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wewese Ty i WATER QUALITY OF CISTERN WATER IN ST. THOMAS, U.S.V.I. A. Preliminary Survey F. Rinehart, R. Peebles, P. Hoffman B. Microbial Analysis and Major Ion Composition M. J. Canoy, A. Knudsen Project No. A-010-VI Agreement No. 14-34-0001-1150 September 1983 The work upon which this report is based was supported in part by funds provided by the United States Department of the Intertor, as authorized by the Water Research and Development Act of 1978 is Technical Report No. 2+ Caribbean Research Institute College of the Virgin Isiands St. Thomas, USVI 00802 [ r r r ~ [ [ [ i: r [ [ DISCLAIMER Contents of this publication do not necessarily r reflect the views anc policies of the U. S. [ Department of the Interior, nor does mention of trade names or commercial vroducts con. ui sti tute [ their endorsement or recomnendations for use by [ the U. S. Government. . ° L - 3 9 9 ABSTRACT A study in two phases was conducted in the Virgin Islands to determine the major ions and microbial species in the cistern water of the U.S. Virgin Islands. The first phase was a survey of a sample set of cisterns to determine the scope and limits of the problem. The second phase was an indepth study of bacterial species and eight ion species. A significant proportion of water supply in the U.S. Virgin Islands comes from the rainfall which is stored in cisterns. All dwelling units are required by law to have cisterns. Since cistern water is not part of the public distribution svstem, it is not covered by the Safe Drinking ater Act (Public Law 93-523). The objective of this study was to determine whether cistern water supplies pose a potential health hazard to their users. Cistern water supplies were studied to assess the types of heterotrophic bacteria and ion species that may be present. The bacterial study was directed towards identifying those organisms capable of causing disease in water supplies. Total coliform, fecal coliform, fecal streptococcus, and Salmonella/shigella spp. were enumerated. The presence of coliform bacteria, fecal streptococcus, and Salmonella/ shigella spp. in most of the cistern water supplies suggest potential health problem. There was no clear pattern of con- tamination found; however, the general prevalence of contam- ination suggests potentially dangerous chronic infection from several possible sources and the levels of contamination were higher in public housing projects, located near main roads, and where trees overhung collection surfaces. Generally the levels of metals contamination found were well within the Public Health standards. Very few of the private cisterns however met microbial standards. Only three of the public housing tests met the legal health standards, and two of those had high Salmonella/shigella test results which meets “legal" standards but may be more significant health-wise. A recommendation is made to carry out a detailed study of contamination types, levels, and sources for water supplies in the Virgin Islands. Also suggested is creation of a local law regulating the quality of all water for sale and all cisterns. Such water sources are not now controlled. iii re rr rn nr 7 — 79 a) p) 4a TN ACKNOWLEDGEMENTS We are grateful to two chemistry students at the College of the Virgin Islands, Miss Leslie Dewar and Mr. Auckland Isaac, who have made technical contributions to the project, Mr. Lorden Warrington, Student Assistant in the CRI Environmental Laboratory, and Mr. Kim G. Stearman, of CVI Agricultural Extension Service, for metal analysis. We are thankful also to the Administrative Staff of CRI, especially Miss Cynthia Rymer, for typing and proofing the final manuscript. - iv a | oy a —~ oJ “FJ FD a TABLE OF CONTENTS Abstract Acknowledgements List of Tables List of Figures Setting Introduction Characteristics of Household Cistern Systems PHASE I Methods of Analysis Results Conclusions PHASE II wee ee ee ee ek kk ee Sampling and Analytical Program Results Discussion Conclusions Recommendations References Page iii iv vi vii 10 15 23 25 31 46 47 50 LIST OF TABLES Page PHASE Table Geographical Distribution of Study Sites 10 Table Most Probable Number Index 12 15 fA Table Cation Detection Limits/ppm. Table Chemical Analysis. 19 Table Bacterial Assays 20 “ . = Table 6A Total Bacterial Count Table 6B Total Coliform Count 21 Table 6C - fo) Total Streptococci Count Table 6D Total Salmonella sp. Count 22 PHASE II Table Media 29 Table Bacterial Profiles for 100 Cisterns 32 rf Table 37 pH and Metal Ions Table Drinking Water Guidelines and Regulations 39 ' Table Chemical and other Characteristics of Cistern and other Water Supplies for 42 St. Thomas, Virgin Islands Table Analyses of Water of St. Thomas 43 | vi LIST OF FIGURES Page PHASE I Figure 1 The U.S. Virgin Islands Location Map . 2 PHASE II Figure l Sample Flow Sheet for Water Analysis .. . 