basins; the upper consists of 2.3 square miles upstream of the historical stream gaging station located near Mt. Zion and the lower consists of 1.1 square miles downstream of this station (Jordan and Cosner, 1973). The major highway routes running through the site are lined with both single and multiple family residences as well as commercial establishments. Public drinking water supply wells are located throughout the site and surrounding area, although at present, clean water is delivered to the area by truck for primary usage (i.e., drinking). The groundwater from some of these wells is currently used for secondary (i.e., non-potable) purposes only, such as clothes laundering and lawn watering. 1.3 Scope of the Risk Assessment Human .health risk assessments have been utilized by regulatory agencies for the development of regulatory guidelines and criteria for environmental pollutants. Guidelines and criteria impact large numbers of potential receptors, therefore, worst-case (conservative) assumptions have typically been used by the regulatory agencies to ensure adequate protection of public health. In the last few years, the USEPA has adopted these same risk assessment techniques to assist in resolving site-specific contamination problems. For these assessments, the goals are quite distinct. The first step is to evaluate the ways in which site contaminants might pose specific health threats to the public. For the sites where the estimated baseline risks are unacceptably high, a second step is taken. This step includes the identification and evaluation of potential 10 TUT OO6 2.197 engineering remedies, including the extent to which each alternative remedy might reduce the baseline risks to an acceptable level. As part of the effort to streamline the process and reduce the cost and time required to conduct the RI/FS and implement a clean up remedy if necessary, the Superfund human health evaluation focuses on providing information to justify action at the site and to select the best remedy for the site (USEPA, 1989a). For remedy decisions, utilizing worst-case approaches to evaluate baseline risks and hazards is clearly inconsistent with those goals. The use of chemicals that are not site-related and the application of overly conservative assumptions to determine potential exposure levels typically results in risk estimates that are one or more orders of magnitude greater than the risks likely to be posed by actual site conditions. Once worst-case risk conclusions have been reached, it becomes difficult to clearly evaluate which receptors are most significantly impacted, which medium poses the highest risks, and whether there are any imminent or substantial health risks posed. A more reasonable approach, and one recommended in the USEPA's Risk Assessment Guidance for Superfund (RAGS) Part A Human Health Evaluation Manual (HHEM) (USEPA, 1989a), involves estimating the reasonable maximum exposure (RME). The RME is the highest exposure that is reasonably expected to occur at a site. The risks and hazard index values estimated in this risk assessment are based on the RME. This baseline risk assessment presents an evaluation of the potential risks and hazards to human health that may exist at the site currently and in the future in the absence of any further remediation (i.e., no further action). The soil and groundwater samples collected by Geraghty 11 TUT 006 2198 & Miller between March and July 1994 as part of their Phase II RI, seven quarterly groundwater sampling reports completed by Geraghty & Miller between February 1991 and March/April 1993, Technical Memorandum II - Results of the Field Program Tutu Service Station Investigation completed by Geraghty & Miller in May 1993, CDM Federal's 1993 Data Comparison and Evaluation Report for Groundwater and Soil Split Samples of the Tutu Wells site, CDM Federal's September 8 through 15, 1988 and June 5 through 10, 1989 sampling reports, and five groundwater samples collected from four monitoring wells located on the O'Henry dry cleaners property by the O'Henry PRP in March 1993, serve as the main sources of the data used in this risk assessment. This baseline risk assessment was prepared utilizing, to the maximum extent possible, site- specific data to define sources, pathways, receptors, chemical concentrations, and exposure input terms. Where specific data were not available, professional judgement was used to select input terms that are assumed to reflect actual site conditions. By having an adequate data base, the need for using conservative sources, pathways, chemical concentrations, and exposure input terms has been minimized. 12 TUT 006 2199 1.4 Organization of the Risk Assessment Data Evaluation In the first step of the assessment, Data Evaluation, a subset of the various chemicals identified at the site was selected for detailed analysis. The primary selection criteria for these chemicals included 1) chemical concentrations in various media; 2) a chemical concentration-toxicity screen; 3) frequency of detection; 4) the physical/chemical parameters; 5) the degree of toxicity, mobility, and persistence of each chemical in the environment; and 6) historical information about site activities and the chemicals reliably associated with these activities. This procedure is described in detail in Data Collection and Evaluation (Section 2.0) of this risk assessment. Appendix E contains the site data utilized in the risk assessment which were collected during the various field investigations. Exposure Assessment In the second step, Exposure Assessment, qualitative or quantitative estimates of the magnitude, frequency, duration, and routes of exposure were made. Numerous pathways through which chemical contaminants could possibly migrate from potential sources to existing receptors were identified. Receptor groups (i.e., human populations) that might potentially be exposed as a result of the presence of one or more chemicals in the environment were also identified. Typically, these receptor populations include persons who might be exposed via ingestion of, 13 TUT 006 2200 dermal contact with, or inhalation of chemicals in or released from media such as soil and water. Receptors who might be exposed under present or potential future land or water use scenarios were evaluated, as appropriate. Exposure point concentrations for chemicals of potential concern were estimated based on the 95 percent Upper Confidence Limit (UCL) on the arithmetic mean (Appendix A). However, if the maximum site detection for a chemical was lower than the calculated 95 percent UCL concentration, the actual maximum site detection was utilized in the estimation of chemical intakes to prevent potential overestimation of human health impacts. In the cases where only one sample was collected, the single detected concentration was utilized in the estimation of chemical intakes. Daily chemical intakes via ingestion, dermal contact, and/or inhalation routes were estimated based on the 95 percent UCL estimate and site-specific, medium-specific, and receptor-specific intake variables. Both chronic (seven years to lifetime) and subchronic (two weeks to seven years) daily intakes were estimated in this risk assessment depending on the specific receptor population being evaluated. Exposures were estimated for the RME which employs the 95 percent UCL (exposure point) concentration and RME assumptions (i.e., 90th and 95th percentile parameters except for skin surface area which utilizes 50th percentile parameters). The RME is the highest exposure that is reasonably expected to occur at a site. 14 TUT OO6 22O: It should be noted that this risk assessment assumes that no reduction in exposure concentrations occurs due to natural physical/chemical processes, site remediation or institutional controls. The results of the exposure assessment evaluation are provided in the Exposure Assessment (Section 3.0) of this risk assessment. Toxicity Assessment The third step of the risk assessment consisted of the Toxicity Assessment. The purpose of the toxicity assessment was to weigh available toxicological evidence regarding the potential for a particular chemical contaminant to cause adverse health effects in exposed individuals and to provide, where possible, an estimate of the relationship between the extent of exposure to a chemical contaminant and the increased likelihood and/or severity of adverse effects (USEPA, 1989a). The USEPA has performed the toxicity assessment step for numerous chemicals and has made available the resulting toxicity information and toxicity values, which have undergone extensive peer review; however, data analysis and interpretation are still required when applying these values to a site. These established toxicity values were obtained from the Integrated Risk Information System (IRIS) data base (June 22 and 30, July 1, August 4, and October 25, 1994) which is updated monthly, or from the Health Effects Assessment Summary Tables (HEAST) FY 1994-Annual, if no value was present IRIS. The Superfund Health Risk Technical Support 15 TUT O06 22O2 Center was consulted for numerous specific chemical toxicity values (i.e., subchronic toxicity values), as directed by HEAST, when no value was presented. A toxicological profile for each of the chemicals of potential concern was developed using the USEPA toxicity assessments and accompanying values. The toxicity data were evaluated to determine if they were appropriate for use in the risk assessment, or if they needed to be modified. When toxicity values were not available for a specific chemical, the chemical was qualitatively discussed. The toxicity values and the limitations of use of the toxicity values are described in the Toxicity Assessment (Section 4.0) of this risk assessment. Toxicological profiles are presented in Appendix B of this report. Risk Characterization In the last step of the risk assessment, Risk Characterization, the chronic or subchronic daily intake for each chemical to which a given receptor group might be exposed was compared to a concentration known or suspected to present some health risk or hazard. Quantitative estimates of the carcinogenic risks and noncarcinogenic health effects (hazard index values) associated with each exposure pathway are presented along with total estimated risks and hazard index values for present and potential future uses of the site. The risks resulting from exposures to carcinogens were estimated based on the following assumptions. 16 TUT OO6 2203 a linear relationship exists between the intake of a carcinogenic substance over a lifetime and the probability of cancer (the linearized multistage model of carcinogenesis) and; • cancer risks from exposures to all carcinogens via all intake routes are additive. The potential for noncarcinogenic effects was evaluated by comparing an exposure level over a specified time period with a reference dose derived for a similar exposure period. Section 5.0 of this risk assessment presents Risk Characterization. Spreadsheet calculations are presented in Appendix C of this risk assessment. Due to the number of assumptions that are required during the risk assessment process, there will inevitably be some degree of uncertainty associated with the baseline risk and hazard estimates. These uncertainties are addressed both qualitatively and quantitatively (i.e., central tendency calculations) in Section 6.0 Uncertainties in Risk Assessment. Central tendency calculations are presented in Appendix D of this report. Risk-based preliminary remediation goals (PRGs) are initial concentration goals for individual chemicals for specific medium and land use combinations. Whether PRGs are required for a site depends on the calculated site risks and hazard estimates, the existence of Applicable or Relevant and Appropriate Requirements (ARARs), and the existence of superseding USEPA guidance on action levels. PRGs for this site were calculated for residential and commercial/industrial exposure to site soil as well as for residential exposure to groundwater and are presented and discussed in Section 7.0 Preliminary Remediation Goals (PRGs). 17 TUT 006 2204 A summary of the results of the baseline human health risk assessment is presented in Section 8.0. 18 TUT OO& 22O5 2.0 DATA COLLECTION AND EVALUATION Field investigations conducted by Geraghty & Miller, CDM Federal, and the O'Henry PRP from 1988 to 1994 serve as the sources of information for site characterization and analytical data for this risk assessment. The investigations include: Geraghty & Miller's Draft Phase II RI field investigation data (soil and groundwater) - (Geraghty & Miller, 1994). Technical Memorandum n - Results of the Field Program Tutu Service Station Investigation (soil and groundwater) - (Geraghty & Miller, 1993a). Seven quarterly groundwater sampling reports (Geraghty & Miller, 199 la, b, 1992a - February, June, and October, Geraghty & Miller, 1992c, d, e - February, May, and September, and Geraghty & Miller, 1993b March/April). CDM Federal's Data Comparison and Evaluation Report for Groundwater and Soil Split Samples at the Tutu Wells site (CDM Federal, 1993). CDM Federal's CLP Sample Analysis Data Summary of the 104(e) Letter Response Sampling Tutu Wellfield Area (September 8 through September 15, 1988) (CDM Federal, 1989a, b). CDM Federal's Final CLP Sample Analysis Data Summary of Soils and Waters Sampled in 1989, Tutu Wellfield, St. Thomas, U.S. Virgin Islands (June 5 through June 10, 1989) (CDM Federal, 1990). O'Henry dry cleaners PRP groundwater sampling of four monitoring wells located on the dry cleaning establishment property (March 1993). This section presents a summary of the results of the sampling and analysis activities conducted to characterize conditions at the Tutu Wells site. The results of these activities are presented along with the criteria used to identify chemicals of potential concern and a list of chemicals of potential concern selected on the basis of these criteria. 19 TUT 006 All site environmental data, including Tentatively Identified Compounds (TICs), which were evaluated and/or utilized in this risk assessment are presented in Appendix E. The sampling results have been summarized in tabular form by area of concern for surface soil, subsurface soil, and groundwater and are presented in Section 2.2. The five areas of concern quantitatively evaluated in this risk assessment include the Tillett Gardens and Art Center, the Curriculum Center Building, the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company, Esso gas station and Splash and Dash car wash, and O'Henry dry cleaners and Liquor Barn. The locations of these areas are presented in Figure 2-1. Each data summary table presents all chemicals detected, the associated frequencies and ranges of detections, the locations of the maximum detected concentrations, and the range of non-detect concentrations. Data are segregated by locations considered to be potentially impacted by the site (i.e., on-site and downgradient) and by locations that may be representative of "background" (i.e., upgradient). All analytical data generated during the Geraghty & Miller, CDM Federal, and O'Henry PRP field investigations and which were utilized in this risk assessment, including TICs, were validated in accordance with USEPA Region II protocols. Accordingly, all data qualifiers have been included in the data summary tables for completeness. Data collected from media to which exposure was considered likely and where exposure pathways were considered complete (i.e., soil and groundwater) formed the basis of the quantitative risk assessment. These data were used to estimate exposure point concentrations as discussed in Section 3.3 and carcinogenic risk and noncarcinogenic hazard estimates as "****"" presented in Section 5.0. 20 • pine o*re z-a-n PHOI3OI |fll£ NO.i -_______|BRAMNffi Tu-lli |CHECX£H: C. UOfflT______| APPMl\tOl T. t>«l*HY SMOOTH —..._ BOX CULVERT W V»EBr2FT "- 2t-NCIAMETCT FBNFOBCeD OONCnBTBPM QPW TOP CULVBTT—li ii SMOOTH CONCRETE BOX CULVBTT UNDER 8C6WALK(4FT«K uirpmfTunA SCALE (APPROXIMATE) 0 200 FEET LEGEND • SOIL BORING • SHALLOW MONITORING WELL A DEEP MONITORING WELL • EXISTIMC SUPPtr WELL IT FEET K INCH GERAGHTY fiT MILLER, INC. £nvi7«n«TMnfa] TUIU SERVICE STATION INVESTIGATION ST. THOMAS, U.S. VIRGIN ISLANDS FIGURE 2-1 Source: Technical Memorandum H - Result! of the Field Projram - Tutu Service Station Iir-«tlguioa br Cenghty A Miller (Mty 1993V 2.1 Summary of Sampling and Analysis Activities The environmental media that were sampled and that were quantitatively evaluated in this risk assessment included surface soil, subsurface soil, and groundwater. The following is a summary of specific data sets for soil and groundwater used in the evaluation of potential human health risks and hazards and a discussion of data for air which was quantitatively evaluated for the O'Henry dry cleaners and Liquor Barn area in the risk assessment. 2.1.1 Soil As part of Geraghty & Miller's Phase II RI field investigation, eight monitoring wells (MW-13, MW-15, MW-16 (a duplicate sample was collected)), MW-17, MW-18, MW-19, MW-24, and MW-25) were installed in March and April 1994. Nine samples were collected from these wells. The only surface soil samples collected were from monitoring well location MW-16 (including a duplicate). Subsurface soil samples were collected from the remaining seven monitoring wells. The locations of these wells were obtained from Geraghty & Miller's study area map showing supply well, monitoring well, and soil sampling locations and which is included in their Draft Phase n RI report. As part of Geraghty & Miller's. Technical Memorandum II (Phase I) (Geraghty & Miller, 1993a), seventeen borings, including B-l through B-13, B-13A, B-14, B-15, and B-l6 and eighteen monitoring wells, including MW-1 through MW-10, MW-14, MW-ID, MW-4D, MW-6D, MW-10P, MW-1 ID, MW-12D, and MW-13D were drilled. Soil samples were collected from June to August 1992 (see Figures 1-3 and 1-4 22 TUT 006 2209 of Technical Memorandum II-May 1993) for locations. Eight surface soil samples, SS-1 through SS-6 (and SS-6FR) and SS-8, were collected from seven locations in August 1992 (see Figure 1-3 of Technical Memorandum II - May 1993). Surface soil samples SS-1, SS-2, and SS-8, located north of the Curriculum Center Building, are considered background samples and were analyzed for Target Analyte List (TAL) metals and cyanide only. Surface soil samples SS-3 through SS-6 (SS-6FR is a duplicate sample of SS-6) were analyzed for Target Compound List (TCL) VOCs, 1,2-dibromomethane, n-propylbenzene, methyl-tertiary-butyl-ether, TCL SVOCs, TAL metals and cyanide, and total petroleum hydrocarbons (TPHs). SS-7 data, as received by CDM Federal from Geraghty & Miller, is a field rinsate blank sample. Surface soil samples were collected at intervals ranging from one to seven inches below land surface after removing the top one inch layer of soil and vegetation. Overall, thirty-nine samples, including four replicates, were collected from thirty-five soil boring and monitoring well locations during the Technical Memorandum II (Geraghty & Miller, 1993a) investigation. These samples were analyzed for TCL VOCs, 1,2-dibromomethane, n- propylbenzene, methyl-tertiary-butyl-ether, TCL SVOCs, TAL metals and cyanide, and TPHs. Soil samples were collected at depth intervals ranging from zero to sixteen feet. Of these, eighteen soil samples were collected at depths ranging from zero to two feet, while twenty-one soil samples were collected at depths ranging from two to twelve feet (with the exception of sample MW-1D which was collected from one to two and one half feet). Of the eighteen soil 23 "n-'T OO6 221O samples collected from zero to two feet, only six are considered surface soil samples since twelve were collected from beneath paved surfaces. Three of the six surface soil sample locations (B-14, B-15, and B-16) will likely be paved over in the near future. Based on this expected activity, these samples were considered surface soils in the present-use scenario, but were considered subsurface soil samples in the future-use scenario. Surface soil samples collected from zero to two feet below unpaved surfaces, and subsurface soil samples collected from under paved surfaces and from two (and one and one half feet - sample MW-1D) to approximately fourteen feet were used to produce data summary tables and calculate chemical concentration-toxicity screens and exposure point concentrations. Subsurface soil data down to approximately fourteen feet were used in the risk assessment, as this is the zone of soils which might be accessed during any potential excavation activities, and, in addition, this approach maximizes use of the available site sample data. Split samples were collected by CDM Federal in August 1992 for each of seven surface soil samples (SS-1 through SS-6 and SS-8) taken by Geraghty & Miller. In July and August 1992, seven subsurface soil samples were split with Geraghty & Miller including MW-8, MW-6D, MW-9, B-6, B-l, MW-5, and B-12. These samples were analyzed for TCL VOCs and SVOCs, TAL metals, and cyanide. Subsurface soil samples were also analyzed for methyl-tertiary-butyl- ether, 1,2-dibromomethane, n-propylbenzene, and TPHs. Prior to Geraghty & Miller's 1992 soil sampling as part of the Technical Memorandum II investigation (Geraghty & Miller, 1993a), CDM Federal collected hand augured surface soil 24 TUT or* samples at the Tutu Wells site during September 8 through 15, 1988 and during June 5 through 10, 1989 in an effort to identify potentially contaminated areas of the site. The locations of the samples were obtained from field logbooks, CDM personnel, and from CDM Federal documents (CDM Federal Programs Corporation, 1989a, 1990). Per the USEPA Remedial Project Manager's (RPM's) request, these data have been included in the endangerment assessment. During the September 1988 sampling event, one surface soil sample (e-01) was collected at O'Henry dry cleaners, two surface soil samples (eR-07s and eR-08s) were collected at the Ramsay motor company, two surface soil samples (eC-09s and eC-lOs) were collected at Antilles auto parts, and two surface soil samples (eTT-14s and eTT-15s) were collected at the Tillett Gardens and Art Center. Samples were analyzed for various combinations of analytes including TCL VOCs, SVOCs, and pesticides/PCBs, TAL metals, and TPHs, and were collected at intervals ranging from zero to twelve inches below land surface. Two samples collected at the Texaco gas station (eT-02s and eT-02sd) were originally identified as surface soil samples. However, based on a recent site visit, the Texaco gas station area was observed to be completely paved. Therefore, these samples will be considered subsurface soil samples in the risk assessment. During the June 1989 sampling event, three surface soil samples (eO-02-01, eO-02-02, and eO-02- 03) were collected at O'Henry dry cleaners, three surface soil samples (eL-02-Ols, eL-02-02s, and eL-02-03s) were collected behind the Curriculum Center Building, and one surface soil samples (eR-02-02s) was collected at the Ramsay motor company. Samples were analyzed for 25 Tl IT .-..- . ".I"-, 1 .—. "~.'~ _l 2 various analyte combinations including TCL VOCs, SVOCs, and pesticides/PCBs, TAL metals, and TPHs, and were collected at intervals ranging from zero to two feet below land surface. 2.1.2 Ground water As part of their Phase I RI field investigation, Geraghty & Miller has been monitoring approximately twenty-five residential and commercial water supply wells at and in the vicinity of the site since September 1990 and has produced eight quarterly sampling reports including the most recent March/April 1993 sampling event results. The seven most recent sampling reports (reports two through eight) have been utilized in the production of the Tutu Wells site risk assessment per the direction of the USEPA RPM. In addition to these reports, Geraghty & Miller has also produced, as part of the Phase I RI, the Technical Memorandum II Tutu Service Station Investigation report (Geraghty & Miller, 1993a) which evaluated fourteen monitoring wells located at the site. During the Phase II RI field investigation, Geraghty & Miller conducted additional monitoring well installation and sampling. O'Henry dry cleaners has independently installed and sampled four monitoring wells from which two rounds of groundwater samples were collected (March and May 1993). Five samples were collected and analyzed for TCL VOC and low detection limit analyte lists in March 1993. These data .have been validated by the USEPA so that they can be incorporated into the endangerment assessment. The May 1993 sample data were not utilized due to the closeness of the sampling dates, general similarity of the results, and the fact that the wells are more cross-gradient than representative downgradient wells under current nonpumping conditions. 26 TUT OO6 2213 Table 2-1 presents the wells sampled and parameters analyzed for the second through eighth ground water sampling events. As part of the second quarterly sampling event in February 1991, twenty-three wells were sampled for TCL VOCs and at least two of the following metals: antimony, mercury, selenium, and thallium. The Four Winds I and VIHA I wells were not sampled due to inoperable pumps. The remaining wells listed on Table 2-1 were not scheduled to be sampled during this event. As part of the third quarterly sampling event in June 1991, fourteen wells were sampled for TCL VOCs only. The Four Winds II and VIHA I wells were not sampled due to inoperable pumps. The remaining wells listed on Table 2-1 were not scheduled to be sampled during this event. As part of the fourth quarterly sampling event in October 1991, fourteen wells were sampled for TCL VOCs only. The Four Winds II and VIHA I wells were not sampled due to inoperable pumps. The remaining wells listed on Table 2-1 were not scheduled to be sampled during this event. As part of the fifth quarterly sampling event in February 1992, eighteen wells were sampled for TCL VOCs and SVOCs, TAL metals, and cyanide. A Water and Power Authority (WAPA) sample was collected from the standpipe at the Virgin Island Housing Authority property on Route 38. The VIHA I, II, and III wells were not sampled due to inoperable pumps. The remaining wells listed on Table 2-1 were not scheduled to be sampled during this event. 27 TUT 006 2214 11/1/94 WEUEVENTS.XIS to oo C ,o /> /<£ 2-1 TUTU WELLS SITE GROUNDWATER MONITORING PROGRAM (FEBRUARY 1991 MARCH/APRIL 1993)' Sampling Event: Date: WELLS SAMPLED: (l)Biyan (2)Dede (1) Dimitri (2) Dench (2) Devcon 1 (2) Devcon II (2) Devcon III Eglinl Eglin II Eglin III Four Winds! Four Winds II Gassed Harthman II Harthman III Harvey La Place (1) Leonard Matthias Ramsay Rodriguez Smith Steele Tillett VIHAI VIHA II (1) VIHA III WAPA Second February 1991 Third June 1991 Fourth October 1991 Fifth February 1992 Sixth May 1992 Seventh September 1992 Eighth March/April 1993 ANALYTICAL PARAMETERS VOCs, Tl. Hg VOCs, Sb. Tl VOCs. Tl, Hg VOCs, Sb, Tl VOCs.Sb.TI - VOCs, Sb, Tl VOCs. Tl, Hg VOCs. Sb. Tl VOCs. Sb, Tl" - VOCs, Sb, Tl VOCs, Tl. Hg VOCs, Sb, Tl VOCs.Sb.TI VOCs, Sb, Tl VOCs.TI. Hg" VOCs, Sb. Tl VOCs, Tl, Hg VOCs, Tl, Hg VOCs, Sb, Tl VOCs. Sb. Tl, Se VOCs. Sb, Tl VOCs, Tl, Hg - - VOCs.Sb.TI - . - - - - - - VOCs VOCs VOCs VOCs - VOCs VOCs VOCs VOCs VOCs" - VOCs VOCs - VOCs VOCs VOCs -. - • - - - - - - - VOCs VOCs VOCs VOCs VOCs VOCs VOCs VOCs VOCs VOCs - VOCs VOCs - VOCs VOCs VOCs" - - • - - VOCs, SVOCs, Metals, CN - - - - - VOCs, SVOCs, Metals, CN VOCs, SVOCs, Metals. CN VOCs, SVOCs, Metals, CN VOCs. SVOCs. Metals, CN VOCs, SVOCs, Metals, CN VOCs, SVOCs, Metals, CN" VOCs, SVOCs. Metals, CN" VOCs, SVOCs, Metals, CN VOCs, SVOCs, Metals, CN VOCs, SVOCs, Metals. CN" VOCs, SVOCs, Metals, CN VOCs, SVOCs. Metals, CN VOCs. SVOCs, Metals, CN VOCs, SVOCs, Metals, CN VOCs. SVOCs, Metals, CN VOCs. SVOCs, Metals, CN VOCs, SVOCs. Metals. CN -. • VOCs, SVOCs. Metals, CN - - - - - - - VOCs VOCs VOCs - - VOCs - - VOCs VOCs - - VOCs - VOCs" VOCs VOCs -. - - . - - - - - - VOCs VOCs VOCs VOCs VOCs VOCs VOCs - - VOCs VOCs - - VOCs" - VOCs VOCs VOCs - - - • - VOCs, SVOCs, Metals, CN . VOCs, SVOCs, Metals, CN - VOCs, SVOCs. Metals. CN - VOCs. SVOCs, Metals, CN - VOCs, SVOCs, Metals, CN VOCs, SVOCs, Metals. CN . VOCs, SVOCs, Metals. CN - - VOCs, SVOCs. Metals, CN" VOCs, SVOCs, Metals, CN VOCs, SVOCs. Metals, CN - VOCs, SVOCs, Metals. CN VOCs, SVOCs, Metals, CN VOCs, SVOCs, Metals. CN VOCs, SVOCs, Metals, CN VOCs. SVOCs, Metals, CN - - - - 'The first sampling event from September/October 1990 was not included per direction of the USEPA RPM. All information on this table was obtained from seven Geraghty & Miller well sampling event reports (February 1991 through March/April 1993) (see reference section of risk assessment). " A field replicate was also collected and analyzed. Abbreviations: - Not sampled. VOCs - volatile organic compounds (TCL) SVOCs - base neutral acid extractabtes (TCL) Metals-TAL CN - cyanide Sb - antimony Hg-mercury Se - selenium Tl - thallium (1) Upgradient and cross-gradient water supply wells. (2) Downgradient water supply wells. /N. As part of the sixth quarterly sampling event in May 1992, ten wells were sampled for TCL VOCs only. The remaining wells listed on Table 2-1 were not scheduled to be sampled during this event. As part of the seventh quarterly sampling event in September 1992, thirteen wells were sampled for TCL VOCs only. The remaining wells listed on Table 2-1 were not scheduled to be sampled during this event. As part of the eighth quarterly sampling event in March and April 1993, fifteen wells were sampled for TCL VOCs and SVOC, TAL metals, and cyanide. A field replicate was collected from the Harvey well and analyzed for the same parameters. The VIHA I, VIHA II, Eglin II, Four Winds II, and Devcon II wells were not sampled due to inoperable pumps. The Matthias well was not sampled as the property owner would not allow access. The Harthman II and Harthman III wells were not sampled due to construction activities at the new Four Winds shopping plaza. The remaining wells listed on Table 2-1 were not scheduled to be sampled during this event. As part of the Technical Memorandum II Tutu Service Station Investigation (Geraghty & Miller, 1993a), Geraghty & Miller installed twelve shallow monitoring wells (MW-1, MW-2, MW-3, MW-4, MW-5, MW-6R, MW-7, MW-8, MW-9, MW-9S, MW-10, and MW-14) and seven deep monitoring wells (MW-1D, MW-4D, MW-6D, MW-10D, MW-1 ID, MW-12D, and MW-13D). 29 TUT 006 221- Groundwater samples were collected from all shallow and deep wells in September and October 1992 and were analyzed for TCL VOCs and SVOCs, TAL metals, cyanide, 1,2- dibromomethane, n-propylbenzene, methyl-tertiary-butyl-ether, and TPHs. CDM Federal collected split samples in September and October 1992 of five Geraghty & Miller aqueous samples (four groundwater samples and one field blank). The groundwater samples (MW-6R, MW-4, MW-5, and MW-14) were analyzed for TCL VOCs and SVOCs, TAL metals, (total only), cyanide, methyl-tertiary-butyl-ether, 1,2-dibromomethane, n-propylbenzene, and TPHs. Geraghty & Miller recently conducted Phase IIRI field activities to supplement the existing data in an effort to further characterize chemical contamination at the site (i.e., identify sources and potential migration pathways of chemical). As part of this groundwater investigation, Geraghty & Miller installed nine shallow monitoring wells (MW-13, MW-15, MW-16, MW-17, MW-18, MW-19, MW-20, MW-24, and MW-25), three very shallow monitoring wells (MW-17, MW-18, and MW-19), and three deep monitoring wells (MW-20D, MW-21D, and MW-22D). Groundwater samples were collected from twelve supply wells and 51 monitoring wells from May to July 1994 and were analyzed for TCL VOCs (some low detection limit) and SVOCs, TAL metals, cyanide, 1,2-dibromomethane, n-propylbenzene, and methyl-tertiary-butyl-ether. Groundwater results from each of the wells from each sampling round, including split samples, 30 TUT 006 2217 as appropriate, have been used to produce a data summary table and to calculate a chemical concentration-toxicity screen and exposure point concentrations. Upgradient supply wells T3 and T4 (VIHA III and VIHA IV (alternate)) have not been included in the calculation of risk/health effects nor have the Bryan, Dimitri, Leonard, and Lockhart (alternate) cross-gradient wells which are impacted by pumping only in the residential area in the immediate vicinity and not by the site. All Harthman wells as well as the KFC-1 well are also considered cross- gradient wells and have not been included for quantitative evaluation in the risk assessment. The Dede, Dench, Devcon I, Devcon II (alternate), and Devcon III supply wells are clean wells downgradient of the contaminant plume, and therefore have not been utilized in quantitative calculations in the risk assessment. Shallow and deep groundwater samples have been grouped together for analysis since the fractured bedrock aquifer and the alluvial fill aquifer are in direct hydraulic communication with each other. 2.1.3 Air No air monitoring data have been collected as part of the Geraghty & Miller, CDM Federal, or O'Henry PRP site investigations. However, air exposure point concentrations have been modelled as particulates released from surface and subsurface soils, and as VOCs released from surface soil and groundwater as part of the exposure assessment. UT 2.2 Summary of Sampling and Analysis Results 2.2.1 Data Quality As part of the data evaluation process, the quality of all site data was evaluated. As stated previously, all data collected as part of the Geraghty & Miller, CDM Federal, and O'Henry PRP site investigations were validated in accordance with USEPA Region II data validation protocols. However, it should be noted that the data for certain samples and analytes that were not rejected during validation were qualified for the following reasons: • The "*" qualifier indicates for inorganics that duplicate analysis was not within control limits. • The "J" qualifier for all chemicals indicates that the reported concentration is estimated. • The "B" qualifier indicates for organic chemicals that the reported concentration is estimated since it was detected in both the sample and in the associated blank; for inorganics, the "B" qualifier indicates that the reported concentration is less than the contract required detection limit and greater than the instrument detection limit. • The "E" qualifier indicates for organics that the concentration exceeds the calibration range of the GC/MS instrument; for inorganics, the "E" qualifier indicates that the value is estimated due to matrix interferences. • The "N" qualifier for organic chemicals indicates that there is only presumptive evidence for their presence; for inorganics the "N" qualifier indicates that the spiked sample recovery is not within control limits. • The "D" qualifier for organics indicates that the chemical was identified in an analysis at a secondary dilution factor. • The "P" qualifier for pesticides and PCBs indicates that the duplicate precision was not met. 32 OO6 2239 2.2.2 Chemicals Detected in Soil Surface Soil; Surface soil sample data summaries are presented in Tables 2-2 through 2-6 for the Tillett Gardens and Art Center, Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company, Curriculum Center Building (Present), Curriculum Center Building (Future), and O'Henry dry cleaners and Liquor Barn. The data used to evaluate exposures for the Curriculum Center Building present and potential future-use scenarios differ in that the sample groups evaluated are not the same. At present, samples B-14, B-15, and B-16 are considered surface soil samples and were collected at a depth range of zero to two feet. However, the area where these samples were collected is expected to be paved over in the near future. Therefore, these samples are considered subsurface soil samples in the future-use scenario. It should be noted that not all samples were analyzed for all chemical classes. In addition, soil samples collected during monitoring well installation were given the sample name prefix MWS (as opposed to MW for groundwater) so that the samples would be recognized properly in the computer data base. Samples having split or duplicate results were given the suffix AVS or AVD, respectively, to differentiate the components of the averaged result. Tillett Gardens and Art Center The results of the analysis of three surface soil samples collected at the Tillett Gardens and Art Center area presented in Table 2-2. Three volatile organic compounds (VOCs) were each detected in a single sample. Xylenes (total) were detected at the highest concentration, 11.0 J 34 TUT 006 2220 OB/11/B4 OSUMM-SS-TQA.XLS TABL I. TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL TILLETT GARDENS AND ART CENTER CONCENTRATION (ug/kg) CHEMICALS VOCs Methylene Chloride Chloroform Xytenes (Total) SVQCs Dl-n-butylphthalate Fluoranthene Pyrene Butytbenzylphthalate Chrysane Benzo(b)fluoranthene Benzo(g,h,l)perytene PESTICIDES/PCBs Arodor 1242 Frequency of Detection 1/2 1/2 1/3 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/2 Range of Detected Concentrations Minimum Maximum 9.00 J 2.00 J 11.0J 55.0 J 100J 76.0 J 134J 59.0 J 84.0 J 82.0 J 120000 J 9.00 J 2.00 J 11.0J 55.0 J 100J 76.0 J 134 J 59.0 J 84.0 J 82.0 J 120000 J Location of Range of Non-Detect Concentrations Maximum Minimum SS-5-AVS 62.0 U SS-5-AVS 7.00 U eTT-148 7.00 U SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS «TT-15s 580 UJ Maximum 62.0 U 7.00 U 11.0 U - - 580 UJ Sample Group: SS-5-AVS, eTT-14s, eTT-15s. ~i M KJ TABLE 2-i TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL TILLETT GARDEN AND ARTS CENTER CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium Beryllium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Mercury Nickel Potassium Silver Sodium Vanadium Zinc Frequency of Detection 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 Range of Detected Concentrations Minimum Maximum 21300 5.05 BNJ 10.0 70.5 0.20 B 35900 25.3 NJ 20.1J 79.7 NJ 32750 86.4 SJ 13250 ARO OD9 0.12 13.9 3390 J 2.15 B 328 B 95.9 NJ 169 21300 5.05 BNJ 10.0 70.5 0.20 B 35900 25.3 NJ 20.1 J 79.7 NJ 32750 86.4 SJ 13250 869 0.12 13.9 3390 J 2.15 B 328 B 95.9 NJ 169 Location of Range of Non-Detect Concentrations Maximum Minimum SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS SS-5-AVS Maximum . - - - - - - - - - - - - - - - - - - - Sample Group: SS-5-AVS, eTT-14s, eTT-15s. !> 08/11/M OSUMM-SS-FTS.XLS TABLi / TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL FIRE DEPARTMENT / TEXACO GAS STATION / ANTILLES AUTO PARTS / RAMSAY MOTOR CO. CONCENTRATION (ug/kg) CHEMICALS VOCs Methylene Chloride Acetone Benzene 4-Methyl-2-Pentanone 2-Hexanone Toluene Ethylbenzene Xytenes (Total) Naphthalene 2-Methylnaphthalene Acenaphthene Fluorene Fluoranthene Pyrene Bis(2-ethylhexyl)phthalata Benzo(b)fluoranthene Benzo(a)pyrene Benzo(g,h,i)perytene PESTICIDES/PCBs None Detected Frequency of Detection 2/6 1/6 2/6 2/6 1/6 3/6 3/6 5/6 1/2 1/2 1/2 1/2 1/2 2/2 1/2 1/2 2/2 2/2 Range of Detected Concentrations Minimum Maximum 17.0 J 14.0 6.00 J 8.00 J 55.0 J 2.00 J 16.0 B 1.00 J 4400 6100 190J 420 J 740 J 220 J 5400 870 J 270 J 290 J 200 14.0 45.0 J 33.0 J 55.0 J 1300 2100 5600 4400 6100 190J 420 J 740 J 2000 5400 870 J 770 J 430 J Location of Maximum eR-02-02s B-2 eC-IOs eC-IOs eR-078 eC-10s eC-IOs eC-10s eR-02-02s eR-02-028 eR-02-02s eR-02-02s eR-02-028 eR-02-02s eR-02-028 eR-02-023 eR-02-028 eR-02-028 Range of Non-Detect Concentrations Minimum 26.0 U 17.0 UJ 6.00 U 11.0 U 11.0U 6.00 U 6.00 U 11.0 U 1400 U 1400 U 1400 U 1400 U 1400 U - 1400 U 1400 U - - Maximum 12000 U 2700 UJ 880 U 1800 UJ 1800 UJ 30.0 UJ 30.0 UJ 11.0U 1400 U 1400 U 1400 U 1400 U 1400 U - 1400 U 1400 U - - Sample Group: B-2, eC-098, eC-IOs. eR-07s, eR-08s, eR-02-02s. TABLE2-; U> OO TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL FIRE DEPARTMEN / TEXACO GAS STATION / ANTILLES AUTO PARTS / RAMSAY MOTOR CO. CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Barium Beryllium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Nickel Potassium Silver Sodium Vanadium Zinc Cyanide Frequency of Detection 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 Range of Detected Concentrations Minimum Maximum 26000 5.90 BJ 67.2 0.26 B 47200 31.7 21.9 79.1 38400 26.0 SJ 17100 834 17.5 1170 2.20 J 319 B 119 108 1.10 26000 5.90 BJ 67.2 0.26 B 47200 31.7 21.9 79.1 38400 26.0 SJ 17100 834 17.5 1170 2.20 J 319 B 119 108 1.10 Location of Range of Non-Detect Concentrations Maximum Minimum B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-2 Maximum . - - . - - - - -. - - - - Sample Group: B-2, eC-09s, eC-10s, eR-07s, eR-08s, eR-02-02s. O tf- K3 W W OV11/94 DSUMM-SS-CCBP.XLS TABl I TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL CURRICULUM CENTER BUILDING - PRESENT CONCENTRATION (ug/kg) CHEMICALS VOCs Mettiytem Chloride Chloroform 2-Butanone Trichtoroethene Tetrachtoroethene Toluene Ethytoenzene Xytenes (Total) SVOCs Phenol 2-Methytphanol 4-Methylphenol 2,4-Dimetfiylphenol Naphthalene 2-Methytnaphthatene Di-n-bulylphthalate Butytbenzylphlhalate PESTICIDES/PCBs Endosulfan 1 Frequency of Detection 3/6 2/9 1/9 3/9 4/9 5/9 2/9 3/9 1/8 1/8 1/8 1/8 2/9 1/9 3/9 219 1/3 Range of Detected Concentrations Minimum Maximum 1.00.1 2.00 J 44.5 J 1.00 J 23.0 2.00 J 3.00 J 19.0 900000 320000 1 300000 J 42000 J 4100 750 J 52.0 J 58.0.1 92.0 22.0 6.75 J 44.5 J 65.0 J 170 200 NJ 420 J 1600 J 900000 320000 1300000 J 42000 J 7700 J 750 J 9400 J 120 J 92.0 Location of Maximum SS-3-AVS SS-3-AVS SS-3-AVS SS-3-AVS B-15 eL-02-Ols eL-02-01S 6L-02-02S eL-02-Ols eL-02-Ols eL-02-01s eL-02-Ols eL-02-Ols eL-02-02s SS-3-AVS eL-02-03s eL-02-Ols Range of Non-Detect Concentrations Minimum 11.0 U 6.00 UJ 11.0U 6.00 UJ 6.00 UJ 6.00 UJ 6.00 UJ 6.00 UJ 350 U 350 U 350 U 350 U 350 U 350 U 370 U 350 U 10.00 U Maximum 12.0 U 29.0 UJ 58.0 UJ 29.0 UJ 39.0 U 29.0 UJ 29.0 UJ 12.0 U 11000 UJ 11000UJ 11000 UJ 11000 UJ 13000 UJ 78000 U 78000 U 78000 U 38.0 U SS-3-AVS, SS-4-AVS, B-14, B-15. B-16, MWS-16-AVD, eL-02-01s, eL-02-02s, eL-02-03s. ~i f-0 k 't ! V r-0 CR TABLE 2 Irfd) TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL CURRICULUM CENTER BUILDING - PRESENT CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Mercury Nickel Potassium Silver Sodium Vanadium Zinc Cyanide Frequency of Detection 6/6 5/6 5/6 6/6 2/6 2/6 6/6 6/6 6/6 6/6 6/6 6/6 6/8 6/6 1/6 6/6 6/6 5/6 5/6 6/6 6/6 2/6 Range of Detected Concentrations Minimum Maximum 18900 4.08 BNJ 1.30 B 32.1 B 0.19 B 0.70 B 38600 13.8NJ 19.0 48.3 NJ 26000 2.90 J 16300 599 0.57 11.1 125 B 0.93 B 181 B 79.7 NJ 50.9 0.64 27350 7.30 BNJ 11.6 96.3 0.27 B 0.99 B 120000* 42.2 J 25.6 J 109 48600 45.6 N*J 26200 673 0.57 21.7 7625 J 1.90 B 489 B 115 459 0.75 Location of Maximum MWS-16-AVD B-14 B-16 SS-3-AVS MWS-16-AVD B-16 B-14 MWS-16-AVD MWS-16-AVD MWS-16-AVD SS-3-AVS B-16 B-14 MWS-16-AVD B-16 MWS-16-AVD SS-3-AVS SS-3-AVS SS-3-AVS MWS-16-AVD B-16 B-15 Range of Non-Detect Concentrations Minimum - 5.10 UJ 0.46 U - 0.18 U 0.48 U . - - - - - - - 0.05 U -. 0.64 U 390 U - - 0.53 U Maximum . 5.10 UJ 0.46 U - 0.23 U 0.70 U - - - - - - - - 0.09 U -. 