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GERAGHTY MILLER, INC. Environmental Services Ground Water Engineering Hydrocarbon Remediation Education September 16, 1991 Ms. Caroline Kwan U.S. Environmental Protection Agency Region II 26 Federal Plaza New York, NY 10278 RE: Response to Laura Scalise's Draft Comments on Tutu Service Station Investigation Work Plan dated Mav 1991 Dear Ms. Kwan: On behalf of the Tutu Environmental Investigation Committee (TEIC), Geraghty & Miller, Inc. has prepared this response for the above-referenced comments received on September 11, 1991 via facsimile from Caroline Kwan, USEPA Project Manager. Most of Ms. Scalise's comments were relatively minor. Based upon our review and telephone discussion today between Laura Scalise and Thomas Danahy, we believe the majority of Ms. Scalise's should be incorporated in the work plan. The significant items are highlighted below. o Page 12 Shallow/Deep Bedrock Monitoring Wells Geraghty & Miller proposed that carbon steel casing be used for monitoring wells constructed with open bedrock intervals. Ms. Scalise stated that contact between the carbon steel casing and the ground water was unacceptable, even if careful purging and sampling procedures were followed. Therefore, stainless steel casing must be used at all well locations. 201 West Passaic Street, 3rd Floor• Rochelle Park, New Jersey 07662-(201) 909-0700-FAX (201) 909-0567/0568 TUT OO& 190 *64919* 64919 GERAGHTY^ MILLER, INC. o Table O - Locations of Samples Ms. Scalise requested in her written comments that a new table be created which lists each location of ground water and subsurface soil samples. During our telephone conversation today, Ms. Scalise stated her intent was to clarify some inconsistencies caused by typographical errors at various locations in the work plan. She stated that if the inconsistencies could be clarified elsewhere, then the new table would not be necessary. o Appendix B - Split-Spoon Sampling 1. Boring B-ll and B-12 will be included on page 17 of the text to be consistent with the first paragraph in Appendix B. 2. 1.7 - A minimum of one soil sample from each boring will be submitted for laboratory analysis. A field split of the sample with highest total VOC content, based on field GC analysis, from each boring will be submitted for laboratory analysis. During sample collection one 40-ml vial will be half-filled with soil for GC analysis. Two other 40-ml vials will be completely filled (avoiding headspace) for possible laboratory analysis. If no elevated VOC concentrations are detected, the sample immediately above the water table or bedrock interface will be sent for laboratory analysis. o Appendix C - Field GC Procedures Ms. Scalise was informed that the field gas chromatograph (GC) will be operated in an air-conditioned field trailer. Ms. Scalise still required daily preparation of a calibration standard. However, this daily standard can be prepared from a higher concentration stock standard which should be kept refrigerated and prepared once per week. During our telephone conversation, Ms. Scalise agreed that (in the interest of productivity) a TUT 006 1904 ,* GERAGHTY& MILLER, INC. calibration check should be run at least every four hours; or sooner if the GC operator believes it is necessary. o Appendix G - Monitoring Well Sampling Protocol The introduction will be revised to state "The 17 monitoring well (MW-1 through MW- 10 and MW-1D, MW-4D, MW-6D, MW-10D, MW-1 ID, MW-12D, and MW-13D) will be sampled...". The remainder of Ms. Scalise's comments will be addressed as proposed. If you have any questions, please call. Sincerely, GERAGHTY & MILLER, INC. ^+JL/ Thomas V. Danahy, P.O. fl Senior Scientist/Project Manager Daniel A. Nachman ' Vice President/Project Director TVD:gv #PR00801/091691a.ltr TUT OO6 19O5