28 vii re rr nr nr ~ 3 a re ne | | 3 E) ~— ya 3 OF OD ~ "> SETTING St. Thomas, a Caribbean island in the U.S. Virgin Islands, relies on a variety of sources for its domestic water supply. In the early 1970's, these sources included wells on the eastern part of the island, three desalinization plants, water barged from Puerto Rico, and a large number of individual household cistern systems. At one time, large municipal cisterns were operating, however, these systems have not been maintained and were functioning only at the College of the Virgin Islands during this study. Duplicate water samples were collected from over 130 household cisterns as well as from other sources of domestic water on the island. THis paper presents the results-of the chemical and microbial analyses. done on these samples and discusses the type and water quality of household cistern water supplies for domestic use. St. Thomas is 4.8 km (3 miles) wide and 19 km (12 miles) long. It has a backbone ridge of mountain which rise to approximately 457 m (1500 ft.) above sea level. The climate of St. Thomas is essentially marked by constant easterly trade winds and maximum average temperatures about 27°C (80°F) in the winter an OO. SC to 352°C (§7-8S°F} during the Summer. Average relative humidity is above 80%. Rainfall fo] f. Ly OCE4N GULF OF MEXICO \)e “ aTLanric ee’ BAHAMAS q CUR HAITS: CaiTEDOMIN IC AN ne a ll HONDURAS “<> ane wine * wre wi BRITANICA JAMAICA a ae) “HONDURAS | CO4RIBBEAN SEA 14 — ~ EL SALVAD NICARAGUA A D PACIFIC ~ oH Lg OSTA\ Sfrainiap OCEAN ICA) COLOMBIA) —_ VENEZUELA al RL RE i ATLANTIC OCEAN ST. THOMAS 5 CHARLOTTE AMALIE SAO, ST. JOHN CARIBBEAN SEA > 4 CHRISTIANSTED FREDERIKSTED ST. CROIX fs THE U.S. VIRGIN ISLANDS 4 LOCATION MAP Fig 1 2 ~ | ~~3 ar) ar) —. ee) frequently occurs in the form of brief showers, with the higher elevations on the island tending to receive greater amounts of rainfall, on the order of 102-186 cm (40-80 in.) per year. Average monthly rainfall for the month of December through June is 5 to 7.5 cm (2-3 in.), while for July through November it is on the order of 10 to 12.5 cm (4-5 in.) of which 80% is during July and November. The population of the Virgin Islands is approximately 110,000 persons, having doubled in 15 years and being ex- pected to double again in the next 10 years. The water problem is expected to parallel oT exceed this growth rate. 4 a) “3 93 | ~~ 3 ~~ 3 a re re a ne) “~~ a) a re INTRODUCTION Fresh water has always been in critical supply in St. Thomas. Rain collected on roofs and stored in cisterns is still the source of water for most rural and urban domes - tic supplies. Before 1960, hillside rain catchments and a few dug wells were the major source of water for public supplies. Since that time desalted water barged from Puerto Rico, was a close second until 1981. Barging has been discontinued for years at this time. i) Charlotte Amalie has a dual public water system. Fresh water is used for drinking anc general household needs, and Salt water is used for sanitary and fire-control purposes. The fresh-water supply is obtained from salt-water distilla- tion plants, hillside rain catchments, and wells. In the late 1950s, with the exception of 1957, a drought year, catch- ments were the major source of water. Barged water became the major source of supply in the early 1960s, but by the jate 1960s, desalted water became the principal source of supply. At the time of sampling, these desalinization plants were producing only 2.5 mgd. Since the desalinized water, well water, and water barged in from Puerto Rico were likely to be of markedly cifferent chemical composition, the com- position of the domestic waters of Charlotte Amalie could be somewhat variable. ae) rr ee rr rr ce | | Rooftop catchments and cisterns are still the major source of water for rural St. Thomas. During prolonged dry periods, rain water is supplemented by water hauled from public-supply points in Charlotte Amalie. Small ponds have been constructed, tapping storm runoff for irrigation water for trutk gardening and drinking water for stock. Since 1962 about 40 wells have been drilled, but these are not systema- tically pumped,and many are contaminated from inadequate septic tank leaching fields or storm runoff. This study represents a follow-up of critical directions indicated by Isquith and Winters (1981), and Lee and Jones (1982). These studies indicated that wells were heavily contaminated,and at least some. cisterns were no better. A preliminary study done by Rinehart, et al, as a guide to areas of concern has been described under Phase I of this report. The Rinehart report showed problems existed but called into question the two other reports in terms of degree and extent. Phase II explores the degree, nature, and possibie pattern of contamination. The conclusions and recommendations > are aimed at local interests and management as well as water resource scientists. 