0.64 U 390 U - - 0.58 U Sample Group: SS-3-AVS. SS-4-AVS. B-14. B-15, B-16, MWS-16-AVD, eL-02-01s, eL-02-02s, eL-02-03s. •H O oe/it«4 DSUMM-SS-CCBF.XLS TABL > TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL CURRICULUM CENTER BUILDING - FUTURE CONCENTRATION (ug/kg) CHEMICALS VOCs Methylene Chloride Chloroform 2-Butanone TricNoroelhene Tetrachloroethene Toluene Ethylbenzene Xytenes (Total) Phenol 2-Metnytphenol 4-Melhylphenol 2,4-Dlmethylphenol Naphthalene 2-Mettiylnaphthatene Di-n-butylphthalate Butylbenzylphthalate PESTICIDES/PCBs Endosulfan 1 Frequency of Detection 3/3 2/6 1/6 2/6 1/6 2/6 2/6 3/6 1/5 1/5 1/5 1/5 2/6 1/6 3/6 1/6 1/3 Range of Detected Concentrations Minimum Maximum 1.00 J 2.00 J 44 .5 J 1.00 J 53.5 J 4.00 J 3.00 J 19.0 900000 320000 1300000 J 42000 J 4100 750 J 52.0 J 120J 92.0 22.0 6.75 J 44.5 J 65.0 J 53.5 J 200 NJ 420 J 1600 J 900000 320000 1300000 J 42000 J 7700 J 750 J 9400 J 120 J 92.0 Location of Maximum SS-3-AVS SS-3-AVS SS-3-AVS SS-3-AVS MWS-16-AVD eL-02-Ols eL-02-Ols eL-02-02s eL-02-Ols eL-02-01s eL-02-01s eL-02-01s eL-02-Ols eL-02-028 SS-3-AVS eL-02-03s eL-02-Ols Range of Men-Detect Concentrations Minimum - 6.00 UJ 11.0 U 6.00 UJ 6.00 UJ 6.00 UJ 6.00 UJ 6.00 UJ 350U 350 U 350 U 350 U 350 U 350 U 850 U 350 U 10.0 U Maximum - 29.0 UJ 58.0 UJ 29.0 UJ 39.0 U 29.0 UJ 29.0 UJ 11.0U 11000UJ 11000 UJ 11000 UJ 11000 UJ 13000 UJ 78000 U 78000 U 78000 U 38.0 U Sample Group: SS-3-AVS, SS-4-AVS, MWS-16-AVD, eL-02-01s, eL-02-02s, eL-02-03s. C _^ TABLE 2-1 J.I'd) K) TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL CURRICULUM CENTER BUILDING - FUTURE CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Nickel Potassium Silver Sodium Vanadium Zinc Cyanide Frequency of Detection 3/3 2/3 3/3 3/3 2/3 1/3 3/3 3/3 3/3 3/3 3/3 3/3 3/3 3/3 3/3 3/3 2/3 2/3 3/3 3/3 1/3 Range of Detected Concentrations Minimum Maximum 25000 4.08 BNJ 1.46BWJ 33.9 B 0.19 B 0.70 B 38600 28.5 NJ 21 .U 67.2 NJ 32450 3.10 18700 677 16.5 125 B 1.17 B 403 B 95.2 NJ 52.0 0.64 27350 4.63 BNJ 2.30 B 96.3 0.27 B 0.70 B 56050 42.2 J 25.6 J 109 48800 20.0 J 23550 873 21.7 7625 J 1.90B 489 B 115 318 0.64 Location of Maximum MWS-16-AVD SS-3-AVS SS-3-AVS SS-3-AVS MWS-16-AVD MWS-16-AVD SS-4-AVS MWS-16-AVD MWS-16-AVD MWS-16-AVD SS-3-AVS SS-3-AVS MWS-16-AVD MWS-16-AVD MWS-16-AVD SS-3-AVS SS-3-AVS SS-3-AVS MWS-16-AVD SS-4-AVS SS-3-AVS Range of Non-Detect Concentrations Minimum - 5.10 UJ - 0.1 8 U 0.48 U -. - ; - - - 0.64 U 390 U - - 0.53 U Maximum . 5.10 UJ - 0.18 U 0.57 U .. - - - - . 0.64 U 390 U . - 0.54 U Sample Grouoi SS-3-AVS, SS-4-AVS, MWS-16-AVD, eL-02-01s, eL-02-02s, eL-02-03s. O - K! CO oo 0- 06/11/M OSUMM-SS-OH.XLS TABL I TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL O'HENRY DRY CLEANERS AND LIQUOR BARN CONCENTRATION (ug/kg) CHEMICALS VOCs Methylene Chloride Acetone 1 ,2-Dtehtofoethene (Total) Chloroform Trichloroethene TetracNoroethene SVOCs Phenol Benzole Add Di-n-butytphthalate Butylbenzylphthalale Bte(2-ettiylhexyl)phthalate PESTICIDES/RGBS None Detected Frequency of Detection 2/6 1/6 1/6 2/6 1/6 5/6 1/5 1/4 1/5 1/5 3/5 Range of Detected Concentrations Minimum Maximum 16.5 64.0,1 20.0 J 2.00 J 75.0 15.0 39.0 NJ 63.0 JN 62.0 J 69 .5 J 280 J 150 J 84.0 J 20.0 J 12.0J 75.0 440000 39.0 NJ 63.0 JN 62.0 J 69.5 J 510 Location of Maximum eO-02-02 eO-02-02 eO-02-02 eO-02-02 eO-02-02 e-01 eO-02-03 SS-6-AVS SS-6-AVS SS-6-AVS eO-02-01 Range of Non-Detect Concentrations Minimum 11.0 UJ 11.0 UJ 6.00 U 11.0 U 6.00 U 11.8 U 350 U 1800 U 350 U 350 U 350 U Maximum 14000 UB 27000 UB 14000 U 14000 U 14000 U 11.8U 420 U 2000 U 420 U 420 U 380 UJ Sample Group: SS-6-AVS, B-13A, e-01, eO-02-01, eO-02-02, eO-02^)3. w >'•-• '••0 TABLE. Xfxtfd) TUTU WELLS SITE SUMMARY OF CHEMICALS IN SURFACE SOIL O'HENRY DRY CLEANERS AND LIQUOR BARN CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium Caldum Chromium Cobalt Copper Iron Lead Magnesium Manganese Nickel Potassium Silver Sodkjm Vanadium Zinc Cyanide Frequency of Detection 2/2 1/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 1/2 Range of Detected Concentrations Minimum Maximum 21100 6.35 BNJ 13.7 59.3 37825 J 19.9NJ 13.9J 52.0 27725 J 4.80 J 9743 J 670 J 11.5J 841 B 0.75 BJ 273 BJ 72.7 NJ 63.1 1.05 22425 J 6.35 BNJ 18.7J 90.4 J 73200' 23.6 16.3 55.0 J 29400 12.2J 18300 870 14.7 2030 J 1.60 BNJ 474 B 83.1 95.8 J 1.05 Location of Range of Non-Detect Concentrations Maximum Minimum SS-6-AVS SS-6-AVS 4.30 UNJ SS-6-AVS SS-6-AVS B-13A B-13A B-13A SS-6-AVS B-13A SS-6-AVS B-13A B-13A B-13A SS-6-AVS B-13A B-13A B-13A SS-6-AVS SS-6-AVS 0.54 U Maximum . 4.30 UNJ - - - -. - - - - - - - - - - 0.54 U Sample Group: SS-6-AVS, B-13A, e-01, eO-02-01. eO-02-02, eO-02-03. -i C ug/kg in sample eTT-14s, while methylene chloride was detected at a maximum concentration of 9.0 J ug/kg in sample SS-5-AVS. Sample SS-5-AVS is an average of sample SS-5 (collected by Geraghty & Miller) and its split (collected by CDM Federal). Chloroform was detected in sample SS-5-AVS at a concentration of 2.0 J ug/kg. Seven semivolatile organic compounds (SVOCs), which include polycyclic aromatic hydrocarbons (PAHs) and phthalates, were each detected in the single surface soil sample analyzed for SVOCs (SS-5-AVS). The highest concentrations were reported for butylbenzylphthalate (134 J ug/kg) and fluoranthene (100 J ug/kg). One polychlorinated biphenyl (PCB), Aroclor 1242, was detected in only one of the two surface soil samples analyzed for PCBs. The detected concentration of 120000 J ug/kg was reported in sample eTT-15s. Twenty inorganics were detected in the single Tillett Gardens and Art Center surface soil sample analyzed for inorganics. Aluminum, antimony, arsenic, barium, beryllium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, mercury, nickel, potassium, silver, sodium, vanadium, and zinc were all detected in sample SS-5-AVS. The highest concentrations were reported for calcium (35900 mg/kg), iron (32750 mg/kg), and aluminum (21300 mg/kg). 45 TUT O06 2231 ^ Fire Department/Texaco Gas Station/ Antilles Auto Parts/Ramsay Motor Company The results of the analysis of six surface soil samples collected at the Fire Department/Texaco gas station/ Antilles auto parts/Ramsay motor company area are presented in Table 2-3. Eight VOCs, including primarily aromatics and ketones, were detected in at least one sample. The most frequently detected VOCs were xylenes (total) (5 of 6 samples), toluene (3 of 6 samples), and ethylbenzene (3 of 6 samples). The chemicals detected at the highest concentrations were xylenes (total) (5600 ug/kg), ethylbenzene (2100 ug/kg), and toluene (1300 ug/kg). These detections were all reported in sample eC-lOs. Ten SVOCs, which include PAHs and phthalates, were detected in at least one surface soil • sample. The most frequently detected SVOCs were pyrene (2 of 2 samples), benzo(a)pyrene (2 of 2 samples), and benzo(g,h,i)perylene (2 of 2 samples). All other SVOCs were detected in only one of two samples. The highest SVOC detections occurred for 2-methylnaphthalene (6100 ug/kg), bis(2-ethylhexyl)phthalate (5400 ug/kg), and napththalene (4400 ug/kg). These detections were all reported in sample eR-02-02s. No pesticides or PCBs were detected in surface soil samples collected from the Fire Department/Texaco gas station/ Antilles auto parts/Ramsay motor company area. Nineteen inorganics were detected in the single surface soil sample analyzed for inorganics. Aluminum, antimony, barium, beryllium, calcium, chromium, cobalt, copper, iron, lead, 46 TUT 22*? ^ magnesium, manganese, nickel, potassium, silver, sodium, vanadium, zinc, and cyanide were all detected in sample B-2. The highest concentrations were reported for calcium (47200 mg/kg), iron (38400 mg/kg), and aluminum (26000 mg/kg). Curriculum Center Building (Present) The results of the analysis of nine surface soil samples collected at the present Curriculum Center Building area are presented in Table 2-4. Eight VOCs, including primarily aromatic and chlorinated chemicals, were detected in at least one sample. The most frequently detected VOCs were toluene (5 of 9 samples), tetrachloroethene (3 of 9 samples), and xylenes (total) (3 of 9 samples). The chemicals detected at the highest concentrations were xylenes (total) (1600 J ug/kg), ethylbenzene (420 J ug/kg), and toluene (200 NJ ug/kg). The toluene and ethylbenzene maximum detections were reported in sample eL-02-Ols, while the xylenes (total) maximum detection was reported in sample eL-02-02s. Eight SVOCs, including phenols, PAHs, and phthalates, were detected in at least one surface soil sample. The most frequently detected SVOCs were di-n-butylphthalate (3 of 9 samples), naphthalene (2 of 9 samples), and butylbenzylphthalate (2 of 9 samples). All other VOCs were detected in only one sample. The highest SVOC detections were reported for 4-methylphenol (1300000 J ug/kg), phenol (900000 ug/kg), and 2-methylphenol (320000 ug/kg). These detections were all reported in sample eL-02-Ols. 47 TUT 006 One pesticide, endosulfan I, was detected in 1 of 3 samples analyzed for pesticides. The single detection, 92.0 ug/kg, was reported in sample eL-02-Ols. Twenty-two inorganics were detected in present Curriculum Center Building surface soil samples. Fourteen inorganics were detected in each of the six samples analyzed for inorganics, including aluminum, barium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, potassium, vanadium, and zinc. The highest concentrations were reported for calcium (120000 * mg/kg), iron (48800 mg/kg), aluminum (27350 mg/kg), and magnesium (26200 mg/kg). The calcium and magnesium maximum detections were reported in sample B- 14, while the aluminum maximum detection was reported as the average of the sample and its associated duplicate (collected by Geraghty & Miller), MWS-16-AVD. The iron maximum detection was reported as the average of the sample (collected by Geraghty & Miller) and the split (collected by COM Federal), SS-3-AVS. Curriculum Center Building (Future) The results of the analysis of six surface soil samples collected from the potential future Curriculum Center Building area are presented in Table 2-5. Eight VOCs, including primarily aromatic and chlorinated chemicals, were detected in at least one sample. The most frequently detected VOCs were methylene chloride (3 of 3 samples), xylenes (total) (3 of 6 samples), chloroform (2 of 6 samples), toluene (2 of 6 samples), and ethylbenzene (2 of 6 samples). All other VOCs were detected in only one sample. The chemicals detected at the highest 48 TUT 006 223 concentrations were xylenes (total) (1600 J ug/kg), ethylbenzene (420 J ug/kg), and toluene (200 NJ ug/kg). The toluene and ethylbenzene maximum detections were reported in sample eL-02- Ols while the xylenes (total) maximum detection was reported in sample eL-02-02s. Eight SVOCs, including phenols, PAHs, and phthalates, were detected in at least one surface soil sample. The most frequently detected SVOCs were di-n-butylph thai ate (3 of 6 samples) and naphthalene (2 of 6 samples). All other SVOCs were detected in only one sample. The highest SVOC detections were reported for 4-methylphenol (1300000 J ug/kg), phenol (900000 ug/kg), and 2-methylphenol (320000 ug/kg). These detections were all reported in sample eL- 02-01 s. ^ One pesticide, endosulfan I, was detected in one of three samples analyzed for pesticides. The single detection, 92.0 ug/kg, was reported in sample eL-02-Ols. Twenty-one inorganics were detected in potential future Curriculum Center Building surface soil samples. Fifteen inorganics were detected in each of the three samples analyzed for inorganics, including aluminum, arsenic, barium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, potassium, vanadium, and zinc. The highest concentrations were reported for calcium (56050 mg/kg), iron (48800 mg/kg), aluminum (27350 mg/kg), and magnesium (23550 mg/kg). The calcium maximum detection was reported as the average of the sample (collected by Geraghty & Miller) and the split (collected by CDM Federal), SS-4-AVS, while the iron maximum detection was reported as the average of the sample (collected by 49 TUT 006 2235 ^ Geraghty & Miller) and the split (collected by CDM Federal), SS-3-AVS. The aluminum and magnesium maximum detections were reported as the average of the sample and its associated duplicate (both collected by Geraghty & Miller), MWS-16-AVD. O'Henry Dry Cleaners and Liquor Barn The results of the analysis of six surface soil samples collected at the O'Henry dry cleaners and Liquor Barn area are presented in Table 2-6. Six VOCs, including primarily chlorinated chemicals, were detected in at least one sample. The most frequently detected VOCs were tetrachloroethene (5 of 6 samples), methylene chloride (2 of 6 samples), and chloroform (2 of 6 samples). All other VOCs were detected in only one sample. The chemicals detected at the highest concentrations were tetrachloroethene (440000 ug/kg) and methylene chloride (150 J ug/kg). The tetrachlorethene maximum detection was reported in sample e-01, while the methylene chloride maximum detection was reported in sample eO-02-02. Five SVOCs, including primarily phthalates, were detected in at least one surface soil sample. The most frequently detected SVOC was bis(2-ethylhexyl)phthalate (3 of 5 samples). All other SVOCs were detected in only one sample. The highest SVOC detection occurred for .bis(2- ethylhexyl)phthalate (510 ug/kg) in sample eO-02-01. All other SVOC maximum detections were well below the bis(2-ethylhexyl)phthalate concentration. No pesticides or PCBs were detected in surface soil samples collected from the O'Henry dry 50 rUT °0= 2236 cleaners and Liquor Barn area. Nineteen inorganics were detected in the O'Henry dry cleaners and Liquor Barn surface soil samples. Seventeen inorganics were detected in each of the two samples analyzed for inorganics, including aluminum, arsenic, barium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, potassium, silver, sodium, vanadium, and zinc. The highest concentrations were reported for calcium (73200 * mg/kg), iron (29400 mg/kg), and aluminum (22425 J mg/kg). The calcium and iron maximum detections were reported in sample B-13A, while the aluminum maximum detection was reported as the average of the sample (collected by Geraghty & Miller) and the split (collected by CDM Federal), SS-6-AVS. Subsurface Soil; Subsurface soil sample data are presented in Tables 2-7 through 2-11 for the Tillett Gardens and Art Center, Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company, Curriculum Center Building, Esso gas station and Splash and Dash car wash, and O'Henry dry cleaners and Liquor Barn. The Curriculum Center Building present and potential future-use scenarios differ in that the sample groups evaluated are not the same. At present, samples B-14, B-15, and B-16 are considered surface soil samples and were collected at a depth ranged zero to two feet. However, the area where these samples were collected is expected to be paved over in the near future. It should be noted that not all samples were analyzed for all chemical classes. In addition, soil samples collected during monitoring well installation were given the sample name prefix MWS (as opposed to MW for groundwater) so that the samples would be recognized as soil in the computer data base. Samples having split 51 OO6 to Oo 0- OSUMM-SB-TGA.XLS TABL TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL TILLETT GARDENS AND ART CENTER CONCENTRATION (ug/kg) CHEMICALS VOCs Tetrachtoroethene Toluene Ethylbenzene SVOCs Phenanthrene Fluoranthene Pyrene Benzo(a)anthraoene Chiysene Benzo(b)fluoranffiene Benzo(k)flouranthene Benzo(a)pyrene lndeno(1 ,2,3-cd)pyrene Benzo(g,h,l)perylene PESTICIDESyPCBs Not Analyzed Frequency of Detection 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 Range of Detected Concentrations Minimum Maximum 3.50 J 4.00 J 2.50 J 160J 233 J 238 J 178 J 193J 213 J 96.0 J 1B8J 87.0 J 84.0 J 3.50 J 4.00 J 2.50 J 168 J 233J 238 J 178 J 193 J 213 J 96.0 J 188 J 87.0 J 84.0 J Location of Maximum B-8-AVD B-8-AVO B-8-AVD B-8-AVD B-8-AVD B-8-AVD B-8-AVD B-8-AVD B-8-AVD B-8-AVD B-8-AVD B-8-AVD B-8-AVD Range of Non-Detect Concentrations Minimum 10.5 U 10.5 U 10.5 U 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ Maximum 10.5 U 10.5 U 10.5 U 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ 345 UJ Sample Group: B-8-AVD. MWS-5-AVS. to f.-J 05 TABLE 2- _H G*- TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL TILLETT GARDEN AND ART CENTER CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium Beryllium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Mercury Nickel Potassium Silver Sodium Vanadium Zinc Cyanide Frequency of Detection 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 2/2 1/1 2/2 2/2 1/2 2/2 2/2 2/2 2/2 2/2 2/2 1/2 Range of Detected Concentrations Minimum Maximum 21650 3.65 BNJ 0.77 B 50.7 0.36 B 54400* 24.2 18.4 103J 30300 10.0 J 17050 746 0.06 14.5 1180 2.20 NJ 381 B 108 106 1.50 27400 5.10 BNJ 49.2 J 75.7 0.46 B 69000* 26.0 24.3 115 37700 10.0J 26200 763 0.06 15.3 2095 BJ 2.75 BNJ 459 B 157 164 1.50 Location of Range of Non-Detect Concentrations Maximum Minimum MWS-5-AVS MWS-5-AVS B-8-AVD B-8-AVD MWS-5-AVS B-8-AVD B-8-AVD MWS-5-AVS MWS-5-AVS MWS-5-AVS B-8-AVD MWS-5-AVS MWS-5-AVS B-8-AVD 0.05 U MWS-5-AVS B-8-AVD B-8-AVD B-8-AVD B-8-AVD MWS-5-AVS B-8-AVD 0.52 U Maximum - - - - - -.. - -. - - 0.05 U -. - - - 0.52 U Sample Group: B-8-AVD, MWS-5-AVS. K) W W ••0 OV11/M DSUMM-SB-FTS.XLS TABL TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL FIRE DEPARTMENT / TEXACO GAS STATION / ANTILLES AUTO PARTS / RAMSAY MOTOR CO. CONCENTRATION (ug/kg) CHEMICALS VOCs Bromome thane Mefhytene Chloride Acetone 1 ,2-Dichlofoethene (Total) 2-Butanone Benzene 4-Methyl-2-Pentanone Tetrachloroethene Toluene Ethytbenzene Methyl-tert-butyl-ether Xytenes (Total) SVOCB Bte<2-chlofo«thyl)ether OI-n-tHitylphthalate Benzo(a)pyrene Bte(2-ethylhexyl)phthalate PESTICIDES/PCBS None Detected Frequency of Detection 1/9 5/10 a/io 1/9 3/9 1/9 1/9 4/9 2/9 1/9 2/8 1/9 1/9 1/9 1/9 1/9 Range of Detected Concentrations Minimum Maximum 2.00 J 1.00 J 3.00 J 2.00 J 18.0 4.25 J 17.0 J 1.00 J 2.00 J 9.00 J 1.30 J 1700J 13.0J 170 J 140 J 370 J 2.00 J 26.0 J 190 B 2.00 J 75.0 J 4.25 J 17.0J 8.00 J 25.0 J 9.00 J 20.0 J 1700 J 13.0J 170 J 140 J 370 J Location of Maximum eT-02s-AVD B-3 MWS-4 MWS-17 «T-02s-AVD *T-02s-AVD eT-02s-AVD B-3 eT-02s-AVD eT-02»-AVD MWS-15 eT-02»-AVD MWS-4 MWS-3 MWS-4 MWS-17 Range of Non-Detect Concentrations Minimum 10.0 U 10.0 U 10.0 U 8.00 UJ 10.0 U 10.0 U 10.0 U 8.00 UJ 10.0 U 10.0 U 10.0 UJ 10.0 U 340 U 340 U 340 U 340 U Maximum 13.0 U 22.0 UBJ 119 UJ 13.0 U 12.0 U 13.0 U 13.0 U 12.0 U 13.0 U 13.0U 55.0 U 13.0 U 410 U 1900 U 410 U 420 U Sample Group: B-3. B-4, B-5. B-7, MWS-3, MWS-4. MWS-4D. MWS-15, MWS-17, eT-02s-AVD. C O TABLE 2 L/l TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL FIRE DEPARTMEN /TEXACO GAS STATION / ANTILLES AUTO PARTS / RAMSAY MOTOR CO. CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Mercury Nickel Potassium Selenium Silver Sodium Vanadium Zinc Cyanide Frequency of Detection 8/8 4/8 6f7 8/8 3/8 2/8 8/8 8/8 8/8 8/8 8/8 B/8 8/8 a/a 2/8 8/8 8/8 2/8 4/8 8/8 a/a 8/8 1/8 Range of Detected Concentrations Minimum Maximum 21100 3.50 BJ 0.54 BWJ 36.9 B 0.27 BJ 0.73 BJ 5730 27.0 J 18.9 47.3 NJ 29800 1.50 J 11100 506 0.08 B 16.7 J 386 B 0.53 BWJ 1.40BJ 217 BJ 93.4 J 42.6 J 0.65 32200 J 7.90 BNJ 1.80BJ 184 0.42 B 1.10B 67200* 38.0 EJ 32.7 J 104 42500 19.8J 23600 J 947 EJ 0.12 BJ 19.4 1270 J 0.55 BWJ 2.10 BJ 2040 167 62.4 0.65 Location of Maximum B-4 B-5 MWS-4 B-3 B-3 MWS-15 B-5 MWS-4 MWS-4 B-3 B-3 B-7 B-4 MWS-4 B-4 B-5 MWS-4 MWS-4 B-4 B-3 B-3 B-7 MWS-4 Range of Non-Detect Concentrations Minimum . 3.00 U 0.46 U - 0.21 U 0.62 U - - - • - - - - 0.05 U -. 0.41 UWJ 0.72 U - - - 0.52 U Maximum . 6.00 UJ 0.46 U - 0.24 U 0.70 U - - - - - - - - 0.06 U -. 0.50 U 0.92 U - - - 0.79 U Sample Group: B-3, B-4, B-5. B-7, MWS-3, MWS-4, MWS-4D, MWS-15, MWS-17, eT-02s-AVD. to DSUMM-SO-CCB.XLS TAl TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL CURRICULUM CENTER BUILDING CONCENTRATION (ug/kg) CHEMICALS VOCs Methylene Chtorkte Acetone 2-Butanone Trlchloroethene TetracHoroethene Toluene Xytones (Total) SVOCs Diethylphthalate Di-n-bulylpMhalate Butytbenzylphthalale Bis(2-ettiylhexyl)phttialate PESTICIDESff'CBs Not Analyzed Frequency of Detection 2/10 3/10 1/10 2/10 a/io 4/10 1/10 1/10 1/10 1/10 2/10 Range of Detected Concentrations Minimum Maximum 2.00 J 10.8 J 59.0 1.00 J 23.0 2.00 J 1.00 J 40.0 J 890 B 58.0 J 49.0 J 34.0 B 370 59.0 6.00 J 170 12.0 1.00J 40.0 J 890 B 58.0 J 210 J Location of Maximum MWS-14 B-6-AVS B-6-AVS B-15 B-15 B-15 MWS-14 MWS-14 MWS-14 B-16 MWS-13 Range of Non-Detect Concentrations Minimum 11.0 U 11.0 UJ 11.0 U 11.0 U 11. OU 11.0 U 11.0 U 350 U 350 U 350 U 350 U Maximum 28.0 UJ 16.0 U 24.5 UJ 20.0 U 24.5U 24.5 U 24.5 U 625 U 625 U 825 UJ 590 UJ Sample Group: B-14-AVD, B-15. B-16, B-1-AVS, B-6-AVS, MWS-1, MWS-1D, MWS-13. MWS-13D. MWS-14. w TABLES TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL CURRICULUM CENTER BUILDING CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium BeiyHium Cadmium Calcium Chromium Cobalt Copper Iron Load Magnesium Manganese Mercury Nickel Potassium Silver Sodium Vanadium Zinc Cyanide Frequency of Detection 10/10 9/10 8/10 10/10 2/10 3/10 10/10 10/10 10/10 10/10 10/10 10/10 10/10 10/10 1/10 10/10 10/10 5/10 9/10 10/10 10/10 2/10 Range of Detected Concentrations Minimum Maximum 18900 3.40 BJ 0.45 BJ 17.9 BJ 0.22 B 0.99 B 6540 15.6NJ 17.1 47.8 J 25550 2.45 J 16300 599 0.57 12.1 181 B 0.70 B 186 B 79.7 NJ 52.1J 0.75 37900 19.0 11.6 59.1J 0.23 BJ 2.87 96500* 36.5 32.7 102 EJ 46400 45.6 N'J 24600 J 973 0.57 27.3 806 B 2.30 J 632 B 132 J 585 0.88 Location of Maximum B-6-AVS B-6-AVS B-16 MWS-1 MWS-1 D B-6-AVS B-14-AVD B-6-AVS B-6-AVS MWS-1 3D &6-AVS B-16 MWS-1 B4-AVS B-16 MWS-13 B-6-AVS MWS-1 D MWS-1 D MWS-1 MWS-13 MWS-1 Range of Non-Detect Concentrations Minimum - 5.20 UJ 0.46 U - 0.21 U 0.63 U . - - ;. 0.05 U - 0.63 U 393 U - - 0.52 U Maximum . 5.20 UJ 0.46 U . 0.42 U 0.86 U . . - ;. 0.13 U . 1.01 U 393 U -. 5.29 U Sample Group: B-14-AVD, B-15, B-16. B-1-AVS, B-6-AVS, MWS-1. MWS-1D, MWS-13, MWS-13D, MWS-14. -i W OSUMM-SB-ESSO.XLS 03 TABL JO TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL ESSO GAS STATION AND SPLASH AND DASH CAR WASH CONCENTRATION (ug/kg) CHEMICALS VOCs Metnytene Chloride Acetone 2-Butanone Trichtoroelhene TetracMoroethene Toluene SVOCs Dt-n-butylphthalate B(s(2-elhylhexyl)phthalate PESTICIDES/PCBs Not Analyzed Frequency of Detection 4/7 3/7 2/7 1/7 1/7 2/7 1/7 3/7 Range of Detected Concentrations Minimum Maximum 3.00 J 33.0J 5.00 J 7.75 J 2.00 J 1.00 J 458 B 130J 20.0 J 50.0 BJ 13.0 BJ 7.75 J 2.00 J 1.00J 458 B 220 J Location of Maximum MWS-10D MWS-18 MWS-18 MWS-9-AVS MWS-8-AVS MWS-8-AVS MWS-8-AVS B-9 Range of Non- Detect Concentrations Minimum 11.0 U 11.0 U 10.5 U 11.0 U 10.5 U 10.5 U 345 U 345 UJ Maximum 21.5UJ 40.5 UJ 12.0U 12.0 UJ 12.0 UJ 12.0 UJ 750 U 370 UJ Sample Group: B-9. MWS-8-AVS, MWS-9-AVS, MWS-10, MWS-10D, MWS-18, MWS-25. TABLE 2- TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL ESSO GAS STATION AND SPLASH AND DASH CAR WASH CONCENTRATION {mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Nickel Potassium Selenium Silver Sodium Vanadum Zinc Cyanide Frequency of Detection 7/7 3/7 4/7 7/7 6/7 1/7 7/7 7/7 7/7 7/7 7/7 7/7 7/7 7/7 7/7 7/7 1/7 5/7 6/7 7/7 7/7 1/7 Range of Detected Concentrations Minimum Maximum 14100 3.65 BJ 0.47 ai 21.9 BJ 0.16 B 0.95 B 2340 4.50 7.90 B 402 30000 1.19 BJ 5770 435 3.20 B 203 B 1.10 B 0.82 B 248 B 57.9 38.5 J 0.41 28000 J 4.40 BJ 1.60 BJ 199 0.35 B 0.95 B 37750 J 35.2 J 23.7 J 105 J 39300 11.7 18550 J 1250 21 .8 J 1440 1.10B 4.12 B 832 B 130 87.2 0.41 Location of Maximum MWS-9-AVS B-9 B-9 MWS-10D MWS-25 MWS-25 MWS-9-AVS B-9 B-9 B-9 MWS-25 MWS-25 MWS-9-AVS MWS-25 B-9 MWS-18 MWS-25 MWS-9-AVS MWS-9-AVS MWS-18 MWS-25 MWS-B-AVS Range of Non-Detect Concentrations Minimum . 4.30 UJ 0.45 UJ - 0.18 U 0.48 U - - - - - - - -. - 0.43 U 0.68 U 430U - - 0.53 U Maximum . 5.60 UJ 2.40 U . 0.18 U 0.91 U ... - -. - -. - 0.47 U 0.85 U 430 U - - 0.59 U Sample Group: B-9, MWS-8-AVS, MWS-9-AVS, MWS-10, MWS-10D, MWS-18, MWS-25. c —5 O1 06/11/94 DSUMM-SB-OH.XLS TABL 11 TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL O'HENRY DRY CLEANERS AND LIQUOR BARN CONCENTRATION (ug/kg) CHEMICALS yocs Methy tone Chloride Tetrachtoroethene Toluene SVQCs Di-n-butylphthalale Fhioranthene Butylbenzylphthalate PESTICIDES/PCBs Not Analyzed Frequency of Detection 1/4 2/4 1/4 1/4 1/4 1/4 Range of Detected Concentrations Minimum Maximum 3.00 J 29.00 3.00 J 160 J 42.0 J 220 J 3.00 J 2000 3.00 J 160 J 42.0 J 220 J Location of Maximum B-11 B-13 B-11 B-10 B-13 B-10 Range of Non-Detect Concentrations Minimum 11.0 UJ 11.5U 11.0 U 380 U 385 U 380 U Maximum 19.5 UJ 12.0 U 12.0U 400 U 400 U 400 U Sample Group: B-10, B-11. B-12-AVS, B-13. O 0- KJ f-J —i C-i G-- TABLE 2-i Int-d) TUTU WELLS SITE SUMMARY OF CHEMICALS IN SUBSURFACE SOIL O'HENRY DRY CLEANERS AND LIQUOR BARN CONCENTRATION (mg/kg) CHEMICALS INORGANICS Aluminum Antimony Arsenic Barium BeryMum Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Mercury Nickel Potassium Silver Sodkim Vanadium Zinc Frequency of Detection 4/4 2/4 3/4 4/4 2/4 4/4 4/4 4/4 4/4 4/4 4/4 4/4 4/4 1/4 4/4 4/4 4/4 4/4 4/4 4/4 Range of Detected Concentrations Minimum Maximum 14300 4.90 BJ 5.00 29.0 B 0.29 B 5150 13.0 15.1 46.4 26800 EJ 1.20 J 5570 430 0.08 B 4.70 B 591 B 1.60B.I 133B 83.9 45.7 EJ 19200 5.20 BJ 185 J 498 0.33 B 14400 21.2 18.2 88.7 34100 EJ 6.90 SJ 14600 2200 0.08 B 16.4 2830 2.00 BJ 352 B 119 99.5 EJ Location of Range of NorvDetect Concentrations Maximum Minimum B-11 B-10 4.40 UJ B-13 2.20 U B-10 B-11 0.22 U B-10 B-12-AVS B-12-AVS B-10 B-11 B-11 B-13 B-10 B-11 0.05 U B-12-AVS B-11 B-10 B-10 B-10 B-11 Maximum - 4.70 UJ 2.20 U . 0.22 U .. - - - - - - 0.06 U -.. - - - Sample Group: B-10. B-11. B-12-AVS. B-13. Kl or duplicate results were given the suffix AVS or AVD, respectively to differentiate the components of the averaged results. Tillett Gardens and Art Center The results of the analysis of two subsurface soil samples collected at the Tillett Gardens and Art Center are presented in Table 2-7. Three VOCs, tetrachloroethene, toluene, and ethylbenzene, were each detected in one of the two samples analyzed for VOCs. The chemical detected at the highest concentration was toluene at 4.0 J ug/kg in sample B-8-AVD. Sample B-8-AVD is an average of sample B-8 and its duplicate, both of which were collected by Geraghty & Miller. Ten SVOCs, which include PAHs, were detected in one of the two samples analyzed for SVOCs. The chemicals detected at the highest concentrations were pyrene (238 J ug/kg), fluoranthene (233 J ug/kg), and benzo(b)fluoranthene (213 J ug/kg). These detections were all reported in sample B-8-AVD. Pesticides and PCBs were not analyzed for in subsurface soil samples collected from the Tillett Gardens and Art Center. Twenty-one inorganics were detected in subsurface soil samples collected from the Tillett Gardens and Art Center area. Nineteen inorganics were detected in each of the two samples 62 TUT OO6 2248 analyzed for inorganics, except for lead which was analyzed for and detected in only one sample. The inorganics detected in each of two samples include aluminum, antimony, arsenic, barium, beryllium, calcium, chromium, cobalt, copper, iron, magnesium, manganese, nickel, potassium, silver, sodium, vanadium, and zinc. The highest concentrations were reported for calcium (69000 * mg/kg), iron (37700 mg/kg), aluminum (27400 mg/kg), and magnesium (26200 mg/kg). The calcium maximum detection was reported in sample B-8-AVD, while the iron, aluminum, and magnesium maximum detections were reported as the average of the sample (collected by Geraghty & Miller) and the split (collected by CDM Federal), MWS-5-AVS. Fire Department/Texaco Gas Station/Antilles Auto Parts/Ramsay Motor Company The results of the analysis of ten subsurface soil samples collected at the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company area are presented in Table 2-8. Twelve VOCs, including primarily ketones and aromatics, were detected in at least one sample. The most frequently detected VOCs were acetone (8 of 10 samples), methylene chloride (5 of 10 samples), tetrachloroethene (4 of 9 samples), and 2-butanone (3 of 9 samples). The chemicals detected at the highest concentrations were xylenes (total) (1700 J ug/kg) and acetone (190 B ug/kg). The maximum xylenes (total) detection was reported as the average of the sample and its associated duplicate (both collected by CDM Federal), eT-02s- AVD. The maximum acetone detection was reported in sample MWS-4. Four SVOCs, including an ether, two phthalates, and a PAH were each detected in one of nine 63 TUT O06 2249 samples analyzed for SVOCs. The highest concentrations were reported for bis(2- ethylhexyl)phthalate (370 J ug/kg) and di-n-butylphthalate (170 J ug/kg). The bis(2-ethylhexyl) phthalate detection was reported in sample MWS-17, while the di-n-butylphthalate detection was reported in sample MWS-3. No pesticides or PCBs were detected in subsurface soil samples collected from the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company area. Twenty-three inorganics were detected in Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company subsurface soil samples. Fifteen inorganics were detected in each of the seven samples analyzed for inorganics, including aluminum, barium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, potassium, sodium, vanadium, and zinc. The highest concentrations were reported for calcium (67200 * mg/kg), iron (42500 mg/kg), aluminum (32200 J mg/kg), and magnesium (23600 J mg/kg). The maximum detection of calcium was reported in sample B-5, while the maximum aluminum and magnesium detections were reported in sample B-4. The maximum iron detection was reported in sample B-3. Curriculum Center Building (Future) The results of the analysis of ten subsurface soil samples collected at the Curriculum Center Building area are presented in Table 2-9. Seven VOCs, including ketones, and chlorinated aliphatic and aromatic chemicals, were detected in at least one sample. The most frequently 64 TUT 006 2250 ^ detected VOCs were toluene (4 of 10 samples), acetone (3 of 10 samples), and tetrachloroethene (3 of 10 samples). The chemicals detected at the highest concentrations were acetone (370 ug/kg) and tetrachloroethene (170 ug/kg). The acetone maximum concentration was reported as the average of the sample (collected by Geraghty & Miller) and the split (collected by CDM Federal), B-6-AVS. The maximum iron detection was reported in sample B-15. Four SVOCs, all phthalates, were detected in at least one subsurface soil sample. The most frequently detected SVOC was bis(2-ethylhexyl)phthalate (2 of 10 samples). All other SVOCs were detected in only one sample. The highest SVOC detections were reported for di-n- butylphthalate (890 B ug/kg) and bis(2-ethylhexyl)phthalate (210 J ug/kg). The di-n- butylphthalate maximum detection was reported in sample MWS-14 while the bis(2-ethylhexyl) phthalate maximum detection was reported in sample MWS-13. Pesticides and PCBs were not analyzed for in subsurface soil samples collected at the Curriculum Center Building area. Twenty-two inorganics were detected in Curriculum Center Building subsurface soil samples. Fourteen inorganics were detected in each of the ten samples analyzed for inorganics, including aluminum, barium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, potassium, vanadium, and zinc. The highest concentrations were reported for calcium (96500 * mg/kg), iron (46400 mg/kg), aluminum (37900 mg/kg), and magnesium (24600 J mg/kg). The calcium maximum detection was reported as the average of the sample and its 65 TUT <l 22bl associated duplicate (collected by Geraghty & Miller), B-14-AVD, while the iron and aluminum maximum detections were reported as the average of the samples (collected by Geraghty & Miller) and their respective splits (collected by CDM Federal), B-6-AVS. The magnesium maximum detection was reported in sample MWS-1. Esso Gas Station and Splash and Dash Car Wash The results of the analysis of seven subsurface soil samples collected from the Esso gas station and Splash and Dash car wash area are presented in Table 2-10. Six VOCs, including primarily ketones and chlorinated aliphatics, were detected in at least one sample. The most frequently detected VOCs were methylene chloride (4 of 7 samples) and acetone (3 of 7 samples). The chemicals detected at the highest concentrations were acetone (50.0 BJ ug/kg) and methylene chloride (20.0 J ug/kg). These concentrations were reported in samples MWS-18 and MWS- 10D, respectively. Two SVOCs, both phthalates, were detected in at least one of seven samples analyzed for SVOCs. Di-n-butylphthalate was detected at 458 B ug/kg while the highest bis(2- ethylhexyl)phthalate detection was reported as 220 J ug/kg. The di-n-butylphthalate detection was reported as the average of the sample (collected by Geraghty & Miller) and the split (collected by CDM Federal), MWS-8-AVS, while the bis(2-ethylhexyl)phthalate detection was reported in sample B-9. 66 TUT OO6 2252 Pesticides and PCBs were not analyzed for in subsurface soil samples collected from the Esso gas station and Splash and Dash car wash. Twenty-two inorganics were detected in subsurface soil samples collected from the Esso gas station and Splash and Dash car wash. Fourteen inorganics were detected in each of the seven samples analyzed for inorganics, including aluminum, barium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, potassium, vanadium, and zinc. The highest concentrations were reported for iron (39300 mg/kg), calcium (37750 J mg/kg), aluminum (28000 J mg/kg), and magnesium (18550 J mg/kg). The calcium, aluminum, and magnesium maximum detections were reported as the average of the sample (collected by Geraghty & Miller) and the split (collected by COM Federal), MWS-9-AVS. The iron maximum detection was reported in sample MWS-25D. O'Henry Dry Cleaners and Liquor Barn The results of the analysis of four subsurface soil samples collected at O'Henry dry cleaners and Liquor Barn are presented in Table 2-11. Three VOCs, methylene chloride, tetrachloroethene, and toluene were each detected in at least one sample. Tetrachloroethene was detected at the highest concentration of the three chemicals, 200 D ug/kg. This detection was reported in sample B-13. Three SVOCs, including PAHs and phthalates, were each detected once in the four samples 67 TUT 006 2253 analyzed for SVOCs. Butylbenzylphthalate was reported at 220 J ug/kg, di-n-butylphthalate at 160 J ug/kg, and fluoranthene at 42.0 J ug/kg. Butylbenzylphthalate and di-n-butylphthalate were reported in sample B-10 while the fluoranthene detection was reported in sample B-13. Pesticides and PCBs were not analyzed for in subsurface soil samples collected from the O'Henry dry cleaners and Liquor Barn area. Twenty inorganics were detected in the O'Henry dry cleaners and Liquor Barn subsurface soil samples. Sixteen inorganics were detected in each of the four samples analyzed for inorganics, including aluminum, barium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, potassium, silver, sodium, vanadium, and zinc. The highest concentrations were reported for iron (34100 EJ mg/kg), aluminum (19200 mg/kg), magnesium (14600 mg/kg), and calcium (14400 mg/kg). The maximum iron and aluminum detections were reported in sample B-ll, while the maximum magnesium detection was reported in sample B-13. The maximum calcium detection was reported in sample B-10. 2.2.3 Chemicals Detected in Groundwater A single site groundwater data summary is presented in Table 2-12. Upgradient, cross-gradient, and downgradient groundwater samples have not been included in this table, but are discussed separately in Section 2.3.2. Since multiple groundwater results exist for many wells sampled during the seven quarterly monitoring events conducted by Geraghty & Miller from 1991 to 68 TUT 006 2254 12/22/94 GW-SUM.XLS 0\ VO -i TABU I TUTU WELLS SITE SUMMARY OF CHEMICALS IN GROUNDWATER (SITE-WIDE) CONCENTRATION (ug/1) CHEMICALS VOCs CMorome thane Vinyl Chloride Meftytene Chloride Acetone Carbon Disultkte 1.1-Dichtoroethena 1,1-Dfchloroethane 1,2-Dichloroethene (Total) Chloroform 1 ,2-Dtchloroethane 2-Butanone I.l.t-Trichloroethane Bromodichlorome thane Trfchtoroethene DibromocNoromethane 1,1,2-TricNoroethane Benzene Bromoform Tetrachkxoethene Toluene Chlorobenzene Ethylbenzene Xylenes (Total) Melhyl-tert-butyl-elher n-Propylbenzene cis-1,2-Dichloroethene Frequency of Detection 1/169 21/164 18/168 13/146 4/168 2/168 5/168 142/169 82/170 1/169 9/145 2/168 11/169 142/172 4/169 5/169 34/168 5/167 143/173 32/168 2/168 13/168 17/168 57/89 10/78 4/4 Range of Detected Concentrations Minimum Maximum 0.62 0.22 J 0.18 BJ 3.90 JB 0.15J 0.06 J 0.05 J 0.1 U 0.05 J 290 2.00 J 2.00 J 0.09 J 0.06 J 6.00 J 1.00J 0.05 J 4.50 J 1.00J 0.05 J 0.13J 1.00 0.40 J 1.00JN 4.20 J 11.5 0.62 1300 64.0 J 2700 J 3.00 J 0.12 J 0.1 U 2100 150J 290 620 J 3.00 J 30.0 190 36.0 5.00 21000 D 29.0 1500 17000 0.20 J 4100 J 22000 J 89000 DJ 3800 J 37.00 Location of Maximum Gassett-5-AVD MW-16-9 MW-5-AVS SW-3-9 MW-14-AVS Steele-4 Steele-4 MW-16-9 SW-3-9 TT-1-9 SW-2-9 Harvey-9 MW-12D MW-1 MW-11D Smith-2 TT-1-9 MW-1 ID Harvey-2 TT-4-9 Tillett-4-AVD SW-3-9 SW-3-9 SW-3-9 SW-3-9 MW02 Range of Non-Detect Concentrations Minimum 0.50 U 0.50 U 0.50 UJ 2.00 UJ 0.50 UJ 0.50 UJ 0.50 UJ 0.50 UJ 0.50 UJ 0.50 UJ 2.00 U 0.50 UJ 0.50 UJ 0.50 UJ 0.50 UJ 0.50 U 0.50 UJ 0.50 UJ 0.50 UJ 0.50 UJ 0.50 UJ 0.50 UJ 0.50 UJ 10.0U 5.00 UJ - Maximum 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 200 U 5000 U 5000 U 200 U 5000 U 1000UJ 200 U 1000 UJ 5000 UJ - Sample Group: MW-1. MW-1D. MW-2. MW-3, MW-4-AVS, MW-4D. MW-5-AVS. MW-6D, MW-6R-AVS. MW-7-AVD, MW-8, MW-9-AVD. MW-9S. MW-10, MW-10D, MW-110. MW-12D, MW-130, MW-14-AVS. Eglin 1-2, Egtin 11-2, Eglinlll-2-AVD, FourWindsll-2, Gassett-2. Harvey-2, LaPlace-2-AVD. Matthias-2, Ramsay-2, Rodriguez-2, Smith-2, Steele-2, Tillett-2, Eglin 1-3. Eglin 11-3, Eglin HI-3. FourWindsl-3, Gassett-3, Harvey-3, LaPlace-3-AVD. Matthias-3, Ramsay-3, Smith-3, Steele-3, Tiflett-3, Eglin M. Eglin 11-4, Eglin HI-4. FourWindsl-4, FourWindsll-4, Gassett-4, Harvey-4, LaPlace-4, Matthias-4, Ramsay-4, Smith-4, Steele-4. Tillett-4-AVD, Eglin 1-5, Eglin 11-5, Eglin HI-5, FourWindsl-5, FourWindsll-5, Gassett-5-AVD, Harvey-5. LaPlace-5-AVD, Matlhias-5, Ramsay-5, Rodriguez-5, Smith-5, Steele-5, Tillett-5, Eglin 1-6, Eglin 11-6, Eglin HI-6, Gassett-6, Harvey-6, LaPlace-6, Ramsay-6. Smith-6-AVD, Steete-6. Tillett-6, Eglin 1-7. Eglin 11-7, Eglin HI-7, FourWindsl-7, FourWinds 11-7, Gassett-7, Harvey-7, LaPlace-7. Ramsay-7-AVD, Smith-7. Steele-7. Tillett-7, Eglin 1-8, Eglin HI-8, FourWindsl-8, Gassett-8. Harvey-8-AVD. LaPlace-8, Ramsay-8, Rodriguez-8, Smith-8. Steele-8, Tiltett-8, MW01, MW02, MW03-AVO, MW04, CHT-3-9, CHT-6D-9. CHT-7D-9. Delegarde-9, Detegarde-9*. DW-1-9, DW-2-9, Eglin 1-9, Eglin HI-9. FourWinds 1-9, FourWindsll9AV, Gassett-9, Harvey-9. LaPlace-9, Matthias-9, MW-1-9. MW-1D-9, MW-2-9, MW-3-9, MW^»-9, MW-4D-9, MW-5-9, MW-6D-9, MW-6R-9, MW-7-9, MW-8-9, MW-9S-9, MW-10-9. MW-10D-9. MW-11D-9-AVD, MW-12D-9, MW-13-9, MW-13D-9, MW-15-9. MW-16-9, MW-17-9, MW-18-9, MW-18R-9. MW-19-9, MW-20-9, MW-20D-9, MW-21D-9, MW-22D-9, MW-24-9, MW-25-9. OHMW-1-9, OHMW-2-9, OHMW-3-9, OHMW-4-9, Ramsay-9, Smith-9, Steete-9. SW-2-9, SW-3-9, SW-4-9, SW-5-9. SW-6-9. SW-7-9-AVD. Tlllett-9. TT-1-9, TT-1D-9, TT-2-9-AVD. TT-3D-9, TT-4-9, TT-5-9, VIHA 1-9. TABLE 2- Ijnt'd) -J O —ic-i TUTU WELLS SITE SUMMARY OF CHEMICALS IN GHOUNDWATER (SITE-WIDE) CONCENTRATION (ug/1) CHEMICALS SVOCs Phenol 1,4-Dichlorobenzene 1 ,2-Dichlorobenzene 2-Melhylphenol 4-Melhylphenol 2-Nitrophenol 2,4-Oimethylphenol Benzole Add 1 ,2,4-Trichtorobenzene Naphthalene 2-Methylnaphthalene Dimettiylphlhalate Acenaphthytene Acenaphlhene Dibenzofuran Dlelhylphthalate Ruorene Phenanthrene Anthracene Carbazote Fhioranthene Frequency of Detection 6/108 1/112 4/112 3/108 4/108 1/108 2/107 3/3 1/108 10/108 10/108 2/108 2/108 1/108 1/108 1/108 7/108 7/108 1/108 1/108 2/108 Range of Detected Concentrations Minimum Maximum 3.00 J 2.00 J 1.00J 4.00 J 3.00 J 3.00 J 13.0J 2.00 JN 3.00 J 2.00 J 1.00J 3.00 J 1.00J 2.00 J 1.50J 60.0 J 2.00 J 1.50J 1.00J 1.00J 1.00J 67.0 J 2.00 J 6.50 J 27.0 J 72.0 J 3.00 J 32.5 J 60.0 J 3.00 J 1000 DJ 450 DJ 8.00 J 1.00 J 2.00 J 1.50J 60.0 J 40.0 J 32.0 J 1.00 J 1.00J 1.00J Location of Maximum TT-1-9 MW-1 6-9 SW-7-9-AVD TT-1-9 TT-1-9 MW-13D-9 SW-7-9-AVD Gassett-9 MW-1 6-9 SW-3-9 SW-3-9 MW-4D MW-9S-9 SW-7-9-AVD MW-14-AVS MW-10D-9 SW-3-9 SW-3-9 SW-7-9-AVD MW-9S-9 MW-9S-9 Range of Non-Detect Concentrations Minimum 8.00 UJ 1.00 U 1.00 U 8.00 U 8.00 UJ 8.00 U 8.00 U . 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U Maximum 50.0 UJ 50.0 UJ 50.0 UJ 50.0 UJ 50.0 UJ 100 U 100 U . 