4 “a 3 a) a) a) 9 —y CHARACTERISTICS OF HOUSEHOLD CISTERN SYSTEMS Many of the homes in St. Thomas are constructed in such a way that all,or at least a substantial part, of the roof collects rain water and transports it to storage tanks located within or below the house. Debris that collects on a roof accumulates in the storage tank along with the rain water. The water from this tank is used to meet most house- hold needs. Some residents find that for a variety of reasons the cistern water supply is inadequate to meet the needs of the household. Supplemental water can be purchased from a private water supplier who delivers water via truck to the cistern systems. The trucked water was, at the time of this study, derived primarily from wells that had been found to have elevated coliform counts, even though the water from these wells was chlorinated. Private trucks also deliver desalinated water from government stand pipes. There are no restrictions on the composition of the cistern roof collection systems or their paint. The cistern tanks were composed of various materials, including painted and unpainted concrete, galvanized metal, sheet-rubber lined concrete and fiberglass. The existing roof collection systems also varied widely in their construction and composition. Some were galvanized iron, usually painted with red lead paint within a fex years after construction. Others were terr 134) cotta tile, concrete, or plywood covered with tar paper | 3 a a re a) a ee 3 ~~" and coated with hypolon. The roofs of many of the newer homes were constructed of fiberglass-desco which was periodi- cally painted. There are several types of paint used frequently for roofs on this island. One is an "asbestos fiber/liquid aluminum" paint containing 4% asbestos and about 18% titanium dioxide. Other paint used frequently contain zinc oxide or tributy] tin oxide for controlling mildew, while many roofs are surfaced with neoprene rubber and "Hypalon". There has been some concern in the past about the use of paints con- taining mercury on roofs that are part of a roof-cistern system. A few cisterns were screened to exclude frogs, lizards, rats, but most either were not or else the screens were rusted or displaced. Survey studies by Isquith and Winters (1981) and Lee and Jones (1982) indicated potential problems with microbes, algae, and protozoa. ~~! [ PHASE I] [ [ [ PRELIMINARY SURVEY [ [ by [ Frank P. Rinehart Patricia A. Hoffman Division of Science and Mathematics [ Al and : Roger Peebles Caribbean Research Institute [ College of the Virgin Islands St. Thomas, U.S.V.I . 00802 [ [ ( [ a nr | ~ "> 3 a) Tan) er ee os ~~" fae PHASE I] Drinking water in the U.S. Virgin Islands is “available in limited supply and is often of questionable quality. Water in private homes, schools and public housing is usually stored in cisterns and comes from one of three primary sources: desalinized water delivered through a leaky distribution syster or by trucks, ground water piped to the surface end delivered by trucks, and rainwater collected on tne roof of each building and delivered to its cistern through gutters. Each source of water has known,or potential, public heeith dangers associated with it. The distribution system for Gesalinized water, for instance, is known to be leaky and to share routes with a , sewage collection network also known tc be leaky. Ground water sources are also prone to contamination, not only from sewage seepage, but from salt water intrusion. Trucking water for home delivery involves transfer prczsedures which are also potential public health hazards. Collected rainwater might also be contaminated from a variety of sources. It contains atmospieric dust and aerosols, accumulated dust and debris from roofs, breakdown products from roofing materials, organic debris from :verhanging trees, micro- organisms, fecal material from rodents, birds, and lizards, 3 3 "9 E) and salt deposited from sea spray. During storage, it inter- acts with cistern walls. Frogs may visit or reside in the cistern. Under special circumstances, the cistern itself can be subjected to ground water seepage. This paper describes a preliminary study done on the quality of collected rainwater stored in the cisterns of private homes. Cisterns selected for study were known to have received only rainwater for at least the previous two years. While study sites were selected from areas all over the island, no special attempt was made to document water Guality such as sites near the Bovoni Dump or close to heavily- traveled roads. The intent of the study was to characterize the quality of water collected and stored under the best circumstances. Samples were tested for chemical composition and bac- terial contamination by a variety of standard methods. Water was tested for total solids, conductivity, chloride, nitrate, calcium, magnesium, iron, copper, and, 10 some cases, lead. The total concentration of bacteria of all types was determined. The concentration of coliform bacteria, an indicator of the possible presence of pathogenic bacteria, was also measured. Other possible chemital.. and biological tests were not per- formed due to limitations in time or experimental facilities. 