50.0 UJ 10.0 U 10.0 U 50.0 UJ 50.0 UJ 50.0 UJ 50.0 UJ 50.0 UJ 25.0 U 25.0 U 50.0 UJ 50.0 UJ 50.0 UJ Sample Group: MW-1, MW-1D. MW-2. MW-3, MW-4-AVS, MW-4D. MW-5-AVS. MW-6D, MW-6R-AVS, MW-7-AVD, MW-8, MW-9-AVD, MW-9S, MW-10. MW-10D, MW-11D, MW-12D, MW-13D. MW-14-AVS, Eglin 1-2. Eglin 11-2, Eglinlll-2-AVD. FourWindsll-2, Gassett-2, Harvey-2. LaPlace-2-AVD, Matthlas-2. Ramsay-2. Rodriguez-2. Smith-2, Steete-2, Tillett-2, Eglin 1-3, Eglin 11-3, Eglin 111-3, FourWindsl-3. Gassett-3. Harvey-3, LaPlace-3-AVD, Matthias-3. Ramsay-3, Smith-3. Steele-3. Tillett-3, Eglin 1-4. Eglin 11-4, Eglin IIM, FourWindst-4, FourWindsll-4, Gassett-4, Harvey-4, LaPlace-4, Matthias-4, Ramsay-4, Smith-4, Steele-4, Tillett-4-AVD, Eglin 1-5. Eglin 11-5, Eglin 111-5, FourWindsl-5. FourWindslt-5, Gassett-5-AVD, Harvey-5, LaPlace-5-AVD. Matthias-5, Ramsay-5, Rodriguez-5, Smith-5, Steele-5, TilteH-5, Eglin 1-6, Eglin 11-6, Eglin 111-6, Gassett-6, Harvey-6, LaPlace-6, Ramsay-6. Smilh-6-AVD. Steele-6, Tillett-6. Eglin 1-7. Eglin 11-7, Eglin HI-7, FourWindsl-7. FourWinds 11-7. Gassett-7, Harvey-7. LaPlace-7, Rarnsay-7-AVD. Smilh-7. Steete-7, Tlllett.7, Eglin 1-8, Eglin HI-8, FourWindsl-8. Gassen-8, Harvey-8-AVD. LaPlace-8. Ramsay-8, Rodriguez-8, Smilh-8, Steele-8. Tiltett-8, MW01. MW02, MW03-AVD. MW04. CHT-3-9, CHT-6D-9. CHT-7D-9, Delegarde-9, Delegarde-9*. DW-1-9, DW-2-9, Eglin 1-9. Eglin HI-9, FourWinds 1-9, FourWindsll9AV, Gassett-9, Harvey-9, LaPlace-9, Matthias-9, MW-1-9, MW-1D-9, MW-2-9, MW-3-9, MW-4-9, MW-4D-9. MW-5-9, MW-6D-9. MW-6R-9, MW-7-9, MW-8-9. MW-9S-9, MW-10-9, MW-10D-9, MW-11D-9-AVD, MW-12D-9, MW-13-9, MW-13D-9, MW-15-9, MW-16-9, MW-17-9, MW-18-9, MW-18R-9, MW-19-9, MW-20-9. MW-20D-9. MW-21D-9, MW-22D-9, MW-24-9, MW-25-9, OHMW-1-9, OHMW-2-9, OHMW-3-9, OHMW-4-9, Ramsay-9. Smith-9, Steele-9, SW-2-9, SW-3-9, SW-4-9. SW-5-9, SW-6-9, SW-7-9-AVD, Tillett-9, TT-1-9, TT-1D-9. TT-2-9-AVD, TT-3D-9, TT-4-9, TT-5-9, VIHA1-9. en TABLE 2- -nt'd) _H O Ul Nj TUTU WELLS SITE SUMMARY OF CHEMICALS \N GROUNDWATER (SITE-WIDE) CONCENTRATION (ug/l) CHEMICALS SVOCs (Confd) Pyrene Butyfcenzylphthalate Benzo(a)anthracera Chrysene Bis(2-ethylhexyl)phlhalate Oi-n-octylphthalate Benzo(b)fluoranthene Benzo(g,h,i)perylene PESTICIDES/PCBS Not Analyzed INORGANICS Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Chromium Cobalt Copper Iron Lead Frequency of Detection 3/108 2/108 1/108 3/108 13/108 2/108 1/108 2/108 73/88 22/115 24/107 107/107 8/108 2/108 106/107 63/107 46/107 92/107 105/106 69/107 Range of Detected Concentrations Minimum Maximum 2.50 J 1.00J 1.00J 1.00J 1.00 BJ 1.00J 1.00 J 1.00J 39.58 14.8 B 1.00 B MOB 0.75 B 2.10 B 6870 3.00 B 3.20 B 2.70 BJ 7.00 BJ 1.40BJ 8.00 J 2.00 J 1.00J 9.00 J 690 D 1.00J 1.00 J 1.00 J 356000 J 424 B 80.8 J 4400 B 40.8 B 2.45 B 11600000 4610 362 B 1730J 572000 J 201 Location ol Maximum SW-3-9 Tillett-9 SW-7-9-AVD SW-3-9 LaPlaoa-5-AVD MW-6R-AVS MW-9S-9 MW-9S-9 OHMW-4-9 MW-13D-9 OHMW-2-9 MW-130-9 MW-13D-9 Gassett-5-AVD Delegarde-9 OHMW-3-9 MW-13D-9 MW-13D-9 OHMW-4-9 OHMW-2-9 Range of Non-Detect Concentrations Minimum 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 8.00 U 35.5 U 15.0 U 1.00 U - 0.25 U 2.00 U 17600UJ 3.00 U 3.00 U 2.00 U 3000 UJ 1.00 UW Maximum 25.0 U 50.0 UJ 50.0 UJ 25.0 U 55.0 U 50.0 UJ 50.0 UJ 50.0 UJ 9420 UJ 300 U 2.50 UWJ - 20.0 U 75.0 U 17600 UJ 60.0 U 60.0 U 60.0 U 3000 UJ 43.4 UJ Sample Group: MW-1, MW-1D, MW-2, MW-3, MW-4-AVS, MW-4D, MW-5-AVS, MW-6D, MW-6R-AVS, MW-7-AVD, MW-8, MW-9-AVD. MW-9S, MW-10. MW-10D, MW-1 ID, MW-12D, MW-13D, MW-14-AVS, Eglin 1-2, Eglin It-2, Eglinlll-2-AVD. FourWindsll-2, Gassett-2. Harvey-2, LaPlace-2-AVD, Matthias-2, Ramsay-2, Rodriguez-2. Smith-2, Steete-2. Tillett-2, Eglin 1-3. Eglin 11-3, Eglin HI-3. FourWindsl-3, Gassett-3, Harvey-3, LaPlace-3-AVD. Matthias-3, Ramsay-3, Smith-3. Steele-3, Tillett-3. Eglin 1-4. Eglin 11-4, Eglin 111-4. FourWindsl-4, FourWindsll-4, Gassett-4. Harvey-4, LaPlace-4, Matthias-4, Ramsay-4, Smith-4, Steele-4. Tillett-4-AVD, Eglin 1-5, Eglin 11-5. Eglin HI-5. FourWindsl-5, FourWindsll-5. Gassett-5-AVD, Harvey 5, LaPlace-5-AVD, Matthias-5, Ramsay-5, Rodriguez-5, Smith-5, Steele-5, Tillett-5, Eglin 1-6, Eglin 11-6, Eglin HI-6, Gassett-6, Harvey-6, LaPlace-6, Ramsay-6. Smilh-6-AVD, Steele-6. Tillett-6, Eglin 1-7, Eglin 11-7, Eglin HI-7, FourWindsl-7, FourWinds 11-7, Gassett-7, Harvey-7, LaPlace-7, Ramsay-7-AVD, Smilh-7, Steele-7, Tillett-7, Eglin 1-8, Eglin 111-8, FourWindsl-8, Gassett-8, Harvey-B-AVD, LaPlace-8, Ramsay-8, Rodriguez-8, Smilh-8, Steele-8. Tiltett-8, MW01, MW02, MW03-AVD, MW04. CHT-3-9, CHT-6D-9, CHT-7D-9. Delegarde-9, Delegarde-9*. DW-1-9, DW-2-9. Eglin 1-9. Eglin HI-9, FourWinds 1-9, FourWJndsll9AV. Gassett-9, Harvey-9, LaPlace-9, MattWas-9. MW-1-9, MW-1D-9, MW-2-9, MW-3-9. MW-4-9. MW-4D-9, MW-5-9, MW-6D-9, MW-6R-9. MW-7-9, MW-8-9, MW-9S-9, MW-10-9, MW-10D-9, MW-11D-9-AVD, MW-12D-9. MW-13-9, MW-13D-9, MW-15-9, MW-16-9, MW-17-9, MW-18-9, MW-18R-9, MW-19-9. MW-20-9, MW-20D-9, MW-21D-9, MW-22D-9, MW-24-9, MW-25-9, OHMW-1-9, OHMW-2-9, OHMW-3-9, OHMW-4-9. Ramsay-9, Smilh-9, Steele-9, SW-2-9, SW-3-9, SW-4-9, SW-5-9, SW-6-9, SW-7-9-AVD, Tillett-9, TT-1-9, TT-1D-9. TT-2-9-AVD, TT-3D-9, TT-4-9, TT-5-9, VIHA 1-9. TABLE 2-12(Cont'd) -J to TUTU WELLS SITE SUMMARY OF CHEMICALS IN GROUNDWATER (SITE-WIDE) CONCENTRATION (ug/l) CHEMICALS INORGANICS (Confd) Magnesium Manganese Mercury Nickel Potassium Selenium Silver Sodium Thallium Vanadium Zinc Cyanide (Total) Frequency of Detection 106/107 104/107 27/113 50/107 103/107 27/109 2/108 106/108 3/121 101/107 106/107 1/100 Range of Detected Concentrations Minimum Maximum 654 B 1.40B 0.08 B 8.70 B 610 B 1.55B 7.00 BJ 11300J 2.10 B 4.90B 4.10 B 11.0 858000 20400 3.10J 2050 11 9000 J 11.7J 47.2 9870000 3.60 BJ 1000J 2510 J 11.0 Location of Maximum Delegarde-9 MW-13D-9 OHMW-1-9 MW-13D-9 OHMW-4-9 Smith-2 Rodriguez-5 Delegarde-9 Tillett-8 OHMW-4-9 OHMW-4-9 LaPlace-B Range of Non-Delect Concentrations Minimum 27900 UJ 1.00 U 0.10 U 7.10 U 490 U 1.50UJ 2.00 UJ 372000 U 1.00UJ 4.00U 80.7 UJ 5.00 U Maximum 27900 UJ 71.6UJ 1.60 UJ 200U 33300 UJ 10.0 UJ 75.0 U 662000 UJ 20.0 UJ 10.0 U 807UJ 100UJ Sample Group: MW-1, MW-1D, MW-2. MW-3, MW-4-AVS, MW-4D, MW-5-AVS, MW-6D, MW-6R-AVS, MW-7-AVD, MW-8, MW-9-AVD, MW-9S, MW-10, MW-10D, MW-1 ID, MW-12D, MW-13D, MW-14-AVS. Eglin 1-2, Eglin 11-2, Eglinlll-2-AVD, FourWindsll-2, Gassett-2, Harvey-2, LaPlace-2-AVD, Matthias-2, Ramsay-2, Rodriguez-2, Smith-2. Steete-2, Tillett-2, Eglin 1-3, Eglin 11-3, Eglin HI-3, FourWindsl-3, Gassett-3, Harvey-3, LaPlace-3-AVD, Matthias-3, Ramsay-3, Smith-3, Steele-3, Tillett-3, Eglin 1-4, Eglin IM. Eglin HI-4. FourWindsl-4, FourWindsll-4, Gassett-4. Harvey-4, LaPlaoe-4. Matthias-4, Ramsay-4, Smith-4, Steele-4. Tillett-4-AVD, Eglin 1-5, Eglin 11-5, Eglin HI-5, FourWindsl-5. FourWindsll-5. Gassett-5-AVD, Harvey-5. LaPlace-5-AVD, Matthias-5, Ramsay-5, Rodriguez-5, Smith-5. Steele-5. TiHett-5. Eglin 1-6. Eglin 11-6, Eglin HI-6. Gassett-6, Harvey-6, LaPlace-6, Ramsay-6. Smilh-6-AVD. Sleele-6, Tillett-6. Eglin 1-7. Eglin 11-7, Eglin HI-7, FourWindsl-7, FourWinds 11-7. Gassett-7, Harvey-7, LaPlace-7, Ramsay-7-AVD, Smith-7. Steele-7. Tillett-7. Eglin 1-8, Eglin HI-8, FourWindsl-8, Gassett-8, Harvey-8-AVD, LaPlace-8, Ramsay-8. Rodriguez-8, Smith-8, Steela-8, Tillett-8, MW01, MW02, MW03-AVD, MW04, CHT-3-9, CHT-6D-9, CHT-7D-9, Delegarde-9, Delegarde-9'. DW-1-9, DW-2-9. Eglin I-9, Eglin HI-9. FourWinds I-9, FourWindsll9AV. Gassett-9, Harvey-9, LaPlace-9. Matthias-9, MW-1-9. MW-1 D-9, MW-2-9, MW-3-9, MW-4-9. MW-4D-9, MW-5-9, MW-6D-9, MW-6R-9, MW-7-9, MW-8-9. MW-9S-9. MW-10-9, MW-10D-9, MW-11D-9-AVD, MW-12D-9. MW-13-9, MW-130-9, MW-15-9, MW-16-9, MW-17-9, MW-18-9, MW-18R-9, MW-19-9. MW-20-9, MW-20D-9, MW-21D-9. MW-22D-9, MW-24-9, MW-25-9. OHMW-1-9. OHMW-2-9, OHMW-3-9, OHMW-4-9, Ramsay-9, Smith-9, Steete-9. SW-2-9, SW-3-9. SW-4-9, SW-5-9, SW-6-9. SW-7-9-AVD, Tillett-9, TT-1-9. TT-1D-9, TT-2-9-AVD. TT-3D-9, TT-4-9, TT-5-9, VIHA1-9. M 1993, a number denoting the sampling event has been added to the end of the well designation (i.e., Harvey-2). This quarterly sampling event designation has been added so that the samples would be recognized as groundwater in the computer data base. For the Geraghty & Miller Phase II groundwater samples, a "9" has been added to the end of the well designation only for the purpose of differentiating them from samples collected during previous sampling events. Samples having split or duplicate results, as for the soils, were given the suffix AVS or AVD, respectively, to differentiate the components of the averaged result. The results of the analysis of 174 groundwater samples collected at and in the vicinity of the Tutu Wells site are presented in Table 2-12. Twenty-six VOCs, including primarily chlorinated aliphatic and aromatic chemicals, were detected in at least one sample. The most frequently detected VOCs were tetrachloroethene (143 of 173 samples), 1,2-dichloroethene (total) (142 of 169 samples), and trichloroethene (142 of 172 samples). The chemicals detected at the highest concentrations were methyl-tertiary-butyl-ether (89000 DJ ug/1), xylenes (total) (22000 J ug/1), and benzene (21000 D ug/1). The maximum methyl-tertiary-butyl-ether and xylenes (total) detections were reported in sample SW-3-9, while the maximum benzene detection was reported in sample TT-1-9. Twenty-nine SVOCs, including primarily phenols, PAHs, and phthalates, were detected in at least one groundwater sample. The most frequently detected SVOC was bis(2- ethylhexyl)phthalate (13 of 108 samples). The highest SVOC detections were reported for naphthalene (1000 DJ ug/1) and bis(2-ethylhexyl)phthalate (690 D ug/1). The maximum 73 TUT 006 2259 naphthalene detection was reported in sample SW-3-9, while the maximum bis(2- ethylhexyl)phthalate detection was reported as the average of the sample and its associated duplicate (both collected by Geraghty & Miller), LaPlace-5-AVD. Pesticides and PCBs were not analyzed for in groundwater samples collected at the site. Twenty-four inorganics were detected in site groundwater samples. Only one inorganic, barium, was detected in each of the samples analyzed for inorganics. The highest concentrations were reported calcium (11600000 ug/1) and sodium (9870000 ug/1). The maximum detections were reported in sample Delegarde-9. 2.3 Criteria for the Selection of Chemicals of Potential Concern Due to the large number of chemicals detected at the Tutu Wells site, the number of chemicals retained for quantitative analysis in this risk assessment was reduced to the most significant (i.e., greatest contributors to risk/hazards). If all chemicals were retained for analysis, the resulting document would be unduly complex and could obscure the dominant risks/hazards associated with the site. Therefore, chemicals of potential concern were selected based on procedures specified in RAGS Part A (USEPA, 1989a) and on professional judgement. The primary considerations for selection or elimination were as follows: • frequency of detection in analyzed medium (i.e., surface soil) 74 TUT 006 2260 • historical site information/activities (i.e., site-relatedness) • chemical concentration - toxicity screen • sample chemical detections relative to blank chemical detections • chemical concentrations relative to upgradient concentrations • chemical toxicity (potential carcinogenic and noncarcinogenic effects, weight-of-evidence for potential carcinogenicity) • chemical properties (i.e., mobility, persistence, and bioaccumulation) • significant exposure routes The frequency of detection is defined as the number of detections (hits) divided by the total number of valid sample analyses. For all chemicals detected in a given environmental medium, a frequency of detection of five (5) percent was utilized as the minimum cutoff point. A number of metals were detected in nearly all soil (surface and subsurface) and groundwater samples analyzed for metals, including the essential nutrients calcium, magnesium, potassium, and sodium. The potential toxicity of the essential nutrients is significantly lower than other inorganics detected at the site. In general, more data are available for these minerals with regard to identifying dietary intake rather than toxicity. These minerals are also typically obtained via food, mineral supplements, etc. and are homeostatically regulated to maintain appropriate body functions. Therefore, these minerals were not selected as chemicals of potential concern in the risk assessment. An additional metal detected at a high frequency, aluminum, which is ubiquitous in soil, air, and water (Klaassen et al., 1986), is not believed to be site-related. In addition, other chemicals not having established toxicity values (i.e., cobalt, copper, dibenzofuran) are qualitatively addressed in Section 4.3. 75 TUT 006 2261 The potential health impact of a chemical is related to the relationship of concentration and toxicity. A chemical detected at a high concentration that may exhibit low noncarcinogenic toxicity may have less impact on human health than a potential carcinogen detected at a relatively low concentration. Therefore, a chemical concentration - toxicity screening procedure was performed for all chemicals detected in the specific areas of concern for surface soil, subsurface soil, and groundwater to aid in the determination of which chemicals were likely to contribute significantly to potential risks and hazards (see Tables 2-13 through 2-23). Individual chemical scores (or risk factors) were calculated for each medium as follows: Where: Ry = risk factor for chemical i in medium j; Qj = concentration of chemical i in medium j; and Ty = toxicity value for chemical i in medium j; (i.e., slope factor or I/oral reference dose) In accordance with RAGS and for conservatism, the maximum detected concentration of each chemical was used in the calculation (USEPA, 1989a). However, for samples having a duplicate analysis, the two values were averaged except when one-half of the sample quantitation limit (SQL) for a non-detect was higher than the actual detection. When this occurred, the SQL was ignored and the actual detection was utilized as the sample result. Chemicals other than essential 76 006 2262 10/25/94 TOXSCRNSSTGA.XLS TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN TILLETT GARDENS AND ART CENTER - SURFACE SOIL CARCINOGENS: CHEMICAL Methylene Chloride Chloroform Chrysene Benzo(b)fluoranthene Arodor 1242 Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no no no no YES YES no Maximum Detected Concentration (mg/kg) 9.0E-03 2.0E-03 5.9E-02 8.4E-02 1.2E+02 1.0E+01 2.0E-01 Slope Factor (mg/kg-day)-1 7.5E-03 6.1E-03 7.3E-03 7.3E-01 7.7E+00 1.75E400 4.3E400 Risk Factor (unitless) 6.8E-05 1.2E-05 4.3E-04 6.1E-02 9.2E+02 1.8E+01 8.6E-01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.01% 98.05% 1.86% 0.09% TOTAL RISK FACTOR = 9.4E+02 100% H O O r-.j K3 0-- r.-.! 10/25/94 TOXSCRNSSTGA.XLS . J.E2-13 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN TILLETT GARDENS AND ART CENTER - SURFACE SOIL NONCARCINOGENS: CHEMICAL Methylene Chloride Chloroform Xylenes (Total) Di-n-butylphthalate Fluoranthene Pyrene Butylbenzylphthalate Antimony Arsenic Barium Beryllium Chromium III ri Chromium VI oo Manganese Mercury Nickel Silver Vanadium Zinc Chemical of Potential Concern (Contributes >1%) no no no no no no no YES YES no no no no YES no no no YES no Maximum Detected Concentration (mg/kg) 9.0E-03 2.0E-03 1.1E-02 5.5E-02 1.0E-01 7.6E-02 1.3E-01 5.1E+00 1.0E+01 7.1E401 2.0E-01 2.2E+01 3.6E+00 8.7E402 1.2E-01 1.4E+01 2.2E+00 9.6E+01 1.7E+02 Reference Dose (mg/kg-day) 6.0E-02 1.0E-02 2.0E+00 1.0E-01 4.0E-02 3.0E-02 2.0E-01 4.0E-04 3.0E-04 7.0E-02 5.0E-03 LOE-fOO 5.0E-03 5.0E-03 3.0E-04 2.0E-02 5.0E-03 7.0E-03 3.0E-01 Risk Factor (unitless) 1.5E-01 2.0E-01 5.5E-03 5.5E-01 2.5E+00 2.SE+00 6.7E-01 1.3E404 3.3E+04 1.0E+03 4.0E+01 2.2E401 7.2E402 1.7E+05 4.0E+02 7.0E402 4.3E+02 1.4E+04 5.6E+02 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 5.32% 14.04% 0.42% 0.02% 0.01% 0.30% 73.23% 0.17% 0.29% 0.18% 5.77% 0.24% TOTAL RISK FACTOR 2.4E+05 100% Oo !> 1IV2S/94 / TOXSCRNSSTEX.XLS LE 2-14 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN FIRE DEPARTMENT / TEXACO GAS STATION / ANTILLES AUTO PARTS / RAMSAY MOTOR CO. - SURFACE SOIL CARCINOGENS: CHEMICAL Methylene Chloride Benzene Benzo(b)fluoranthene Benzo(a)pyrene Beryllium Chemical of Potential Concern (Contributes >1%) no no YES YES YES Maximum Detected Concentration (mg/kg) 2.0E-01 4.5E-02 8.7E-01 7.7E-01 2.6E-01 Slope Factor (mg/kg-day)-1 7.5E-03 2.9E-02 7.3E-01 7.3E+00 4.3E+00 Risk Factor (unitless) 1.5E-03 1.3E-03 6.4E-01 5.6E+00 1.1E+00 Contribution to Total Risk for Matrix (Percent) 0.02% 0.02% 8.61% 76.20% 15.16% TOTAL RISK FACTOR 7.4E+00 100% oo 0- 10/2S94 ' TOXSCRNSSTEX.XLS ,MdLE2-14 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN FIRE DEPARTMENT / TEXACO GAS STATION / ANTILLES AUTO PARTS / RAMSAY MOTOR CO. - SURFACE SOIL NONCARCINOGENS: CHEMICAL Methylene Chloride Acetone 4-Methyl-2-Pentanone Toluene Ethylbenzene Xylenes (Total) Naphthalene Acenaphthene Fluorene Fluoranthene Pyrene Bis(2-ethylhexyl)phthalate Antimony Barium Beryllium Chromium III Chromium VI Manganese Nickel Silver Vanadium Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no no no no no no no no no no no YES no no no no YES no no YES no no Maximum Detected Concentration (mg/kg) 2.0E-01 1.4E-02 3.3E-02 1.3E+00 2.1E400 5.6E+00 4.4E+00 1.9E-01 4.2E-01 7.4E-01 2.0E+00 5.4E+00 5.9E+00 6.7E+01 2.6E-01 2.7E401 4.5E400 8.3E+02 1.8E+01 2.2E+00 1.2E+02 1.1E+02 1.1E400 Reference Dose (mg/kg-day) 6.0E-02 1.0E-01 8.0E-02 2.0E-01 1.0E-01 2.0E400 4.0E-02 6.0E-02 4.0E-02 4.0E-02 3.0E-02 2.0E-02 4.0E-04 7.0E-02 5.0E-03 1.0E+00 5.0E-03 5.0E-03 2.0E-02 5.0E-03 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unitless) 3.3E+00 1.4E-01 4.1E-01 6.5E+00 2.1E401 2.8E+00 1.1E-»02 3.2E400 1.1E401 1.9E401 6.7E+01 2.7E402 1.5E404 9.6E+02 5.2E+01 2.7E+01 9.0E+02 1.7E+05 8.8E402 4.4E+02 1.7E+04 3.6E+02 5.5E401 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.01% 0.00% 0.05% 0.00% 0.01% 0.01% 0.03% 0.13% 7.28% 0.47% 0.03% 0.01% 0.44% 82.28% 0.43% 0.22% 8.39% 0.18% 0.03% TOTAL RISK FACTOR = 2.0E+05 100% o ,•"". 'v~-' 0- 0" 10/25/94 TOXSCRNSSCURJCLS LE 2-15 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN CURRICULUM CENTER BUILDING (PRESENT) - SURFACE SOIL CARCINOGENS: CHEMICAL Methylene Chloride Chloroform Trichtoroethene Tetrachktroethene Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no no no no YES YES Maximum Detected Concentration (mg/kg) 2.2E-02 6.8E-03 6.5E-02 1.7E-01 1.2E+01 2.7E-01 Slope Factor (mg/kg-day)-1 7.5E-03 6.1E-03 1.1E-02 5.2E-02 1.75E+00 4.3E+00 Risk Factor (unitless) 1.7E-04 4.1E-05 7.2E-04 8.8E-03 2.0E+01 1.2E+00 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.04% 94.55% 5.41% TOTAL RISK FACTOR 2.1E-tO1 100% oo c H KV25/94 TOXSCRNSSCUR.XLS ILE 2-15 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN CURRICULUM CENTER BUILDING (PRESENT) - SURFACE SOIL NONCARCINOGENS: oo H 4™ W_H CHEMICAL Methylene Chloride Chloroform 2-Butanone Trlchloroethene Tetrachtoroethene Toluene Ethylbenzene Xylenes (Total) Phenol 2-Methylphenol 4-Methylphenol 2.4-Dimethylphenol Naphthalene Dl-n-butylphthalate Butylbenzylphthalate Endosultan 1 Antimony Arsenic Barium Beryllium Cadmium Chromium III Chromium VI Manganese Mercury Nickel Silver Vanadium Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no no no no no no no no YES YES no no no no no YES YES no no no no no YES no no no YES no no Maximum Detected Concentration (mg/kg) 2.2E-02 6.8E-03 4.SE-02 6.5E-02 1.7E-01 2.0E-01 4.2E-01 1.6E400 9.0E+02 3.2E+02 1.3E+03 4.2E+01 7.7E+00 9.4E400 1.2E-01 9.2E-02 7.3E400 1.2E+01 9.6E+01 2.7E-01 9.9E-01 3.6E+01 6.0E+00 8.7E+02 5.7E-01 2.2E401 1.9E+00 1.2E+02 4.6E+02 7.5E-01 Reference Dose (mg/kg-day) 6.0E-02 1.0E-02 6.0E-01 6.0E-03 1.0E-02 2.0E-01 1.0E-01 2.0E+00 6.0E-01 5.0E-02 5.0E-03 2.0E-02 4.0E-02 1.0E-01 2.0E-01 6.0E-03 4.0E-04 3.0E-04 7.0E-02 5.0E-03 1.0E-03 1.0E+00 5.0E-03 5.0E-03 3.0E-04 2.0E-02 5.0E-03 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unitless) 3.7E-01 6.8E-01 7.4E-02 1.1E+01 1.7E401 1.0E+00 4.2E400 8.0E-01 1.5E+03 6.4E+03 2.6E+05 2.1E403 1.9E+02 9.4E+01 6.0E-01 1.5E401 1.8E+04 3.9E+04 1.4E+03 5.4E401 9.9E-M32 3.6E4O1 1.2E403 1.7E+05 1.9E+03 1.1E+03 3.8E-f02 1.6E+04 1.5E403 3.8E+01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.28% 1.21% 49.35% 0.40% 0.04% 0.02% 0.00% 0.00% 3.46% 7.34% 0.26% 0.01% 0.19% 0.01% 0.23% 33.14% 0.36% 0.21% 0.07% 3.12% 0.29% 0.01% TOTAL RISK FACTOR = 5.3E405 100% CD 1<V2Stt4 TOXSCRNSSCURF.XLS TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN CURRICULUM CENTER BUILDING (FUTURE) - SURFACE SOIL CARCINOGENS: CHEMICAL Methylene Chloride Chloroform Tetrachlorothene Trichloroethene Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no no no no YES YES Maximum Detected Concentration (mg/kg) 2.2E-02 6.8E-03 5.4E-02 6.5E-02 2.3E400 2.7E-01 Slope Factor (mg/kg-day)-1 7.5E-03 6.1E-03 5.2E-02 1.1E-02 1.75E-MDO 4.3E+00 Risk Factor (unitless) 1.7E-04 4.1E-05 2.8E-03 7.2E-04 4.0E+OO 1.2E+00 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.05% 0.01% 77.56% 22.37% TOTAL RISK FACTOR 5.2E+00 100% oo •-0 107V94 TOXSC' TABLE 2-16 •yRF.)i \ \ WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN CURRICULUM CENTER BUILDING (FUTURE) - SURFACE SOIL NONCARCINOGENS: oo CHEMICAL Methylene Chloride CNoroform 2-Bulanone Tetrachtoroethene Trichloroethene Toluene Elhy (benzene Xytenes (Total) Phenol 2-Methylphend 4-Methylphenol 2,4-Dimethylphenol Naphthalene Di-n-butylphthalate Butylbenzylphthalate EndosuHan 1 Antimony Arsenic Barium Beryllium Cadmium Chromium III Chromium VI Manganese Nickel Silver Vanadium Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no no no no no no no no YES YES no no no no no YES YES no no no no no YES no no YES no no Maximum Detected Concentration (mg/kg) 2.2E-02 6.8E-03 4.5E-02 5.4E-02 6.5E-02 2.0E-01 4.2E-01 1.6E-KX) 9.0E+02 3.2E402 1.3E+03 4.2E+01 7.7E400 9.4E+00 1.2E-01 9.2E-02 4.6E+00 2.3E400 9.6E+01 2.7E-01 7.0E-01 3.6E401 6.0E400 8.7E402 2.2E+01 1.9E400 1.2E402 3.2E+02 6.4E-01 Reference Dose (mg/kg-day) 6.0E-02 1.0E-02 6.0E-01 1.0E-02 6.0E-03 2.0E-01 1.0E-01 2.0E+00 6.0E-01 5.0E-02 5.0E-03 2.0E-02 4.0E-02 1.0E-01 2.0E-01 6.0E-03 4.0E-04 3.0E-04 7.0E-02 S.OE-03 1.0E-03 1.0E+00 5.0E-03 5.0E-03 2.0E-02 5.0E-03 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unitless) 3.7E-01 6.8E-01 7.4E-02 5.4E+00 1.1E+01 1.OE+00 4.2E400 8.0E-01 1.5E+03 6.4E403 2.6E+05 2.1E+03 1.9E402 9.4E+01 6.0E-01 1.5E401 1.2E+04 7.7E+03 1.4E+03 5.4E401 7.0E+02 3.6E+01 1.2E+03 1.7E405 1.1E403 3.8E+02 1.6E+04 1.1E+03 3.2E+01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.31% 1.32% 53.44% 0.43% 0.04% 0.02% 0.00% 0.00% 2.38% 1.58% 0.28% 0.01% 0.14% 0.01% 0.25% 35.89% 0.22% 0.08% 3.38% 0.22% 0.01% TOTAL RISK FACTOR 4.9E+05 100% NJo KV26/94 / TOXSCRNSSOH.XLS •-E 2-17 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN O'HENRY DRY CLEANERS AND LIQUOR BARN - SURFACE SOIL \ CARCINOGENS: CHEMICAL Methylene Chloride Chloroform Trichloroethene Tetrachloroethene 8is(2-ethylhexyl)phthalate Arsenic Chemical of Potential Concern (Contributes >1%) no no no YES no YES Maximum Detected Concentration (mg/kg) 1.5E-01 1.2E-02 7.5E-02 4.4E+02 5.1E-01 1.9E+01 Slope Factor (mg/kg-day)-1 7.5E-03 6.1E-03 1.1E-02 5.2E-02 1.4E-02 1.75E+00 Risk Factor (unitless) 1.1E-03 7.3E-OS 8.3E-04 2.3E+01 7.1E-03 3.3E401 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 41.21% 0.01% 58.78% TOTAL RISK FACTOR 5.6E+01 100% oo d H fO Nf 1W2JY94 TOXSCRNSSOH.XLS i>LE 2-17 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN O'HENRY DRY CLEANERS AND LIQUOR BARN - SURFACE SOIL NONCARCINOGENS: oo CHEMICAL Methylene Chloride Acetone 1,2-Dichloroettiene (Total) Chloroform Trichloroethene Tetrachloroethene Phenol Benzole Add Dl-n-butylphthalate Butylbenzylphthalate B!s(2-ethylhexyl)phthalate Antimony Arsenic Barium Chromium III Chromium VI Manganese Nickel Silver Vanadium Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no no no no YES no no no no no YES YES no no no YES no no YES no no Maximum Detected Concentration (mg/kg) 1.5E-01 8.4E-02 2.0E-02 1.2E-02 7.5E-02 4.4E+02 3.9E-02 6.3E-02 6.2E-02 7.0E-02 S.1E-01 6.4E+OO 1.9E+01 9.0E+01 2.0E+01 3.4E+00 8.7E402 1.5E401 1.6E+00 8.3E+01 9.6E+01 1.1E+00 Reference Dose (mg/kg-day) 6.0E-02 1.0E-01 9.0E-03 1.0E-02 6.0E-03 1.0E-02 6.0E-01 4.0E+00 1.0E-01 2.0E-01 2.0E-02 4.0E-04 3.0E-04 7.0E-02 1.0E+00 5.0E-03 5.0E-03 2.0E-02 S.OE-03 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unitless) 2.5E+00 8.4E-01 2.2E400 1.2E400 1.3E401 4.4E-f04 6.5E-02 1.6E-02 6.2E-01 3.5E-01 2.6E+01 1.6E-t04 6.2E+04 1.3E+03 2.0E+01 6.7E402 1.7E+05 7.4E+02 3.2E402 1.2E+04 3.2E+02 5.3E+01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.00% 14.13% 0.00% 0.00% 0.00% 0.00% 0.01% 5.1 0% 19.97% 0.41% 0.01% 0.22% 55.88% 0.24% 0.10% 3.81% 0.10% 0.02% TOTAL RISK FACTOR 3.1E405 100% H K) w KV85/94 ) TOXSCRNi3C.GA.XLS ZLE 2-18 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN TILLETT GARDENS AND ART CENTER - SUBSURFACE SOIL CARCINOGENS: CHEMICAL Tetracnloroethene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene lndeno(1 ,2,3-cd)pyrene Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no no no no no YES no YES YES Maximum Detected Concentration (mg/kg) 3.5E-03 1.8E-01 1.9E-01 2.1E-01 9.6E-02 1.9E-01 8.7E-02 4.9E+01 4.6E-01 Slope Factor 5.2E-02 7.3E-01 7.3E-03 7ff-°1 7,3fT0.2 7.3E+00 7.3E-01 1.75E+00 4.3E+00 V- Risk Factor (unitless) ti$N fJl-01 1.4E-03 1.6E-01 7.0E-03 1.4E+00 6.4E-02 8.6E401 2.Qf,H$P Contribution to Total RWsfor Matrix (Perctnt) 0.00% 0.14% 0.00% 0.17% 0.01% J^|3% 0!$l$& ^SXf%, 2$M, TOTAL RISK FACTOR 9.0E+01 oo-j H C KJ M X! KV25/94 , TOXSCRNSOTGA.XLS .E 2-18 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN TILLETT GARDENS AND ART CENTER - SUBSURFACE SOIL NONCARCINOGENS: CHEMICAL Tetrachloroethene Toluene Ethylbenzene Fluoranthene Pyrene Antimony Arsenic Barium Beryllium Chromium III Chromium VI Manganese Mercury Nickel Silver oo Vanadium 00 -« Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no no no no YES YES no no no no YES no no no YES no no Maximum Detected Concentration (mg/kg) 3.5E-03 4.0E-03 2.5E-03 2.3E-01 2.4E-01 5.1E+00 4.9E+01 7.6E+01 4.6E-01 2.2E401 3.7E400 7.6E+02 6.0E-02 1.5E+01 2.8E+00 1.6E+02 1.6E402 1.5E+00 Reference Dose (mg/kg-day) 1.0E-02 2.0E-01 1.0E-01 4.0E-02 3.0E-02 4.0E-04 3.0E-04 7.0E-02 5.0E-03 1.0E+00 5.0E-03 S.OE-03 3.0E-04 2.0E-02 5.0E-03 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unitless) 3.5E-01 2.0E-02 2.5E-02 5.8E+00 7.9E+00 1.3E404 1.6E-MD5 1.1E+03 9.2E+01 2.2E+01 7.4E+02 1.5E+05 2.0E402 7.7E402 5.5E+02 2.2E404 5.5E+02 7.5E+01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.00% 3.58% 46.08% 0.30% 0.03% 0.01% 0.21% 42.88% 0.06% 0.21% 0.15% 6.30% 0.15% 0.02% TOTAL RISK FACTOR 3.6E+05 100% -H C.-I M HV2EW4 / TOXSCRNSOTEX.XLS JL£ 2-19 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN FIRE DEPARTMENT / TEXACO GAS STATION / ANTILLES AUTO PARTS / RAMSAY MOTOR CO. - SUBSURFACE SOIL CARCINOGENS: CHEMICAL Methylene Chloride Benzene Tetrachloroethene Bls(2-chloroethyl)ether Bis(2-ethylhexy))phthalate Benzo(a)pyrene Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no no no no no YES YES YES Maximum Detected Concentration (mg/kg) 2.6E-02 4.3E-03 6.0E-03 1.3E-02 3.7E-01 1.4E-01 1.8E+00 4.2E-01 Slope Factor (mg/kg-day)-1 7.5E-03 2.9E-02 5.2E-02 1.1E+00 1.4E-02 7.3E+00 1.75E+00 4.3E+00 Risk Factor (unitless) 2.0E-04 1.2E-04 3.1E-04 1.4E-02 S.2E-03 1.0E+00 3.2E+00 1.8E+00 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.01% 0.24% 0.09% 17.04% 52.52% 30.11% TOTAL RISK FACTOR 6.0E+00 100% oo VO !> KV2S/94 , TOXSCHNSOTcXXLS 2-19 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN FIRE DEPARTMENT / TEXACO GAS STATION / ANTILLES AUTO PARTS / RAMSAY MOTOR CO. - SUBSURFACE SOIL NONCARCINOGENS: C H o !> CHEMICAL Bromomethane Methylene Chloride Acetone 1,2-Dlchloroethene 2-Butanone 4-Methyl-2-Pentanone Tetrachloroethene Toluene Efhylbenzene Xylenes (Total) Bis(2-ettiylhexyl)phthalate Dl-n-butylphthalate Antimony Arsenic Barium Beryllium Cadmium Chromium III Chromium VI Manganese Mercury Nickel Selenium Silver Vanadium Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no no no no no no no no no no no YES YES YES no no no no YES no no no no YES no no Maximum Detected Concentration (mg/kg) 2.0E-03 2.6E-02 1.9E-01 2.0E-03 7.5E-02 1.7E-02 6.0E-03 2.5E-02 9.0E-03 1.7E+00 3.7E-01 1.7E-01 7.9E400 1.8E+00 1.8E+02 4.2E-01 1.1E+00 3.3E+01 5.4E+00 9.5E402 1.2E-01 1.9E+01 5.5E-01 2.1E+00 1.6E+02 6.2E4O1 6.5E-01 Reference Dose (mg/kg-day) 1.4E-03 6.0E-02 1.0E-01 9.0E-03 6.0E-01 8.0E-02 1.0E-02 2.0E-01 1.0E-01 2.0E+00 2.0E-02 1.0E-01 4.0E-04 3.0E-04 7.0E-02 5.0E-03 1.0E-Q3 1.0E+00 5.0E-03 5.0E-03 3.0E-04 2.0E-02 5.0E-03 5.0E-03 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unitless) 1.4E+00 4.3E-01 1.9E+00 2.2E-01 1.3E-01 2.1E-01 6.0E-01 1.3E-01 9.0E-02 8.5E-01 1.9E+01 1.7E+00 2.0E+04 6.0E+03 2.6E+03 8.4E+01 1.1E+03 3.3E+01 1.1E+03 1.9E+05 4.0E+02 9.7E+02 1.1E402 4.2E+02 2.2E+04 2.1E+02 3.3E-M)1 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.01% 0.00% 8.07% 2.45% 1.07% 0.03% 0.45% 0.01% 0.44% 77.41% 0.16% 0.40% 0.04% 0.17% 9.17% 0.09% 0.01% TOTAL RISK FACTOR 2.4E+05 100% W Nj 1/3/95 •' I TOXSCRNSOCCB.XLS 2-20 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN CURRICULUM CENTER BUILDING (FUTURE) - SUBSURFACE SOIL CARCINOGENS: CHEMICAL Methylene Chloride Trichloroethene Tetrachloroethene Bis(2-ethylhexyl)phthalate Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no no no no YES YES Maximum Detected Concentration (mg/kg) 3.4E-02 6.0E-03 1.7E-01 2.1E-01 1.2E+01 2.3E-01 Slope Factor (mg/kg-day)-1 7.5E-03 1.1E-02 5.2E-02 1.4E-02 1.75E+00 4.3E+00 Risk Factor (unitless) 2.6E-04 6.6E-05 8.8E-03 2.9E-03 2.0E+01 9.9E-01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.04% 0.01%. 95.30% 4.64% TOTAL RISK FACTOR 2.1E+01 100% W X! ••••i 1/3/95 \ I TOXSCRNSOCCB.XLS iE 2-20 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN CURRICULUM CENTER BUILDING (FUTURE) - SUBSURFACE SOIL NONCARCINOGENS: CHEMICAL Methylene Chloride Acetone 2-Butanone Trichloroethene Tetrachloroethene Toluene Xylenes (Total) Diethylphthalate Di-n-butylphthalate Butylbenzylphthalate Bis(2-ethyViexyl)phthalat9 Antimony to Arsenic Barium Beryllium Cadmium Chromium lit Chromium VI Manganese Mercury Nickel Silver Vanadium Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no no no no no no no no no no YES YES no no no no no YES no no no YES no no Maximum Detected Concentration (mg/kg) 3.4E-02 3.7E-01 5.9E-02 6.0E-03 1.7E-01 1.2E-02 1.0E-03 4.0E-02 8.9E-01 5.8E-02 2.1E-01 1.9E401 1.2E+01 5.9E+01 2.3E-01 2.9E+00 3.1E+01 5.2E+00 9.7E402 5.7E-01 2.7E401 2.3E+00 1.3E402 5.9E+02 8.8E-01 Reference Dose (mg/kg-day) 6.0E-02 1.0E-01 6.0E-01 6.0E-03 1.0E-02 2.0E-01 2.0E-H30 8.0E-01 1.0E-01 2.0E-01 2.0E-02 4.0E-04 3.0E-04 7.0E-02 5.0E-03 1.0E-03 1.0E+00 5.0E-03 5.0E-03 3.0E-04 2.0E-02 5.0E-03 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unitless) 5.7E-01 3.7E400 9.8E-02 1.0E+00 1.7E401 6.0E-02 5.0E-04 S.OE-02 8.9E+00 2.9E-01 1.1E+01 4.8E+04 3.9E+04 8.4E402 4.6E401 2.9E+03 3.1E401 1.0E+03 1.9E+05 1.9E403 1.4E403 4.6E402 1.9E+04 2.0E403 4.4E+01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.01% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 15.32% 12.47% 0.27% 0.01% 0.93% 0.01% 0.34% 62.72% 0.61% 0.44% 0.15% 6.08% 0.63% 0.01% TOTAL RISK FACTOR 3.1E+05 100% Oo OB KV25/94 TOXSCRNSOESSO.XLS CARCINOGENS: JLE 2-21 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN ESSO GAS STATION AND SPLASH AND DASH CAR WASH - SUBSURFACE SOIL CHEMICAL Methylene Chloride Trichloroethene Telrachloroethene Bls(2-ethylhexyl)phthalale Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no no no no YES YES Maximum Detected Concentration (mg/kg) 2.0E-02 7.8E-03 2.0E-03 2.2E-01 1.6E+00 3.5E-01 Slope Factor (mg/kg-day)-1 7.5E-03 1.1E-02 5.2E-02 1.4E-02 1.75E+00 4.3E+00 Risk Factor (unitless) 1.5E-04 8.5E-05 1.0E-04 3.1E-03 2.8E+00 1.5E+00 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.07% 64.99% 34.93% TOTAL RISK FACTOR 4.3E+00 100% i-J •xi KV2S/94 TOXSCRN. -3O.XLS IE 2-21 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN ESSO GAS STATION AND SPLASH AND DASH CAR WASH - SUBSURFACE SOIL NONCARCINOGENS: CHEMICAL Methytena Chloride Acetone 2-Butanone Trichloroettiene Tetrachloroethene Toluene Di-n-butylptithalate Bls(2-ethylhexyl)phthalate Antimony Arsenic Barium Beryllium Cadmium Chromium III Chromium VI Manganese Nickel Selenium Silver Vanadium Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no no no no no no no YES YES no no no no no YES no no no YES no no Maximum Detected Concentration (mg/kg) 2.0E-02 5.0E-02 1.3E-02 7.8E-03 2.0E-03 1.0E-03 4.6E-01 2.2E-01 4.4E+00 1.6E+00 2.0E+02 3.5E-01 9.5E-01 3.0E+01 5.0E+00 1.3E+03 2.2E+01 1.1E+00 4.1E400 1.3E+02 8.7E+01 4.1E-01 Reference Dose (mg/kg-day) 6.0E-02 1.0E-01 6.0E-01 6.0E-03 1.0E-02 2.0E-01 1.0E-01 2.0E-02 4.0E-04 3.0E-04 7.0E-02 5.0E-03 1.0E-03 1.0E+00 5.0E-03 5.0E-03 2.0E-02 5.0E-03 S.OE-03 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unltless) 3.3E-01 5.0E-01 2.2E-02 1.3E400 2.0E-01 5.0E-03 4.6E+00 1.1E401 1.1E+04 5.3E+03 2.8E+03 7.0E+01 9.5E+02 3.0E+01 1.0E403 2.5E+05 1.1E+03 2.2E+02 8.2E402 1.9E+04 2.9E+02 2.1E+01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 3.76% 1.82% 0.97% 0.02% 0.33% 0.01% 0.34% 85.54% 0.37% 0.08% 0.28% 6.35% 0.10% 0.01% TOTAL RISK FACTOR 2.9E+05 100% M M TOXSCh,»SC6H.XLS ,LE 2-22 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN O'HENRY DRY CLEANERS AND LIQUOR BARN - SUBSURFACE SOIL CARCINOGENS: CHEMICAL Methylene Chloride Tetrachloroethene Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no no YES no Maximum Detected Concentration (mg/kg) 3.0E-03 2.0E-01 1.9E+02 3.3E-01 Slope Factor (moykg-day)-l 7.5E-03 S.2E-02 1.75E+00 4.3E+00 Risk Factor (unltless) 2.3E-05 1.0E-02 3.2E+02 1.4E400 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 99.56% 0.44% TOTAL RISK FACTOR 3.3E+02 100% vo —i H m 10/25^ | TOXSCRNSOOH.XLS AJE 2-22 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN O'HENRY DRY CLEANERS AND LIQUOR BARN - SUBSURFACE SOIL NONCARCINOGENS: CHEMICAL Methylene Chloride Tetrachloroethene Toluene Di-n-butylphthalate Fluoranthene Butylbenzylphthalate Antimony Arsenic Barium Beryllium Chromium III Chromium VI Manganese Mercury Nickel Silver Vanadium Zinc Chemical of Potential Concern (Contributes >1%) no no no no no no YES YES no no no no YES no no no YES no Maximum Detected Concentration (mg/kg) 3.0E-03 2.0E-01 3.0E-03 1.6E-01 4.2E-02 2.2E-01 5.2E+00 1.9E+02 5.0E402 3.3E-01 1.8E401 3.0E+00 2.2E403 8.0E-02 1.6E+01 2.0E400 1.2E402 1.0E402 Reference Dose (mg/kg-day) 6.0E-02 1.0E-02 2.0E-01 1.0E-01 4.0E-02 2.0E-01 4.0E-04 3.0E-04 7.0E-02 5.0E-03 1.0E400 5.0E-03 5.0E-03 3.0E-04 2.0E-02 5.0E-03 7.0E-03 3.0E-01 Risk Factor (unitless) 5.0E-02 2.0E+01 1.5E-02 1.6E+00 1.1E-KX) 1.1E+00 1.3E+04 6.2E+05 7.1E+03 6.6E+01 1.8E+01 6.1E+02 4.4E+05 2.7E+02 8.2E+02 4.0E+02 1.7E+04 3.3E+02 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 1.19% 56.25% 0.65% 0.01% 0.00% 0.06% 40.13% 0.02% 0.07% 0.04% 1.55% 0.03% TOTAL RISK FACTOR = 1.1 E-M)6 100% H C H - K3 K) 00 KJ 12/12/94 CARCINOGENS: LE 2-23 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN GROUNDWATER (SITE-WIDE) CHEMICAL Chloromethane Vinyl Chloride Methylene Chloride 1,1-Dichloroethena Chloroform 1.2-Dichloroethane Bromodichloromethane Trichloroethene Dibromochloromethane 1,1,2-Trichloroethane Benzene Bromoform Telrachloroethene 1,4-Dichlorobenzene Carbazole Benzo(a)anthracene Chrysene Bis(2-ethylhexyl)phthalate Benzo(b)lluoranthene Arsenic Beryllium Chemical of Potential Concern (Contributes >1%) no YES no no no no no no no no YES no YES no no no no no no YES YES Maximum Detected Concentration (mo/I) 6.2E-04 1.3E+00 6.4E-02 1.2E-04 1.5E-01 2.9E-01 3.0E-02 1.9E-01 3.6E-02 5.0E-03 2.1E+01 2.9E-02 1.5E+OO 2.0E-03 1.0E-03 1.0E-03 9.0E-03 6.9E-01 1.0E-03 8.1E-02 4.1E-02 Slope Factor (mg/kg-day)-1 1.3E-02 1.9E+00 7.5E-03 6.0E-01 6.1E-03 9.1E-02 6.2E-02 1.1E-02 8.4E-02 5.7E-02 2.9E-02 7.9E-03 5.2E-02 2.4E-02 2.0E-02 7.3E-01 7.3E-03 1.4E-02 7.3E-01 1.75E+00 4.3E400 Risk Factor (unitless) 8.1E-06 2.5E+00 4.8E-04 7.2E-05 9.2E-04 2.6E-02 1.9E-03 2.1E-03 3.0E-03 2.9E-04 6.1E-01 2.3E-04 7.8E-02 4.8E-05 2.0E-05 7.3E-04 6.6E-05 9.7E-03 7.3E-04 1.4E-01 1.8E-01 Contribution to Total Risk for Matrix (Percent) 0.00% 70.16% 0.01% 0.00% 0.03% 0.75% 0.05% 0.06% 0.09% 0.01% 17.30% 0.01% 2.22% 0.00% 0.00% 0.02% 0.00% 0.27% 0.02% 4.02% 4.98% TOTAL RISK FACTOR = 3.52E-MX) 100% W •W CO 1Z/12/9| j TOXSCHNGW.XLS LE 2-23 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN GROUNDWATER (SITE-WIDE) NONCARCINOGENS: oo C 0- CHEMICAL Methylene Chloride Acetone Carbon Disutflde 1,1-Dlchloroethene 1,1-Dlchloroethane 1.2-Dlchloroethene (Total) Chloroform 2-Butanone Bromodichloromethane Trichloroethene Dibromochloromethane 1,1,2-Trichloroethane Bromoform Tetrachloroethene Toluene Chlorobenzene Ethylbenzene XytenesfTotal) cis-1 ,2-Dichloroethene Phenol 1,2-Dichlorobenzene 2-Methylphenol 4-Methylphenol 2,4-Dimethylphenol Benzole Add 1 ,2,4-Trichlorobenzene Naphthalene Dimethylphthalate Acenaphthene Diethylphthalate Fluorene Anthracene Fluoranthene Pyrene Butylbenzylphthalate Bis(2-erhylhexyl)phthalate Chemical of Potential Concern (Contributes >1%) no no no no no YES no no no no no no no YES YES no no no no no no no no no no no no no no no no no no no no no Maximum Detected Concentration (mgfl) 6.4E-02 2.7E+00 3.0E-03 1.2E-04 1.1E-04 2.1E+00 1.5E-01 6.2E-01 3.0E-02 1.9E-01 3.6E-02 S.OE-03 2.9E-02 1.5E+00 1.7E+01 2.0E-04 4.1E+00 2.2E+01 3.7E-02 6.7E-02 6.5E-03 2.7E-02 7.2E-02 3.3E-02 6.0E-02 3.0E-03 1.0E+00 8.0E-03 2.0E-03 6.0E-02 4.0E-02 1.0E-03 1.0E-03 8.0E-03 2.0E-03 6.9E-01 Reference Dose (mg/kg-day) 6.0E-02 1.0E-01 1.0E-01 9.0E-03 1.0E-01 9.0E-03 1.0E-02 6.0E-01 2.0E-02 6.0E-03 2.0E-02 4.0E-03 2.0E-02 1.0E-02 2.0E-01 2.0E-02 1.0E-01 2.0E+00 1.0E-02 6.0E-01 9.0E-02 5.0E-02 5.0E-03 2.0E-02 4.0E400 1.0E-02 4.0E-02 1.0E+01 6.0E-02 8.0E-01 4.0E-02 3.0E-01 4.0E-02 3.0E-02 2.0E-01 2.0E-02 Risk Factor (unitless) 1.1E+00 2.7E+01 3.0E-02 1.3E-02 1.1E-03 2.3E+02 1.5E+01 1.0E+00 1.5E+00 3.2E+01 1.8E+00 1.3E+00 1.5E+00 1.5E+02 8.5E4O1 1.0E-02 4.1E+01 1.1E+01 3.7E+00 1.1E-01 7.2E-02 5.4E-01 1.4E+01 1.6E+00 1.5E-02 3.0E-01 2.5E+01 8.0E-04 3.3E-02 7.5E-02 1.0E400 3.3E-03 2.5E-02 2.7E-01 1.0E-02 3.5E+01 Contribution to Total Risk for Matrix (Percent) 0.02% 0.41% 0.00% 0.00% 0.00% 3.52% 0.23% 0.02% 0.02% 0.48% 0.03% 0.02% 0.02% 2.26% 1.28% 0.00% 0.62% 0.17% 0.06% 0.00% 0.00% 0.01% 0.22% 0.02% 0.00% 0.00% 0.38% 0.00% 0.00% 0.00% 0.02% 0.00% 0.00% 0.00% 0.00% 0.52% TOXSCRNGW.XLS 3LE 2-23 TUTU WELLS SITE CHEMICAL CONCENTRATION - TOXICITY SCREEN GROUNDWATER (SITE-WIDE) NONCARCINOGENS: CHEMICAL Di-n-octylphthalate Phthalic Anhydride (TIC) Antimony Arsenic Barium Beryllium Cadmium Chromium III Chromium VI Manganese Mercury Nickel Selenium Silver Thallium Vanadium Zinc Cyanide Chemical of Potential Concern (Contributes >1%) no no YES YES no no no no YES YES no YES no no no YES no no Maximum Detected Concentration (mo/l) 1.0E-03 3.0E-03 4.2E-01 8.1E-02 4.4E+00 4.1E-02 2.5E-03 4.0E+00 6.6E-01 2.0E401 3.1E-03 2.1E+00 1.2E-02 4.7E-02 3.6E-03 1.0E+00 2.5E+00 1.1E-02 Reference Dose (mg/kg-day) 2.0E-02 2.0E+00 4.0E-04 3.0E-04 7.0E-02 5.0E-03 5.0E-04 1.0E400 5.0E-03 5.0E-03 3.0E-04 2.0E-02 5.0E-03 5.0E-03 8.0E-05 7.0E-03 3.0E-01 2.0E-02 Risk Factor (unitless) S.OE-02 1.5E-03 1.1E-tO3 2.7E402 6.3E+01 8.2E+00 4.9E+00 4.0E+00 1.3E+02 4.1E403 1.0E+01 1.0E+02 2.3E+00 9.4E400 4.5E+01 1.4E-HJ2 8.4E+00 5.5E-01 Contribution to Total Risk for Matrix (Percent) 0.00% 0.00% 16.00% 4.06% 0.95% 0.12% 0.07% 0.06% 1.99% 61.57% 0.16% 1.55% 0.04% 0.14% 0.68% 2.16% 0.13% 0.01% TOTAL RISK FACTOR = 6.63E403 100% HI nutrients, which do not have established toxicity values (i.e., aluminum, copper, lead) could not be screened; however, they were not eliminated as chemicals of potential concern from the risk assessment for this reason. These chemicals were evaluated qualitatively as part of Section 4.3 and/or Appendix B. The chemical-specific risk factors per area of concern for surface soil, subsurface soil, and groundwater were summed to obtain a total risk factor for all chemicals for each area of concern. Separate total risk factors were calculated for carcinogens (using the appropriate slope factors) and noncarcinogens (using the appropriate oral reference doses). The ratio of the risk factor for each chemical in each area of concern in a medium to the total risk factor for each area of concern in a medium provided the relative contribution from each chemical in each area of concern in a medium. A contribution of one percent was used as a lower limit so that the chemicals contributing at least 94 percent to the total risk per area of concern per medium were retained. The potential toxicity of each chemical to human health was qualitatively evaluated based on a review of acute and chronic noncarcinogenic effects, toxicity endpoint/target organ, potential carcinogenicity, and weight-of-evidence classification for potential carcinogenicity. For the purposes of clarity, presented below is the USEPA's weight-of-evidence classification system for carcinogenicity (USEPA, 1989a). 100 TUT OOfc 2286 Group A: Human Carcinogen Group Bl or B2: Probable Human Carcinogen Bl indicates that limited human data are available indicates sufficient evidence in animals and inadequate or no evidence in humans Group C: Possible Human Carcinogen Group D: Not Classifiable as to human carcinogenicity Group E: Evidence of noncarcinogencity in humans Chemicals given a Group A weight-of-evidence classification were retained for conservatism even if they were detected at low concentrations. This was done based on the fact that the weight-of-evidence classification is an indication of the quality and quantity of data underlying a chemical's designation as a potential human carcinogen. For the evaluation of chromium in this risk assessment, total chromium was speciated into its +3 and +6 valence states using a ratio of 6:1, respectively, per the IRIS data base (on-line June-October, 1994). This ratio was assumed, as laboratory analysis was not performed since hexavalent chromium in soil is very unstable and analysis is difficult. Hexavalent chromium analysis in groundwater is also difficult to perform. In addition, carcinogenic PAHs were evaluated using the slope factor for benzo(a)pyrene in conjunction with relative potency values from USEPA's Provisional Guidance for Risk Assessment of Polycyclic Aromatic Hydrocarbons (USEPA, 1993a). Only those noncarcinogenic PAHs having available toxicity values could be evaluated using the screening procedure. Table 2-24 presents a summary of PAH classification. 101 TUT OO6 2287 TABLE 2-24 TUTU WELLS SITE POLYCYCLIC AROMATIC HYDROCARBON COMPOUND CLASSIFICATION The following PAHs detected at the site were considered carcinogenic or noncarcinogenic: Carcinogenic: Weieht-of-Evidence Classification Benzo(a)anthracene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Chrysene Indeno(l ,2,3-cd)pyrene B2 B2 B2 B2 B2 B2 Noncarcinogenic: Acenaphthene Acenaphthylene Anthracene Benzo(g, h, i)perylene Fluoranthene Fluorene 2-Methylnaphthalene Naphthalene Phenanthrene Pyrene Weight-of-Evidence Classification D D D D D D D D D B2: Indicates sufficient evidence of carcinogenicity in animals and inadequate or no evidence in humans. D: Not classifiable as to human carcinogenicity. *: No classification is specified in IRIS or HEAST Sources: USEPA, 1993a and IRIS, 1994 102 TUT OO6 2283 2.3.1 Blank Concentrations As part of the data validation process, the chemicals detected in soil and groundwater samples collected at the site were compared with chemicals detected in field, trip, water, and equipment blanks to prevent the inclusion of non site-related chemicals in the risk assessment. Concentrations of the chemicals in soil could not be directly compared, however, as soil and water units are different. The organic chemicals acetone, 2-butanone (methyl ethyl ketone), methylene chloride, toluene, and the phthalate esters are considered by the USEPA to be common laboratory contaminants. It should be recognized, however, that toluene is a constituent of gasoline which has been found at the site. Soil; One VOC, tetrachloroethene, was selected as a chemical of potential concern in O'Henry dry cleaners and Liquor Barn area surface soil. Tetrachloroethene was detected at a maximum concentration of 440000 ug/kg in sample e-01 and in one trip blank at a concentration of 0.10 J ug/1. Of the four SVOCs selected as chemicals of potential concern in soil (benzo(b)fluoranthene, benzo(a)pyrene, 2-methylphenol, and 4-methylphenol), none were detected in any blank samples. Aroclor 1242, the only PCB selected as a chemical of potential concern in site soil, was detected in a single surface soil sample collected from the Tillett Gardens and Art Center at a concentration of 120000 J ug/kg. Aroclor 1242 was detected in field blank eC-12a (deionized water) at a concentration of 76.0 ug/1. 