3 a rr) a a ne METHODS OF ANALYSIS Sampling Samples were obtained from Private homes around St. Thomas. The geographical distribution is indicated in Table 1. TABLE 1 Geographical Distribution of Study Sites Study Site Number Location 1 Estate Hope, Fortuna 2 CVI, Contant, Solberg 3 Dorothea, Hull Caret, Pearl 4 Charlotte Amalie 5 Frenchman's Bay, Bolongo 6 Bovoni, Nazareth 7 Wintberg, Rosendahl 8 Tutu, Anna's Retreat Each donor was asked to fill out a questionnaire describing the cisterm from which water vas drawn and the roof which collected the water. Each donor collected water samples froma well-used household tap according to written instructions. For bacteriological tests, donors were supplied with a sterile - 10 3 re re re | 3 collecting bottle. If the cistern water had been pre- viously chlorinated, 0.2 ml of 10% sodium thiosulfate was added to the collecting jar before sterilization to de- activate the chlorine. Samples to be used for chemical analysis were collected in treated glass or polypropylene bottles. The treatment consisted of a detergent wash, chromic acid rinse, distilled water rinse, nitric acid rinse, and repeated distilled water rinses. Bacteriological Testing Water samples were tested for total bacterial con- centration and also for coliform bacterial concentration by standard water testing methods. a. Total Plate Count: A total bacterial count was done on each sample. ‘Several dilutions of the samples were made in buffered water. Then, 0.100 ml of each dilution was mixed with 10.0 ml of standard method agar in petri dishes. After incubation in an in- verted position for 48 hours, the number of colonies was determined. Colonies were counted on those plates which had between 30-300 colonies per plate. b. Most Probable Number (MPN) Determination: Lactose lauryl sulfate tryptose broth (LLSTB) was used in a presumptive coliform test. For this test, tubes contained 20.5 ml of the fermentation broth and ii re re | ee ne ee ee ee | 3 er nr rr rr ere inverted Durham tubes, 10.0 ml of the sample was added to each of tubes, the tubes were incubated at 35°C for 24 hours and checked for gas formation. All negative tubes were incubated for another 24 hours and -checked for gas formation. A tube with even a small amount of gas is considered to be a positive indica- tion of gas forming bacteria. From each positive tube, a loopful of material was transferred to a tube containing 10.5 ml of brilliant green lactose bile broth (BGLBB) and an inverted Durham tube for a confirmation test. All tubes were incubated at 35°C for 24 hours, checked for gas formation, and re- incubated for an additional 24 hours if no gas had formed. The MPN index was determined from the number of tubes containing gas-forming bacteria. TABLE 2 Most Probable Number Index Postitive Tubes Index 0 < 2.2 1 2.2 2 S.l 3 c.? 4 1€.0 bs) >16.0 12 a J re re: rn re | | “9 Any index equal or greater than 5.1 is considered a positive indication of the presence of coliform bacteria and is presumptive of the presence of human fecal: material. Confirmation tests were done on any sample for which three or more tubes gave positive indi- Cations of gas formation. A loopful of the BGLBB Culture was streaked on a plate of Levin EMB agar and incubated at 37°C, transferred to LLSTB medium and checked for gas formation after in- cubation at 35°C for 48 hours. Slants were prepared, incubated 18-24 hours at 35°C and Stained with gram stain to check for the presence of gram negative rods, single or in pairs. Membrane Filter Technique: This is a second standard test for the presence of coliform bacteria. 25.0 mil of each sample was filtered through sterilized 0.45 micron gridded filters and rinsed twice with buffered water. Each filter was placed in a petri dish on a sterile pad saturated with about 2 ml of M-endo broth. Inverted dishes were incubated at 35°C and 95% humidity for 24 hours. Total colonies were then counted as were those colonies which appeared dark rec with a green-gold metallic sheen under fluores- cent light. These colonies are indicative of 15 a ae) —4 OT >B re ee “QJ FZ rr ee eee eee coliform bacteria. Filters chosen for counting had between 20-80 colonies of all types. If the number of coliform colonies per 100 ml of sample is greater than 4, it is considered excessive. Coliform bacteria were confirmed by sampling typical colonies and incubating them in LLSTB broth. Tubes which were positive for gas formation were used to innoculate BGLBB cultures which were in turn checked for gas formation. Depending on the number of colonies from the membrane filter verified as coliforms, adjustments in the number of coliform colonies per 100 ml were made. Chemical Analysis Total solids were determined by placing 100 ml of fresh, unfiltered ‘samples in pre-weighed evaporating dishes and evaporated -. over steam. Residues were dried overnight at 105°C before re-weighing. Some samples were also filtered through pre-washed 0.45 micron Milli- pore filters to remove suspended solids prior to evapo- ration. No significant difference between the measure- ment oz total solids and dissolved solids was reliably detected. Conductivity studies were done on fresh samples using @ Beckman conductivity bridge with a calibrated Gip cell. 14 Chloride analysis was done with the Mohr argenometric technique. Nitrate was determined with the standard brucine sulfate colorimetric assay. Cation analysis was done using atomic absorption spectrophotometry. A Varian Techtron Single beam spectro- photometer was used. Samples were stored for extended periods prior to analysis in pre-treated bottles in the presence of distilled nitric acid to prevent adsorption. Minimum detection limits for the determined cations are in Table 3. TABLE 3 Cation Detection Limits/ppm , Ca"* Mp** so pp?