103 TUT 006 2289 Several inorganics including antimony, arsenic, barium, manganese, and vanadium were retained as chemicals of potential concern in soil based on selection criteria, even though they were detected in some of the blank samples. Of these chemicals, only one was detected at concentrations resulting in exceedance of the target risk range or a hazard index value of one. Manganese showed hazard quotients above one for the surface soil ingestion and inhalation routes of exposure for children in the Tillett Gardens and Art Center. Manganese was detected in the single Tillett Gardens and Art Center surface soil sample analyzed for inorganics (SS-5- AVS) at a concentration of 869 mg/kg. While manganese was not detected in any water blanks, it was detected in an equipment blank at a concentration of 3.2 B ug/1. Manganese was also detected in twelve field blanks with a maximum reported concentration of 672 J ug/1. Due to the difference in reported soil and water concentration units, a direct comparison of concentrations cannot be made. The inorganic beryllium also selected as chemicals of potential concern, was not detected in any blank samples. Groundwater; Of the volatile organic chemicals of potential concern selected in site groundwater (benzene, 1,2-dichloroethene (total), tetrachloroethene, toluene, and vinyl chloride), benzene, tetrachloroethene, and toluene were detected in blank samples. Benzene was detected in a single trip blank at 0.14 BJ ug/1. This chemical was detected in 34 of 168 site groundwater samples (a frequency of detection over 20 percent) with a maximum reported concentration of 21000 D ug/1. Tetrachloroethene was detected in a single trip blank at 0.10 J ug/1. This chemical was detected in 143 of 173 site groundwater samples (a frequency of detection of over 82 percent) with a maximum reported concentration of 1500 ug/1. Toluene was detected in one 104 PUT 006 2290 field blank, two water blanks, and ten trip blanks at a maximum concentration of 2.0 ug/1. This chemical was detected in 32 of 168 site groundwater samples (a frequency of detection of 19 percent) with a maximum reported concentration of 17000 ug/1. No SVOCs were selected as chemicals of potential concern in site groundwater. Pesticides and PCBs were not analyzed for in site groundwater. Seven inorganics, antimony, arsenic, beryllium, chromium VI, manganese, nickel, and vanadium, were selected as chemicals of potential concern in site groundwater. Of these, antimony, arsenic, chromium (total), manganese, nickel, and vanadium were detected in blank samples. The maximum site groundwater detections of these six chemicals exceeded the maximum blank concentrations by a minimum of four times (arsenic) to a maximum of 245 times (chromium). In addition, these chemicals combined contributed greater than 87 percent to the total risk for the matrix for noncarcinogens in the groundwater chemical concentration- toxicity screen. 2.3.2 Background Concentrations Three background surface soil samples (SS-1, SS-2, and SS-8) were collected as part of Geraghty & Miller's Technical Memorandum II (Geraghty & Miller, 1993a) field activities (Table 2-25). According to this document, these samples were collected north of the Curriculum 105 TUT -~v^ Center Building from one to seven inches below the ground surface after removing the top one inch layer of soil and vegetation. CDM Federal collected splits of these samples which are also reported in Table 2-25. These samples were analyzed for TAL metals and cyanide only. Although a soil sample and duplicate from monitoring well MW-2 were collected from zero to two feet at the northern end of the Four Winds Shopping Center parking lot, they were collected from below the paved surface. According to Technical Memorandum II, this area is not a suspected source of chemical contamination. Monitoring well MW-2 laboratory results showed only the presence of three common laboratory contaminants, and inorganics at similar levels to Table 2-25 surface soil background samples SS-1, SS-2, and SS-8. It should be noted that no background samples were analyzed for pesticides and PCBs. Based on the above, monitoring well MW-2 results, as discussed with the USEPA RPM and Risk Assessment Specialist, are _^ considered representative of subsurface soil background and are presented in Table 2-25. Tables 2-26 and 2-27 present minimum and maximum site and background detections for chemicals of potential concern for the areas of concern at the site. Frequencies of detection for the chemicals of potential concern in site soils have also been included. Surface soil background samples (SS-1, SS-2, and SS-8) were collected at the site by Geraghty & Miller during field activities relating to Technical Memorandum II (Geraghty & Miller, 1993a). Since split samples were collected for each of these samples by CDM Federal, the averaged result of the samples and their associated splits were used to determine minimum and • /*"" v maximum detections in Table 7-26. Several of the organic and inorganic maximum site surface 106 TUT 006 2, 1 u < BACKGROUND.XLS c —i i> •-Q TUTU WELLS SITE SOIL BACKGROUND SAMPLES ANALYTICAL DATA - DETECTIONS ONLY SURFACE SOIL SAMPLE NAME SAMPLE DATE SAMPLE TYPE SAMPLE DEPTH VOLATILE ORGANICS Methytene Chloride Acetone 2-Butanone SEMIVOLATILE ORGANICS PESTICIDES/PCB* INORGANIC ANALYTES Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Mercury Nickel Potassium Selenium Silver Sodium Thallium Vanadium Zinc Cyanide ug/kg ug/kg ug/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg SS-1 8/19/92 SOIL 0.08' -0.58' NA NA NA NA NA 23600 6.10 BNJ ND 41 .9 B ND ND 75100 23.4 NJ 25.7 J 55.3 NJ 31300 2.1 OSJ 20500 763 ND 18.9 412 B ND 0.98 B 557 B ND 109 NJ 50.6 1.20 SS-1-CDM 8/19/92 SOIL 0.08' - 0.58' NA NA NA NA NA 35600 ND 1.20B 47.0 0.20 B ND 74700 29.9 28.6 73.9 43400 2.50 22400 814 ND 19.6 723 B ND 1.90B 577 B ND 151 54.8 ND SS-2 8/19/92 SOIL 0.08' - 0.58" NA NA NA NA NA 16100 ND ND 30.1 B ND ND 9630 25.8 NJ 18.0 J 40.3 NJ 22600 1.70J 13200 535 ND 15.5 568B ND 0.99 B 157 B ND 74.9 NJ 40.1 ND SS-2-CDM 8/19/92 SOIL 0.08' - 0.58' NA NA NA NA NA 33100 ND 1.30 B 43.6 0.34 B ND 18700 30.6 27.4 70.0 40900 4.00 19700 810 ND 18.8 1090J ND 2.20 257 B ND 139 56.8 ND SS-8 8/19/92 SOL 0.08' - 0.58' NA NA NA NA NA 21 500 J 14.7 BNJ 0.99 BJ 29.3 BJ ND ND 1 44000 J 16.2NJ 16.9 BJ 43.1 NJ 25400 J 2.50 SJ 21400J 888J ND 12.9BJ 325 BJ ND ND 187 BJ ND 82.1 NJ 43.8 J 1.10 SS-8-CDM 8/19/92 SOIL 0.0&-0.5S NA NA NA NA NA 31000 ND 0.67 BJ 30.4 B 027 B ND 100000 20.4 20.0 56.1 33100 R 23800 911 ND 10.3 520 B ND ND 184B ND 108 51.3 ND 11 Pli ill III HI III! •:•:•$::•:•: 111 118in II HI 11III si usill ill 11! HIill 111! Ill:IBill 111 III ill pin tiltnil fell 111ii! tils 111 SUBSURFACE SOIL MWS-2 8/13/92 SOIL 0.0' - 2.0' 10.0J 58.0 J ND ND NA 13300 ND 3.00 81.0 ND ND 68500 'J 16.1 NJ 11.3 40.0 NJ 21700 5.60 J 9160 582 ND 12.7 557 B ND ND 717 B ND 58.0 NJ 66.2 ND MWS-2-FR 8/13/92 SOIL 0.0' - 2.0' 10.0 J 130J 25.0 ND NA 15700 ND 1.20B 45.6 B ND ND 8720 'J 7.60 NJ 12.8 58.0 NJ 30800 1.90J 9640 1110 ND 5.60 B 299 B • NO 1.20 B 536B ND 52.8 NJ 119 ND Notes: NA - Not Analyzed ND- Not Detected R - Rejected \ o oo CTH &- CC-V-BC.XLS TABLt.^6 TUTU WELLS SITE CHEMICAL CONCENTRATIONS IN SITE SURFACE SOIL VS SURFACE SOIL BACKGROUND CONCENTRATIONS CHEMICALS OF POTENTIAL CONCERN TILLETT GARDENS AND ART CENTER Arodor1242 Antimony Arsenic Barium Chromium (Total) Manganese Vanadium FREQUENCY OF DETECTION 1/2 1/1 1/1 1/1 1/1 1/1 1/1 MINIMUM DETECTION (mgfcg) 120000 J 5.05 BNJ 10.0 70.5 25.3 NJ 869 95.9 NJ MINIMUM BACKGROUND* (mg/kg) NA 3.90 BNJ 0.71 B 29.9 BJ 18.3NJ 673 95.1 NJ MAXIMUM DETECTION (mg/kg) 1 20000 J 5.05 BNJ 10.0 70.5 25.3 NJ 869 95.9 NJ MAXIMUM BACKGROUND* (mgfcg) NA 8.15 BNJ 0.83 BJ 44.5 B 28.2 NJ 900 J 130 NJ FIRE DEPT7TEXACO GAS STATION / ANTILLES AUTO PARTS/ RAMSAY MOTOR CO. Benzo(b)fluoranthene Benzo(a)pyrene Antimony Barium Beryllium Chromium (Total) Manganese Nickel Silver Vanadium 1/2 2/2 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 870 J 270 J 5.90 BJ 67.2 0.26 B 31.7 834 17.5 2.20 J 119 NA NA 3.90 BNJ 29.9 BJ 0.16 B 18.3 NJ 673 11.6BJ 1.44 B 95.1 NJ 870 J 770 J 5.90 BJ 67.2 0.26 B 31.7 834 17.5 2.20 J 119 NA NA 8.15 BNJ 44.5 B 0.24 B 28.2 NJ 900 J 19.3 1.60 B 130 NJ CURRICULUM CENTER BUILDING - PRESENT - USE 2-Methylphenol 4-Methylphenol Antimony Arsenic Beryllium Manganese Vanadium 1/8 1/8 5/6 5/6 2/6 6/6 6/6 320000 1 300000 J 4.08 BNJ 1.30 B 0.19 B 599 79.7 NJ NA NA 3.90 BNJ 0.71 B 0.16 B 673 95.1 320000 1300000J 7.30 BNJ 11.6 0.27 B 873 115 NA NA 8.15 BNJ 0.83 BJ 0.24 B 900 J 130 NJ CURRICULUM CENTER BUILDING - FUTURE • USE 2-Methylphenol ' 4-Methylphenol Antimony Arsenic Beryllium Manganese Vanadium 1/5 1/5 2/3 3/3 2/3 3/3 3/3 320000 1 300000 J 4.08 BNJ 1.46BWJ 0.19 B 677 95.2 NJ NA NA 3.90 BNJ 0.718 0.16 B 673 95.1 NJ 320000 1 300000 J 4.63 BNJ 2.30 B 0.27 B 873 115 NA NA 8.15 BNJ 0.83 BJ 0.24 B 900 J 130 NJ TAL /2^-{ TUTU WELLS SITE CHEMICAL CONCENTRATIONS IN SITE SURFACE SOIL VS SURFACE SOIL BACKGROUND CONCENTRATIONS FREQUENCY OF DETECTION CHEMICALS OF POTENTIAL CONCERN O'HENRY DRY CLEANERS AND LIQUOR BARN fetrachloroethene Antimony Arsenic Manganese Vanadium 5/6 1/2 2/2 212 2fl2 MINIMUM DETECTION (mg/kg) 15.0 6.35 BNJ 13.7 670 J 72.7 NJ MINIMUM BACKGROUND* (nig/kg) NA 3.90 BNJ 0.71 B 673 95.1 NJ MAXIMUM DETECTION (mg/kg) 440000 6.35 BNJ 18.7J 870 83.1 MAXIMUM BACKGROUND* (mg*9) NA 8.15 BNJ 0.83 BJ 900 J 130 NJ 'Three surface soil background samples (SS-1, SS-2 , and SS-8) and a split of each were collected at the site. The averaged results for these samples were used to determine minimum and maximum concentrations. NA: Not Analyzed H •-13 cn oo 0- 8/17/94 ,X U7 CCSB-V-BCJCLS TUTU WELLS SITE CHEMICAL CONCENTRATIONS IN SITE SUBSURFACE SOIL VS SUBSURFACE SOIL BACKGROUND CONCENTRATIONS CHEMICALS OF POTENTIAL CONCERN riLLEn GARDENS AND ART CENTER Benzo(a)pyrene Antimony Arsenic BeryNktm Manganese Vanadium FREQUENCY OF DETECTION 1/2 2/2 2/2 2/2 2/2 2/2 MINIMUM DETECTION (mg'kg) 188J 3.65 BNJ 0.77 B 0.36 B 746 108 MINIMUM BACKGROUND* (mg/kg) ND ND 2.10 B ND 846 55.4 NJ MAXIMUM DETECTION <mg/kg) 188J 5.10 BNJ 49.2 J 0.46 B 763 157 MAXIMUM BACKGROUND* (mo/kg) ND ND 2.10 B ND 846 55.4 NJ FIRE DEPTJTEXACO GAS STATION / ANTILLES AUTO PARTS/ RAMSAY MOTOR CO. Benzo(a)pyrene \nfomony Arsenic Barium Beryllium Cadmium Chromium (Total) Manganese Nickel Vanadium CURRICULUM CENTER BUILDING Antimony Arsenic Beryllium Cadmium Manganese Mercury Nickel Vanadium Zinc 1/9 4/8 5/7 8/8 a'e 2/8 a'8 8/8 8/8 8/8 9/10 8/10 2/10 3/10 10/10 1/10 10/10 10/10 10/10 140J 3.50 BJ 0.54 BWJ 36.9 B 0.27 BJ 0.73 BJ 27.0 J 506 16.7 J 93.4 J 3.40 BJ 0.45 BJ 0.22 B 0.99 B 599 0.57 12.1 79.7 NJ 52.1 J ND ND 2.10B 63.3 ND ND 11.9 NJ 846 9.1 SB 55.4 NJ ND 2.10 B ND ND 846 ND 9.15 B 55.4 NJ 92.6 140 J 7.90 BNJ 1.80 BJ 184 0.42 B 1.10 B 38.0 EJ 947 EJ 19.4 157 19.0 11.6 0.23 BJ 2.87 973 0.57 27.3 132J 585 ND ND 2.10 B 63.3 ND ND 11.9 NJ 846 9.15 B 55.4 NJ ND 2.10 B ND ND 846 ND 9.15 B 55.4 NJ 92.6 •43 TABLE 2-27 (Confd) TUTU WELLS SITE CHEMICAL CONCENTRATIONS IN SITE SUBSURFACE SOIL VS SUBSURFACE SOIL BACKGROUND CONCENTRATIONS CHEMICALS OF POTENTIAL CONCERN FREQUENCY OF DETECTION MINIMUM DETECTION (n&W MINIMUM BACKGROUND* (rogftg) MAXIMUM DETECTION (mgfcg) MAXIMUM BACKGROUND' (ma/kg) ESSO GAS STATION AND SPLASH AND DASH CAR WASH Antimony Arsenic Barium Beryllium Cadmium Chromium (Total) Manganese Nickel Silver Vanadium O'HENRY DRY CLEANERS AND LIQUOR Antimony Arsenic Barium Manganese Vanadium 3/7 4/7 7/7 &7 1/7 7/7 7/7 7/7 5/7 7/7 BARN 2/4 3/4 4/4 4/4 4/4 3.65 BJ 0.47 BJ 21.9BJ 0.16 B 0.95 B 4.50 435 3.20 B 0.82 B 57.9 4.90 BJ 5.00 29.0 B 430 83.9 ND 2.10 B 63.3 ND ND 11.9 NJ 846 9.15 B 0.82 B 55.4 NJ ND 2.10 B 63.3 846 55.4 NJ 4.40 BJ 1.60 BJ 199 0.35 B 0.95 B 35.2 J 1250 21. 8 J 4.12 B 130 5.20 BJ 18SJ 498 2200 119 ND 2.10 B 63.3 ND ND 11.9 NJ 846 9.15 B 0.82 B 55.4 NJ ND 2.10 B 63.3 846 55.4 NJ 'MWS-2 was the only subsurface soil background sample collected at the site. Since this sample has a duplicate result, the averaged result is reported as both the minimum and maximum background concentration. ND: Not Detected "£: soil detections in the areas of concern exceeded surface soil background detections. Although inorganics are common constituents of volcanic rocks which underly the site, inorganics were included in this risk assessment as a group; any significant contributions to total risk by inorganics at the site will be addressed as part of a risk management decision. One site subsurface soil background sample, MWS-2 was collected by Geraghty & Miller during field activities relating to Technical Memorandum II (Geraghty & Miller, 1993a). A split sample was collected by CDM Federal, and the averaged result is presented in Table 7-27 as both the minimum and maximum background concentrations. Due to the limited subsurface soil background results, the background comparison criterion has not been used to select or eliminate chemicals of potential concern in subsurface soil. However, in general, maximum site detections of the chemicals of potential concern in subsurface soil exceeded the background detection. Any significant contributions to total risk by inorganics at the site will be addressed as part of a risk management decision. As stated in Section 2.1.2, supply wells VIHA III and VIHA IV (alternate) are considered upgradient of or not influenced by the site while the Bryan, Demitri, Leonard, Lockhart (alternate), Harthman (all three), and KFC-1-9 supply wells are considered to be cross-gradient of the site. It should be noted that no samples have been collected from the VIHA IV (alternate) or Lockhart (alternate) wells. Dede, Dench, Devcon I, Devcon II (alternate), and Devcon HI are clean supply wells downgradient of the contaminant plume. Therefore, a qualitative review of the data from these wells versus the site wells has been performed. 112 TUT' OO6 2'?9R Of the twelve chemicals contributing at least one percent to the total risk in the groundwater chemical concentration - toxicity screen, none were detected in the single upgradient well sampled (VIHA HI) and nine were detected in cross-gradient wells (four VOCs and five inorganics). Of the seven cross-gradient wells sampled for VOCs, benzene was detected in only one well (KFC-1-9) at a concentration of 110 J ug/1. This benzene concentration at KFC-1 is part of a separate groundwater plume related to a release from a former leaking tank at this location. This concentration is well below the maximum detected concentration of benzene in site groundwater (21000 D ug/1) but is approximately 2200 times greater than the minimum detected concentration (0.05 J ug/1) in site groundwater. 1,2-Dichloroethene (total) was detected in seven samples collected from two wells. A maximum concentration of 11.0 ug/1 was reported in sample Harthman II-7. This concentration is well below the maximum detected concentration in site groundwater (2100 ug/1) but is 100 times greater than the minimum detected concentration (0.11 J ug/1) in site groundwater. Tetrachloroethene was detected in ten samples collected from four wells. A maximum concentration of 10.0 ug/1 was reported in sample Harthman II-7. This concentration is well below the maximum detected concentration in site groundwater (1500 ug/1) but is ten times greater than the minimum detected concentration (1.0 J ug/1) in site groundwater. Toluene was detected in one well (KFC-1-9) at a concentration of 2.0 J ug/1. This concentration is well below the maximum detected concentration of toluene in site groundwater (17000 ug/1) but is 40 times greater than the minimum detected concentration (0.05 J ug/1) in site groundwater. 113 TUT OO6 2299 Antimony was detected in two groundwater samples collected from two cross-gradient wells. A maximum concentration of 30.0 BJ ug/1 was reported in sample Harthman II-2. This concentration is well below the maximum detected concentration in site groundwater (424 B ug/1) but is approximately two times greater than the minimum detected concentration (14.8 B ug/1) in site groundwater. Chromium was detected in one well (KFC-1-9) at a concentration of 14.3 J ug/1. One seventh of this concentration or 2.0 J ug/1 would be considered hexavalent chromium according to the speciation presented in IRIS (1994). This concentration is well below the maximum detected concentration in site groundwater (4610 ug/1 for total chromium and approximately 659 ug/1 from chromium VI) and is greater than four times the minimum detected concentration (0.43 B ug/1) in site groundwater. Manganese was detected in three groundwater samples collected from three cross-gradient wells. A maximum concentration of 1030 J ug/1 was reported in sample KFC-1-9. This concentration is well below the maximum detected concentration in site groundwater (20400 ug/1) but is greater than 700 times the minimum detected concentration (1.40 B ug/1) in site groundwater. Nickel was detected in one well (KFC-1-9) at a concentration of 12.1 BJ ug/1). This concentration is well below the maximum detected concentration of nickel in site groundwater (2050 ug/1) but is only slightly greater than the minimum detected concentration (8.7 B ug/1) in site groundwater. Vanadium was detected in six groundwater samples collected from five cross-gradient wells. A maximum concentration of 313 J ug/1 was reported in sample KFC-1-9. This concentration is approximately three times less than the maximum detected concentration in site groundwater (1000 J ug/1) but is more than 60 times greater than the minimum detected concentration (4.90 B ug/1) in site groundwater. 114 TUT OO6 23OO Of the twelve chemicals contributing at least one percent to the total risk in the groundwater chemical concentration-toxicity screen, only three chemicals, chromium (total), manganese, and vanadium were detected in downgradient wells. A total of eight downgradient samples plus one field replicate were collected, although all samples were not analyzed for all chemical classes. Chromium was detected in two of four downgradient groundwater samples analyzed for inorganics. A maximum concentration of 6.6 B ug/1 (one seventh of this concentration or 0.94 B ug/1 is assumed to be chromium VI per IRIS (1994)) was reported in sample Dede-5. This concentration is well below the maximum detected concentration of chromium VI in site groundwater (659 ug/1) and is approximately twice the minimum detected concentration (0.43 B ug/1) in site groundwater. Manganese was detected in all four downgradient groundwater samples analyzed for inorganics. The maximum downgradient manganese concentration (538 ug/1) is nearly 38 times less than the maximum site groundwater concentration of 20400 ug/1. The minimum downgradient manganese concentration (45.9 ug/1) is approximately 33 times greater than the minimum site groundwater concentration of 1.4 B ug/1. Vanadium was detected in three of four downgradient groundwater samples analyzed for inorganics. The maximum downgradient vanadium concentration (9.6 B ug/1) is well below the maximum site groundwater concentration of 1000 J ug/1. The minimum downgradient vanadium concentration (5.9 B ug/1) is slightly greater than the minimum site groundwater concentration of 4.9 B ug/1. The upgradient and cross-gradient as well as the downgradient groundwater data are presented in Appendix E. 115 TUT OO6 2301 2.3.3 Physical and Chemical Properties The chemicals detected in surface soil, subsurface soil, and groundwater samples collected from the site can be classified into categories according to their similarity in chemical structure and/or physicochemical properties (factors which would influence mobility in the environment). The chemical categories and examples of chemicals detected at the site within each category are listed below: • chlorinated aliphatic compounds: 1,1-dichloroethane, 1,1-dichloroethene, 1,2- dichloroethene, methylene chloride, chloroform, trichloroethene, tetrachloroethene, vinyl chloride • Simple aromatic compounds: benzene, ethylbenzene, toluene, xylenes (total), n- propylbenzene • Ethers: bis(2-chloroethyl)ether, methyl-tert-butyl-ether • Ketones: acetone, 2-hexanone, 2-butanone, 4-methyl-2-pentanone • Organic acids: benzoic acid • Phenolic compounds: phenol, 2-methylphenol, 4-methylphenol, 2,4- dimethylphenol • Phthalate esters: bis(2-ethylhexyl)phthalate, di-n-butylphthalate, butylbenzylphthalate • Polycyclic aromatic hydrocarbons: carcinogenic and noncarcinogenic PAHs • Chlorinated pesticides: endosulfan I • Polychlorinated biphenyls: Aroclor 1242 • Inorganics (behaving as cations in water): aluminum, barium, cadmium, trivalent chromium, copper, iron, lead, manganese, mercury, nickel, zinc • Inorganics (behaving as anions in water): arsenic, vanadium 116 TUT 006 2302 • Inorganics (behaving as neutral molecules in water): cyanide The physical and chemical properties that are important in determining a chemical contaminant's persistence and mobility in the environment were evaluated. The main properties that were reviewed were water solubility, K^. (organic carbon partitioning coefficient), K^, (octanol-water partitioning coefficient), volatilization, vapor pressure, vaporization, and Henry's law constant. This information is more difficult to evaluate for the inorganic chemicals because the migration of inorganics depends upon several site-specific factors such as the following: The presence of other cations and anions which can enhance or limit mobility by forming complexes pH differences between infiltrating precipitation, soil pore water, and aquifer materials the ability of the soil to retain metals through cation or anion exchange the presence of oxidizing or reducing agents the presence of humic materials or other organic chelating agents The mobility of metals is therefore greatly dependent upon external factors which are seldom measured and cannot be easily determined based upon chemical-specific properties such as vapor pressure, solubility, and sorption to organic carbon. Moreover, physicochemical properties depend upon the identity of the metal complex which is almost never known (i.e., the analysis provides only information on total metal concentration, not on the metal complex or valence state). 117 TUT O06 23O3 The water solubility of a chemical is a critical property affecting its environmental fate. Chemicals with high water solubility can be rapidly leached from contaminated soil and are generally mobile in the groundwater. Solubilities can range from less than one mg/liter to totally miscible with most common organic chemicals falling between one mg/liter to 106 mg/liter (Lyman et al., 1982). The solubility of a chemical which is not readily soluble in water can become enhanced in the presence of other organic solvents which in and of themselves are more soluble in water. The organic carbon partitioning coefficient (K^) is used to reflect the potential of a chemical to sorb to the organic matter found in soil. The normal range of K«. is one to 107, with higher values indicating greater sorption potential and lower values indicting limited retardation of a chemical. The octanol-water partition coefficient (K^) is used to estimate the extent to which a chemical will partition from water into lipophilic parts of organisms (i.e., animal fat). The greater the K^, the more likely a chemical is to partition to octanol (considered a surrogate for lipids). Volatilization of a chemical is dependent on its vapor pressure, water solubility, and diffusion coefficients. Vapor pressure is a measure of the volatility of a chemical in its pure state. Vapor pressures typically range from 10" 3 to 760 mm Hg for liquids, with solids ranging to less than 10"10. Highly water soluble compounds generally have lower volatilization rates from water unless they also have high vapor pressures. Vaporization is also a major transport process. The rate of vaporization depends on temperature, degree of adsorption, soil properties, and soil water 118 TUT O06 23O4 content. Airflow over the evaporating surface also affects the rate of vaporization. Henry's law constant, which combines vapor pressure with solubility and molecular weight, is more appropriate for estimating releases from water to air than the vapor pressure. Chemicals with Henry's law constants in the range of 10"3 and larger can be expected to be readily released to the atmosphere through volatilization. Chemicals with values ranging from 10"3 to 10~5 are associated with moderate volatilization, while chemicals with values less than Ifr5 will only volatilize to a limited extent. 2.4 Evaluation of Tentatively Identified Compounds (TICs) The RAGS document (USEPA, 1989a) specifies that both the identity and reported concentration of a TIC are questionable. The USEPA's Contract Laboratory Program (CLP) Routine Analytical Services (RAS) requires the contracted laboratory to analyze samples for organic chemicals on the Target Compound List (TCL) and for inorganic chemicals on the Target Analyte List (TAL). Chemicals on the TCL and TAL, however, may be a limited subset of the chemicals which may actually be encountered at the site. The analysis of VOCs and SVOCs may indicate the presence of additional organics not on the TCL. These additional chemicals appear as peaks on a chromatogram. A chromatogram is a paper representation of the response of the analytical instrument to the presence of a chemical. The laboratory attempts to identify the thirty highest peaks (ten VOCs and twenty SVOCs) using computerized searches of a library containing mass spectra (essentially "fingerprints" for particular chemicals). When the mass 119 TUT OO6 23O5 spectra match to a certain degree, the chemical or chemical class is named; however, the assigned identity is highly uncertain in most cases. These chemicals are therefore called TICs (USEPA, 1989a). Site Data (Appendix E) presents the TIC results. All results are listed as "Unknown" or with the prefix "Unknown" (i.e., Unknown Amide Record), or as "TID Compound" followed by a number (i.e., TID Compound 5) except for the new 1994 Geraghty & Miller groundwater data in which one TIC, phthalic anhydride, was identified for evaluation in the risk assessment. Phthalic anhydride has an established lexicological value and was included in the chemical concentration-toxicity screening procedure for groundwater. This TIC, however, was not selected as a chemical of potential concern to be evaluated in the risk assessment. 2.5 Selected Chemicals of Potential Concern Using the criteria discussed in Section 2.3, chemicals of potential concern were selected for surface soil, subsurface soil, and groundwater. Table 2-28 presents the chemicals selected for quantitative evaluation in this risk assessment. 120 TUT OO& 23O6 K) TABLE 2-28 TUTU WELLS SITE SUMMARY OF CHEMICALS OF POTENTIAL CONCERN IN SITE MATRICES BY AREA OF CONCERN SURFACE SOIL Tlllett Gardens and Art Center VOCs; None Selected SVOCs: None Selected Pasllddas/PCBsi ArodoM242 Inorganics: Antimony Arsenic Manganese Vanadium Fir* DepL/Texaco Gas Station/Antilles Auto Parts/Ramsay Motor Co. VOCs; None Selected SVOCs; Benzo(b)fluoranthene Benzo(a)pyrene Pestlcldes/PCBs: None Selected Inorganics: Antimony Beryllium Manganese Vanadium Curriculum Center Building (Present) VOCs; None Selected SVOCs; 2-Methylphenol 4-Methylphenol EssHsldaaECBsi None Selected Inorganics: Antimony Arsenic Beryllium Manganese Vanadium Curriculum Center Building (Future) VOCs; None Selected SVOCs; 2-Methylphenol 4-Methytphenol Pestiddos/PCBs: None Selected Inorganics: Antimony Arsenic Beryllium Manganese Vanadium O'Henry Dry Cleaners and Liquor Barn VOCs; Tetrachloroethene SVOCs; None Selected Pestlcldes/PCBs: None Selected Inorganics: Antimony Arsenic Manganese Vanadium _l oo TABLE ii-28 (Cont'd) TUTU WELLS SITE SUMMARY OF CHEMICALS OF POTENTIAL CONCERN IN SITE MATRICES BY AREA OF CONCERN Tlllett Gardens and Art Center VOCs: None Selected SVDCs: Benzo(a)pyrene f3 ^ Pesticides/PCBs: Not Analyzed Inorganics: ,.' Antimony Arsenic Beryllium Manganese Vanadium Fire DepL/Texaco Gas Station/Antilles Auto Parts/Ramsay Motor Co. VOCs: None Selected SVOCs: Benzo(a)pyrene Pesticides/PCBs: None Selected Inorganics: Antimony Arsenic Barium Beryllium Manganese Vanadium SUBSURFACE SOIL Curriculum Center Building (Future) VOCs: None Selected SVOCs: None Selected Pesticides/PCBs: Not Analyzed Inorganics: Antimony Arsenic Beryllium Manganese Vanadium Esso Gas Station and Splash and Dash Car Wash VOCs: None Selected SVOCs: None Selected Pesticides/PCBs: Not Analyzed Inorganics: Antimony Arsenic Beryllium Manganese Vanadium O'Henry Dry Cleaners and Liquor Barn VOCs: None Selected SVOCs: None Selected Pesticides/PCBs: Not Analyzed Inorganics: Antimony Arsenic Manganese Vanadium GROUNDWATER f!| Site-Wide 1- |! Benzene 11 1 ,2 Dichloroethene (Total) flf Tetrachloroethene if Toluene Iff Vinyl Chloride ij SVOCs: • None Selected HI Pesticides/PCBs: 11 || Not Analyzed lii Inorganics: & Antimony pi Arsenic 11 Beryllium M Chromium VI ||| Manganese |!| Nickel It Vanadium t-'-io 3.0 EXPOSURE ASSESSMENT This section of the risk assessment presents the approach used for identifying the potential human exposure pathways at the Tutu Wells site for present and potential future land use scenarios. The exposure pathways identified in this section are combined with chemical-specific toxicity data in Section 4.0 to characterize potential risks and health effects. All plausible exposures to receptor populations (i.e., residents, site workers, and construction workers) associated with current and potential future conditions have been evaluated. Present conditions are as they exist today and future conditions are based on potential future land uses of the site assuming no additional institutional controls are put in place and no remediation has occurred. For present and potential future-use conditions, exposure scenarios which identify plausible routes of exposure to site-related chemical contaminants were developed. Exposure pathways were identified by assessing the various ways in which people living in the area and workers at the site could be exposed to chemicals originating from the site. The exposure point concentration of each chemical to which a person may be exposed via each pathway was estimated using the 95 percent UCL calculation. From the estimated exposure point concentrations, potential chemical intakes were calculated in terms of the mass of a substance in contact with the body per unit body weight per unit time, expressed as milligrams of a chemical per kilogram of body weight per day. Variables such as contact rate, exposure frequency, and exposure duration were considered in the calculation of the chemical intakes. 123 TUT 006 2309 3.1 Potential Release and Transport Mechanisms Chemical contaminants present in waste materials and contaminated source media may migrate through a number of release and transport mechanisms. In general, potential release and transport mechanisms may include: • The leaching of chemical contaminants from subsurface soil into underlying groundwater due to infiltration of precipitation. • The migration of chemical contaminants in soil via surface runoff. • The adsorption of chemical contaminants onto soil. • The volatilization of chemical contaminants present in soil and groundwater into the ambient air. • The generation of fugitive dust from contaminated soils into the ambient air via wind erosion or mechanical disturbances of soil. • The transport of VOCs and dust to ambient air downwind locations. • The uptake of chemical contaminants present in soil and surface water by biota. 3-2 Identification of Exposure Pathways The objective of the exposure assessment is to estimate the types and magnitudes of exposures to chemicals of potential concern at or migrating from the site. The results of the exposure assessment are then combined with chemical-specific toxicity data to determine site-specific carcinogenic risks and noncarcinogenic hazards. 124 TUT OO6 2310 In accordance with RAGS (USEPA, 1989a), when determining the exposure pathways for a site two steps are followed. The initial step consists of characterizing the exposure setting. This step includes consideration of the physical characteristics of the site and the human receptors at or in the vicinity of the site (i.e., residents). Site characteristics, which are noted during the site visit, may include climate, soil type (i.e., sandy), vegetation (i.e., grassy or bare), presence of paved surfaces, and presence of surface water. Potential human receptors such as on-site residents or workers may be observed with respect to activity patterns, presence of sensitive receptors (i.e., children, occupationally exposed individuals), and location. Potentially exposed off site receptors (i.e., local residents - trespassers, downgradient public water supply consumers, downwind receptors) must also be considered. This step must also take into account the presence of potential future receptors under an alternate land use condition (i.e., zoning changes, currently unused water that is of potable quality for future use). The second step of exposure assessment involves identifying the appropriate exposure pathways for the site. As described in RAGS (USEPA, 1989a), an exposure pathway describes the course a chemical or physical agent takes from the source to the exposed individual. An exposure pathway analysis links the sources, locations, types of environmental releases, and environmental fate with receptor locations and activity patterns. An exposure pathway generally consists of four elements. • Source and mechanism of release • A transport medium 125 TUT 006 2311 • An exposure point (point of potential contact with a contaminated medium) • An exposure route (i.e., ingestion) at the exposure point The following presents the basic analytical process for identifying and selecting exposure pathways in the risk assessment. An environmental medium contaminated by a previous release can be a contaminant source for other media. The identification of potential release mechanisms and receiving media may be determined utilizing site histories and data from existing reports. Examples of typical release sources, mechanisms of release, and receiving media include the following: • Volatilization of chemicals from surface soil, surface water, lagoons or spills into the air • Leaching from surface or buried wastes into soil; surface runoff from contaminated surface soil; episodic overland flow resulting from lagoon overflow, spills or leaking containers; and fugitive dust generation/deposition from contaminated surface soil or waste piles • Leaching from surface or buried wastes and contaminated soil into groundwater The fate and transport of the chemicals from release media are then considered in order to identify media that are receiving or may receive site-related chemicals. Points of potential contact with contaminated media (or sources) by human receptors are then considered. After exposure points are identified, potential exposure routes (i.e., ingestion, dermal contact, inhalation) may be selected. 126 TUT 006 2312 By integrating the information presented above, complete exposure pathways at a site may be selected. Based on additional considerations such as the potential magnitude of exposure from the pathway or probability of exposure occurring, the complete exposure pathways may be retained for quantitative evaluation in the risk assessment or eliminated from further analysis. 3.2.1 Present - Use Scenarios Since residents currently live at the Tutu Wells site and workers are employed at commercial establishments at the site, numerous potential present exposure scenarios were selected for quantitative evaluation in this risk assessment. Table 3-1 presents the environmental media, receptors, and scenarios considered for analysis with a "yes" next to those selected and justification for the pathway's elimination from or retention for quantitative analysis. Justifications are based on visual observations made during a March 23rd through March 25th, 1994 site visit, conversations with the USEPA RPM and Risk Assessment Specialist, and review of the sample data for each area of concern. Surface Soil; During the March 1994 site visit, a residence was observed to be located at the Tillett Gardens and Art Center. Residents may inadvertently ingest and/or dermally contact surface soil in the vicinity of their home during their daily activities. The inhalation of suspended surface soil particulates route was not selected for quantitative evaluation as the areas from which the soil samples were collected consist of hard packed soil or are covered by vegetation. 127 TUT 006 7>-.r -, • -1— "—* J. -, 8/17/94 EXP-PWAY.XLS TUTU WELLS SITE POTENTIAL EXPOSURE PATHWAYS Matrix Receptor Populations) Exposure Retained for Route(»)______Quantitative Analysis Justification PRESENT - USE SCENARIOS: Surface Soil K) oo (> f'-Jw !-*• Site Residents Ingestion (Adults and Children) Dermal Contact' (Tillett Gardens and Art Center) Inhalation of Partculates inhalation of VOCs Site Workers 1- (Employees of the Fire Dept, Texaco gas station, Antilles auto parts, and Ramsay motor company)" 2- (Employees of the Curriculum Center Building) 3- (Employees of the Esso gas station and the Splash and Dash car wash) 4- (Employees of O'Henry dry cleaners and Liquor Bam) Ingestion Dermal Contact* Inhalation of Partculates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Partculates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Partculates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Partculates Inhalation of VOCs Yes Yes No No Yes Yes No No Yes Yes No No No No No No Yes Yes No Yes Site residents are expected to come into direct contact with surface soil in the vicinity of their home and Tillett Gardens and Art Center. The inhalation of partculates from surface soil is assumed to be negligible, as the areas where samples were collected either consist of hard packed soil or are covered by vegetation. The inhalation of VOCs is also assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation pathways were therefore not selected for further evaluation. Site workers may come into direct contact with surface soil during the course of a normal work day (i.e., outdoor work, lunch hour). The inhalation of particulates from surface soil is assumed to be negligible, as the areas where samples were collected consist of either hard packed soil or are covered to a large extent by vegetation. The inhalation of VOCs is also asumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation pathways were therefore not selected for further evaluation. Site workers may come into direct contact with surface soil during the course of a normal work day (i.e., outdoor work, lunch hour). The inhalation of particulates from surface soil is assumed to be negligible, as the areas where samples were collected consist of either hard packed soil or are coveted to a large extent by vegetation. The inhalation of VOCs is also assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation pathways were therefore not selected for further evaluation. Since the Esso gas station and Splash and Dash car wash properties are completely paved, no surface soil is available for contact. Therefore, no surface soil exposure can occur. Site workers may come into direct contact with surface soil during the course of a normal work day (i.e., outdoor work, lunch hour). The inhalation of particulates from surface soil is assumed to be negligible, as the area where samples were collected is covered to a large extent by dense vegetation. Since a VOC was selected as a chemical of potential concern for this area, the inhalation of VOCs pathway was retained for further evaluation. B/17/M EXP-PWAYJOS TAb. -1 TUTU WELLS SITE POTENTIAL EXPOSURE PATHWAYS Matrix Receptor Population^) Exposure Retained for Route(s)_____Quantitative Analysis Justification PRESENT - USE SCENARIOS CONTD: Surface Soil (Confd) Construction Workers (Site-Wide) Ingestion Dermal Contact* Inhalation of Particulates Inhalation o» VOCs No No No No No construction work is currently in progress in any areas of concern at the site. Subsurface Sot Site Residents (Adults and Children) (Tillett Gardens and Art Center) Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs No No No No No construction work (i.e., excavation activity) is currently in progress in this area of the site. to Site Workers 1- (Employees of the Fire Dept., Texaco gas station, Antilles auto parts, and Ramsay motor company) 2- (Employees of the Curriculum Center Building) Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs No No No No No No No No No construction work (i.e., excavation activity) is currently in progress in this area of the site. No construction work (i.e., excavation activity) is currently in progress in this area of the site. i— <—— —i 3- (Employees of the Esso gas station and the Splash and Dash car wash) 4- (Employees of O'Henry dry cleaners and Liquor Bam) Construction Workers (Site-Wide) Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Particulates No No No No No No No No No No No No construction work (i.e., excavation activity) is currently in progress in this area of the site. No construction work (i.e., excavation activity) is currently in progress in this area of the site. No construction work (i.e., excavation activity) is currently in progress in any areas of concern at the site. rji 8/17/94 EXP-PWAY.XLS Matrix Receptor Population!*) TUTU WELLS SITE POTENTIAL EXPOSURE PATHWAYS Exposure Retained for Route(s) ____Quantitative Analysis Justification PRESENT - USE SCENARIOS CONTD: Groundwater Site Residents (Adults and Children) Site Workers (All) Ingestion Yes Deimal Contact (Shower) Yes Inhalation of VOCs (Shower) Yes Ingestion Yes Dermal Contact (Shower) No Inhalation of VOCs (Shower) No Currently, an order against drinking and bathing in groundwater at the site has been issued. However, since evidence of pumping exists at the Ramsay well, residents may be using the groundwater for these purposes in addition to secondary purposes such as clothes washing, lawn watering, etc. Currently, an order against drinking and bathing in groundwater at the site has been issued. However, since evidence of pumping exists at the Ramsay well, site workers may be using the groundwater for drinking. Site workers are not expected to shower on-site. Construction Workers (Site-Wide) Ingestion Dermal Contact (Shower) Inhalation of VOCs (Shower) FUTURE • USE SCENARIOS: Surface Soil Residents Ingestion (Adults and Children) Dermal Contact* (TiHett Gardens and Art Center) Inhalation of Particulates Inhalation of VOCs No No No Yes Yes Yes No No construction work (i.e., excavation activity) is currently in progress in any areas of concern at the site. Site residents are expected to come into direct contact with surface soil in the vicinity of their home and Tillett Gardens and Art Center. The inhalation of particulates exposure route may be of concern due to the potential for future construction work (i.e., excavation activity) in this area. The inhalation of VOCs is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Site Workers 1- (Employees of the Fire Dept., Texaco gas station, Antilles auto parts, and Ramsay motor company)** Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs Yes Yes Yes No Site workers may come into direct contact with surface soil during the course of a normal work day (i.e., outdoor work, lunch hour). The inhalation of particulates exposure route may be of concern due to the potential for future construction work (i.e., excavation activity) in this area. The inhalation of VOCs is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. 8/17/94 EXP-PWAY.XLS TA_ 1-1 TUTU WELLS SITE POTENTIAL EXPOSURE PATHWAYS Matrix Receptor Population^) Exposure Retained for Route(s)______Quantitative Analysis Justification FUTURE - USE SCENARIOS CONT'D: Surface Soil (Confd) 2- (Employees of the Curriculum Center Building) Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs . 3- (Employees of the Esso gas station and the Splash and Dash car wash) 4- (Employees of O'Henry dry cleaners and Liquor Bam) Construction Workers (TiRett Gardens and Art Center) Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs Subsurface So9 o cf- K3 Residents Ingestion (Adults and Children) Dermal Contact* (Tillett Gardens and Art Center) Inhalation of Particulates Inhalation of VOCs Yes Yea Yes No No No No No Yes Yes Yes Yes Yes Yes Yes No No Yes Yes No Site workers may come into direct contact with surface soH during the course of a normal work day (i.e., outdoor work, lunch hour). The inhalation of particulates exposure route may be of concern due to the potential for future construction work (i.e., excavation activity) in this area. The inhalation of VOCs is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Since the Esso gas station and Splash and Dash car wash properties are completely paved, no surface soil would be available for contact Therefore, no surface soil exposure can occur. Site workers may come into direct contact with surface soil during the course of a normal work day (i.e., outdoor work, lunch hour). The inhalation of particulates exposure route may be of concern due to the potential for future construction work (i.e., excavation activity) in this area. Since a VOC was selected as a chemical of potential concern for this area, the inhalation of VOCs pathway was retained for further evaluation. The potential exists for further commercial or residential development of the Tillett Gardens and Art Center area of concern. Construction workers would be expected to routinely contact surface soil during excavation activities. The inhalation of particulates exposure route may also be of concern as a result of this activity. The inhalation of VOCs is assumed to be negligible as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. During potential future construction work (i.e., excavation activity), residents may come into direct contact with exposed subsurface soil. However, they are assumed to ingest a negligible amount of excavated subsurface soil. The inhalation of VOCs is also assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. 6/17/94 EXP-PWAY.XLS \ TUTU WELLS SITE POTENTIAL EXPOSURE PATHWAYS Matrix Receptor Populations) Exposure Retained for Route(s)_______Quantitative Analysis Justification FUTURE - USE SCENARIOS CONT'D: Subsurface So/7 (Contd) u> N) Site Workers 1- (Employees of the Fire Dept., Texaco gas station, Antilles auto parts, and Ramsay motor company) 2- (Employees of the Curriculum Center BuHdng) 3- (Employees of the Esso gas station and the Splash and Dash car wash) Ingestion Dermal Contact* Inhalation of Partculates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Partculates Inhalation of VOCs Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs No Yes Yes No No Yes Yes No No Yes Yes No During potential future construction work (i.e., excavation activity), site workers may come into direct contact with exposed subsurface soil. However, they are assumed to ingest a negligible amount of excavated subsurface soil. The inhalation of VOCs is also assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. During potential future construction work (i.e., excavation activity), site workers may come into direct contact with exposed subsurface soil. However, they are assumed to ingest a negligible amount of excavated subsurface soil. The inhalation of VOCs is also assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. During potential future construction work (i.e., excavation activity), site workers may come into direct contact with exposed subsurface soil. However, they are assumed to ingest a negligible amount of excavated subsurface soil. The inhalation of VOCs is also assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. 4- (Employees of O'Henry dry cleaners and Liquor Bam) Ingestion Dermal Contact* Inhalation of Particulates Inhalation of VOCs No Yes Yes No During potential future construction work (i.e., excavation activity), site workers may come into direct contact with exposed subsurface soil. However, they are assumed to ingest a negligible amount of excavated subsurface soil. The inhalation of VOCs is also assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. ww H- CD Construction Workers Ingestion (Tillett Gardens and Art Center) Dermal Contact* Inhalation of Particulates Inhalation of VOCs Yes Yes Yes No The potential exists for further commercial or residential development of the Tillett Gardens and Art Center area of concern. Construction workers would be expected to routinely contact subsurface soil during excavation activities. The inhalation of participates exposure route may also be of concern as a result of this activity. The inhalation of VOCs is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. B/17/D4 EXP-PWAY.XL.S TAu. 1-1 TUTU WELLS SITE POTENTIAL EXPOSURE PATHWAYS Matrix Receptor Population^) Exposure Retained for Route(s)_____Quantitative Analysis Justification FUTURE - USE SCENARIOS CONT'D: Groundwater u> Site Residents (Adults and Children) Site Workers (AH) Construction Workers Ingestion Yes Dermal Contact (Shower) Yes Inhalation of VOCs(Shower) Yes Ingestion Yes Dermal Contact (Shower) No Inhalation of VOCs (Shower) No Ingestion Yes Dermal Contact (Shower) No Inhalation of VOCs (Shower) No Currently, an order against drinking and bathing in groundwater at the site has been Issued. However, since evidence of pump- ing exists at the Ramsay well, residents may continue to use the groundwater in the future for these purposes in addition to secondary purposes such as clothes washing, lawn watering, Currently, an order against drinking and bathing in groundwater at the site has been issued. However, since evidence of pumping exists at the Ramsay well, site workers may continue to use the groundwater in the future for drinking. Site workers are not expected to shower on-site. Currently, an order against drinking and bathing in groundwater at the site has been issued. However, since evidence of pump- ing exists at the Ramsay well, construction workers may continue to use the groundwater in the future for drinking. Construction workers are not expected to shower on-site. 0- The dermal contact pathway can only be quantitatively evaluated for PCBs and cadmium as only these chemicals have established dermal absorption factors (PCBs - 6% and cadmium - 1%). All other chemicals will be qualitatively discussed. "It should be noted that present and potential future site workers at the Fire Department and Texaco gas station were not considered receptors for surface soil since no surface soil samples were collected at the Fire Department, and the Texaco gas station is completely paved (all soil samples would be subsurface). However, all individual areas in the area of concern are listed to be consistent with those listed for the subsurface soil area of concern. •-0 The inhalation of VOCs exposure route was assumed to be negligible as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Site workers currently employed at the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company may inadvertently ingest and/or dermally contact surface soil while performing their daily job activities or during lunch hour. The inhalation of suspended surface soil particulates route was not selected for quantitative evaluation as the areas from which the samples were collected consist of hard packed soil or are largely covered by vegetation. The inhalation of VOCs exposure route was assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Site workers currently employed at the Curriculum Center Building may inadvertently ingest and/or dermally contact surface soil while performing their daily job responsibilities or during their lunch hour. The inhalation of suspended surface soil particulates route was not selected for quantitative evaluation as the areas from which the samples were collected consist of hard packed soil or are largely covered by vegetation. The inhalation of VOCs exposure route was assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. 134 TUT OO6 2320 Site workers currently employed at the Esso gas station and Splash and Dash car wash are not exposed to surface soil, as the entire area was observed to be paved during the site visit. Site workers currently employed at O'Henry dry cleaners and Liquor Barn may inadvertently ingest and/or dermally contact surface soil while performing their daily job activities or during lunch hour. The inhalation of suspended surface soil particulates route was not selected for quantitative evaluation as the area where the samples were collected is covered to a large extent by dense vegetation. The inhalation of VOCs exposure route was selected for quantitative evaluation, as one VOC, tetrachloroethene, was selected as a chemical of potential concern. Based on observations made during the March 1994 site visit, no construction work is currently in progress in any of the areas of concern at the site. Therefore, no construction worker exposure to surface soil is occurring. Subsurface Soil; Based on observations made during the March 1994 site visit, no construction work involving excavation activity is currently in progress in any of the areas of concern. Therefore, no exposure to subsurface soil by any of the potential receptors (i.e., residents, site workers, and construction workers) is occurring at present. Groundwater; Event though an order against drinking and bathing in groundwater at the site has been issued, evidence of pumping at the Ramsay well exists. Therefore, current residents of the site may be ingesting groundwater and/or using the water for showering in addition to 135 006 2321 secondary purposes such as clothes laundering and lawn watering. The showering scenario, which has been selected for quantitative evaluation, includes dermal contact with SVOCs, and inorganics and the inhalation pathway which addresses VOCs only. Pesticides and PCBs were not analyzed for in groundwater. Dermal contact with volatilized VOCs is assumed to be negligible. Based on the fact that the Ramsay well has undergone pumping in the recent past, it is reasonably assumed that site workers may be ingesting this water (i.e., Ramsay motor company employees). Site workers, however, are not assumed to shower while at work. Therefore, the dermal contact and the inhalation of VOCs routes of exposure associated with the showering scenario have not been selected for quantitative evaluation. 3.2.2 Future Use-Scenarios The potential exists, in the future, for further commercial or residential development of the Tutu Wells site. Based on visual observations made during the site visit, site history, discussions with the USEPA RPM and Risk Assessment Specialist, and professional judgement, potential future- use exposure scenarios and human receptors were selected for quantitative evaluation. Table 3-1 presents the media, receptors, and scenarios considered for analysis with a "yes" next to those selected and justification for the pathway's elimination from or retention for quantitative analysis. 136 TIJT 006 2322 Surface Soil; As discussed for the present-use scenario, during the March 1994 site visit a residence was observed to be located at the Tillett Gardens and Art Center. Residents may continue to come into direct contact with surface soil via the ingestion and dermal contact routes of exposure during the course of their daily activities. The inhalation of suspended surface soil particulates may be of concern due to the potential for future construction activity in this area of concern. Therefore, this route of exposure has been selected for quantitative evaluation in the risk assessment. The inhalation of VOCs is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Site workers at the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company are assumed to remain in their respective areas while performing their various daily activities in the future. The ingestion and dermal contact routes of exposure were therefore selected for quantitative evaluation. The inhalation of suspended surface soil particulates exposure pathway may be of concern due to the potential for future construction activity in the areas. The inhalation of VOCs is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Site workers at the Curriculum Center Building are assumed to remain in that area while performing their various daily activities in the future. The ingestion and dermal contact routes of exposure were therefore selected for quantitative evaluation. The inhalation of suspended 137 TUT 006 232v surface soil participates exposure pathway may be of concern due to the potential for future construction activity in the area. Therefore, this route of exposure has been selected for quantitative evaluation in the risk assessment. The inhalation of VOCs exposure route is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Since the Esso gas station and Splash and Dash car wash areas are completely paved at present, any future excavation activity would result in the exposure of subsurface soil. Therefore, no site worker exposure to surface soil in this area of concern may occur in the future. Site workers at O'Henry dry cleaners and the Liquor Barn are assumed to remain in their respective areas while performing their various daily activities. The ingestion and dermal contact routes of exposure were selected for quantitative evaluation. The inhalation of suspended surface soil particulates may also be of concern due to the potential for future construction activities in this area. The inhalation of VOCs exposure route was selected for quantitative evaluation in the risk assessment, as one VOC, tetrachloroethene, was selected as a chemical of potential concern. Construction worker exposure to surface soil in the Tillett Gardens and Art Center area of concern were selected for quantitative evaluation, as this area may be further developed in the future, is the most chemically contaminated (for soil), and presents the highest risks/hazards to future residents. The ingestion and dermal contact routes of exposure were selected for 138 TUT 006 23; quantitative evaluation. The inhalation of suspended surface soil particulates was also selected due to the potential for future excavation activities in this area. Subsurface Soil; The possibility exists for the Tillett Gardens and Art Center area to be further developed either commercially or residentially in the future. Residents may dermally contact exposed subsurface soil during recreational activity. However, they are assumed to ingest only a negligible amount of the exposed subsurface soil during such activity. The inhalation of suspended subsurface soil particulates from soil piles and/or excavated holes may be of concern. The inhalation of VOCs exposure route is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Since the potential exists for future construction work involving excavation activity at the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company, potential future site workers in these areas may inadvertently come into direct contact (i.e., dermal contact) with exposed subsurface soil during the course of a normal workday. However, workers are assumed to ingest only a negligible amount of this exposed subsurface soil. The inhalation of suspended subsurface soil particulates from soil piles and/or excavated holes may be of concern. The inhalation of VOCs is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. 139 TUT 006 2325 The potential exists for future construction work involving excavation activity at the Curriculum Center Building. Potential future site workers may inadvertently come into direct contact (i.e., dermal contact) with exposed subsurface soil during the course of a normal workday. However, workers are assumed to ingest only a negligible amount of this exposed subsurface soil. The inhalation of suspended subsurface soil particulates from soil piles and/or excavated holes may be of concern. The inhalation of VOCs exposure route is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Since the potential exists for future construction work involving excavation activity at the Esso gas station and Splash and Dash car wash, potential future site workers may inadvertently come into direct contact (i.e., dermal contact) with exposed subsurface soil during the course of a normal workday. However, workers are assumed to ingest only a negligible amount of this exposed subsurface soil. The inhalation of suspended subsurface soil particulates from soil piles and/or excavated holes may be of concern. The inhalation of VOCs exposure route is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. The potential exists for future construction work involving excavation activity at the O'Henry dry cleaners and Liquor Barn. Potential future site workers may inadvertently come into direct contact (i.e., dermal contact) with exposed subsurface soil during the course of a normal workday. However, workers are assumed to ingest only a negligible amount of this exposed 140 TU''" 006 2326 subsurface soil. The inhalation of suspended subsurface soil particulates from soil piles and/or excavated holes may be of concern. The inhalation of VOCs exposure route is assumed to be negligible, as no VOCs were selected as chemicals of potential concern. The inhalation of VOCs pathway was therefore not selected for further evaluation. Groundwater; Even though an order against drinking and bathing in groundwater at the site has currently been issued, evidence of pumping at the Ramsay well exists. Residents at the site may continue to use the groundwater indefinitely into tFje future for ingestion and/or showering (dermal contact with SVOCs and inorganics, and inhalation of VOCs) as well as for secondary purposes such as clothes washing and lawn watering. 3.3 Exposure Point Concentrations Concentrations at potential exposure points (any point of potential contact with a contaminated medium) were developed individually for chemicals of potential concern in the selected areas of concern for appropriate site media for use in calculation of the chronic and subchronic daily intakes. This concentration is the 95 percent UCL on the arithmetic mean of the concentration that is contacted over the exposure period. Although this concentration does not reflect the maximum concentration that could be contacted at any one time, it is considered a reasonable estimate of the concentration likely to be contacted over time, since long-term contact with the maximum concentration is not a reasonable assumption. 141 006 2327 Due to the uncertainty associated with an estimate of exposure concentration, the 95 percent UCL on the arithmetic mean is used for this variable. If there is a large variability in measured or modeled concentrations, the 95 percent UCL may exceed the maximum measured or modeled values, in which case, the maximum detected or modeled value is used. The formula used to calculate the 95 percent UCL for a lognormal distribution is as follows: UCL = e (* + °'5s2 Where: UCL = upper confidence limit e = constant (base of the natural log, equal to 2.718) x = mean of the transformed data s = standard deviation of the transformed data H = H-statistic (i.e., from table published in Gilbert, 1987) n = number of samples The lognormal distribution formula was selected based on the limited number of surface and subsurface soil samples collected in each area of concern and on the plotting of groundwater data. In calculating this 95 percent UCL value, non-detects were accounted for by using one- half the SQL as the proxy concentration. In some cases, one-half the SQL exceeded the maximum (or only detected) value. If, in a group of samples, only one (one-half the) SQL exceeded the maximum detection, the SQL was eliminated from the calculation; if all (one-half the) SQLs exceeded the maximum detection, the maximum detection was utilized as the default value. Appendix A presents the calculated 95 percent UCL concentrations used to estimate carcinogenic risks and noncarcinogenic hazards. 142 TUT 006 2328 3.3.1 Exposure Point Concentration Modeling In performing this risk assessment, modeling was required for the evaluation of inhalation exposure to VOCs in groundwater while showering. In this scenario, potential future human receptors were assumed to inhale VOCs while showering and during time spent in the bathroom after showering. Dermal contact with volatilized VOCs was assumed to be negligible although dermal contact with SVOCs and inorganics is evaluated in Section 3.5. A chapter entitled Estimating Dermal and Inhalation Exposure to Volatile Chemicals in Domestic Water by J. Schaum et al. (1994) which appears as Chapter 13 in the recently published book entitled Water Contamination and Health: Integration of Exposure Assessment, Toxicology, and Risk Assessment was utilized to perform the shower modeling. This Chapter presents a methodology for estimating exposure to VOCs in domestic water supplies for the inhalation and dermal contact exposure routes. The dermal contact methodology was not utilized, as the dermal permeability coefficient for all but one chemical evaluated was the default value for water, (i.e., chemical-specific values are not available). The procedure for estimating exposure to VOCs was based on research performed by Julian Andelman (Andelman, 1990). This model treats the bathroom as one compartment and yields an air concentration averaged over the time of the actual shower and the time spent in the bathroom after the shower. The model was derived by assuming that the chemical contaminant volatilizes at a constant rate, instantly mixes uniformly with the bathroom air, and that ventilation with clean air does not occur. This implies that contaminant concentration in the air increases linearly from zero to a 143 TUT 006 2329 maximum at the end of the shower, and then remains constant during the time an individual spends in the bathroom immediately after the shower. C(a) = r(CfaMAXV2H tl + C(aMAX) t2 ti + a Where: C(a) C(aMAX) tl t2 concentration of chemical contaminant in air (mg/m3) maximum concentration of chemical contaminant in air (mg/m3) time of shower (hr) time after shower (hr) C(aMAX) is estimated as follows: C(aMAX) Cfvrt f F(w) tl V(a) Where: C(aMAX) C(w). f F(w) V(a) maximum air concentration in bathroom (mg/m3) water concentration (mg/1) fraction volatilized (unitless) water flow rate (1/hr) bathroom volume (m3) The water concentration, C(w), is a site-specific value that refers to the concentration of a chemical in water as it enters the shower. The 95 percent UCL value, or the maximum detected value, was utilized as the water concentration. 144 "UT 006 The fraction volatilized, f, is a chemical-specific value that refers to the mass fraction of chemical in water that volatilizes over the course of the shower. Volatilization rates depend on properties such as Henry's law constants and molecular weights, although the relationship is not well established. Andelman (1990) has reported volatilization factors of 0.5 to 0.9 based on experiments with chloroform and trichloroethene. These chemicals have Henry's law constants of 2.87E-03 atm-m3/mol and 9.10E-03 atm-m3/mol, respectively, and are assumed to be representative of other VOCs (i.e., those having Henry's law constants that are similar or greater). A review of the Henry's law constants for the VOCs modeled showed all to be similar to or greater than those for chloroform and trichloroethene. The fraction volatilized for all chemicals in the shower model was assumed to be 75 percent, based on the assumptions used in the model. The water flow rate, F(w), refers to the rate at which water flows into the shower. A value of 750 1/hr was assumed in the model. The bathroom volume, V(a), refers to the volume of the bathroom including the shower stall. A value of 12 m3 was assumed in the model. The shower time, tl, refers to the actual time of the shower. A 90th percentile value of 12 minutes (0.2 hr) (USEPA, 1989a) was assumed in the model. 145 TOT The time spent in the bathroom after showering, t2, was assumed to be 20 minutes (0.3 hr). The variables selected for input into the shower model generally represent average values in an attempt to reduce over conservatism inherent in the model. The model is very conservative in nature due to the following assumptions, constant volatilization no ventilation the concentration of the chemical contaminant is assumed to be zero at the start of the shower (i.e., no residual chemical concentrations) the exchange between air in the shower chamber and bathroom air is so rapid that the combined volume of the two compartments can be treated as a single chamber with a single concentration of volatilized chemical the model does not account for the exchange rate that occurs when an exhaust fan is turned on Since groundwater at the site has been found to contain VOC contamination and the potential exists in the future for the groundwater to again be used as a potable source, it has been evaluated for potential health impacts. Table 3-2 presents the daily intake equation for VOC inhalation during and after showering. 3.4 Calculation of Chronic and Subchronic Daily Intakes To quantitatively assess the potential carcinogenic risks and health hazards to human populations based on the present and potential future-use scenarios discuss in Section 3.2, daily intakes were. 146 TUT O06 233 TABLE 3-2 TUTU WELLS SITE INHALATION OF AIRBORNE CHEMICALS (SHOWER SCENARIO)* Equation: Intake (mg/kg-day) = CA x IR x ET x EF x ED BWx AT Where: CA = Chemical Concentration in Air (mg/m3) IR = Inhalation Rate (mVhour) ET = Exposure Time (hours/day) EF = Exposure Frequency (days/year) ED = Exposure Duration (years) BW = Body Weight (kg) AT = Averaging Time (period over which exposure is averaged - days) *Schaum et al. (1994) based on the Andelman (1990) Shower Model '147 TUT 006 2333 calculated. These daily intakes were evaluated for both chronic (approximately seven year to lifetime) and subchronic (two week to approximately seven year) exposures (USEPA, 1989a). For the chronic and subchronic daily intakes, intakes were averaged over a lifetime for carcinogenic chemicals and over the period of exposure for noncarcinogens. The daily intake was expressed in terms of the mass of the chemical per unit of body weight over the averaging time (mg chemical/kg body weight-day). Equations presented and described in RAGS (USEPA, 1989a) were used to estimate daily intakes from ingestion and dermal contact exposures. The inhalation of particulates daily intake was calculated based on the equation presented in USEPA (1989b). The inhalation of VOCs daily intake was calculated based on the equation presented in USEPA (1991b). These equations are presented in Tables 3-3 through 3-8 and also appear at the top of the appropriate spreadsheets for clarity. 3.5 Exposure Assumptions All exposure parameters selected for use in chronic and subchronic daily intake calculations are presented in Table 3-9. The following sections describe the reasoning behind their selection and the sources from which the values were obtained. Daily intakes were calculated for residents (adults and children), site workers, and construction workers. Children have been identified as a subpopulation that is potentially at higher risk from chemical exposure due to increased sensitivity and behavior patterns that may result in higher exposure (i.e., surface soil) than in 148 TUT 006 2334 TABLE 3-3 TUTU WELLS SITE INGESTION OF CHEMICALS IN SOIL Equation: Intake (mg/kg-day) = CS x IR x CF x FI x EF x ED BW x AT Where: CS = Chemical Concentration in Soil (mg/kg) IR = Ingestion Rate (mg soil/day) CF = Conversion Factor (10"6 kg/mg) FI = Fraction Ingested from Contaminated Source (unitless) EF = Exposure Frequency (days/year) ED = Exposure Duration (years) BW = Body Weight (kg) AT = Averaging Time (period over which exposure is averaged - days) 149 TUT 006 2335 TABLE 3-4 TUTU WELLS SITE DERMAL CONTACT WITH CHEMICALS IN SOIL Equation: Absorbed Dose (mg/kg-day) = CS x CF x SA x AF x ABS x EF x ED BW x AT Where: CS = Chemical Concentration in Soil (mg/kg) CF = Conversion Factor (10'6 kg/mg) SA = Skin Surface Area Available for Contact (cnWevent) AF = Soil-to-Skin Adherence Factor (mg/cm2) ABS = Absorption Factor (unitless) EF = Exposure Frequency (events/year) ED = Exposure Duration (years) BW = Body Weight (kg) AT = Averaging Time (period over which exposure is averaged - days) 150 TUT O06 2336 TABLE 3-5 TUTU WELLS SITE INHALATION OF INDOOR AND OUTDOOR PARTICULATES Equation: Intake (mg/kg-day) = CS x SSC x RF x IR x ET x EF x ED x CF BWx AT Where: CS = Chemical Concentration in Soil (mg/kg) SSC = Suspended Soil Concentration (mg/m3) RF = Respirable Fraction (unitless) IR = Inhalation Rate (mVhour) ET = Exposure Time (hours/day) EF = Exposure Frequency (days/year) ED = Exposure Duration (years) CF = Conversion Factor (10'6 kg/mg) BW = Body Weight (kg) AT = Averaging Time (period over which exposure is averaged - days) 151 TUT' 006 2337 TABLE 3-6 TUTU WELLS SITE INHALATION OF VOCS FROM SURFACE SOIL Equation: Intake (mg/kg-day) = CS x 1/VF x IR x ET x EF x ED BW x AT Where: CS = Chemical Concentration in Soil (mg/kg) VF = Soil-to-Air Volatilization Factor (nrVkg) IR = Inhalation Rate (nWhour) ET = Exposure Time (hours/day) EF = Exposure Frequency (days/year) ED = Exposure Duration (years) BW = Body Weight (kg) AT = Averaging Time (period over which exposure is averaged - days) 152 TUT OO6 2338 TABLE 3-7 TUTU WELLS SITE INGESTION OF CHEMICALS IN DRINKING WATER Equation: Intake (mg/kg-day) = CW x IR x EF x ED BW x AT Where: CW = Chemical Concentration in Water (mg/liter) IR = Ingestion Rate (liters/day) EF = Exposure Frequency (days/year) ED = Exposure Duration (years) BW = Body Weight (kg) AT = Averaging Time (period over which exposure is averaged - days) 153 TUT O06 2339 TABLE 3-8 TUTU WELLS SITE DERMAL CONTACT WITH CHEMICALS IN GROUNDWATER WHILE SHOWERING Equation: Absorbed Dose (mg/kg-day) = CW x SA x PC x ET x EF x ED x CF BWx AT s-^. Where: CW = Chemical Concentration in Water (mg/liter) SA = Skin Surface Area Available for Contact (cm2) PC = Chemical-Specific Dermal Permeability Constant (cm/hr) ET = Exposure Time (hours/day) EF = Exposure Frequency (days/year) ED = Exposure Duration (years) CF = Volumetric Conversion Factor for Water (1 liter/1000 cm3) BW = Body Weight (kg) AT = Averaging Time (period over which exposure is averaged - days) 154 TUT 2340 1212/94 EXPVAR1.XLS } 3-9 TUTU WELLS SITE VARIABLES USED FOR CHRONIC AND SUBCHHONIC DAILY INTAKE CALCULATIONS Matrices and Receptor Populations Surface Soil Residents (Tiltett Gardens and Art Center) Adults Children (0-6 years] Adults Children (0-6 years] Adults Children (0-6 years) Site Workers Adults Construction Workers Adults Subsurface Soil Residents (Tiltett Gardens and Art Center) Adults Children (0-6 years) Adults Children (0-6 years) Site Workers Adults Construction Workers Adults Exposure Route digestion Ingestion Dermal Contact Dermal Contact Inhalation of Particulates Inhalation of Particulates Ingestkxi Dermal Contact Inhalation of Particulates Inhalation of VOCs Ingestion Dermal Contact Inhalation of Particulates Dermal Contact Dermal Contact Inhalation of Particulates Inhalation of Particulates Dermal Contact Inhalation of Particulates Ingestion Dermal Contact Inhalation of Particulates CONCENTRATIONS CW CA/SSC CS VF (mo/I) (mg/m3) (mg/kg) {m3/kg Site Data Site Data • Site Data Site Data 0.070 Site Data - 0.070 Site Data Site Data Site Data 0.070 Site Data - Site Data (4) Site Data - Site Data - 0.070 Site Data - Site Data - Site Data - 0.070 Site Data • 0.070 Site Data - Site Data 0.070 Site Data - Site Data - Site Data 0.070 Site Data CONTACT PARAMETERS SA PC IR(1) RF AF ABS Fl (cm2) (cnVhr) (variable) (unifess) (mg/cm2) (unitless) (unitless) 100 mo/day i 200 mo/day 1 5065 - 1 (5) 1270 - t (5) 0.83 m3/hr 0 75 0.83m3/hr 0.75 50 mo/day 1 1940 - 1 (5) 0.83m3/hr 0.75 0.83m3/hr . . . . - 480mg/day 1 6125 - - 1 (5) 0.83m3/nr 0.75 5065 - - 1 (5) 1270 - - - 1 (5) 0.83m3/hr 0.75 0.83m3/hr 0.75 1940 - - 1 (5) 0.83m3/hr 0.75 - 480mg/day 1 6125 - - 1 (5) 0.83m3/hr 0.75 TIME VARIABLES ET EF ED AT (2) (hr/day) (day/yr) (yrs) (years) 350 24 70(24) 350 6 70(6) 350events/yr 24 70(24) 350events/yr 6 70(6) 18 350 24 70(24) 18 350 6 70(6) 250 25 70(25) 250events/yr 25 70(25) 8 250 25 70(25) 8 250 25 70(25) 225 1 70(1) 225evenls/yr 1 70(1) 8 225 1 70(1) 91events/yr 1 70(1) 91events/yr 1 70(1) 18 91 1 70(1) 18 91 1 70(1) 65events/yr 1 70(1) 8 65 1 70(1) 65 1 70(1) 65events/yr 1 70(1) 8 65 1 70(1) CF(3) (variable) lE-6kg/mg 1E-«kg/mg 1E-6kg/mg lE-6kg/mg lE-6kg/mg 1 E-6 kg/mg lE-6kg/mg IE-6 kg/mg IE-6 kg/mg IE-6 kg/mg 1E-6 kg/mg IE-6 kg/mg 1E-6 kg/mg 1 E-6 kg/mg IE-6 kg/mg IE-6 kg/mg IE-6 kg/mg IE-6 kg/mg 1 E-6 kg/mg 1 E-6 kg/mg 1 E-6 kg/mg BW ( kq) 70 15 70 15 70 15 70 70 70 70 70 70 70 70 15 70 15 70 70 70 70 70 TUT 00& 2341 )j (ContU) TUTU WELLS SITE VARIABLES USED FOR CHRONIC AND SUBCHRONIC DAILY INTAKE CALCULATIONS Matrices and Receptor Populations Groundwater Site Residents Adults Children (0-6 years) Adults Children (0-6 years) Adults Children (0-6 years) Site Workers Adults Construction Worker: Adults Exposure Route Ingestion Ingestion Dermal Contact (Shower) Dermal Contact (Shower) InhalaHon(Showef) Inhalation(Shower) Ingestion Ingestion CONCENTRATIONS CONTACT PARAMETERS CW CA/SSC CS VF (mgfl) (mg/m3) (mg/kg) (m3/kg Site Data Site Data - Site Data Site Data (6) - (6) Site Data Site Data SA PC IR(1) RF AF ABS Fl (cm2) (cnVhr) (variable) (unittess) (mqfcm2) (uniHess) (unittess) 2Vday - - - iWay . . . . 18150 ( 7 ) . . . . 5400 (7) 0.6m3/hr . . . . 0.6m3Av . . . . 1 1/day . . . . 1 W a y . . . . TIME VARIABLES ET EF ED AT (2) (hr/day) (day/yr) (yrs) (years) 350 30 70(30) 350 6 70(6) 0.2 350 30 70(30) 0.2 350 6 70(6) 0.2 350 30 70(30) 0.2 350 6 70(6) 250 25 70(25) 225 1 70(1) CF(3) (variable) . - 1E-3Vcm3 lE-3l/cm3 . - - - BW (kq) 70 15 70 15 70 15 70 70 5, NOTES: (1) Ingestion or inhalation rate (2) 70 years for carcinogens. 30 years for noncarcinogens for adult residents, 25 years lor noncaroinogens for site workers. 6 years for noncarcinogens for children and 1 year for all construction workers and subsurface soil (multiplied by 365 days). (3) Conversion Factor (4) The soil-to-air volatilization factor (VF) wiH be calculated individually for chemicals of potential concern as appropriate. (5)'Soil dermal contact absorption factors: 6% « PCBs and 1% » cadmium. (6) This value was modeled from Rl Data. (7) This value is the default value for water when no chemical-specific values were available in USEPA (1992c). Other Abbreviations: K3 >>•! CW - Contaminant concentration in water CA > Contaminant concentration in air CS « Contaminant concentration in soil SA * Skin surface area available for dermal contact PC - Chemical-specific dermal permeability constant RF > Respirabte fraction of particulates AF = Soil-to-skin adherence factor SSC = Suspended soil concentration Fl - Fraction ingested from contaminant source ET - Exposure Time EF «= Exposure Frequency ED * Exposure Duration BW = Body Weight AT = Averaging Time adults. For soil, a 30 year exposure is separated into a six year exposure for children (age 0 - 6 years) and a 24 year exposure for older children and adults. The spreadsheet calculations present the individual as well as the combined estimates. For all receptor populations, the chemical concentrations in the various matrices (except for groundwater chemical concentrations in the shower model) were based on actual site data from which 95 percent UCLs were calculated. In cases where the 95 percent UCL exceeded the maximum detected site concentration, the maximum site detection was used in the daily intake calculation. It should be noted for subsurface soil that exposure is considered to be subchronic for the residential and worker receptor groups as the potential for exposure would only occur during excavation activities. All child exposures to noncarcinogens are considered chronic per USEPA direction since the exposure duration (6 years) is at the upper-bounds of subchronic exposure. 3.5.1 Surface Soil Residents; For present and potential future adult and child residents in the Tillett Gardens and Art Center, surface soil data were used to calculate chemical concentrations for the intake equations. 157 TUT 006 For potential future adult and child residents, daily soil ingestion rates (IR) of 100 and 200 mg/day, respectively, were obtained from USEPA (1991a). The fraction ingested (FI) from contaminated surface soil was conservatively assumed to be one for both adults and children. An exposure frequency (EF) of 350 days/year was assumed for potential future residents (USEPA, 1991a). This value was based on the assumption that residents would be away on vacation two weeks per year. Exposure durations (ED) were assumed to be 24 years for adults and 6 years for children (USEPA, 1991a) for a 30 year total exposure which corresponds to the 90th percentile national upper-bound time spent at the same residence. The averaging time (AT) was calculated from USEPA (1989a) as the exposure duration (ED) multiplied by 365 days/year for noncarcinogens and 70 years (lifetime) multiplied by 365 days/year for carcinogens. An adult body weight (BW) of 70 kg and a child body weight (BW) of 15 kg were assumed (USEPA, 1991a). For potential future residential dermal contact exposure, the skin surface area (SA) available for contact was calculated from information presented in USEPA (1989b, 1992c). For adult males and females, the skin surface areas (SA) for the head, hands, forearms, and lower legs were summed by sex, then averaged, resulting in a value of 5065 cm2. For children (age 0-6 years), the average skin surface area (SA) was calculated as 25 percent of the average adult male and female skin surface area (SA=5065 cm2), resulting in an exposed surface area of 1270 cm2. An adherence factor (AF) of 1 mg/cm2 for adults and children was obtained from USEPA (1992c). Soil dermal absorption factors (ABS) of six percent for PCBs and one percent for cadmium were obtained from USEPA (1992c). All other chemicals of potential concern were qualitatively 158 TUT 006 addressed in the risk assessment for dermal contact exposure since no other dermal absorption factors are currently established for USEPA Region II. The exposure frequency (EF), exposure duration (ED), averaging time (AT), and body weight (BW) values for adults and children are the same as ingestion exposure, except for the exposure frequency unit, which for dermal contact is reported in events/year instead of days/year. For potential future residential inhalation exposures, an outdoor suspended soil concentration (SSC) of 70 ug/m3 (Hawley, 1985) was assumed to occur during construction activities. It was further assumed that 75 percent of the inhaled paniculate mass is retained (respirable fraction - RF) (Hawley, 1985). An inhalation rate (IR) of 0.83 mVhour was assumed based on an adult average rate of 20 m3/day as reported in USEPA (1989a). An exposure time (ET) of 18 hours was assumed to be the average combined amount of time spent both indoors and outdoors (i.e., at home) per day. The exposure frequency (EF), exposure duration (ED), averaging time (AT), and body weight (BW) values for adults and children are the same as ingestion exposure. Site Worker (Employee); For present and/or potential future site worker (employee) surface soil exposures at the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company, Curriculum Center Building, Esso gas station and Splash and Dash car wash, and O'Henry dry cleaners and Liquor Barn areas of concern, site data were used to calculate chemical concentrations for use in the intake equations. Workers (employees) at the Fire Department were not considered receptors for surface soil exposure, as no surface soil samples were collected from the Fire Department area. Workers (employees) at the Texaco gas station 159 TU"<" 006 2345 were also not considered receptors for surface soil exposure as the entire gas station area is paved. A daily ingestion rate (IR) of 50 mg/day was assumed for commercial land use scenarios (USEPA, 1991a). The fraction ingested (FI) from contaminated surface soil was conservatively assumed to be one. An exposure frequency (EF) of 250 days/year (five days/week for twelve months minus two weeks/year vacation) for 25 years (exposure duration (ED)) was assumed (USEPA, 199la). The averaging time (AT) was calculated from USEPA (1989a) as the exposure duration (ED) multiplied by 365 days/year for noncarcinogens and 70 years (lifetime) multiplied by 365 days/year for carcinogens. An adult body weight (BW) of 70 kg was assumed (USEPA, 1991a). For present and potential future site worker (employee) dermal contact exposure, a skin surface area (SA) of 1940 cm2/event was calculated based on information contained in USEPA (1989b, 1992c). For males and females, the average skin surface area (SA) for the head and hands were summed by sex, then averaged, resulting in the final value. An adherence factor (AF) of 1 mg/cm2 was obtained from USEPA (1992c). Soil dermal absorption factors (ABS) of six percent for PCBs and one percent for cadmium were obtained from USEPA (1992c). All other chemicals of potential concern were qualitatively addressed in the risk assessment for dermal contact exposure since no other dermal absorption factors are currently established for USEPA Region II. The exposure frequency (EF), exposure duration (ED), averaging time (AT), and body weight (BW) are the same as site worker (employee) ingestion exposure except for the 160 T<JT 006 2346 exposure frequency unit, which for dermal contact is reported in events/year instead of days/year. For present and potential future site worker (employee) inhalation of particulates exposure, an outdoor suspended soil concentration (SSC) of 70 ug/m3 (Hawley, 1985) was assumed to occur during construction activities. It was further assumed that 75 percent of the inhaled particulate mass is retained (respirable fraction - RF) (Hawley, 1985). An inhalation rate (IR) of 0.83 m 3/hour was assumed based on an adult average rate of 20 mVday as reported in USEPA (1989a). An exposure time (ET) of eight hours was assumed, based on the length of a typical workday. The exposure frequency (EF), exposure duration (ED), averaging time (AT), and body weight (BW) are the same as site worker ingestion exposure. For present and potential future site worker (employee) inhalation of VOCs exposure, a soil-to- air volatilization factor (VF) was calculated for the single VOC, tetrachloroethene, selected as a chemical of potential concern. The VF calculation was based on equations presented in USEPA (1991b). An inhalation rate (IR) of 0.83 mVhour was assumed based on an adult average rate of 20 m3/day as reported in USEPA (1989a). An exposure time (ET) of eight hours was assumed, based on the length of a typical workday. The exposure frequency (EF), exposure duration (ED), averaging time (AT), and body weight (BW) are the same as site worker ingestion exposure. 