* (Fe 2*g Fe3*) Ag* Cu’* 0.02 0.001 0.05 0.05 0.007 0.03 RESULTS Fresh samples usually were Slightly turbid (no direct measurements of turbidity were done) and were often slightly ceiorec, usually golden-brovwn thougn occasionally green. Qualitative statements about suspended solids may be made from the appearance of 0.45 micron Millipore filters 15 [Rey “og ~D 5) a ee eee eee ee: en | 3 after a portion of each water sample had been filtered. The material retained on the filters was, like the solutions, golden brown or occasionally green. Some were not heavily colored, others were and these often clogged. Measurements (not reported) of the weight of retained solids after drying were not consistent. This was in large part due to inadequate experimental measures but also strongly suggested that the dry weight of retained substances was not large. It is likely that bacteria and algae, which would dessicate on drying, are responsible for the bulk of the colored retained material. Results of the chemical analysis on 24 cistern water samples are presented in Table 4. Inorganic substances in cistern water are present in small quantities. - Measurements of total solids (after drying) and conductivity both show the concentrations of dissolved salts to be small. For purposes of comparison, Table 4 also contains a summary of the results of an earlier study (Robinson et al.) on well water. Both means and ranges of measurements on nine wells chosen random- ly from their study are presented. The primary constituent of the solids in cistern water is calcium ion, about 20% by mass. Since cistern water is well-equilibrated with the concrete walls of the cistern, this observation is not start- ling. (Concrete is composed of Carbonate, sulfate, and sd 3} 2: au ny ninosilicate saits of calcium}. Sediur ion is present in large enough quantities to intensely color the flame in 16 4aaa4| aI oll 3 a ees eee eee the atomic absorbtion spectrophotometer. Sodium was not directly measured due to the lack of a suitable method. Chloride is another major constituent (10% of total solids). One obvious source of chloride would be atmospheric aerosols containing NaCl from the surrounding sea. Although not directly measured, carbonates and sulfates are probable important constituents. It is interesting to note that,if one assumes that the chloride is present as NaCl and calcium carbonate, the two would comprise,-on average, about 31 mg/1 of sample, or about 60% of the total solids. Measurements of heavy metal content of cistern water were done for only a few metals, lead, cadmium, silver, iron, and copper. Only copper and iron were found in anv of the samples and only in very low concentrations. Iron could leach from cistern walls or from plumbing. Copper is also likely to leach from plumbing. It should be remembered that all samples were collected at the tap. Nitrate concentrations were small. It may be significant that the cistern with the largest nitrate concentration (&.1 mg/1) was also found to harbor a large concentration of bacteria. Bacterial assays are reported in Table 5. Two diitferent types of assavs were done. The first estimates the total mumber of bacterie present in the semnle. There is no ec- cepted limit for totai bacteriel count in drinking water. ~~ 3 “3 7S 3 re rr ne re es: er ne Second, an estimate of the concentration of coliform bacteria was made by two methods. The most probable number assay relies upon the gas-forming characteristic of coliform bacteria. Five tubes of diluted sample were examined for the presence of gas bubbles. If two or more éontained gas,- coli- forms were subjected to confirmatory tests. A separate estimate of the number of coliform bacteria was obtained by trapping bacteria on a membrane filter and culturing them in conditions favoring growth of coiiforms. Any suspect coli- form colonies were subjected to confirmatory tests. Four or more coliform bacteria per 100 ml of water is unacceptable. Ox the 30 cisterns tested, only four were contaminated by either of these standards. There is no clear correlation between total bacterial count and the presence of coliforms in these samples. Al- though three of the four cisterns with large coliform counts also had very large total bacterial concentrations (29,000, 58,000 and 92,000 bacteria per ml), one (sample 3.6) had a relatively low concentration (2,100 bacteria/ml). In addi- tion, several cisterns with relatively large numbers of bacteria had no detectable ccliform bacteria, e.g. 2.5, 4.2 No attempt was made to identify bacteria other than coliforms at this stage of the Study. Many samples containec nmon-coliforr, be fan) m4 rj as) ie] ct ww 3 49 lon 3° we teria, most likely Aerobacter, a@ soil bacterium. No measurements of algae or unicellular organisms were attempted. 