161 TUT 006 2347 Construction Worker; For potential future construction worker site surface soil exposure, sample data were again used to calculate chemical concentrations for use in the intake equations. For potential future construction workers, a surface soil ingestion rate (IR) of 480 mg/day was assumed based on information presented for the commercial/industrial setting (USEPA, 1991a). The fraction ingested (FI) from contaminated site surface soil was conservatively assumed to be one. An exposure frequency (EF) of 225 days/year based on eleven months of exposure/year, five days/week minus ten vacation days was assumed. Approximately one month's time was assumed to be spent on non-invasive activities such as planning, mobilization, and demobilization. A twelve month exposure duration (ED) was assumed to be the length of time a construction project would last. The averaging time (AT) was calculated by the same method described for site worker surface soil ingestion. A body weight (BW) of 70 kg was assumed (USEPA, 1991a). For potential future construction worker dermal contact exposure, a skin surface area (SA) of 6125 cm2/event was calculated from information presented in USEPA (1989b, 1992c). For males and females, the average skin surface area (S A) for the head, upper extremities, and lower legs were summed by sex, then averaged, resulting in the final value. An adherence factor (AF) of 1 mg/cm2 was obtained from USEPA (1992c). Soil dermal absorption factors (ABS) of six percent for PCBs and one percent for cadmium were obtained from USEPA (1992c). All other 162 chemicals of potential concern were qualitatively addressed in the risk assessment for dermal contact exposure since no other dermal absorption factors are currently established for USEPA Region II. The exposure frequency (EF), exposure duration (ED), averaging time (AT), and body weight (BW) are the same as ingestion exposure except for the exposure frequency unit, which for dermal contact is reported in events/year instead of days/year. For present and potential future construction worker particulate inhalation exposure, an outdoor suspended soil concentration (SSC) of 70 ug/m3 (Hawley, 1985) was assumed to occur during construction activities. Additionally, 75 percent of the inhaled particulate mass was assumed to be retained (respirable fraction-RF) (Hawley, 1985). An inhalation rate (IR) of 0.83 m3/hour was assumed as described for site worker (employee) inhalation exposure. An exposure time (ET) of eight hours/day was assumed to be the length of a normal workday. The exposure frequency (EF), exposure duration (ED), averaging time (AT), and body weight (BW) are the same as construction worker ingestion exposure. 3.5.2 Subsurface Soil Potential future subsurface soil contact parameters for residents, site workers, and construction workers in the Tillett Gardens and Art Center, Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor company, Curriculum Center Building, Esso gas station and Splash and Dash car wash, and O'Henry dry cleaners and Liquor Barn areas of concern are the same as 163 TUT 006 2349 those selected for surface soil exposures for the same receptor groups. These contact parameters are presented in Table 3-9. For all receptor groups, chemical concentrations for the intake equations were calculated based on site data. Differences between the surface soil and subsurface soil pathways, beside chemical concentrations, lie basically with the time variables, specifically the exposure frequency (EF), exposure duration (ED), and averaging time (AT). For subsurface soil, exposure is considered to be subchronic for all receptor groups, as the potential for exposure would only exist during construction (i.e., excavation) activities. The exposure duration (ED) for residents, site workers (employees), and construction workers was assumed to be one year, which corresponds to the assumed length of a construction project at the site. The exposure frequency (EF) for residents was assumed to be 91 days (or events) per year which corresponds to the assumed length of excavation activities (three months/year, seven days/week). For conservatism, no vacation away from home is assumed during the three months of excavation. The exposure frequency (EF) for site workers was assumed to be 65 days (or events) per year which also corresponds to the length of excavation activities (three months, five days/week) during the construction project. Again, no vacation time is assumed during the period of excavation. The exposure frequency (EF) for construction workers was also assumed to be 65 days (or events) per year corresponding to the length of the excavation activities (three months, five days/week) during a construction project. No vacation time is assumed during the period of excavation. 164 TUT OO6 23 5O 3.5.3 Groundwater Residents: For present and potential future residential groundwater exposure, site sample data were used to calculate chemical concentrations for use in the intake equations. Ingestion rates (IR) of two liters/day for adults and one liter/day for children living at the site at present and potentially in the future were assumed based on information presented in USEPA (1989b). The two liter/day adult ingestion rate represents an historical long-term average consumption rate and includes drinking water consumed in the form of beverages (i.e., juices containing tap water). The one liter/day child ingestion rate is assumed to be protective of the sensitive receptor, who is also expected to ingest beverages other than those containing water. An exposure frequency (EF) of 350 days/year was assumed based on the assumption that two weeks/year are spent away from home on vacation (USEPA, 1991a). The exposure duration (ED) was assumed to be 30 years for adults and six years for children (USEPA, 1989a). Thirty years corresponds to the national upper-bound (90th percentile) time spent at one residence. The averaging time (AT) was calculated in the same manner as soils where the exposure duration (30 years for adults and 6 years for children) was multiplied by 365 days/year for noncarcinogens, and 70 years (lifetime) for adults and was multiplied by 365 days/year for carcinogens. Body weights (BW) of 70 kg for adults and 15 kg for children were assumed (USEPA, 1991a). For potential future residential dermal contact with groundwater during showering, the dermal absorption of SVOCs, pesticides/PCBs, and inorganics have been evaluated. The skin surface 165 TUT 006 2351 areas available for contact was calculated from information presented in USEPA (1989a, 19895, and 1992c). Whole body exposure was assumed to occur during showering. For adult males and females, the average total body surface areas were summed, then averaged, resulting in a value of 18150 cm2. For children age 0-6 years, the average skin surface area (SA) was calculated as 75 percent of the average male and female total body surface area for 3 - 6 year olds (7195 cm 2). The 3-6 year old age group was utilized as this is the closest age group for which data are available. Based on the fact that children grow (i.e., skin surface area increases) rapidly during the early years, a skin surface area (SA) of 5400 cm2 is assumed to be a reasonable value for the 0 - 6 year old age group. Chemical-specific dermal permeability constants were obtained from USEPA (1992c). When a dermal permeability constant was not available for a specific chemical, the dermal permeability constant for water was utilized as a default value. An exposure time (ET) of 0.2 hours/day (12 minutes) was assumed to be the length of a typical shower and is the 90th percentile value specified in USEPA (1989a). An exposure frequency (EF) of 350 days/year was assumed for daily showering, taking into account two weeks/year spent away from home (USEPA, 199la). The exposure duration (ED) was assumed to be 30 years for adults and six years for children corresponding to the national upper- bound (90th percentile) time spent at the same residence (USEPA, 1989a). The averaging time (AT) was calculated in the same manner as residential groundwater ingestion. An adult body weight (BW) of 70 kg and a child body weight (BW) of 15 kg were assumed (USEPA, 1991a). For residential inhalation of VOCs during showering, the Andelman (1990) shower model was run utilizing the procedures discussed in Schaum et al. (1994). The details of the model are 166 °°6 2352 presented in Section 3.3.1. Using the two equations presented, the average concentration of a volatile chemical in the shower air over the period of time spent in the shower was calculated. This value was then used in the intake calculation. An inhalation rate (IR) of 0.6 mVhour was assumed based on information presented in USEPA (1989a). This value assumes that showering represents light activity and is representative of the entire exposed population (USEPA, 1989a, 1989b). The exposure time (ET), exposure frequency (EF), exposure duration (ED), averaging time (AT), and body weight (BW) are the same as residential dermal contact exposure. Groundwater ingestion exposure may be occurring for present site workers since evidence of pumping exists at the Ramsay well. This ingestion exposure may continue indefinitely into the future. The concentrations of chemicals in groundwater used in the intake equation were determined based on actual site data. An ingestion rate (IR) of 1 liter/day was assumed for the commercial/industrial setting (USEPA, 199la) since it is assumed that other beverages would be ingested besides water. An exposure frequency (EF) of 250 days/year (5 days/week for 12 months minus 2 weeks/year vacation) for 25 years (exposure duration (ED)) was assumed (USEPA, 199la). The averaging time (AT) was calculated in the same manner as residential groundwater ingestion. A body weight (BW) of 70 kg was assumed (USEPA, 199la). Site workers were assumed to have negligible dermal contact exposure with groundwater and were not assumed to shower on-site. Construction workers may also be exposed to groundwater via the ingestion route, if the site is further developed in the future. The same exposure parameters selected for site workers were 167 006 2353 assumed to apply to construction workers except for the time variables exposure frequency (EF), exposure duration (ED), and averaging time (AT). An exposure frequency (EF) of 225 days/year was assumed based on eleven months of exposure/year, five days/week minus ten days vacation. A twelve month exposure duration (ED) was assumed to be the length of time a construction project would last. The averaging time (AT) was calculated in the same manner as residential groundwater ingestion. Construction workers were assumed to have negligible dermal contact exposure with groundwater and were not assumed to shower on-site. 168 TUT 006 2354 4.0 TOXICITY ASSESSMENT The toxicity assessment presents the general toxicological properties of the selected chemicals of potential concern using the most current toxicological human health effects data. Toxicity profiles for each of the chemicals of potential concern are presented in Appendix B. Each chemical can produce a wide variety of human health effects. While only certain chemicals can produce potentially carcinogenic effects, all chemicals have the potential to produce noncarcinogenic effects, depending on the type and duration of exposure. The USEPA has developed a qualitative weight-of-evidence classification system in which available data for a chemical are evaluated to determine the likelihood that the agent is a human carcinogen. Evidence is characterized separately for human and animal studies as sufficient, limited, or inadequate evidence, no data, or evidence of no effect. The characterizations of these two types of data are combined and the chemical is given a provisional weight-of-evidence classification based on the extent to which the agent has been shown to be carcinogenic in experimental animals, humans, or both. Supporting evidence of carcinogenicity may adjust the provisional weight-of-evidence classification up or down. The USEPA weight-of-evidence classification system for carcinogenicity, as discussed in Section 2.3, is described again below for the purposes of clarity. GROUP DESCRIPTION A Human Carcinogen. Bl Probable Human Carcinogen. Limited human data are available. B2 Probable Human Carcinogen. Sufficient evidence of carcinogenicity in animals and inadequate or no evidence in 169 TUT 006 2355 humans. C Possible Human Carcinogen. D Not Classifiable as to human carcinogenicity. E Evidence of noncarcinogenicity for humans. Two measurements used to quantify the toxic effects of a chemical on human health include a chemical's carcinogenic slope factor (SF) and noncarcinogenic reference dose (RfD). Many of the carcinogenic slope factors and reference doses (including reference concentrations which are often converted to references doses) used in this assessment were obtained from USEPA's IRIS data base. IRIS is an on-line data base which is updated monthly. It provides chemical-specific risk data that represent a USEPA scientific consensus. The quantitative risk values and supporting explanations in IRIS have been reviewed and agreed upon by scientists across the USEPA using available studies on a chemical. Slope factors and reference doses/concentrations not available on IRIS were obtained from the USEPA's second most current source of toxicity information, the Health Effects Assessment Summary Tables (HEAST) FY 1994-Annual (USEPA, 1994). Per HEAST direction, toxicity information for certain chemicals was obtained from the Superfund Health Risk Technical Support Center (See Tables 4-1 and 4-2). 4.1 Health Effects Criteria for Carcinogens Generally, a slope factor is a plausible upper-bound estimate of the probability of a response per unit intake of a chemical over a lifetime. In risk assessment, a slope factor is used to estimate an upper-bound probability of an individual developing cancer as a result of a lifetime of exposure to a particular level of a potential carcinogen. Slope factors are calculated by the USEPA's Carcinogen Assessment Group (CAG) and are verified by the USEPA's Carcinogen 170 1 UT O06 23fi6 12W94 TOXNOS.XLS |>BLE 4-1 TUTU WELLS SITE TOXICITY VALUES FOR POTENTIAL CARCINOGENIC HEALTH EFFECTS DOSE - RESPONSE RELATIONSHIP (1) C H K) V-cri CHEMICALS Volttllf Organic* Acetone Benzene Bromodtehloromeihane Brornoforrn Bromomethane 2-Butanone Carbon DisulMe Chlorobenzene Chloroform Chloromelhane Dibromochloromethane 1,1-Dichloroethane, 1,2-Dlchloroethane 1,1-Dtchtoroelhene els 1 ,2-Dfchtoroethene 1 ,2-Dichloroelhene (Total) Ethylbenzene 2-Hexanone MethyMert-Butyl-Elher 4-Melhyl-2-Penlanonfl Merhytene Chloride n-Propylbenzene Tetrachloroethene Toluene 1 ,1 ,1-Trichloroethane 1 , t ,2-Trichloroethane Trichloroethene Vinyl Chloride Xytenes (Total) $»mlvolatll» Organic* Acenaphlhene Acenaphthylene Anthracene Benzole Acid Benzo(a)anttiracene Benzo(a)pyrene Benzo(b)fluoranthene Benzo(g,h,i)perylene • Benzo(k)fluoranthene Bis(2-chloroethyl)ether Bls(2-9thylhexyl)phltialale Butylbenzylphthalate CARCINOGENS: SLOPE FACTORS (SF) Oral SF (mgfeg-day)-l - 2.9E-02 62E-02 7.9E-03 - - - - 6.1E-03 1.3E-02(2) 8.4E-02 - 9.1E-02 6.0E-01 - - • • - - 7.5E-03 - 52E-02(3) - - 5.7E-02 1. IE-02 (3) 1.9E+00(2) • - - - • 7.3E-01* 7.3E+00 7.3E-01' - 7.3E-02* 1.1E+00 1.4E-02 - Inhalation SF (mg/kg-day)-1 . 2.9E-02 - 3.9E-03 - - - - 8. IE-02 6.3E-03 (2) - - 9.1E-02 1.8E-01 - - - - - • 1.6E-03 - 2.0E-03 (3) - - 5.6E-02 6.0E-03 (3) 3.0E-01 (2) - - - - - - - - - - 1.1E+00 - • Weighl-of- Evidence D A B2 B2 D D - D B2 C C C B2 C 0 - - - - - B2 - C-B2 D D C B2 A D - D D D B2 B2 B2 D B2 B2 B2 C TOXNOS.XLS JBLE 4-1 TUTU WELLS SITE TOXICITY VALUES FOR POTENTIAL CARCINOGENIC HEALTH EFFECTS DOSE - RESPONSE RELATIONSHIP (1) N) ~i Oa- f'-Jw CHEMICALS Simlvolattl* Orgtnlct (Cont'd) Carbazoto Chrysene Di-n-butylphlhalale Di-n-oclylphlhalale Oibenzofuran 1 ,2-Dichlorobenzene 1.4-Dichlorobenzene Diethylphthalate 2,4-Dimethylphenol Dimethylphthalale Fluoranthene Fiuorene lndeno(1 ,2,3-cd)pyrene 2-Methyinaphthalene 2-Melhylphenol 4-Melhylphenol Naphthalene 2-Nitrophenol Phenanthrene Phenol Phthalic Anhydride (TIC) Pyrene 1 ,2,4-Trichk>robenzene Chtordane EndosuHan (4) PCBs(Aroclors) Inorganlet Aluminum Antimony Arsenic Barium Beryllium Cadmium Chromium III Chromium VI Cobalt Copper" Cyanide Lead (and compounds-inorg.) Manganese (water) CARCINOGENS: SLOPE FACTORS (SF) Oral SF (mgftg-dayM 2.0E-02 (2) 7.3E-03' • - - - 2.4E-02 (2) - - • -. 7.3E-01' - - - - • -. - - - 1.3E400 - 7.7E4OO - - 1.75E+00 - 4.3E+00 - - - - - - - - Inhalation SF (mg/kg-dayM - - - - - - - - - - - - - - - - - • -. - - - 1.3E+00 - - - - 1.5E+01 - 8.4E+00 6.3E+00 • 4.2E+01 - - - . - Weight-of- Evidence B2 B2 0 - D D 82 D - D D D B2 - C C 0 - D D - D D B2 - B2 - - A - B2 B1 - A - D D B2 D 00 12/8/94 TOXNOS.XLS LE4-1 TUTU WELLS SITE TOXICITY VALUES FOR POTENTIAL CARCINOGENIC HEALTH EFFECTS DOSE - RESPONSE RELATIONSHIP (1) CHEMICALS Inorganic! (Confd) Mercury Nickel (sol. salt) Selenium Silver Thallium (chloride) Vanadium Zinc (and compounds) CARCINOGENS: SLOPE FACTORS (SF) Oral SF Inhalation SF (mg/kg-day)-1 (mg/kg-day)-1 . - - - - - - Weight-of- Evidence 0 - 0 D D - D NOTES: - Calcium, iron, magnesium, potassium, and sodum are considered essential nutrients and win not be quantitatively evaluated in the risk assessment. •Relative Potency Values were used in conjunction with slope factors per USEPA Provisional Guidance for Quantitative Risk Assessment of Potycydic Aromatic Hydrocarbons (July 1993). "The current drinking water standard for copper is 1.3 mg/l. The DWCO (1987) concluded that toxicity data are inadequate for calculation of a reference dose for this chemical. (1) All toxicity values obtained from IRIS (on-line June 22 and 30,1994, July 1,1994, August 4,1994, and December 6,1994) unless otherwise noted. (2) Toxidly values obtained from HEAST Annual FY-1994. (3) Toxldty values were originally obtained from the Superfund Health Risk Technical Support Center, September 27,1993. These values were confirmed by the USEPA Risk Assessment Specialist. (4) The endosulfan toxicily values are reported, as none are available for the endosulfan I isomer. C USEPA WEIGHT - OF - EVIDENCE: A • Human Carcinogen. B1 - Probable Human Carcinogen. Limited human data are available. B2 • Probable Human Carcinogen. Sufficient evidence of carcinogenicity in animals and inadequate or no evidence in humans. C - Possible Human Carcinogen. D - Not Classifiable as to human carcinogenicity. E - Evidence of noncardnogenicity for humans. TOXNOS-2.xls | TABLE 4-2 TUTU WELLS SITE CHRONIC TOXICITY VALUES FOR POTENTIAL NONCARCINOGENIC HEALTH EFFECTS DOSE - RESPONSE RELATIONSHIP (1) •H K) CHEMICALS Volatllf Organic* Acetone Benzene Bromodichloromethane Brornoforrn Bromomelhane 2-Bulanone Carbon Dteulflde Chlorobenzene Chloroform Chloromelhane Dibromochloromethane 1,1-Dichloroelhane 1,2-Dichloroelhane 1,1-DJchloroeSiene cas 1,2-Dichloroethene 1,2-Dichlofoetnene (Total) Ethylbenzene 2-Hexanone Melhyt-tert-Butyl-Ether 4-Methyl-2-Pentanone Methytene Chloride n-Propybenzene Tetrachkxoethene Toluene 1,1,1-Trichloroelhane 1.1,2-Trfchtoroelhane Trichloroeirtene Vinyl Chloride Xytenes (Total) Stmlvolatllt Organic* Acenaphthene Acenaphthytene Anthracene Benzoic Acid Benzo(a)anthracene Benzo(a)pyrene Benzo(b)(luoranlhene Benzo(g,h,i)perylene Benzo(k)fluoran!hene Bis(2-chloroelhyl)elher Bis(2-ethylhexyl)phthalate , Butylbenzylphthalate Carbazole NONCARCINOGENS: REFERENCE DOSES (RfD) OralRfD (mg/kg-day) 1.0E-01 - 2.0E-02 2.0E-02 1.4E-03 6.0E-01 1.0E-01 2.0E-02 1.0E-02 - 2.0E-02 1.0E-01(2) - 9.0E-03 1.0E-Q2(2) 9.0E-03 (2) 1.0E-01 - - 8.0E-02 (2) 6.0E-02 ' 1.0E-02 2.0E-01 - 4.0E-03 6.0E-03 (4) . 2.0E+00 6.0E-02 - 3.0E-01 4.0E+00 - - - - - - 2.0E-02 2.0E-01 - Uncertainly Factor 1000 - 1000 1000 1000 3000 100 1000 1000 - 1000 1000 - 1000 3000 1000 1000 - - 3000 100 - 1000 1000 - 1000 3000 - 100 3000 - 3000 1 - - - • - - 1000 1000 - Inhalation RfD (mg/kg-day) - - - - 1.4E-03 2.9E-01 2.9E-03 (2) 5.7E-03 (3) - - - 1.4E-01(3) - - - - 2.9E-01 - 9.0E-01 2.3E-02 (3) 8.6E-01 (2) - - 1. IE-01 - - - - - - - - - - - - - - • - - - Uncertainty Factor - -.. 100 1000 1000 10000 - - - 1000 - - - - 300 - 100 1000 100 - - 300 - - - - - - - - - - - - - - - - - - 12WB4 TOXNOS-2.xl» TABLE 4-2 TUTU WELLS SITE CHRONIC TOXICITY VALUES FOR POTENTIAL NONCARCINOGENIC HEALTH EFFECTS DOSE - RESPONSE RELATIONSHIP (1) Q &" CHEMICALS S»ml mlmttt» Organic* (Cont'd) Chrysene Di-n-tMJtylphlhalale Di-n-octylphtoalate Dtbenzoftiran 1,2-Dichlorobenzene 1 ,4-Dichlorobenzene Oiethylphlhalate 2,4-Dimethylphenol Oimothylphlhalate Fluor anlhene Fluorene lndeno(1 ,2,3-cd)pyrene 2-Methylnaphthalene 2-Methylphenol 4-Melhylphenol 2-Nitrophenol Naphthalene Phenanlhrene Phenol Phlhalte Anhydride (TIC) Pyrene 1 ,2,4-Trtehtof obenzene Pt*Ucld»*ff>CBt Chtordane EndosuHan PCBs(Arockxs) Inorganic* Aluminum Antimony Arsenic Barium Beryllum Cadmium (food) Cadmium (water) Chromium III Chromium VI Cobalt Copper* Cyanide Lead (and compounds-inorg.) NONCARCINOGENS: REFERENCE DOSES (RfO) Oral RIO (mgfeg-day) - 1 OE-01 2.0E-02 (2) - 9.0E-02 - 8.0E-01 2.0E-02 1.0E+01 (2) 4.0E-02 40E-02 - - 5.0E-02 (4) 5.0E-03 (2) - 4.0E-02 (4) - 6.0E-01 2.0E+00 3.0E-02 1.0E-02 6.0E-05 6E-03(2) - - 4.0E-04 3.0E-04 7.0E-02 5.0E-03 1.0E-03 5.0E-04 1.0E+00 5.0E-03 - - 2.0E-02 - Uncertainty Factor - 1000 1000 - 1000 - 1000 3000 100 3000 3000 - - 1000 1000 - 1000 - . 100 1000 3000 1000 1000 100 - - 1000 3 3 100 10 10 100 500 - - 100 - Inhalation RIO (mgflcg-day) - - - - 5.7E-02 (3) 2.3E-01 - - - - - - - - - - - - 3.4E-02 (2) - 5.7E-02 (2) - - - -' - - 1.4E-04(3) - - - - - - - - - Uncertainty Factor -... 1000 100. -.. - - - - - - - -. 300 - 1000 . - - . - - 1000 - - - - - - - • - Kj Ch 12/9/94 TOXNOS-Z.xb TABLE 4-2 TUTU WELLS SITE CHRONIC TOXICITY VALUES FOR POTENTIAL NONCARCINOGENIC HEALTH EFFECTS DOSE - RESPONSE RELATIONSHIP (1) CHEMICALS Inorganic* Manganese (water) Mercury Nickel (sol. salt) Selenium Silver Thallium (chloride) Vanadium Zinc (and compounds) Oral RID (mg/kg-day) 50E-03 3.0E-04 (2) 2.0E-02 5.0E-03 5.0E-03 8.0E-05 7.0E-03 (2) 3.0E-01 NONCARCINOGENS: REFERENCE DOSES (RfD) Uncertainty Inhalation RID Factor (mg/kg-day) 1 1.4E-OS 1000 8.6E-05(2) 300 3 3 3000 100 3 Uncertainty Factor 1000 30 - -. - - - -J ON NOTES: - Calcium, Iron, magnesium, potassium, and sodium are considered essential nutrients and wM not be quantitatively evaluated in the risk assessment. 'The current drinking water standard for copper is 1.3 mg/l. The DWCD (1987) concluded that loxiciry data are inadequate lor calculation of a reference dose for this chemical. (1) All toxiclty values obtained from IRIS (on-line June 22 and 30,1994, July 1,1994, August 4,1994, and December 6,1994) unless otherwise noted. (2) Toxicity values obtained from HEAST Annual FY-1994. (3) Toxicity values obtained from HEAST Annual FY-1994: Toxicity values are found in USEPA documents but were calculated by alternative methods not currently practiced by the RfD Work Group. (4) Toxicity values were originally obtained from the Superfund Health Risk Technical Support Center, September 27,1993. These values were confirmed by the USEPA Risk Assessment Specialist. (5) The endosulfan toxteily values are reported, as none are available for the endosulfan I isomer. USEPA WEIGHT - OF - EVIDENCE: A - Human Carcinogen B1 • Probable Human Carcinogen. Limited human data are available. B2 - Probable Human Carcinogen. Sufficient evidence of carcinogenicity in animals and inadequate or no evidence in humans. C • Possible Human Carcinogen D - Not Classifiable as to human carcinogenicity. E - Evidence of noncarcinogenicNy for humans. H 1— w Risk Assessment Verification Endeavor (CRAVE) Workgroup. Slope factors for the potential carcinogenic chemicals of concern are presented in Table 4-1. Oral and inhalation unit risk estimates were converted to slope factors, per HEAST and USEPA Region II guidance, by multiplying by 70 kg (assumed human body weight), dividing by 20 mVday (assumed human inhalation rate) or by 2 liters/day (assumed human water consumption rate) and multiplying by 1000 ug/mg (conversion factor). The slope factor, which is usually the upper 95th percent confidence limit of the slope of the dose-response curve, is expressed in (mg/kg/day)"1. It represents the probability of an individual developing cancer as a result of chronic exposure to a given carcinogenic chemical over a lifetime of 70 years. A risk of 10"6 indicates that the probability of an individual developing cancer from a given exposure is unlikely to exceed one in one million (106). In several instances, when slope factors were not available for specific chemicals, the slope factor for one isomer or chemical within a chemical class was used to represent the slope factor for all other isomers or chemicals in the same class (i.e., PAHs and PCBs). For several carcinogenic PAHs, the benzo(a)pyrene slope factor was used in conjunction with relative potency values to develop slope factors for benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, and indeno(l,2,3-cd)pyrene, in accordance with provisional CERCLA USEPA Region II guidance. Although it is known that PCB congeners vary greatly as to their potency in producing biological effects, the USEPA has not developed slope factors for most of the PCB congeners. For the 177 TUT 006 2363 purposes of this risk assessment, the oral slope factor for Aroclor 1260 was used to represent the oral toxicity of Aroclor 1242, the only PCB detected at the site. Since benzo(a)pyrene and Aroclor 1260 are more toxic than some of the other PAH and PCB congeners, these procedures may overestimate the risks and hazards generated as part of this assessment and are, therefore, a source of uncertainty in this risk assessment. 4.2 Health Effects Criteria for Noncarcinogens The determination of the potential health hazards associated with exposure to noncarcinogens was made by comparing the estimated chronic or subchronic daily intake of a chemical with the reference dose. Various reference doses are available depending on the exposure route, the critical effect, and the length of exposure evaluated in the scenario. For this assessment, both chronic and subchronic oral and inhalation reference doses (RfDs) were used. It should be noted that inhalation RfDs were developed by converting a concentration in air (mg/m3) to a corresponding inhaled dose (mg/kg-day) by dividing by 70 kg (assumed human body weight) and multiplying by 20 mVday (assumed human inhalation rate) per HEAST and USEPA Region II direction. Tables 4-2 and 4-3 present these values along with their uncertainty factors. It should be noted for the chemicals benzene, vinyl chloride, bis(2-ethylhexyl)phthalate, and hexavalent chromium that the Superfund Health Risk Technical Support Center was contacted directly per HEAST direction on August 5, 1994 for subchronic toxicity values. These values are reported in Table 4-3. 178 TUT 006 TOXNOSSUB.XLS ABLE 4-3 TUTU WELLS SITE SUBCHRONIC TOXICITY VALUES FOR POTENTIAL NONCARCINOGENIC HEALTH EFFECTS DOSE • RESPONSE RELATIONSHIP (1) CHEMICALS Volatile Organic* Benzene 1,2-Dichloroethene (Total) Tetrachkxoethene Toluene Vinyl Chloride Simivolatil* Organic* Benzo(a)pyrene P»ttlcid«sfi>CBs PCBs (Aroclors) Inorganic » Antimony Arsenic Beryllium Chromium VI (insol. salt) Manganese (water) racket (sol. salt) Vanadium NONCARCINOGENS: SUBCHRONIC REFERENCE DOSES (RfD) Oral RfD (mg/kg-day) - 9.0E-03 1.0E-01 2.0E+00 -(2) - - 4.0E-04 3.0E-04 5.0E-03 2.0E-02 5.0E-03 2.0E-02 7.0E-03 Uncertainty Factor • 1000 100 100 • - - 1000 3 100 100 1 300 100 Inhalation RfO (mg/kg-day) 1 .7E-02 (2) - - 2.9E-01 (2) -(2) - - - - - 1. IE-06 (2) 1.1E-04 - - Uncertainty Factor 100 - - 300 - - - -. - 100 900 - - NOTES: - Calcium, iron, magnesium, potassium, and sodium are considered essential nutrients and are not quantitatively evaluated in the risk assessment. (1) Toxicity values were obtained from HEAST Annual FY-1994. (2) Toxicity values were obtained from the Superfund Health Risk Technical Support Center - June 9,1994 and August 9,1994. USEPA WEIGHT - OF • EVIDENCE: A - Human Carcinogen B1 - Probable Human Carcinogen. Limited human data are available. B2 - Probable Human Carcinogen. Sufficient evidence of carcinogenicity in animals and inadequate or no evidence in humans. C • Possible Human Carcinogen ' D - Not Classifiable as to human carcinogenicity. E - Evidence of noncarcinogenicity for humans. H CTH A chronic reference dose is defined as an estimate (with uncertainty spanning possibly an order of magnitude or greater) of a daily exposure level for the human population, including sensitive subpopulations, that is likely to be without an appreciable risk of deleterious effects during a lifetime. The chronic reference doses derived by the USEPA's Reference Dose Workgroup are specifically developed to be protective for long-term exposure to a chemical. In general, chronic reference doses are used to evaluate the potential noncarcinogenic effects associated with exposure periods between seven years (approximately ten percent of a human lifetime) and a lifetime. Subchronic reference doses, which are useful in characterizing potential noncarcinogenic effects associated with shorter-term exposures, may generally be used to evaluate the potential noncarcinogenic effects of exposure periods between two weeks and approximately seven years. In this risk assessment, exposures of six years and greater were considered chronic while exposures of less than six years were considered subchronic. Per USEPA direction, a six year exposure is at the upper-bounds of subchronic exposure and therefore chronic toxicity values are more appropriately used. For many noncarcinogenic effects, it is believed that protective mechanisms exist which must be overcome before an adverse effect is manifested. For example, when a large number of cells perform the same or similar function, a significant number of the cells may have to be depleted before an effect is seen. Therefore, there is a range of exposures between zero and some finite value that can be tolerated by the organism with essentially no chance of expression of adverse effects. 180 TUT O06 2366 Oral and inhalation chronic reference doses are derived from the no-observed-adverse-effect-level (NOAEL) or the lowest-observed-adverse-effect-level (LOAEL) for the critical toxic effect by application of uncertainty factors (UFs) and a modifying factor (MF-oral only). Subchronic reference doses are derived from subchronic NOAELs by application of UFs and MFs as done for chronic reference doses. The distinction between the two RfDs lies with exposure duration which is shorter for subchronic studies. Uncertainty related to toxicity information will be discussed in Section 6.0 Uncertainties in Risk Assessment. 4.2.1 Toxicity Endpoints/Target Organs for Noncarcinogenic Chemicals of Potential Concern Quantitatively Evaluated in the Risk Assessment Table 4-4 presents the available toxicity endpoints (i.e., target organs) for the noncarcinogenic chemicals of potential concern which have been quantitatively evaluated in this risk assessment, and show hazard quotients above 1. Per the RAGS (USEPA, 1989a) guidance, in the calculation of the hazard index (see Section 5.2 for a detailed discussion of hazard index), limitations exist which include the following: 1) the level of concern does not increase linearly as the reference dose is approached or exceeded since reference doses do not have equal accuracy or precision and are not based on the same severity of effect; 2) hazard quotients are often combined for substances with reference doses based on critical effects of varying lexicological significance; 3) reference doses of varying levels of confidence that include different uncertainty adjustments 181 TUT 006 2367 .am TOXENDPT.XLS TUTU WELLS SITE TOXICITY ENDPOINTS/TARGET ORGANS FOR NONCARCINOGENIC CHEMICALS OF POTENTIAL CONCERN QUANTITATIVELY EVALUATED IN THE RISK ASSESSMENT CHEMICALS TOXICITY ENDPOINT/TARGET ORGAN* oo to 1 ,2-Dichloroethene (Total) Liver Tetrachloroethene Liver Antimony Blood Manganese Central Nervous System Vanadium Respiratory Tract MATRIX Surface Soil: (THIett Gardens and Art Center) Groundwatar: (Site-Wide) EXPOSURE ROUTE Ingest ion Inhalation of Particulates Ingestton Ingestton Ingestton Ingestton RECEPTOR HAZARD INDEX Residents: Children 3.0 Children 3.1 Residents: Adults 29 Children 67 Site Workers 10 Construction Workers 9.1 HAZARD INDEX BY TOXICITY ENDPOINT/TARGET ORGAN Manganese - 2.2 Manganese - 3.1 1.2-Dtehloroethene (Total) - 1.2 Manganese - 26 1,2-Dfchloroethene (Total) - 2.8 Tetrachloroethene - 1.3 Antimony -1.6 Manganese - 60 Vanadium -1.0 Manganese - 9.2 Manganese - 8.2 oo 'Sources: Integrated Risk Information System (IRIS) on-line June-August 1994, HEAST FY1994 - Annual, and Klaassen et al, (1986). and modifying factors (i.e., extrapolation from animals to humans, from LOAELS to NOAELS, and from one exposure duration to another) and, 4) application of the hazard index equation to chemicals not expected to induce the same type of effects or that do not act by the same mechanism may overestimate the potential for adverse health effects. If the hazard index is greater than one due to the summing of several hazard quotients of similar value, segregation of the hazard index by critical effect and mechanism of action is performed. Upon review of the hazard indices calculated in this risk assessment in Section 5.0 and presented in Appendix C, it was observed that six hazard index values exceeded one including surface soil ingestion and inhalation by children in the Tillett Gardens and Art Center, and groundwater ingestion by residents (adults and children), site workers (employees), and construction workers. Table 4-4 also presents the breakout of the hazard indices exceeding one by chemical. It should be noted that two chemicals in Table 4-4 have the same toxicity endpoint/target organ (liver), 1,2-dichloroethene (total) and tetrachloroethene. For surface soil ingestion by children in the Tillett Gardens and Art Center, the hazard index of 3.0 is due mainly to manganese with a smaller contribution from arsenic. While the manganese hazard quotient exceeds one (2.2), the arsenic hazard quotient (0.43) does not. The toxicity endpoint for manganese, as shown on Table 4-4, is the central nervous system while the toxicity endpoint for arsenic is the skin.. For surface soil inhalation by children in the Tillett Gardens and Art Center, the hazard index of 3.1 is due entirely to manganese. 183 OO6 •?••!•69 For groundwater ingestion by adults, the hazard index of 29 is due mainly to 1,2-dichloroethene (total) and manganese which have individual hazard quotients above one. Although the hazard quotient for 1,2-dichloroethene (total) only slightly exceeds one (1.2), the manganese hazard quotient of 26 is well above the target value. As shown in the table, 1,2-dichloroethene (total) and manganese have different toxicity endpoints. For groundwater ingestion by children, the hazard index of 67 is due in large part to 1,2-dichloroethene (total), tetrachloroethene, antimony, and manganese which have individual hazard quotients above one. Vanadium has an individual hazard quotient of one. As shown in the table, two of the five chemicals have the same toxicity endpoint (liver). For groundwater ingestion by site workers, the hazard index of 10 is due in large part to manganese with a smaller contribution from 1,2-dichloroethene (total). While the manganese hazard quotient exceeds one (9.2), the 1,2-dichloroethene (total) hazard quotient (0.42) does not. Table 4-4 shows that these two chemicals have different toxicity endpoints. For groundwater ingestion by construction workers, the hazard index of 9.1 is due mainly to manganese with a smaller contribution from 1,2-dichloroethene (total). While the manganese hazard quotient exceeds one (8.2), the 1,2-dichloroethene (total) hazard quotient (0.38) does not. As presented in the table, these two chemicals have different toxicity endpoints. 184 TUT 006 2370 4.3 Qualitative Discussion of Chemicals Not Quantitatively Evaluated in the Risk Assessment Numerous VOCs, SVOCs, and inorganics could not be quantitatively evaluated in this risk assessment due to the lack of established toxicity values. This section presents brief lexicological profiles for these chemicals. benzo(g. h .i)perylene - This chemical is a PAH and is currently classified in Group D - Not Classifiable as to human carcinogenicity (USEPA, 1992b). PAHs are a ubiquitous class of chemicals formed during the combustion of fossil fuels (Klaassen et al., 1986). Little information is available regarding nonmalignant changes due to PAH exposure although liver and kidney effects may occur (Clement Associates, Inc., 1985). 2-hexanone - This chemical is an industrial solvent which causes neurotoxicity in chronically exposed workers. 2-Hexanone may also be involved in the potentiation of hepatotoxicity. (Klaassen et al., 1986). dibenzofuran - Dibenzofurans may cause adverse health effects in man due to their high toxicity (Klaassen et al., 1986). This chemical has been given a Group D weight-of-evidence classification (IRIS, 1994). 185 TUT 006 2371 2-nitrophenoI - Little specific toxicity information for this chemical has been located in the literature. Nitrophenol may cause liver and kidney damage in experimental animals (Clement Associates, Inc., 1985). 1.1.1 -trichloroethane - This chemical may induce liver tumors in female mice and may be mutagenic. Inhalation of high concentrations of 1,1,1-trichloroethane by animals and humans may depress the central nervous system, affect the, cardiovascular system, and damage the lungs, liver and kidneys. Human exposure may also result in irritation of the skin and mucous membranes. (Clement Associates, Inc., 1985). This chemical has been given a Group D weight-of-evidence classification (IRIS, 1994). n-propylbenzene - This chemical, also known as 1-phenylpropane, is used for dyeing and printing textiles (Merck Index, 1989). The primary effects resulting from exposure to alkylbenzenes include narcosis, central nervous system anomalies, and irritation, especially of the mucous membranes (Clement Associates, Inc., 1985). total petroleum hydrocarbons (TPHs) - TPHs are components of gasoline. Human exposure to TPHs may result in a variety of health effects ranging from membrane irritation and vomiting to death. A full lexicological profile for TPHs is presented in Appendix B Toxicological Profiles. 186 TUT 006 237; methyl-tertiary-butyl-ether - Methyl-tertiary-butyl-ether may be mixed into gasoline to reduce air pollution. Human exposure to methyl-tertiary-butyl-ether may result in a variety of health effects including headaches, nausea, dizziness, and nose and throat irritation (ATSDR, 1994). A full lexicological profile for this chemical is presented in Appendix B Toxicological Profiles. 2-methylnaphthalene - This chemical is a PAH which has not currently been given a weight-of- evidence classification. No specific toxicity information for this chemical has been located in the literature. acenaphthylene - This chemical is a PAH and is currently classified in Group D - Not Classifiable as to human carcinogenicity (IRIS, 1994). Little specific toxicity information for this chemical has been located in the literature, although it is thought to be a skin irritant (Clement Associates, Inc., 1985). phenanthrene - This PAH has been given a Group D weight-of-evidence classification (IRIS, 1994). Although limited information is available regarding nonmalignant changes due to PAH exposure, generally, liver and kidney effects may occur (Clement Associates, Inc., 1985). aluminum - This chemical is ubiquitous in the environment. It may affect the absorption of other elements in the gastrointestinal tract and may alter intestinal function. There has been increasing interest in the possible relationship of aluminum to dementia in humans. (Wills and Savory, 1983 and Klaassen et al., 1986). 187 TUT 006 2373 cobalt - This chemical is a component of vitamin B12 required for the production of red blood cells and prevention of pernicious anemia. Ingestion of excessive amounts of cobalt in humans may cause polycythemia. High levels of chronic oral administration may result in goiter. Occupational inhalation of cobalt salts may result in respiratory symptoms (Klaassen et al., 1986). copper - This chemical is an essential element widely distributed in nature. Acute poisoning from ingestion of excessive amounts of oral copper salts may produce death. Symptoms include vomiting, hematemesis, hypotension, melena, coma, and jaundice. (Klaassen etal., 1986). This chemical has been given a Group D weight-of-evidence classification (IRIS, 1994). A full lexicological profile for this chemical is located in Appendix B Toxicological Profiles. iron - This chemical is an essential element (Klaassen et al., 1986). The ingestion of excessive amounts of this chemical can irritate the gastrointestinal tract. Inhaling some iron containing dusts and fumes can cause siderosis, a type of benign pneumoconiosis (Clement Associates, Inc., 1985). lead - A full lexicological profile for this chemical is located in Appendix B Toxicological Profiles due to the extensive amount of information available and its Group B2 weight-of- evidence classification. 188 TUT O06 2374 The inability to quantitatively evaluate these chemicals (and other essential nutrients) is a source of uncertainty in this risk assessment as the potential of underestimation of risks or health impacts exists. Uncertainty related to chemical toxicity data is addressed further in Section 6.0 Uncertainties in Risk Assessment. 189 TUT O06 2375 5.0 RISK CHARACTERIZATION The characterization of potential carcinogenic risks and noncarcinogenic health effects estimates associated with the "no action" alternative are presented for the exposure pathways identified in Section 3.2. The spreadsheet calculations which present quantitative estimates of carcinogenic risks and noncarcinogenic health effects are presented in Appendix C. Applicable or Relevant and Appropriate Requirements (ARARs) are discussed for those chemicals contributing the greatest amount to carcinogenic risks and noncarcinogenic hazard indices in groundwater. 5.1 Carcinogenic Risk Characterization For carcinogens, risks are estimated as the incremental probability of an individual developing cancer over a lifetime as a result of exposure to a potential carcinogen (i.e., incremental or excess individual lifetime cancer risk). Per RAGS (USEPA, 1989a), the slope factor converts estimated daily intakes averaged over a lifetime of exposure directly to incremental risk of an individual developing cancer. Since the slope factor is often an upper 95th percentile confidence limit of the probability of response based on experimental animal data used in the multistage model, the carcinogenic risk estimate will generally be an upper-bound estimate. This means that the USEPA is reasonably confident that the "true risk" will not exceed the risk estimate derived through use of this model and is likely to be less than that predicted. Since relatively low intakes (in comparison to those experienced 190 TUT 006 2376 by test animals) are most likely from environmental exposures at Superfund sites, the USEPA assumes that the dose-response relationship is linear in the low dose portion of the multistage model dose-response curve. Under this assumption, the slope factor is constant and risk will be directly related to intake. Therefore, the linear form of the carcinogenic risk equation, as presented below, was used to estimate risk. Risk = GDI x SF Where: Risk = a unitless probability of an individual developing cancer; GDI = chronic daily intake averaged over 70 years (mg/kg-day); SF = slope factor expressed in (mg/kg-day)'1 5.2 Noncarcinogenic Effects Characterization The potential for noncarcinogenic effects is evaluated by comparing an exposure level over a specified time period with a reference dose derived for a similar exposure period. This ratio of exposure to toxicity is referred to as a hazard quotient; the sum of the individual hazard quotients is referred to as a hazard index. The formula for the hazard index is presented below. Noncancer Hazard Index = B^Rfl^ + E2/RfD2 = E/RfDj Where: Ej = Exposure Intake (chronic or subchronic) for the i* chemical RfD = Reference Dose (chronic or subchronic) for the i* chemical 191 TUT QO6 2377 The noncancer hazard quotient assumes that there is a level of exposure (i.e., RfD) below which it is unlikely even for sensitive populations to experience adverse health effects. If the exposure intake exceeds the threshold (i.e., the noncancer hazard quotient exceeds one), there may be concern for potential noncancer effects. Generally, the greater the value of the noncancer hazard quotient above one, the greater the level of concern. However, the ratio should not be interpreted as a statistical probability. It is important to note that the level of concern does not increase linearly as the RfD is approached or exceeded, as RfDs do not have equal accuracy or precision and are not based on the same severity of toxic effects. If the hazard index exceeds one due to the summing of several hazard quotients, segregation of the hazard index by critical effect or mechanism is performed. 