1& a o TABLE 4 Chemical Analysis Concentrations in mg/l (ppm) Sample Solids Cl NO, cat Me 2* Fe ions cu2* Conductivity 1.1 47 5.6 1.37 5.3 0.14 0.15 0.03 70 1.2 37 4.6 1.06 6.6 0.17 0.04 56 2.4 60 7.7, 1.76 53-9 0.13 0.16 94 2.5 75 ND 0.24 10.4 0.56 ND ND 75 3.1 75 5.0 1.51 9.5 0.40 ND 0.01 139 3.2 38 4.6 1.00 7.2 0.15 0.07 68 3.3 33 4.6 1.06 6.5 0.24 ND 0.01 75 3.4 24 4.5 0.85 4.6 0.39 ND 0.04 49 3.5 53 4.9 0.91 7.0 0.25 ND 69 3.7° 53 8.4 0.94 10.8 0.17 0.06 0.06 99 3.8 31 5.5 0.91 6.5 0.57 ND 62 3.9 39 ND 0.27 1l.1 0.40 ND ND 79 3.10 59 ND 0.32 20.2 1.68 ND ND 136 4.1 56 5.1 10.7 0.19 0.08 4.2 62 3.9 1.14 11.6 0.25 0.12 0.03 81 5.1 49 4.8 1.33 7.3 0.10 0.09 0.04 £8 5.2 27 4.2 0.55 5.8 0.29 ND 0.03 56 6.1 65 5.6 8.2 0.20 0.03 0.03 6.2 54 6.4 1.19 7.5 0.15 73 6.3 39 ND 0.26 9.6 0.73 ND ND 81 7.1 ND 0.22 9.9 WD ND ND 7.2 28 ND 0.22 9.9 ND ND ND 62 8.1 63 4.7 3.68 10.1 0.29 0.10 0.06 89 wells 1079 227 19 49 41 1705 (641- (35- (4.5- (30- (24- (858- 1300) 300) 68) 88) 68) 2200) &. concuctivity in units cf micromhos dD. Not Detected c. this sample has been previously chlorinated d. well water samples, nine samples chosen tandemly from Robinson et al. (ranges in parenthesis) ray vo) “3 TABLE 5 Bacterial Assays Total Coliform Bacterial Assays Sample Assay MPND MFC Roof Construction Environment 1.1 100 0 0 paint, good condition overhang trees 1.2 610 ie) 0 2.1 1,430 0 8) permacoat 2.2 92,000 5 38 . hypalon overhang trees 2.3 25,000 0 0 hypalon overhang trees 2.4 950 1 1 desco clear 2.5 220 ¢) 0 plywood, plastic roof cement clear 2.6 1,800 0 0 permacoat clear 2.7 1,000 0 0 permacoat clear 3.1 10,000 fe) 0 unpainted concrete salt spray 3.2 1,030 0 0 hypalon roof annually scribbed 3.3 1,800 8) 0 paint on insulfoan poor paint 3.4 600 0 0 good paint clear 3.5 1,400 0 0 galvanized overhang trees 3.6 2,100 3 8 desco overhang trees 3.7 22,000 5 tntc4 hypalon overhang trees 3.8 2,900 0 0 galvanized, painted poor paint, overhang trees 3.9 1,100 8) 0 good paint clear 3.10 2,700 ie) 0 concrete overhang trees dust 4.1 1,150 1 0 concrete town, 100 feet from busy street 4.2 16,300 i 1 galvanized, 2 months old paint overhang tree 5.1 3,200 0 0 permacoat overhang tree smoke from auap 5.2 3.000 0) 0 painted metal clea 6.1 6,600 fe) 0 concrete beach, smoke, dust 6.2 20,000 6 0 hypalon, recent birds 6.5 430 0 0 galvanizec, hypalon near lagoon, coated highway 6.4 2,200 1 1 7.1 1,460 1 0 Gesce over plywood overhang trees 7.2 180 0 0 unpeintec ¢géivanizec overhang trees o.i 58,000 5 16 rooizven over Plywood overhang trees a. Bacteria per milliliter of water b. MPN Index (See Table II) c. Millipore filter Assay, coliforms per 100 ri. €. TNTC means “roc numberous to count" 20 higteay a ee a) re rn Pre “jy 3 , ~ 39 ~3 3 “3 " “~~ 3 J TS TABLE 6A: TOTAL BACTERIAL COUNT Bacteria/100ml1 Site Dec. 1979 Feb. 1980 July 1980 Oct. 1980 St. Thomas Bovoni 8.7 x 102 2.0 x 104 5.8 x 10° >1.0 x 10° Smith Bay 7.2x 105 1.5 x 10° 2.4x 107 >1.0 x 10° Coliege of the Virgin Isiands 7.0x 102 7.8x10% 7.3108 >1.0 x 10% Hoff 5.6 102 4.0 x 104 4.0 x 10° 6.0 x 103 TABLE 6B: TOTAL COLIFORM COUNT Coliform/100m1 Site Dec. 1979 Feb. 1980 July 1980 Oct. 1980 St. Thomas Bovoni 9.1 x 10! 2.1 x 104 0 >2.0 x 103 Smith Bay 7.5 x 102 2.1 x 102 0 1.0 x 103 College of the Virgin Islands 2.3 x 102 N.D. 0 >2.0 x 103 Hoi 1.6 x 102 0 j.1 x 105 8.75 x 10° 21 (continued...) TABLE 6C: TOTAL STREPTOCOCCI] COUNT Fecal Strep/100mi Site Feb. 1980 July 1980 Oct. 1980 St. Thomas Bovoni 3.6 x 10) <l1 x 103 4.0 x 10? Smith Bay oO. <l x 105 5.0 x 105 College of the Virgin Islands N.D. <1 x 103 5.0 x 10° Hoff 0 <1 x 103 7.5 x 102 TABLE 6D: TOTAL SALMONELLA SP. COUNT Salmonella sp./100m1 rr eee eee en my Site Feb. 1980 July 1980 Oct. 1980 St. Thomas Bovoni + N.D. 4.0 x 105 Smith Bay - N.D. 8.0 x 105 College of the Virgin Islands + 6.0 x 103 9.3 x 10" Hoff - 4.2 x 10" 3.3 x 10" N.D. - Not Done TNTC ~ Too Numerous to Count All counts were done using the standard plate count described in the 14th Edition of Standard Methods for Exazination of FROM: Isquith and Winters, 1981 22 ’ ater and Vastevrater. ae es ee ee: ee ce Se Pie: Pair CONCLUSION This study has resulted in a partial characterization of rainwater caught in cisterns. Cistern water, although it often appears turbid, is relatively devoid of inanimate material. The principal components are calcium, sodium, chloride, carbo- nate (inferred), sulfate (inferred), and silicate (inferred). Few cisterns are contaminated with coliforms, although other non-pathogenic bacteria abound. Many of these are likely to be soil bacteria and will also be found in other water supply sources in the Virgin Islands. One may compare these findings in a general way with what is known about