5.3 Quantitative Results of Carcinogenic Risk and Noncarcinogenic Effects Evaluation In accordance with the National Oil and Hazardous Substance Pollution Contingency Plan (NCP) Section 300.430 (e)(2) for known or suspected carcinogens, acceptable exposure levels are generally concentration levels that represent an excess upper-bound lifetime cancer risk to an individual in the range of 10"4 to lO"6. Per RAGS Part B: Development of Risk-Based Preliminary Remediation Goals (USEPA, 1991b), for noncarcinogenic effects, the NCP does not specify a range, but it is generally appropriate to assume a hazard index equal to one. In general, the USEPA recommends a target range and a target level (i.e., carcinogenic risk = 10" 4 to 10"6 or noncarcinogenic hazard index = 1) as threshold values for potential human health impacts (USEPA, 1989a). The 10"4 to 10"6 target risk range may be interpreted as meaning 192 TUT 2378 carcinogenic risks should not be greater than approximately 1 in 10,000 to 1 in 1,000,000. For this site, the upper-bound of the target risk range, as discussed with the USEPA, is l.OE-04. A risk greater than 1 in 10,000 or l.OE-04 is considered to be in exceedance of the USEPA's 10~* to 10"6 target risk range. These values aid in determining the objectives of the baseline human health risk assessment which include determining whether additional response action is necessary at the site, by providing a basis for determining residual chemical levels that are adequately protective of human health, by providing a basis for comparing potential health impacts of various remedial alternatives, and to help support selection of the "no action" remedial alternative, where appropriate. Tables C-l through C-36 in Appendix C present the results of carcinogenic risk and noncarcinogenic health effects calculations for the environmental matrices and human receptors quantitatively evaluated in this risk assessment. 5.3.1 Surface Soil The results of carcinogenic risk and noncarcinogenic hazard index calculations for present and potential future resident (adult and child) and site worker exposures and potential future construction worker exposure to surface soil for the Tillett Gardens and Art Center, Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co., Curriculum Center Building, and O'Henry dry cleaners and Liquor Barn areas of concern are presented in Tables C-l through C-18. Surface soil exposure at the Esso gas station and Splash and Dash car wash area was not evaluated since the properties are completely paved (i.e., no exposure is occurring). 193 TUT OO6 2379 Residents (Tillett Gardens and Art Center); The results of carcinogenic risk and noncarcinogenic hazard index calculations for present and/or potential future residents in the Tillett Gardens and Art Center area are presented in Tables C-l through C-3. Table C-l, present and potential future residential surface soil ingestion in the Tillett Gardens and Art Center area, shows total carcinogenic risks for adults and children of 4.4E-04 and l.OE- 03, respectively. Both risks exceed the upper-bound of the USEPA's 104 to 10"6 target risk range. Aroclor 1242, which shows risks of 4.3-04 for adults and l.OE-03 for children, is responsible for nearly the entire risk in adults and the entire risk in children. The 30-year combined risk for adults and children, 1.5E-03, also exceeds the upper-bound of the USEPA's target risk range for the site and is due almost entirely to Aroclor 1242. The hazard index values for present and potential future adult and child surface soil ingestion in the Tillett Gardens and Art Center area are 3.2E-01 and 3.0E+00, respectively. The hazard index value for children only exceeds the USEPA's target level of one. Manganese shows a hazard quotient of 2.2E+00 and contributes greater than 73 percent to the hazard. No other chemicals show hazard quotients in exceedance of one. The 30-year combined hazard index for adults and children, 3.3E+00, also exceeds the USEPA's target level of one and is due largely to manganese. Table C-2, present and potential future residential dermal contact with surface soil in the Tillett Gardens and Art Center area, shows total carcinogenic risks for adults and children of 1.3E-03 and 3.9E-04, respectively. Both risks exceed the upper-bound of the USEPA's 104 to 10"6 target risk range. Aroclor 1242 is responsible for the entire risk in both cases. The 30-year combined 194 TUT 006 23SO risk for adults and children, 1.7E-03, exceeds the upper-bound of the USEPA's target risk range and is due entirely to Aroclor 1242. For present and potential future residential dermal contact with surface soil in the Tillett Gardens and Art Center area, neither adult nor child hazard index values could be calculated as no chronic oral reference dose is currently established for Aroclor 1242. Table C-3, potential future residential indoor and outdoor surface soil inhalation in the Tillett Gardens and Art Center area, shows total carcinogenic risks for adults and children 5.5E-07 and 6.4E-07, respectively. These risks fall outside and below the USEPA's lO" 4 to 1Q- 6 target risk range. The 30-year combined risk for adults and children, 1.2E-06, falls within the USEPA's target risk range. The hazard index values for potential future adult and child indoor and outdoor surface soil inhalation in the Tillett Gardens and Art Center area are 6.7E-01 and 3.1E+00, respectively. While the adult hazard index falls below the USEPA's target level of one, the child hazard index exceeds this level. Manganese shows a hazard quotient of 3.1E+00 for children and is responsible for the entire hazard index. The 30-year combined hazard index for adults and children, 3.8E+00, exceeds the USEPA's target level of one and is due entirely to manganese. Site Workers/Employees (Fire Department/Texaco Gas Station/Antilles Auto Parts/Ramsav Motor Co.): The results of carcinogenic risk and noncarcinogenic hazard index calculations for present and/or potential future site workers (employees) in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area are presented in Tables C-4 through C-6. 195 TUT QO6 2~!;fij Table C-4, present and potential future site worker (employee) surface soil ingestion in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area, shows a total carcinogenic risk of 1.3E-06. This risk falls within the USEPA's 104 to 10'6 target risk range. The hazard index for present and potential future site worker (employee) surface soil ingestion in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area, 9.7E-02, falls well below the USEPA's target level of one. In Table C-5, present and potential future dermal contact with surface soil in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area by site workers (employees), neither a carcinogenic risk nor a noncarcinogenic hazard index could be calculated as no chemicals of potential concern have established dermal absorption factors. Table C-6, potential future site worker (employees) surface soil inhalation in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area, shows a total carcinogenic risk of 2.7E-09. This risk falls outside and below the USEPA's 104 to 10"6 target risk range. The hazard index for potential future site worker (employee) surface soil inhalation in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area, 2.0E-01, falls below the USEPA's target level of one. 196 TUT OO6 2382 Site Workers/Employees (Curriculum Center Building - Present); The results of carcinogenic risk and noncarcinogenic hazard index calculations for present site workers (employees) in the Curriculum Center Building area are presented in Tables C-7 and C-8. Table -C-7, present site worker (employee) surface soil ingestion in the Curriculum Center Building area, shows a total carcinogenic risk of 3.7E-06. This risk falls within the USEPA's 10^ to 10"6 target risk range. The hazard index for present site worker (employee) surface soil ingestion in the Curriculum Center Building area, 2.5E-01, falls below the USEPA's target level of one. In Table C-8, present dermal contact with surface soil in the Curriculum Center Building area by site workers (employees), neither a carcinogenic risk nor a noncarcinogenic hazard index could be calculated as no chemicals of potential concern have established dermal absorption factors. Site Workers/Employees (Curriculum Center Building - Future); The results of carcinogenic risks and noncarcinogenic hazard index calculations for potential future site workers (employees) in the Curriculum Center Building area are presented in Tables C-9 through C-ll. Table C-9, potential future site worker (employee) surface soil ingestion in the Curriculum Center Building area, shows a total carcinogenic risk of 9. IE-07. This risk falls outside and below the USEPA's lO^to KT6 target risk range. 197 TUT OO6 2383 The hazard index for potential future site worker (employee) surface soil ingestion in the Curriculum Center Building area, 2.3E-01, falls below the USEPA's target level of one. In Table C-10, potential future dermal contact with surface soil in the Curriculum Center Building area by site workers (employees), neither a carcinogenic risk nor a noncarcinogenic hazard index could be calculated as no chemicals of potential concern have established dermal absorption factors. Table C-ll, potential future site worker (employee) surface soil inhalation in the Curriculum Center Building area, shows a total carcinogenic risk of 4.5E-08. This risk falls outside and below the USEPA's 1CT* to 10" 6 target risk range. The hazard index for potential future site worker (employee) surface soil inhalation in the Curriculum Center Building area, 2. IE-01, falls below the USEPA's target level of one. Site Workers/Employees (O'Henry Dry Cleaners and Liquor Barn); The results of carcinogenic risk and noncarcinogenic hazard index calculations for present and/or potential future site workers (employees) in the O'Henry dry cleaners and Liquor Barn area are presented in Tables C-12 through C-15. Table C-12, present and potential future site worker (employee) surface soil ingestion in the O'Henry dry cleaners and Liquor Barn area, shows a total carcinogenic risk of 9.7E-06. This risk falls within the USEPA's 10"4 to 10" 6 target risk range. 198 ' UT on- „„_ „ :>84 The hazard index for present and potential future site worker (employee) surface soil ingestion in the O'Henry dry cleaners and Liquor Barn area, 1.5E-01, falls below the USEPA's target level of one. In Table C-13, present and potential future dermal contact with surface soil in the O'Henry dry cleaners and Liquor Barn area by site workers (employees), neither a carcinogenic risk nor a noncarcinogenic hazard index could be calculated as no chemicals of potential concern have established dermal absorption factors. Table C-14, potential future site worker (employee) surface soil inhalation in the O'Henry dry cleaners and Liquor Barn area, shows a total carcinogenic risk of 3.4E-07. This risk falls outside and below the USEPA's 10"4 to 1Q-6 target risk range. The hazard index for potential future site worker (employee) surface soil inhalation in the O'Henry dry cleaners and Liquor Barn area, 2. IE-01, falls below the USEPA's target level of one. Table C-15, present and potential future site worker (employee) surface soil inhalation of VOCs in the O'Henry dry cleaners and Liquor Barn area, shows a total carcinogenic risk of 4.9E-07. This risk falls outside and below the USEPA's 10"4 to 10"6 target risk range. The hazard index for potential future site worker (employee) surface soil inhalation in the O'Henry dry cleaners and Liquor Barn area, 2. IE-01, falls below the USEPA's target level of one. 199 TUT 006 2385 Table C-15, present and potential future site worker (employee) surface soil inhalation of VOCs in the O'Henry dry cleaners and Liquor Barn area, shows a total carcinogenic risk of 4.9E-07. This risk falls outside and below the USEPA's 10" 4 to 10'6 target risk range. A hazard index for present and potential future site worker (employee) surface soil inhalation of VOCs in the O'Henry dry cleaners and Liquor Barn area could not be calculated as tetrachloroethene does not currently have an established chronic inhalation reference dose. Construction Workers (Tillett Gardens and Art Center); The results of carcinogenic risk and noncarcinogenic hazard index calculations of potential future construction workers in the Tillett Gardens and Art Center area are presented in Tables C-16 through C-18. Table C-16, potential future construction worker surface soil ingestion in the Tillett Gardens and Art Center area, shows a total carcinogenic risk of 5.7E-05. This risk falls within the USEPA's 10" 4 to 10'6 target risk range. The hazard index for potential future construction worker surface soil ingestion in the Tillett Gardens and Art Center area, 9.9E-01, falls below the USEPA's target level of one. Table C-17, potential future dermal contact with surface soil in the Tillett Gardens and Art Center area by construction workers, shows a total carcinogenic risk of 4.3E-05. This risk falls within the USEPA's 10" to 10"6 target risk range. 200 TUT OO6 2386 A hazard index for potential future construction worker dermal contact with surface soil in the Tillett Gardens and Art Center area could not be calculated as a subchronic noncarcinogenic oral reference dose is not currently established for Aroclor 1242. Table C-18, potential future construction worker surface soil inhalation in the Tillett Gardens and Art Center area, shows a total carcinogenic risk of 6.6E-09. This risk falls outside and below the USEPA's 1&4 to lO* target risk range. The hazard index for potential future construction worker surface soil inhalation in the Tillett Gardens and Art Center area, 2.4E-02, falls well below the USEPA's target level of one. 5.3.2 Subsurface Soil The results of carcinogenic risk and noncarcinogenic hazard index calculations for potential future resident (adult and child), site worker, and construction worker exposure to subsurface soil for the Tillett Gardens and Art Center, Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co., Curriculum Center building, Esso gas station and Splash and Dash car wash, and O'Henry dry cleaners and Liquor Barn areas of concern are presented in Tables C-19 through C-31. Residents (Tillett Gardens and Art Center); The results of carcinogenic risk and noncarcinogenic hazard index calculations for potential future residents in the Tillett Gardens and Art Center area are presented in Tables C-19 and C-20. OO6 2387 In Table C-19, potential future dermal contact with subsurface soil in the Tillett Gardens and Art Center area by residents, neither carcinogenic risk nor noncarcinogenic hazard index values could be calculated as no chemicals of potential concern have established dermal absorption factors. Table C-20, potential future residential indoor and outdoor subsurface soil inhalation in the Tillett Gardens and Art Center area, shows total carcinogenic risks for adults and children of 3.0E-08 and 1.4E-07, respectively. These risks fall outside and below the USEPA's 104 to 10'6 target risk range. The 30-year combined risk for adults and children, 1.7E-07, also falls outside and below the USEPA's target risk range. The hazard index values for potential future adult and child indoor and outdoor subsurface soil inhalation in the Tillett Gardens and Art Center area are, 1.9E-02 and 9.0E-02, respectively. These values fall well below the USEPA's target level of one. The 30-year combined hazard index for adults and children, 1. IE-01, also falls below the USEPA's target level. Site Workers/Employees (Fire Department/Texaco Gas Station/Antilles Auto Parts/Ramsav Motor Co.); The results of carcinogenic risk and noncarcinogenic hazard index calculations for potential future site workers (employees) in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area are presented in Tables C-21 and C-22. In Table C-21, potential future dermal contact with subsurface soil in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area by site workers 202 TUT 006 2388 (employees), neither a carcinogenic risk nor a noncarcinogenic hazard index could be calculated as no chemicals of potential concern have established dermal absorption factors. Table C-22, potential future site worker (employee) subsurface soil inhalation in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area, shows a total carcinogenic risk of 3.8E-10. This risk falls outside and below the USEPA's 104 to 10* target risk range. The hazard index for potential future site worker (employee) subsurface soil inhalation in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co. area, 7.4E-03, falls well below the USEPA's target level of one. Site Workers/Employees (Curriculum Center Building - Future): The results of carcinogenic risk and noncarcinogenic hazard index calculations for potential future site workers (employees) in the Curriculum Center Building area are presented in Tables C-23 and C-24. In Table C-23, potential future dermal contact with subsurface soil in the Curriculum Center Building area by site workers (employees), neither a carcinogenic risk nor a noncarcinogenic hazard index could be calculated as no chemicals of potential concern have established dermal absorption factors. 203 TUT 006 2389 Table C-24, potential future site worker (employee) subsurface soil inhalation in the Curriculum Center Building area, shows a total carcinogenic risk of 1. IE-09. This risk falls outside and below the USEPA's 104 to 10"6 target risk range. The hazard index for potential future site worker (employee) subsurface soil inhalation in the Curriculum Center Building area, 6.9E-03, falls well below the USEPA's target level of one. Site Workers/Employees (Esso Gas Station and Splash and Dash Car Wash); The results of carcinogenic risk and noncarcinogenic hazard index calculations for potential future site workers (employees) in the Esso gas station and Splash and Dash Car Wash area are presented in Tables C-25 and C-26. In Table C-25, potential future dermal contact with subsurface soil in the Esso gas station and Splash and Dash car wash by site workers (employees), neither a carcinogenic risk nor a noncarcinogenic hazard index could be calculated as no chemicals of potential concern have established dermal absorption factors. Table C-26, potential future site worker (employee) subsurface soil inhalation in the Esso gas station and Splash and Dash car wash area, shows a total carcinogenic risk of 3.4E-10. This risk falls outside and below the USEPA's 10"4 to 10"6 target risk range. The hazard index for potential future site worker (employee) subsurface soil inhalation in the Esso gas station and Splash and Dash car wash area, 8.2E-03, falls well below the USEPA's target level of one. 204 .» ;<• f- ^-: ". Vf \ Tu.i . ' u Site Workers/Employees (O'Henry Dry Cleaners and Liquor Barn); The results of carcinogenic risk and noncarcinogenic hazard index calculations for potential future site workers (employees) in the O'Henry dry cleaners and Liquor Barn area are presented in Tables C-27 and C-28. In Table C-27, potential future dermal contact with subsurface soil in the O'Henry dry cleaners and Liquor Barn area by site workers (employees), neither a carcinogenic risk nor a noncarcinogenic hazard index could be calculated as no chemicals of potential concern have established dermal absorption factors. Table C-28, potential future site worker (employee) subsurface soil inhalation in the O'Henry dry cleaners and Liquor Barn area, shows a total carcinogenic risk of 3.5E-08. This risk falls outside and below the USEPA's 10" 4 and 1C)- 6 target risk range. The hazard index for potential future site worker (employee) subsurface soil inhalation in the O'Henry dry cleaners and Liquor Barn area, 1.8E-02, falls well below the USEPA's target level of one. Table C-29, potential future construction worker subsurface soil ingestion in the Tillett Gardens and Art Center area, shows a total carcinogenic risk of 1.6E-06. This risk falls within the USEPA's ID" 4 to 1Q- 6 target risk range. The hazard index for potential future construction worker subsurface soil ingestion in the Tillett Gardens and Art Center area, 4.3E-01, falls below the USEPA's target level of one. 205 TUT 006 2391 In Table C-30, potential future dermal contact with subsurface soil in the Tillett Gardens and Art Center area by construction workers, neither carcinogenic risks nor hazard index values could be calculated as no chemicals of potential concern have established dermal absorption factors. Table C-31, potential future construction worker subsurface soil inhalation in the Tillett Gardens and Art Center Area, shows a total carcinogenic risk of 9.4E-09. This risk falls outside and below the USEPA's 10"4 to 10^ target risk range. The hazard index value for potential future construction worker subsurface soil inhalation in the Tillett Gardens and Art Center area, 6.2E-03, falls well below the USEPA's target level of one. 5.3.3 Ground water The results of carcinogenic risk and noncarcinogenic hazard index calculations for present and potential future resident (adult and child) and site worker, and potential future construction worker exposures to groundwater are presented in Tables C-32 through C-36. Residents (Site-Wide); The results of carcinogenic risk and noncarcinogenic hazard index calculations for present and potential future residential groundwater exposure are presented in Tables C-32 through C-34. Table C-32, present and potential future residential groundwater ingestion across the site, shows total carcinogenic risks for adults and children of 6.6E-04 and 3. IE-04, respectively. Both risks 206 TUT OO6 2392 exceed the upper-bound of the USEPA's 104 to.10"6 target risk range. For adults, tetrachloroethene and vinyl chloride show individual risks of 1.2E-04 and 4.5E-04, respectively, which combined contribute greater than 86 percent to the total risk. For children, tetrachloroethene and vinyl chloride show individual risks of 5.7E-05 and 2. IE-04, respectively, which combined also contribute greater than 86 percent to the total risk. The hazard index values for adult and child groundwater ingestion are 2.9E+01 and 6.7E+01, respectively. These values exceed the USEPA's target level of one. For adults, 1,2- dichloroethene (total) and manganese show hazard quotients of 1.2E+00 and 2.6E+01, respectively, which combined contribute nearly 94 percent to the hazard index. For children, 1,2-dichloroethene (total), tetrachloroethene, antimony, manganese, and vanadium show hazard quotients of 2.8E+00, 1.3E+00, 1.6E+00, 6.0E+01, and l.OE+00, respectively, which combined contribute greater than 99 percent to the hazard index. Table C-33, present and potential future residential dermal contact with site-wide groundwater during showering, shows total carcinogenic risks for adults and children of 1.3E-07and 3.6E-08, respectively. These risks fall outside and below the USEPA's lO^to 10"6 target,risk range. The hazard index values for present and potential future adult and child groundwater dermal contact are 4.9E-02 and 6.8E-02, respectively. These values fall well below the USEPA's target level of one. 207 TUT OO6 239- Table C-34, present and potential future residential inhalation of VOCs in site-wide groundwater (shower model), shows total carcinogenic risks of 4.3E-05 and 4.0E-05, respectively. These risks fall within the USEPA's 10"4 to IV6 target risk range. The hazard index values for present and potential future adult and child inhalation of VOCs in site-wide groundwater (shower model) are 3.4E-03 and 1.6E-02, respectively. These values fall well below the USEPA's target level of one. Site Workers/Employees (Site-Wide); The results of carcinogenic risk and noncarcinogenic hazard index calculations for present and potential future site workers (employees) site-wide are presented in Table C-35. Table C-35, present and potential future site worker (employee) ingestion of site-wide groundwater, shows a total carcinogenic risk of 2.0E-04. This risk exceeds the upper-bound of the USEPA's 10"4 to 10'6 target risk range. Tetrachloroethene and vinyl chloride show individual risks of 3.6E-05 and 1.3E-04, respectively, which combined contribute 83 percent to the total risk. The hazard index for present and potential future site worker (employee) ingestion of site-wide groundwater is l.OE+01. This value exceeds the USEPA's target level of one. Manganese shows a hazard quotient of 9.2E+00 and contributes approximately 92 percent to the hazard. No other chemicals have hazard quotients in exceedance of one. 208 TUT OO6 2394 Construction Workers (Site-Wide); The results of carcinogenic risk and noncarcinogenic hazard index calculations for potential future construction workers site-wide are presented in Table C-36. Table C-36, potential future construction worker ingestion of site-wide groundwater, shows a total carcinogenic risk of 7. IE-06. This risk falls within the USEPA's 104 to KT6 target risk range. The hazard index for potential future construction worker ingestion of site-wide groundwater is 9.1E+00. This value exceeds the USEPA's target level of one. Manganese shows a hazard quotient of 8.2E+00 and contributes greater than 90 percent to the hazard. No other chemicals have hazard quotients in exceedance of one. 5.4 Combining Cancer Risks and Noncancer Hazard Index Values Across Exposure Pathways Multichemical cancer risk/noncancer hazard estimates may be combined across exposure pathways for exposed receptor group(s) provided that the same group(s) would consistently face the RME by more than one pathway. Cancer risks from various exposure pathways are assumed to be additive, as long as the risks are for the same individuals and time period. For noncarcinogens, the total hazard index for each exposure duration (i.e., chronic, subchronic) was calculated separately. The summing of appropriate carcinogenic risks and noncarcinogenic hazard index values is presented in Tables 5-1 and 5-2, respectively. 209 TUT OO6 239? PWAYADOXLS TABLE 5-1 TUTU WELLS SITE COMBINING CARCINOGENIC RISKS ACROSS PATHWAYS > > H CH MEDIA SURFACE SOIL Tilled Gardens and Art Center Area Fire Dept /Texaco gas station/ Antilles auto parts/ Ramsay motor co. Area Curriculum Center Building Area (Present-Use) Curriculum Center Building Area (Future-Use) O'Henry dry cleaners and Liquor Barn Area Tilled Gardens and Art Center Area (Future-Use) O RECEPTOR POPULATION Residents: Adults Children (0-6 years; Site Workers (Employees) Site Workers (Employees) Site Workers (Employees) Site Workers (Employees) Construction Workers EXPOSURE ROUTE Ingestion Dermal Contact Inhalation of Participates Total Carcinogenic Risk = Ingestion Dermal Contact Inhalation of Particulates Total Carcinogenic Risk = Ingestion Dermal Contact Inhalation ol Particulates Total Carcinogenic Risk a Ingestion Dermal Contact Total Carcinogenic Risk = Ingestion Dermal Contact Inhalation of Particulates Total Carcinogenic Risk = Ingestion Dermal Contact Inhalation of Parliculales Inhalation of VOCs Total Carcinogenic Risk = Ingestion Dermal Contact Inhalation of Particulates Total Carcinogenic Risk = INDIVIDUAL CANCER RISK 4.4E-04 1.3E-03 55E-07 1.7E-03 10E-03 3.9E-04 6.4E-07 1.4E-03 1.3E-06 NA 2.7E-09 1.3E-06 37E-06 NA 3.7E-06 9. IE-07 NA 4.5E-08 96E-07 9.7E-06 NA 34E-07 49E-07 1.1E-05 5.7E-05 4.3E-05 6.6E-09 1.0E-04 CHEMICALS CONTRIBUTING THE GREATEST AMOUNT TO RISK Aroclor 1242, Arsenic Aroclor 1242 .. Aroclor 1242, Arsenic Aroclor 1242, Arsenic Aroclor 1242 . Aroclor 1242, Arsenic „ -- -- -- .. -- •- .. --- - -- .. .. .. • . --- " to O -Q D-- 3/8/95 PWAYADD.XIS TABLE b-1 TUTU WELLS SITE COMBINING CARCINOGENIC RISKS ACROSS PATHWAYS MEDIA SUBSURFACE SOIL Tillelt Gardens and Art Center Area (Future-Use) Fire Depl / Texaco gas station/ Antilles auto parts/ Ramsay motor co. Area (Future-Use) Curriculum Center Building Area (Future-Use) Esso gas station and Splash and Dash car wash Area (Future-Use) O'Henry dry cleaners and Liquor Barn Area Tillelt Gardens and Art Center Area (Future-Use) RECEPTOR POPULATION Residents: Adults Children (0-6 years) Site Workers (Employees) Site Workers (Employees) Site Workers (Employees) Site Workers (Employees) Construction Workers EXPOSURE ROUTE Dermal Contact Inhalation of Particulates Total Carcinogenic Risk = Dermal Contact Inhalation ol Particulates Total Carcinogenic Risk = Dermal Contact Inhalation of Particulates Total Carcinogenic Risk = Dermal Contact Inhalation of Particulates Total Carcinogenic Risk = Dermal Contact Inhalation of Particulates Total Carcinogenic Risk » Dermal Contact Inhalation of Parliculates Total Carcinogenic Risk = Ingeslibn Dermal Contact Inhalation of Particulates Total Carcinogenic Risk a INDIVIDUAL CANCER RISK NA 30E-08 30E-08 NA 14E-07 1.4E-07 NA 38E-10 38E-10 NA 1. IE-09 1. IE-09 NA 34E-10 3.4E-10 NA 35E-08 3.5E-08 1.6E-06 NA 9.4E-09 1.6E-06 CHEMICALS CONTRIBUTING THE GREATEST AMOUNT TO RISK -- — » -- •- ' -- •-0 3/8/95 PWAYADO.XLS TABLbi / TUTU WELLS SITE COMBINING CARCINOGENIC RISKS ACROSS PATHWAYS MEDIA GROUNDWATER (Site-Wide) RECEPTOR POPULATION Residents: Adults Chitdren(0-6 years) Site Workers (Employees) Construction Workers EXPOSURE ROUTE Ingestion Dermal Contact (Shower) Inhalation of VOCs (Shower) Total Carcinogenic Risk = Ingestion Dermal Contact (Shower) Inhalation of VOCs (Shower) Total Carcinogenic Risk = Ingestion Total Carcinogenic Risk = Ingeslion Total Carcinogenic Risk = INDIVIDUAL CANCER RISK 66E-04 13E-07 43E-05 70E-04 3. IE 04 36E^)8 40E-05 35E-04 2.0E-04 20E^)4 7. IE-06 7.1E06 CHEMICALS CONTRIBUTING THE GREATEST AMOUNT TO RISK Telrachloroethene, Vinyl Chloride -- « Telrachloroethene, Vinyl Chloride Tetrachloroelhene, Vinyl Chloride -- - Telrachloroelhene, Vinyl Chloride Telrachloroethene, Vinyl Chloride Tetrachloroethene, Vinyl Chloride ~ -- O COMBINING CARCINOGENIC RISKS ACROSS ENVIRONMENTAL MATRICES: Residents: Surface soil exposure durations are different than subsurface soil exposure durations and therefore cannot be combined. The child (6 year) surface soil exposure duration is the same as the child groundwater exposure duration and therefore may be combined. Children: Surface Soil + Groundwater (Site-Wide) Tillett Gardens and Art Center Area: 1.4E-03 + 3.5E-04 1.8E-03 Site Workers: Surface soil exposure durations are different than subsurface soil exposure durations and therefore cannot be combined. The site worker surface soil exposure duration is the same as the site worker groundwater exposure duration and therefore may be combined. Site Workers: Surface Soil + Groundwater (Site-Wide): Fire Department/Texaco gas station/ Antilles auto parts/ Ramsay motor co. : 1 .3E-06 + 2.0E-04 = 2.0E-04 Curriculum Center Building Area (Present-Use): 3.7E-06 + 2.0E-04 = 2.0E-04 Curriculum Center Building Area (Future-Use): 9.6E-07 + 2.0E-04 = 2.0E-04 O'Henry dry cleaners and Liquor Bam Area: 1 . 1 E-05 + 2.0E-04 = 2. 1 E-04 Construction Workers: Surface Soil •»• Subsurface Soil + Groundwater (Site-Wide) Tillett Gardens and Art Center Area: 1.0E-04 + 1.6E-06 + 7.1E-06 = 1.1E-04 Notes -- Indicates that the carcinogenic risk does not exceed the target risk range or could not be calculated; therefore, no chemicals were selected as contributors. NA:The carcinogenic risk for dermal contact with soil could not be calculated as carcinogenic chemicals of potential concern either do not have established dermal absorption factors or do not have established carcinogenic loxicity values. 3/8/95 PWAYADDNC »ls TA. ^ TUTU WELLS SITE COMBINING NONCARCINOGENIC HAZARD INDEX VALUES ACROSS PATHWAYS MEDIA SURFACE SOIL Tillett Gardens and Art Center Area Fire Dept./ Texaco gas station/ Antilles auto parts/ Ramsay motor co. Area Curriculum Center Building Area (Present-Use) Curriculum Center Building Area (Future-Use) O'Henry dry cleaners and Liquor Barn Area Tillett Gardens and Art Center Area (Future-Use) RECEPTOR POPULATION Residents: Adults Children (0-6 years) Site Workers (Employees) Site Workers (Employees) Site Workers (Employees) Site Workers (Employees) Construction Workers EXPOSURE ROUTE Ingestion Dermal Contact Inhalation ol Parliculates Total Hazard Index a Ingestion Dermal Contact Inhalation of Particulates Total Hazard Index a Ingestion Dermal Contact Inhalation of Particulates Total Hazard Index a Ingestion Dermal Contact Total Hazard Index = Ingeslion Dermal Contact Inhalation of Parliculates Total Hazard Index « Ingestion Dermal Contact Inhalation of Particulates Inhalation ol VOCs Total Hazard Index = Ingestion Dermal Contact Inhalation of Particulales Total Hazard Index =» INDIVIDUAL HAZARD INDEX 3.2E-01 NA 6.7E-01 9.9E-01 3.0E+00 NA 3.1E+00 6.1E+00 9.7E-02 NA 2.0E-01 3.0E-01 2.5E-01 NA 2.5E-01 2.3E-01 NA 2. IE-01 4.4E-01 I.5E-01 NA 2.1E-Ot NA 3.6E-Ot 9.9E-Ot NA 2.4E-02 t.OE+00 CHEMICALS CONTRIBUTING THE GREATEST AMOUNT TO HAZARD INDEX VALUES . Manganese Manganese Manganese -- — -- - -- to ~H O r--. CT- N2 W-0 •-0 3/8/95 PWAYADDNC.xls T, TUTU WELLS SITE COMBINING NONCARCINOGENIC HAZARD INDEX VALUES ACROSS PATHWAYS MEDIA SUBSURFACE SOIL Tilled Gardens and Art Center Area (Future- Use) Fire Dept./ Texaco gas station/ Antilles auto parts/ Ramsay motor co. Area (Future-Use) Curriculum Center Building Area (Future-Use) Esso gas station and Splash and Dash car wash Area (Future-Use) O'Henry dry cleaners and Liquor Barn Area Tillett Gardens and Art Center Area (Future-Use) RECEPTOR POPULATION Residents: Adults Children (0-6 years) Site Workers (Employees) Site Workers (Employees) Site Workers (Employees) Site Workers (Employees) Construction Workers EXPOSURE ROUTE Dermal Contact Inhalation of Particulates Total Hazard Index • Dermal Contact Inhalation of Particulates Total Hazard Index = Dermal Contact Inhalation ol Particulates Total Hazard Index = Dermal Contact Inhalation of Parliculates Total Hazard Index = Dermal Contact Inhalation ol Particulars Total Hazard Index = Dermal Contact Inhalation of Particulates Total Hazard Index = Ingeslion Dermal Contact Inhalation of Particulates Total Hazard Index 3 INDIVIDUAL HAZARD INDEX NA 1.9E-02 I.9E-02 NA 90E-02 90E-02 NA 7.4E-03 7.4E-03 NA 6.9E-03 69E-03 NA 8.2E-03 8.2E-03 NA 1.8E-02 1.8E-02 4.3E-01 NA 62E-03 4.4E-OI CHEMICALS CONTRIBUTING THE GREATEST AMOUNT TO HAZARD INDEX VALUES - ~ „ -- « » ~ Ni ~i o hj O 3/8/95 PWAYADDNC.Hls TA. |2 TUTU WELLS SITE COMBINING NONCARCINOGENIC HAZARD INDEX VALUES ACROSS PATHWAYS MEDIA GROUNDWATER (Site-Wide) RECEPTOR POPULATION Residents: Adults Children (0-6 years) Site Workers (Employees) Construction Workers EXPOSURE ROUTE Ingeslion Dermal Contact (Shower) Inhalation of VOCs (Shower) Total Hazard Index = Ingeslion Dermal Contact (Shower) Inhalation ol VOCs (Shower) Total Hazard Index = Ingestion Total Hazard Index = Ingestion Total Hazard Index = INDIVIDUAL HAZARD INDEX 2.9E+01 4.9E-02 3.4E-03 2.9E+01 67E+OI 68E-02 16E-02 6.7E+01 t.OE+01 1.0E+01 9. IE +00 9.1E+00 CHEMICALS CONTRIBUTING THE GREATEST AMOUNT TO HAZARD INDEX VALUES 1.2-Dichloroethene (Total), Manganese t ,2-Dichloroethene (Total), Manganese 1,2-Dichloroethene (Total). Tetrachloroelhene, Antimony, Manganese, Vanadium 1 ,2-Dichloroethene (Total), Telrachloroelhene. Antimony. Manganese, Vanadium Manganese Manganese Manganese Manganese to C —iI o Cf~ f-o COMBINING NONCARCINOGENIC HAZARD INDEX VALUES ACROSS ENVIRONMENTAL MATRICES: Residents: Surface soil exposure durations are different than subsurface soil exposure durations and therefore cannot be combined. The child (6 year) surface soil exposure duration is the same as the child groundwater exposure duration and therefore may be combined. Children: Surface Soil + Groundwater Tillett Gardens and Art Center Area: 6.1E+00 + 6.7E+01 = 7.3E+01 Site Workers: Surface soil exposure durations are different than subsurface soil exposure durations and therefore cannot be combined. The site worker surface soil exposure duration is the same as the site worker groundwater exposure duration and therefore may be combined. Site Worker: Surface Soil + Groundwater (Site-Wide) Rre Department/Texaco gas station/ Antilles auto parts/ Ramsay motor co. Area: 3.0E-01 + 1.0E+01 = 1.0E+01 Curriculum Center Building Area (Present-Use): 2.5E-01 + 1.0E+01 = 1.0E+01 Curriculum Center Building Area (Future-Use): 4.4E-OI + t.OE+01 = I.OE+Ot O'Henry dry cleaners and Liquor Bam Area: 3.6E-01 + t.OE+01 = 1.0E+01 Construction Workers: Surface Soil + Subsurface Soil + Groundwater (Site-Wide) Tillett Gardens and Art Center Area: 1.0E+00+ 4.4E-OI+9.1E+00= 1.1E+01 Notes -- Indicates that the noncarcinogenic hazard index does not exceed the target level or could not be calculated; therefore no chemicals were selected as contributors. NA: The noncarcinogenic hazard index for dermal contact with soil could not be calculated as noncarcinogenic chemicals of potential concern either do not have established dermal absorption factors or do not have noncarcinogenic toxicity values. ^^ 5.5 Applicable or Relevant and Appropriate Requirements (ARAKS') The National Contingency Plan (NCP) and Section 121(d) of CERCLA (cleanup standards) requires that the selected remedial actions at Superfund sites attain or exceed applicable or relevant and appropriate requirements (ARARs) of Federal laws and more stringent promulgated state laws. ARARs are identified to determine media and chemical contaminants that may require remediation and regulations that may apply to remedial action. A requirement under CERCLA and under other environmental laws may be either "applicable" ^ or "relevant and appropriate" to a remedial action, but not both. A two-tiered approach may be applied: first, to determine whether a given requirement is applicable, then, if it is not applicable, to determine whether it is relevant and appropriate. These terms are defined in the NCP as follows: • Applicable requirements are those cleanup standards, standards of control, and other substantive requirements, criteria, or limitations promulgated under federal or state environmental or facility siting laws that specifically address a hazardous substance, pollutant, contaminant, remedial action, location, or other circumstance found at a CERCLA site. Only those state standards that are identified by a state in a timely manner and that are more stringent than federal requirements may be applicable. Examples of applicable requirements are Maximum Contaminant Levels (MCLs) promulgated under the Safe Drinking Water Act for contamination of a drinking water supply aquifer. 216 TUT OO6 24O2 * Relevant and appropriate requirements are those cleanup standards, standards of control, and other substantive requirements, criteria or limitations described above, that, while not "applicable", address problems or situations sufficiently similar to those encountered at a CERCLA site that their use is well-suited to the particular site. • Other requirements to be considered (TBCs) are non-promulgated federal and state advisories or guidance documents. These do not have status as potential ARARs; however, these advisories or guidance documents may be considered in determining the necessary level of cleanup for the protection of health or the environment. The USEPA divides ARARs into three categories: chemical-specific, location-specific, and action-specific. This distinction is based on whether the requirement is triggered by the presence or emission of a chemical, by a sensitive or protected location, or by a particular remedial action, respectively. Chemical-specific ARARs are useful in identifying chemicals that may pose a risk and require remediation, and may be selected as cleanup levels that must be achieved by a particular action. Chemical-specific requirements set concentration limits or ranges in various environmental media for specific hazardous substances, pollutants or contaminants. These requirements (i.e., MCLs) may represent protective levels for designated media. USEPA Region II federal MCLs have been identified in this risk assessment for the selected chemicals of potential concern in site groundwater (See Table 2-28). These MCLs were obtained from the Region II Drinking and Groundwater Standards Update (USEPA, 1993b). 217 TUT 006 2403 Table 5-3 presents the MCLs along with the range of detected concentrations of chemicals of potential concern for comparative purposes. Preliminary remediation goals have been calculated for those chemicals of potential concern in groundwater not having established MCLs (i.e., 1,2-dichloroethene (total) and manganese), and are presented in Section 7.1. A preliminary remediation goal was not developed for vanadium since it did not result in a hazard quotient in exceedance of one (i.e., hazard quotient was equal to one). It should be noted that manganese does have a secondary MCL of 50 ug/1 in drinking water; however, this level is an unenforceable federal guideline which is based on taste, odor, and non-aesthetic effects. For VOCs in Table 5-3, all maximum detected concentrations far exceed established MCLs, except for 1,2-dichloroethene (total), which does not have an established MCL. For the inorganics in Table 5-3, all maximum detected concentrations exceed established MCLs except for manganese. Manganese does not currently have an established MCL, although as mentioned above, it does have a nonenforceable secondary MCL of 50 ug/1. 218 TUT 006 2404 12/12/94 MCL.XLS TABLE 5-3 TUTU WELLS SITE DETECTED CONCENTRATIONS VERSUS FEDERAL MAXIMUM CONTAMINANT LEVELS (MCLS) FOR CHEMICALS OF POTENTIAL CONCERN IN SITE GROUNDWATER (ug/l) K) Range ol Detected Conoentr ations CHEMICALS VQCS: Benzene 1 .2-Dfchtoroelhene (Total) Telrachkxoethene Toluene VkiylChtorida Inorganics: Antimony Arsenic BeryMum Chromium VI Manganese Nickel Vanadhim Minimum 0.05 J 0.11 J 1.00J 0.05 J 0.22 J 14.8 B 1.00 B 0.758 0.43 B 1.40B 8.70 B 4.90 B Maximum 21000 D 2100 1500 17000 1300 424 B 80.8 J 40.88 659 20400 2050 1000 J MCLtn 5 NA 5 1000 2 6 50 4 100 (Total) NA 100 NA C —! (1) Region II Drinking and Groundwater Standards Update (USEPA. 1993b). NA: Not Available to Ul 6.0 UNCERTAINTIES IN RISK ASSESSMENT As in any risk assessment, the estimates of potential health threats (carcinogenic risks and noncarcinogenic health effects) for the Tutu Wells site data have numerous associated uncertainties. In general, the primary areas of uncertainty include the following: • Environmental data • Exposure pathway assumptions • Toxicological data • Risk Characterization Uncertainty is always involved in the estimation of chemical concentrations. Errors in the analytical data may stem from errors inherent in sampling and/or laboratory procedures. One of the most effective methods of minimizing procedural or systematic error is to subject the data to a strict quality control review. This quality control review procedure helps to eliminate many laboratory errors. However, even with all data vigorously validated, it must be realized that error is inherent in all laboratory procedures. The lack of site-specific exposure measurements requires that estimates be made on the basis of literature values and/or professional judgement. These types of estimates were required in the evaluation of exposure scenario input parameters. For example, assumptions were made for the exposure time, frequency, and duration of potential chemical exposures, as well as for the 220 TUT OO6 2406 quantity of ingested and/or inhaled chemical contaminants. In general, assumptions were made based on reasonable maximum exposures. Other standard assumptions used throughout this risk assessment (i.e., 70 kg average adult body weight) or upper-bounds of potential exposure (i.e., inhalation rate) have been used as appropriate. Other sources of error in the risk assessment can stem from the use of estimated concentrations and can arise during the calculation of 95 percent UCLs. For example, one-half the SQL was used in the 95 percent UCL calculation as a proxy concentration for non-detect chemicals. An additional uncertainty involved in the calculation of 95 percent UCLs involved selection of the H-statistic when more than 101 samples are included (i.e., groundwater). In cases where the number of samples exceeded 101, the H-statistics for 101 samples were utilized for conservatism. While the use of these H-statistics may tend to overestimate the 95 percent UCL concentration, the amount would be slight since H-statistics decrease by small increments as the number of samples increases. Toxicological data uncertainty is one of the largest sources of error in this risk assessment. Numerous uncertainties are associated with USEPA-derived toxicity values used in risk assessment. One source of uncertainty may include using dose-response information from effects observed at high doses in animals to predict adverse health effects from low level exposures to humans in contact with the chemical in the environment. Another source may be the use of dose-response information from short-term exposure studies to predict the effects of long-term exposure and vice versa. Uncertainties may also arise from using dose-response information in 221 TUT 006 2407 x—*-^ animals to predict human health effects and from homogeneous animal and healthy human populations to predict effects likely to be observed in the general population which consists of individuals with varying sensitivities. In addition, the inability to quantitatively evaluate all chemicals detected at the site due to the lack of sufficient toxicological data may result in underestimation of risks and/or health effects. The potential toxicological effects of these chemicals have been discussed in Section 4.3 and in Appendix B Toxicological Profiles. Other toxicological data uncertainty in this risk assessment includes the use of the established Aroclor 1260 oral slope factor to represent all Aroclors (i.e., Aroclor 1248); the use of the benzo(a)pyrene oral slope factor in conjunction with relative potency values to develop slope factors for numerous other carcinogenic PAHs; and the combining of carcinogens with different ,o-s weights-of-evidence in the calculation of risk. Uncertainty is also involved in the calculation of risk and hazard estimates via the dermal contact with soil pathway. Only cadmium and PCBs (as a class) could be quantitatively evaluated via this route since these are the only chemicals detected in site soil which have USEPA-established soil dermal absorption factors. The potential exists to underestimate risks/impacts via this pathway since all other chemicals detected in the soil could only be qualitatively addressed. An additional source of uncertainty may include the use of oral reference doses to evaluate dermal exposure (i.e., cadmium and PCBs in soil, and SVOCs and inorganics in groundwater). It should be noted for the dermal contact with groundwater during showering pathway, that a specific dermal permeability constant was available for only two chemicals and all others defaulted to the value for water. Considering that all of the chemicals in the spreadsheet are 222 TUT 006 2408 inorganics and that inorganics generally have low dermal permeabilities, the use of the default value for water may overestimate risks/impacts via this pathway. As a result of the uncertainties described above, this risk assessment should not be construed as presenting absolute risks or hazards. Rather, it is a conservative analysis intended to indicate the potential for adverse impacts to occur, based on a reasonable maximum exposure. 6.1 Central Tendency Calculations Central tendency is a statistical measure that identifies the single most representative value for an entire distribution of values. As a quantitative measure of uncertainty in this risk assessment, central tendency calculations have been performed utilizing 5 0th percentile input parameters (i.e., exposure duration) in the risk and hazard index calculations as opposed to the 90^ percentile parameters generally used in risk assessment calculations. Ninetieth percentile input parameters are used in the risk assessment for calculation of risk and hazard index values in a given pathway so that the combination of all intake variables results in an estimate of the RME for that pathway. The RME is the maximum exposure that is reasonably expected to occur at a site. The 50th percentile values used in the central tendency calculations are considered to be representative of the general receptor population, but may underestimate the true carcinogenic risk and/or noncarcinogenic health effects to sensitive receptors. Table 6-1 presents the 50th percentile exposure parameters utilized in the calculation of central tendency for those exposure pathways which have results in exceedance of the upper-bounds of the 10" 4 to 10~ 6 risk range, 1.0E-04,for carcinogens and one for noncarcinogens. These 223 TUT 006 2409 3/7/9S CICXPVARIXIS TUTU WELLS SITE VARIABLES USED FOR CHRONIC AND SUBCHRONIC DAILY INTAKE CALCULATIONS FOR CENTRAL TENDENCY EVALUATION Matrices and Receptor Populations Surface Soil Residents (Tillett Gardens and Art Center Area) Adults Children (0-6 years) Adults Children (0-6 years) Children (0-6 years) Groundwater Site Residents Adults Children (0-6 years) Site Workers Adults Construction Workers Adults Exposure Route Ingestion Ingestion Dermal Contact Dermal Contact Inhalation of Participates Ingeslioh Ingeslion Ingestion Ingestion CONCENTRATIONS CW CA/SSC CS VF (mgfl) (mq/m3) (mg/kg) (m3/kg Site Data Site Data Site Data Site Data 7.0E-02 Site Data Site Data Site Data Site Data Site Data CONTACT PARAMETERS SA PC IR(1) RF AF ABS Fl (cm2) (cm/hr) (variable) (unifJess) (mg/cm?) (unilless) (unitless) 50mg/day - - - 1 tOO mg/day - - • 1 5065 - 06 (4) 1270 - 06 (4) 0.83m3/hr 0.75 1.4 I/day - 0 . 7 W a y . . . . - - 1 1/day . . . . 1 1/day TIME VARIABLES ET EF ED AT (2) (hr/day) (day/yr) (yrs) (years) 275 9 70(9) 275 6 70(6) 275events/yr 9 70(9) 275events/yr 6 70(6) 12 275events/yr 6 70(6) 275 9 70(9) 275 6 70(6) 185 25 70(25) 130 1 70(1) CF(3) (variable) lE-6kg/mg 1E-6kg/mg lE-6kg/mg 1E-6kg/mg lE-6kg/mg - - - - BW (k9) 70 15 70 15 15 70 15 70 70 NOTES: (1) Ingestion or inhalation rate (2) 70 years for carcinogens, 9 years for noncarcinogens for adult residents, and 6 years for noncarcinogens for children (multiplied by 365 days). (3) Conversion Factor (4) Soil dermal contact absorption factors: 3.3% = PCBs. Other Abbreviations: o o- H- CW = Chemical concentration in water CA = Chemical concentration in air CS = Chemical concentration in soil SA = Skin surface area available for dermal contact PC = Chemical-specific dermal permeability constant RF - Respirable fraction of participates AF = Soil-to-skin adherence factor SSC = Suspended soil concentration Fl = Fraction ingested Irom chemical source ET - Exposure Time EF = Exposure Frequency ED = Exposure Duration BW = Body Weight AT = Averaging Time parameters were obtained from several USEPA guidance documents including RAGS (USEPA, 1989a), Exposure Factors Handbook (USEPA, 1989b), and Dermal Exposure Assessment: Principles and Applications (USEPA, 1992c) as well as through discussion with the USEPA site Risk Assessment Specialist. The 95 percent UCL concentrations have been utilized in these calculations. Tables D-l through D-6 in Appendix D present the results of the central tendency calculations. 6.1.1 Surface Soil The results of central tendency calculations for residential exposure to carcinogens and noncarcinogens in surface soil of the Tillett Gardens and Art Center area via the ingestion (adults and children), dermal contact (adults and children), and inhalation (child only) routes are presented in Tables D-l through D-3, respectively. Table D-l, central tendency calculation for adult and child exposures to surface soil in the Tillett Gardens and Art Center area via ingestion, shows total carcinogenic risks of 6.5E-05 and 4. IE- 04, respectively. The adult total risk of 6.5E-05 is approximately 6.8 times less than the RME adult total risk of 4.4E-04 (Table C-l, Appendix C) and falls within the USEPA's 104 to lO" 6 target risk range. The child total risk of 4. IE-04 is approximately 2.4 times less than the RME child total risk of l.OE-03 and still exceeds the upper-bound of the USEPA's 104 to 10~ 6 target risk range. The 30-year combined risk for central tendency, 4.7E-04, is approximately 3.2 times less than the RME 30-year combined risk of 1.5E-03 (Table C-l, Appendix C) and still exceeds the upper-bounds of the USEPA's 104 to 10' 6 target risk range. 225 *~£~ *J "£'• I 1 ••(« |U' 006 2411 The central tendency calculation for child exposure to surface soil in the Tillett Gardens and Art Center area via ingestion shows a hazard index value of 1.2E+00. This value is approximately 2.5 times less than the RME child hazard index of 3.0E+00 (Table C-l, Appendix C) and still exceeds the USEPA's target level of one. Table D-2, central tendency calculation for adult and child exposures to surface soil in the Tillett Gardens and Art Center area via dermal contact, shows total carcinogenic risks of 1.3E-04 and l.OE-04, respectively. The adult total risk of 1.3E-04 is ten times less than the RME adult total risk of 1.3E-03 (Table C-2, Appendix C) and still exceeds the upper-bound of the USEPA's 104 to 10'6 target risk range. The child total risk of l.OE-04 is 3.9 times less than the RME child total risk of 3.9E-04 and falls within the USEPA's 104 to 10'6 target risk range. The 30-year combined risk for central tendency, 2.3E-04, is approximately 7.4 times less than the RME 30- year combined risk of 1.7E-03 (Table C-2, Appendix C) and still exceeds the upper-bound of the USEPA's 10"4 to 10'6 target risk range. Table D-3, central tendency calculation for child exposure to surface soil in the Tillett Gardens and Art Center area via inhalation, shows a hazard index value of 1.6E+00. This value is approximately 1.9 times less than the RME child hazard index of 3.1E+00 (Table C-3, Appendix C) and still exceeds the USEPA's target level of one. 226 6.1.2 Groundwater The results of central tendency calculations for residential, site worker (employee), and construction worker exposures to carcinogens and noncarcinogens in site groundwater via the ingestion route are presented in Tables D-4 through D-6. Table D-4, central tendency calculation for adult and child exposures to site groundwater via ingestion, shows total carcinogenic risks of 1.IE-04 and 1.7E-04, respectively. The adult total risk of 1. IE-04 is six times less than RME adult total risk of 6.6E-04 (Table C-32, Appendix C) and still exceeds the upper-bound of the USEPA's Ifr 4 to 10"6 target risk range. The child total risk of 1.7E-04 is approximately 1.8 times less than the RME child total risk of 3. IE-04 and still exceeds the upper-bound of the USEPA's 104 to 10"6 target risk range. The central tendency calculations for adult and child exposures to site groundwater via ingestion show hazard index values of 1.6E+01 and 3.7E+01, respectively. The adult hazard index of 1.6E+01 is approximately 1.8 times less than the RME adult hazard index of 2.9E+01 (Table C-32, Appendix C) and still exceeds the USEPA's target level of one. The child hazard index of 3.7E+01 is approximately 1.8 times less than the RME child hazard index of 6.7E+01 (Table C-32, Appendix C) and still exceeds the USEPA's target level of one. Table D-5, central tendency calculation for site worker (employee) exposure to site groundwater via ingestion, shows a total carcinogenic risk of 1.5E-04. This total risk is approximately 1.3 times less than the RME site worker (employee) total risk of 2.0E-04 (Table C-35, Appendix C) and still exceeds the upper-bound of the USEPA's 104 to 10'6 target risk range. 227 TUT OO6 2413 X"""' The central tendency calculation for site worker (employee) exposure to site groundwater via ingestion shows a hazard index value of 7.6E+00. This value is approximately 1.3 times less than the RME site worker (employee) hazard index of l.OE+01 (Table C-35, Appendix C) and still exceeds the USEPA's target level of one. Table D-6, central tendency calculation for construction worker exposure to site groundwater via ingestion, shows a hazard index value of 5.2E+00. This value is approximately 1.8 times less than the RME construction worker hazard index of 9.1E+00 (Table C-36, Appendix C) and still exceeds the USEPA's target level of one. Residential carcinogenic risks for ingestion and dermal contact exposure decreased approximately 2.5 to ten times in the calculation of central tendency when compared to RME residential ingestion and dermal contact carcinogenic risks for surface soil in the Tillett Gardens and Art Center area. Child hazard index values for ingestion and inhalation decreased approximately two to 2.5 times in the calculation of central tendency when compared to RME child ingestion and inhalation hazards for surface soil in the Tillett Gardens and Art Center area. For groundwater, residential carcinogenic risks for ingestion decreased approximately 1.8 to six times in the calculation of central tendency when compared to RME residential ingestion risks, for groundwater. Site worker (employee) carcinogenic risk for ingestion decreased approximately 1.3 times in the calculation of central tendency when compared to the RME site worker (employee) ingestion risk for groundwater. Noncarcinogenic hazard index values decreased by less than two times in the calculation of central tendency for residential, site worker (employee), and construction worker groundwater ingestion when compared to RME ingestion hazard index values for the same receptors. 228 TUT JT 006 2414 7.0 PRELIMINARY REMEDIATION GOALS (PRGs) Chemical - specific preliminary remediation goals (PRGs) are concentration goals for individual chemicals for specific medium and land use combinations at CERCLA sites. In this section, chemical-specific PRGs were developed based on the risk assessment (i.e., risk-based calculations). Site-specific parameter values were used in place of default parameters, where appropriate, to reflect site-specific conditions. Risk-based PRGs are initial guidelines only; they do not establish that cleanup to these goals is warranted. A risk-based concentration will be considered a final remediation level after analysis in the RI/FS and ROD. For this risk assessment, risk-based PRGs were not needed for any chemicals in a medium with a cumulative cancer risk of less than l.OE-04, where a hazard index was less than or equal to one, where the PRGs were clearly defmed by ARARs (i.e., MCLs), or where superseding USEPA guidance on action levels exists (i.e., PCBs in soil). Upon review of the spreadsheet calculations for site soils, several exceedances of the USEPA's target levels were noted. For surface soil, Aroclor 1242 showed carcinogenic risks in exceedance of l.OE-04 while hazard index values for manganese exceeded the target level of one. Per the USEPA's direction, recommended soil action levels for PCBs at the Tutu Wells site were obtained from the USEPA's 1990 fact sheet entitled "A Guide on Remedial Actions at Superfund Sites With PCB Contamination" (USEPA, 1990). For residential land use, an action level of 1 ppm was specified for PCBs. For industrial land use, an action level range of 10 to 25 ppm was specified. These levels, according to the USEPA, supersede risk-based 229 MJT 415 PRGs. No risk-based PRGs have therefore been calculated for the PCB Aroclor 1242 in site soil. Risk-based PRGs have been calculated for the noncarcinogen manganese in site soil. The risk- based equations used have been derived to reflect the potential risk from exposure to a chemical, given a specific pathway, medium, and land use combination. By setting the hazard index equal to one for a noncarcinogen, the concentration term (risk-based PRG) could be calculated. The formulas presented below have been obtained from the RAGS Human Health Evaluation Manual, Part B: Development of Risk-Based Preliminary Remediation Goals (USEPA, 1991b). 7.1 Residential Land Use: Soil Ingestion and Inhalation Under residential land use, risk from the chemical in soil is generally assumed to be due to the direct ingestion route only. For this site, however, the inhalation of suspended soil particulates route has also been included since the hazard quotient for manganese via the inhalation route is slightly is greater than that calculated for the ingestion route and both exceed the USEPA's target level of one. Total risk from soil = Risk from ingestion of soil (child to adult) + Risk from inhalation of particulates from soil (child to adult) Because the soil ingestion rate is different for children and adults, the risk due to direct ingestion of soil is calculated using an age-adjusted ingestion factor. The age-adjusted soil ingestion factor (IF soii/adj) takes into account the difference in daily soil ingestion rates, body weights, and 230 TUT OO6 2416 exposure durations for two exposure groups - children (0 to 6 years) and others (7 to 30 years). Exposure frequency (EF) is assumed to be identical for the two exposure groups. For convenience, this ingestion factor has been calculated separately as a time-weighted soil intake, normalized to body weight, and then substituted in the total intake equations (see Equations (2) and (3)). This ingestion factor leads to a more protective risk-based concentration compared to an adult-only assumption. The ingestion factor is in units mg-yr/kg-day and therefore is not directly comparable to daily soil intake rate in units of mg/kg-day. Equation (1) presents the formula for calculation of the age-adjusted soil ingestion factor. Age-Adjusted Soil Ingestion Factor TP ir soil/adj (mg-yr/kg-day) = JR_soU/agc 0 6 x ED 3ge p.6) + £HL«a/.ie 7-30 * ED BW Vagi age 0-6 BW (1) age 7-30 Parameters Definitions (units) age-adjusted soil ingestion factor (mg-yr/kg-day) o_6 average body weight from ages 0-6 (kg) BW age 7.30 average body weight from ages 7-30 (kg) ^e 0-6 exposure duration during ages 0-6 (yrs) age 7-30 exposure duration during ages 7-30 (yrs) IR joa/age M ingestion rate of soil for ages 0-6 (mg/day) IR sou/age 7-30 ingestion rate of soil for all other ages (mg/day) Site-Specific Values 114 mg-yr/kg-day 15kg 70kg 6 yrs 24 yrs 200 mg/day 100 mg/day 231 TUT OO6 2417 7.1.1 Noncarcinogens The total hazard index has been calculated by combining the appropriate oral and inhalation reference doses with the intakes from soil. These intakes were combined and a risk-based PRG was derived to be protective for both exposure pathways. Hazard Index = Intake from ingestion of soil 4- Intake from inhalation of soil particulates RfD0 RfD; Adding appropriate parameters and solving for the concentration (C) results in Equation (2). Equation (3) is the reduced version of Equation (2), using site-specific input parameters where appropriate. This reduced equation was used for calculating the risk-based PRG at the target level of one. It combines the toxicity information of a specific chemical with site- specific exposure parameters for residential land use to generate a concentration for that chemical that corresponds to a hazard index of one. The risk-based PRGs calculated for site soil are presented in Table 7-1. Residential Soil - Noncarcinogenic Effects THI = C x 10-6kg/mg x EF x IF.^,,^ + C x ED x EF x IR.;, x (1/PEF) RfD0 x AT x 365 days/yr RfD; x BW x AT x 365 days/yr (2) C (mg/kg; = THI x AT x 365 days/yr__________________________ risk based) [(l/RfD0 x 10'6 kg/mg x EF x IF ^^ + (1/RfDj x ED x EF x IR air x 1/BW x (1/PEF))] 232 TUT 006 2418 where: Parameters C THI RfD0 BW AT EF ED IRair PEF Definitions (units') chemical concentration in soil (mg/kg) target hazard index (unitless) chronic oral reference dose (mg/kg-day) chronic inhalation reference dose (mg/kg- day) adult body weight (kg) averaging time (yrs) exposure frequency (days/yr) exposure duration (yrs) age-adjusted ingestion factor (mg-yr/kg-day) inhalation rate (m3/day) particulate emission factor (m3/kg) Site-Specific Values 1 chemical-specific chemical-specific 70kg 30 yrs (for noncarcinogens, equal to ED [which is incorporated in 350 days/yr 30 yrs 114 mg-yr/kg-day (see Equation 1) 20 mVday 4.63 x 109 m3/kg Reduced Equation: Residential Soil - Noncarcinogenic Effects Risk-based PRO = (mg/kg; THI = 1) 1.095E+04 [(4.0E-02/RfD0) + (6.5E-07/RfDj)] (3) where: RfD0 = chronic oral reference dose in mg/kg-day RfD; = chronic inhalation reference dose in mg/kg-day 233 TUT O06 2419 TABLE 7-1 TUTU WELLS SITE SOIL RISK-BASED PRELIMINARY REMEDIATION GOALS (PRGs) FOR NONCARCINOGENS (mg/kg) RESIDENTIAL INGESTION AND INHALATION: Chemical Risk-Based PRGs Manganese 1,360 COMMERCIAL/INDUSTRIAL INGESTION AND INHALATION: * Chemical Risk-Based PRGs Manganese 9,900 234 TUT OO6 2420 7.2 Commercial/Industrial Land Use : Soil Ingestion and Inhalation Under commercial/industrial land use, risk from the chemical in soil was also assumed to be due to direct ingest:on and inhalation of particulates from the soil, and was calculated for an adult worker only. For this type of land use, it was assumed in calculating risk-based PRGs that the potential exists for use of heavy equipment and related traffic in and around contaminated soils and thus for soils to be disturbed and produce particulate emissions. Intakes from the two exposure pathways were combined and the risk-based PRG was derived to be protective for exposures from both pathways. Total risk from soil = Risk from ingestion of soil (worker) + Risk from inhalation of particulates from soil (worker) 7.2.1 Noncarcinogens The total hazard index has been calculated by combining the appropriate oral and inhalation reference doses with the two intakes from soil: Hazard Index = Intake from ingestion of soil + Intake from inhalation of particulates RfD0 RfD; Adding appropriate parameters and solving for the concentration (C) results in Equation (4). Equation (5) is the reduced version of Equation (4), using site-specific input parameters where appropriate. This reduced equation was used for calculating the risk-based PRG at the target level of one. It combines the toxicity information of a specific chemical with site-specific 235 TUT OO6 2421 exposure parameters for commercial/industrial land use to generate a concentration for that chemical that corresponds to a hazard index of one. The risk-based PRO calculated for commercial/industrial soil land use is presented in Table 7-1 along with the residential soil land use risk-based PRG. Commercial Industrial Soil - Noncarcinogenic Effects THI = C x IP'6 kg/mg x EF x ED x IR..;, -I- C x EF x ED x IR.ir x fl/VF + 1/PEF) RfD0 x BW x AT x 365 days/yr RfD; x BW x AT x 365 days/yr (4) C (mg/kg; = __________THI x BW x AT x 365 days/vr______________ risk based)[ED x EF x [((l/RfD0) x 1Q- 6 kg/mg x IRsoil) + ((1/RfDj) x IR^ x 1/VF-f 1/PEF))] where: Parameters Definitions (units) C THI RfD0 RfDs BW AT EF ED VF PEF chemical concentration in soil (mg/kg) target hazard index (unitless) chronic oral reference dose (mg/kg-day) chronic inhalation reference dose (mg'/kg-day) adult body weight (kg) averaging time (yrs) exposure frequency (days/yr) exposure duration (yrs) soil ingestion rate (mg/day) workday inhalation rate (mVday) soil-to-air volatilization factor (m3/kg) paniculate emission factor (mVkg) Site-Specific Values 1 chemical-specific chemical-specific 70kg 25 yrs (always equal to ED) 250 days/yr (site worker) 25 yrs (site worker) 50 mg/day (site worker) 20 m'/day not applicable 4.63 x 109 mVkg 236 TUT O06 2422 Reduced Equation: Commercial Industrial Soil - Noncarcinogenic Effects Risk-based = ______________102_____________ (5) PRO (mg/kg; [(5E-5/RfD0) + ((4.3E-9/RfDi)] THI = 1) (Site worker) where: RfD0 = chronic oral reference dose in mg/kg-day RfDj = chronic inhalation reference dose in mg/kg-day 7.3 Residential Land Use: Groundwater Ingestion and Inhalation In reviewing the spreadsheet calculations for site groundwater, tetrachloroethene and vinyl chloride showed carcinogenic risks in exceedance of l.OE-04. However, since these chemicals /—N have established MCLs of 5 and 2 ug/1, respectively, PRO calculations were not necessary per direction from the USEPA. The chemicals 1,2-dichloroethene (total), tetrachloroethene, antimony, and manganese were found to individually exceed a hazard index of one in site groundwater. Vanadium showed a hazard index of 1 .OE+00 for child ingestion of groundwater which is equal to the target level. Of these chemicals, only tetrachloroethene and antimony have established MCLs. PRGs were therefore calculated for 1,2-dichorethene (total) and manganese. For the calculation of risk-based PRGs, risk-based equations have been derived to reflect the potential risk from exposure to a chemical, given a specific pathway, medium, and land use combination. By setting the total risk for carcinogenic effects at a target level of 10"6, (the /""""X NCP's point of departure for analysis of remedial alternatives) or the hazard index equal to one for noncarcinogens, the concentration terms (risk-based PRGs) can be calculated. The formulas 237 TUT 006 2423 presented below have been obtained from the RAGS HHEM, Part B: Development of Risk-based Preliminary Remediation Goals (USEPA, 1991b). Under residential land use, risk from chemicals in groundwater was assumed to be due primarily to direct ingestion and to inhalation of VOCs while showering, and was calculated for an adult. Intakes from the two exposure pathways were combined and the risk-based PRGs were derived to be protective for exposures from both pathways. Total risk from water = Risk from ingestion of water (adult) + Risk from inhalation of VOCs while showering (adult) . Risk from indoor inhalation of VOCs is assumed to be relevant only for VOCs that easily volatilize. 7.3.1 Noncarcinogens The total hazard index has been calculated by combining the appropriate oral reference doses with the groundwater ingestion intakes (the inhalation of VOCs has not been evaluated as no inhalation reference dose is available for 1,2-dichloroethene (total), the only VOC for which a PRG is being calculated). 238 TUT 006 2424 Hazard Index = Intake from ingestion of groundwater RflX Adding appropriate parameters and solving for the concentration (C) results in Equation (6). Equation (7) is the reduced version of Equation (6), using site-specific input parameters, where appropriate. This reduced equation was used for calculating the risk-based PRO at the target level of one. It combines the toxicity information of a specific chemical with site-specific exposure parameters for residential land use to generate a concentration for that chemical that corresponds to a hazard index of one. The risk-based PRGs calculated for the residential groundwater scenario for this site are presented in Table 7-2. Residential Groundwater - Noncarcinogenic Effects Parameters C THI RfD0 BW AT EF ED THI = C x IR... x EF x ED RfD0 x BW x AT x 365 days/yr C (mg/1; risk = THI x BW x AT x 365 days/yr (6) based) EFxED x !/RfD 0xIR w Definitions (units') chemical concentration in water (mg/1) target hazard index (unitless) chronic oral reference dose (mg/kg/day) adult body weight (kg) averaging time (yrs) exposure frequency (days/yr) exposure duration (yrs) daily water ingestion rate (I/day) 239 Site-Specific Values 1 chemical-specific 70kg 30 yrs (for noncarcinogens, equal to ED) 350 days/yr 30 yrs 2 I/day TUT 006 2425 Reduced Equation: Residential Groundwater - Noncarcinogenic Effects Risk-based PRG = ____________73____________ (7) (mg/1; THI = 1) 2/RfD0 where: RfD0 = chronic oral reference dose in mg/kg-day Although the Tutu Wells site may continue to be commercially developed, the site will likely remain residential, at least in part, indefinitely into the future. Since the NCP encourages protection of groundwater to its maximum beneficial use, once the groundwater is determined to be suitable for drinking, risk-based PRGs should be based on residential exposure (USEPA, 1991b). Therefore, risk-based PRGs have been developed for residential groundwater use only, to be protective of human health. 240 TUT O06 2426 TABLE 7-2 TUTU WELLS SITE GROUNDWATER RISK-BASED PRELIMINARY REMEDIATION GOALS (PRGs) FOR NONCARCINOGENS (mg/1) RESIDENTIAL INGESTION: Chemicals Risk-Based PRGs 1,2-Dichloroethene (Total) 0.33 Manganese 0.18 241 TUT 006 2427 8.0 SUMMARY OF THE BASELINE RISK ASSESSMENT In this baseline human health risk assessment, the site matrices surface soil, subsurface soil, and groundwater were quantitatively evaluated for potential health threats to human receptors via the ingestion, dermal contact, and inhalation routes of exposure. Receptors including residents (adults and children), site workers (employees), and construction workers were evaluated under present and potential future land use conditions, as appropriate. The results of the risk and hazard index calculations and the greatest chemical contributors to these estimates have been presented and discussed. Chemicals of potential concern were selected for each matrix based on criteria outlined in RAGS (USEPA, 1989a) and presented in Section 2.3. The chemicals of potential concern included VOCs, SVOCs, a PCS, and inorganics. The chemicals 2-hexanone, n-propylbenzene, 1,1,1- trichloroethane, benzo(g,h,i)perylene, dibenzofuran, 2-nitrophenol, acenaphthylene, methyl- tertiary-butyl-ether, 2-methylnaphthalene, phenanthrene, TPH, aluminum, cobalt, copper, iron, and lead could not be quantitatively evaluated in this risk assessment due to their lack of established toxicity values. The essential nutrients (i.e., calcium, magnesium, potassium, and sodium) were not quantitatively evaluated as their potential toxicity is significantly lower than other inorganics at the site, and most existing toxicological data pertain to dietary intake. Exposure routes and receptor groups were identified and quantitative estimates of the magnitude, frequency, and duration of exposure were made. Exposure points were estimated using the 95 percent UCL calculation, as appropriate. Chronic and subchronic daily intakes for ingestion, 242 TUT 006 2428 dermal contact, and inhalation routes were calculated for the reasonable maximum exposure (i.e., using 95 percent UCL concentrations and 90th and 95th percentile exposure parameters). In the toxicity assessment, current lexicological human health data (i.e., reference doses, reference concentrations, and slope factors) were obtained from various sources and were utilized in the order specified by RAGS (USEPA, 1989a). Brief lexicological profiles for chemicals which could not be quantitatively evaluated in the risk assessment have been included in this section (4.0). Toxicological profiles for the chemicals of potential concern have been developed and are presented in Appendix B. Risk characterization involved integrating the exposure and toxicity assessments into quantitative expressions of risks/health effects. Specifically, chronic and subchronic daily intakes were compared with concentrations known or suspected to present health risks or hazards. The carcinogenic risks and noncarcinogenic hazard index values calculated at the site are based on the reasonable maximum exposure (the highest exposure reasonably expected to occur at a site). The intent is to estimate a conservative exposure case that is still within the range of possible exposures. In accordance with the National Oil and Hazardous Substance Pollution Contingency Plan (NCP) Section 300.430 (e)(2) for known or suspected carcinogens, acceptable exposure levels are generally concentration levels that represent an excess upper-bound lifetime cancer risk to an individual of between 10^ and 10'6. Per the RAGS Part B: Development of Risk-Based Preliminary Remediation Goals (USEPA, 199Ib), for noncarcinogenic effects, the NCP does not specify a range, but it is generally appropriate to assume a hazard index equal to one. 243 TUT O06 2429 In general, the USEPA recommends a target range and a target level (i.e., carcinogenic risk of 10^ to 10* or noncarcinogenic hazard index of one) as threshold values for potential human health impacts (USEPA, 1989a). The 1Q-4 to IQ-6 target risk range may be interpreted as meaning carcinogenic risks should not be greater than approximately 1 in 10,000 to 1 in 1,000,000. For this risk assessment, the upper-bound of the target risk range is l.OE-04. A risk greater than 1 in 10,000 or l.OE-04 is considered to be in exceedance of the USEPA's 104 to 10"6 target risk range. These target values aid in determining the objectives of the baseline human health risk assessment which include determining whether additional response action is necessary at, the site, by providing a basis for determining residual chemical levels that are adequately protective of human health, by providing a basis for comparing potential health impacts of various remedial alternatives, and to help support selection of the "no action" remedial alternative, where appropriate. In addition, the chemicals of potential concern in site groundwater were compared to federal MCLs (Table 5-3). All VOC maximum detections, except for 1,2-dichloroethene (total) which does not have an established MCL, far exceed their respective established MCLs. The maximum concentrations of all of the inorganics except for manganese exceed their respective MCLs. Manganese does not currently have an established primary MCL, although it does have a nonenforceable secondary MCL of 50 ug/1. Vanadium, which also does not have an established MCL, did not result in any hazard quotients above one. Human Health Risks and Hazards Identified The following discussion presents by receptor group carcinogenic risks and noncarcinogenic hazard index values in exceedance of the USEPA's target values for the matrices evaluated in 244 IUr 006 2430 this risk assessment. Brief mention of those risks and hazards not exceeding any target values are also included for completeness. Residents Surface Soil: Present and potential future residents in the Tillett Gardens and Art Center area were quantitatively evaluated for surface soil exposure via the ingestion, dermal contact, and inhalation of particulates (future-use only) routes. The ingestion and dermal contact routes of exposure showed carcinogenic risks in exceedance of the upper-bound of the target risk range (i.e., greater than l.OE-04). These risks ranged from 4.4E-04 (ingestion) to 1.3E-03 (dermal contact) for adults and from 3.9E-04 (dermal contact) to l.OE-03 (ingestion) for children. These risks were due largely to Aroclor 1242. The child ingestion and inhalation of surface soil routes of exposure showed hazard index values in exceedance of one. The child ingestion hazard index (3.0E4-00) and the child inhalation hazard index (3.1E+00) combined resulted in a total hazard index of 6.1E+00 which was due largely to manganese. No adult hazard index values exceeded one. Subsurface Soil: Potential future residents in the Tillett Gardens and Art Center area were quantitatively evaluated for subsurface soil exposure via the dermal contact and inhalation of particulates routes. Neither of these routes of exposure (the dermal contact route could not be quantitatively evaluated) resulted in carcinogenic risks or hazard index values in exceedance of the upper-bound of the USEPA's ICr 4 to 10"6 target risk range for carcinogens or target level of one for noncarcinogens. 245 TUT 006 2431 Groundwater: Present and potential future residents at the site were quantitatively evaluated for site-wide ground water exposure via the ingestion, dermal contact (during showering), and inhalation of VOCs (during and after showering) routes. Only the ingestion route of exposure showed carcinogenic risks in exceedance of the upper-bounds of the target risk range (i.e., greater than l.OE-04). These risks, 6.6E-04 for adults and 3.IE-04 for children, were due largely to tetrachlorethene and vinyl chloride. The ingestion of groundwater by adults and children showed hazard index values in exceedance of one. The adult hazard index of 2.9E+01 was due largely to 1,2-dichloroethene (total) and manganese, while the child hazard index of 6.7E+01 was due largely to 1,2-dichloroethene (total), tetrachloroethene, antimony, manganese, and vanadium. Site Workers (Employees) Surface Soil: Present and potential future site workers (employees) in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co., Curriculum Center Building, and O'Henry dry cleaners and Liquor Barn were quantitatively evaluated for surface soil exposure via the ingestion, dermal contact, inhalation of particulates (future-use only), and inhalation of VOCs (O'Henry dry cleaners and Liquor Barn only) routes. None of these routes of exposure (the dermal contact route could not be quantitatively evaluated) resulted in carcinogenic risk or hazard index values in exceedance of the upper-bound of the USEPA's 104 to 10"6 target risk range for carcinogens or target level of one for noncarcinogens. 246 TUT 006 2432 Subsurface Soil; Potential future site workers (employees) in the Fire Department/Texaco gas station/Antilles auto parts/Ramsay motor co., Curriculum Center Building, Esso gas station and Splash and Dash car wash, and O'Henry dry cleaners and Liquor Barn areas of concern were quantitatively evaluated for subsurface soil exposure via the dermal contact and inhalation of particulates routes. None of these routes of exposure (the dermal contact route could not be quantitatively evaluated) resulted in carcinogenic risks or hazard index values in exceedance of the upper-bound of the USEPA's 1CF* to 10"6 target risk range for carcinogens or target level of one for noncarcinogens. Groundwater; Present and potential future site workers (employees) were quantitatively evaluated for site groundwater exposure via the ingestion route. The carcinogenic risk of 2.0E- 04 is in exceedance of the upper-bound of the USEPA's 104 to 10"6 target risk range and is due largely to tetrachloroethene and vinyl chloride. The hazard index of 1 .OE+01 exceeds the target level of one and is largely due to manganese. Construction Workers Surface and Subsurface Soil; Potential future construction workers in the Tillett Gardens and Art Center area were quantitatively evaluated for surface soil and subsurface soil exposure via the ingestion, dermal contact, and inhalation of particulates routes. None of these routes of exposure resulted in carcinogenic risks or hazard index values in exceedance of the upper-bound of the USEPA's 10"4 to 10~6 target risk range for carcinogens or target level of one for noncarcinogens. 247 TUT OO6 2433 Groundwater; Potential future site construction workers were quantitatively evaluated for site groundwater exposure via the ingestion route. The carcinogenic risk of 7. IE-06 is not in exceedance of the upper-bound of the USEPA's 1CF 4 to 10' 6 target risk range. The hazard index of 9.1E+00 exceeds the target level of one and is due largely to manganese. Summary of Risks and Hazards A review of the carcinogenic risks for the various matrices and receptor populations showed that present and potential future residential exposure to surface soil in the Tillett Gardens and Art Center via ingestion and dermal contact, and to groundwater via ingestion were in exceedance of the upper-bound of the USEPA's target risk range of 1Q4 to 10" 6. Site worker (employee) and construction worker carcinogenic risks from exposure to groundwater were also in exceedance of the upper-bound of the USEPA's 1Q4 to 10"6 target risk range. A review of the noncarcinogenic hazard index values for the site matrices and receptors showed that present and/or potential future child exposures to surface soil in the Tillett Gardens and Art Center via ingestion and inhalation and present and potential future resident, site worker (employee), and construction worker (future-use only) exposures to groundwater via ingestion were in exceedance of USEPA's target level of one. MCLs for the chemicals of potential concern in groundwater have been presented in Table 5-3 for comparison to site detections. The maximum detected site concentrations of benzene, tetrachloroethene, toluene, vinyl chloride, antimony, arsenic, beryllium, chromium VI, and nickel were found to exceed current Federal drinking water standards. 248 Site-specific uncertainties relating to the risk assessment were qualitatively and quantitatively addressed in Section 6.0. In accordance with standard risk assessment practice, central tendency calculations were performed as a quantitative measure of uncertainty in the risk assessment and are presented in Tables D-l through D-6 in Appendix D. The 50th percentile parameters used in these calculations and presented in Table 6-1 were assumed to be representative of the general population. These central tendency calculations, however, have the potential to underestimate true risks/hazard index values for sensitive receptors. Finally, risk-based PRGs were calculated for residential and commercial/industrial land use and for residential groundwater use for risks greater than l.OE-04 and hazard indices greater than one and are presented in Tables 7-1 and 7-2. Per USEPA direction, PRGs were not calculated for chemicals of potential concern in soil where superseding USEPA guidance on action levels exists or in groundwater if MCLs exist. Risk-based PRGs are initial guidelines only and do not establish that cleanup to these goals is required. A risk-based concentration is considered a final remediation level only after analysis in the RI/FS and ROD. 249 TUT 006 2435 REFERENCES Agency for Toxic Substances and Disease Registry (ATSDR). 1994. Toxicological Profile for Methyl-t-Butyl Ether (Draft). U.S. Public Health Service, August 1994. Andelman, J. 1990. Total Exposure to Volatile Organic Compounds in Potable Water, Chapter 20. In: Significance and Treatment of Volatile Organic Compounds in Water Supplies. 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