other local sources of water. Groundwater has a large mineral content (see Table 4). Nitrate levels in well water are often unacceptably large and such water is prone to coliform contamination from septic fields. Wells are also noto- riously prone to salt water contamination. Desalinated sea water, delivered through pipes, is subject to similar kinds of contamination. The community is often warned by public heaith officials to boil this water prior to consumption. Provided that cisterns are occasionally checked for coli- form bacteria, nothing in this study suggests the violation of health standards for consumers of cistern water (unless one's intake of minerals from other sources is insufficient). One cistern which did not show coliform bacteria in this survey 23 a) “3 rr rr re en ie re ee es: re Pre 9 (sample 3.3) later became contaminated. The source of conta- mination was found to be drainage from a septic field uphill from the cistern and subsequent seepage into the cistern underground. There are many questions not addressed in this preliminary study. A conscious choice was made to sample water from the tap. It is quite likely that the composition of cistern water varies with depth, particularly close to the bottom where sediments accumulate. Analysis of sediments for the presence of pesticides was done several years ago (report on file, CRI) but a more general study of the composition of sediments might prove interesting. Certain materials might be found in particular cisterns such as asbestos particles from degrading roofs or high concentrations of zinc from galvanized roofs. Some cisterns may contain potentially harmful non- coliform bacteria such as Salmonella or pathogenic unicelluiar organisms. Some cisterns near heavily traveled roads might have detectable levels of lead from auto emissions, although this potential problem is apt to disappear with the advent of unleaded fuel. Hydrocarbons might be present in some cisterns from a Similar source or in locations downwind from the air- port. Although this study does not answer these questions, it does provide a baseline for examination of the contents of rainwater stored in cisterns. “mt PHASE I] ao) MICROBIAL ANALYSIS AND MAJOR ION COMPOSITION AY by ram Annelise Knudsen. Michael J. Canoy m= Fay Fay Caribbean Research Institute College of the Virgin Islands ta 00802 St. Thomas, U.S.V.1. m= | a) ro] SAMPLING AND ANALYTICAL PROGRAM Over 100 private home cistern supplies from all parts of the island were selected for study. The sampling procedure involved lowering a sterile BOD bottle into the cistern oF Pp] where that was not feasible, afiowing the kitehen sink faucet to run for about one minute, then collecting the water from this faucet in a sterile BOD bottle. Samples were pro- cessed at the Environmental Laboratory at the Caribbean Research Institute (CRI). Metal ions were determined by atomic absorption spectroscopy. All values reported in this Study are for the total element content without regard to form. In addition to individual home cistern water supplies, several public and private wells were sampled, as well as the municipal water supply for Charlotte Amalie, the principal city on St. Thomas. The city has had water from two sources; one is thedesalinization plants, the other was barged water from Puerto Rico (not currently done). The barged water was from Roosevelt Road Navy Base (U.S.)}, ‘which originally came from the Rio Blanco River on the east coast of Puerto Rico in Sen Juan. The Rio Blaco water is purified by coagulation with alum, fluorination, and chlorination. The barged water was supposed to be mixed with the desalinized water in aratio-of one 25 part barged water to nine parts desalinized water. <A League of Women Voters of St. Thomas (1970) brochure indicates that the demand for fresh water on St. Thomas averaged 1.44 mgd, 68% of which was provided from the three desalinization piants that exist on the island. An elevated number of coliforms present would be expected, because many individual household waste disposal systems ‘are septic tanks, many of which failed, resulting in untreated waste water entering cisterns via subsurface cracks or coming to the surface. Birds, frogs, lizards, and other animals such as rats and mongooses, could readily transport ‘bacteria from the domestic sewage on the surface of the ground or from their feces to the roof-cistern collection system. Visual inspection of the cisterns in some households revealed that there were a few centimeters to as much 2s 44 centimeters of sludge in the bottom of the cisterns. This sludge consisted largely of plant debris, dust, animal feces, and decomposing animal remains, which had been washed in from the roof collection system. It is evident that the individual household cistern water supplies on St. Thomas are subject to potentially signi- ficant contamination from a variety of materials, including fecal materials transported from improperly constructed and managed septic tanks by birds or other animals. Leaf and other litter, debris, and dustfall, as well as materials used in roof construction and maintenance, may also be present. Because of the inadequacy of the cistern system to reliably provide for the total water needs of some families, contami- Fm Nation of the household water supply could readily occur through purchased water. a [mr Baza frat lr" - r re ee er re S."MLE FLOw SHEET -- (acidify) [ [cart FORM PFESUSFTIVE: Multiple Lactose Lauryl tryptose Lrorh fercentation tube, 10 ml-121-0.1n) Incubate 24-46 hr. 35C. ( . { GAS PRODUCED | Positive } | NO GAS PRODUCED Necative FECAL Sine? i [SHIGELLA/SALSONELLA | PETALS T t Multiple Salnonella tomic Shigella Agar plate. Incudate 24-120 7 plet 35C : NO COLOXIES PRODUCED | Necative CONFIRMED: Multiple Briliiant green bile broth iersentation tube, 10=2-1n)- O.lml. Incubate 4E hr. - 35C€ Moltiple EC medium broth fersentation tube, 10 m)- N=1-O.lni. Incubate 24 hr. + 44.5C, RED COLONIES PRODUCED, erative ——___! NO CAS PRODUCED Mecative GAS FRODUCED t Fesitive ! | 'xO GAS PRODUCED cative ICONPLEIED: Multiple E.M.B. plate ltnenbate 24 hr. - 35C OPAGUL TRANSPARENT COLONIES PRODUCED — Tositive 4 'GAS FRODUCED | Fositive Multiple Phenol Red Lacrese fermentation tube. Incubare 24 hr 35C. i TYPICAL OR ATYPICAL NEGATIVE COLONIES - POSITIVE ICOLONIES i I Nutrient Agar © |— iCoiifore | Incubate 24 hr. jot OUF 35C. absent Streptococcus Agar. Fr sires Filtration 10021 Mncukate 46 hr. 35C Lauryl tryptose broth fermenta—- tion tube. Inco- bate 24~48 hr. —- 35C. GAS PRODUCED NO CAS PRODUCED Coliform group Coliform group present absent Gram stain growth Grar—negative rods present, no spores present. Coliform proup present. F1GuRE 1: { fo COLONIES PRODUCED eepative COLONIES PRODUCED Positive, counted L GAS PRODUCED: Necative NO GAS PRODUCED Positive Sanple Flow Sheet for Kater Analysis z8 bsorption oy LAURYL TRYPTOSE BROTH (DIFCO) TABLE 1 CONSTITUANTS OF THE MEDIA USE IN MICROBIAL TESTS Bacto-Tryptose Bacto-Lactose Dipotassium Phosphate Monopotassium Phosphate Sodium Chloride MEDIA Sodium Lauryl Sulfate PHENOL RED LACTOSE BROTH (BBL) BRILLIANT EC MEDIUM Trypticase Peptone Sodium Chloride Lactose ... Phenol Red. . ° GREEN BILE BROTH (BBL) Bacto-Peptone Bacto-Lactose Bacto-Oxgall . Bacto-Brilliant Green (BBL) . Bacto-Tryptose . Bacto-Lactose Bacto-Bile Saits No. Dipotassium Phosphate Monopotassium Phosphate Sodium Chloride 29 i) ° OMNNWOS ° ss uti — 10 0.018 10 10 20 0.0133 nH hei oO ° . (Fa) LT) go 09 9a Qa ga 7a ga ga ga oa ga ga 0a (a 99 0a Jo Ga FO 00 rr er ~ "9 a rr rr) (continued. LEVIN E.M. --) B. AGAR (BBL) Bacto-Peptone ............ Bacto-Lactose .. oe ew ee Dipotassium Phosphate Bacto-Agar ...........42.424 Bacto-Eosin Y . Bacto-Methylene Blue er SALMONELLA, SHIGELLA AGAR (BBL) Beef Extractives Polypeptone!M Peptone Lactose Bile Salts Mixture. Sodium Citrate Sodium Thiosulfate Ferric Citrate Neutral Red Agar .. . Brilliant Green KF STREPTOCOCCUS AGAR (DIFCO) NUTRIENT A Proteose Peptone No. 3, Difco. . Bacto-Yeast Extract ...... Sodium Chloride . . ce ee Sodium Glycerophosphate oe ee Maltose ..... oe Lactose ........4.42.2. Sodium Azide .. . Bacto-Brom Cresol Purple . . Bacto-Agar . ......... GAR (BBL) Pancreatic Digest of Gelatine Peptone Beef Extractives Agar ..... 10 10 15 0. 065 be ° wmintn }! COWOrFOMMOMMN e , e e WNoe W N uw 10 10 10 20 0.4 0.015 20 8 02 00 92 00 00 tA 0a fa GO (7 fra 19 GA Om 09 9 e ° ° ta $2 09 (a 09 ba 09 Ga fo 72 GA Ga ya a ee) | rs rr en ne nen | RESULTS The bacterial profile by site (Table 2) provided a means for determining the density of aerobic and facultative anaerobic heterotrophic bacteria in the cistern waters. This was an empirical measurement,since no single growth medium could satisfy the physiological requirements of all bacteria in the waters sample. Therefore, the actual number of bacte- Tia was probably higher than the actual number of viable bacteria counted. Many different genera of bacteria were isolated. These genera included Pseudomonas, Aerobacter, Proteus, Achromobac- ter, and Serratia. Many of these organisms are considered secondary pathogens, can grow in low nutrient waters, or are chlorine resistant. The high density of bacteria in some of the cistern waters (Table 2) suggested an undesirable deterioration of the water quality. This monitoring of bac- terial density seemed important in light of the fact that chlorine was not often used. This bacteriological measurement can be used as an indicator of nutrient input into the system. While there was no maximum level for the general bacterial population covered by the Safe Drinking Water Act, it has been generally recom- mended that drinking water should contain fewer that 5 x 104 bacteria per 100 ml. Some special standard should be devised to cover the allowable levels of secondary pathogens also. 31 “3 TABLE 2: BACTERIAL PROFILES FOR 100 CISTERNS Bacteria/100 ml Dates Location P.Cc.* P.H.C.* Rainfall Total Coliform Salmonella sp. Shigella Fecal Strep. { 3/09 Pearl * Dry 33 - 90 N.D. 3/11 Hidden Valley * Dry 22 - - N.D. 3/14 Pearl * Dry 240 - - N.D. 3/14 Caret Ray x Dry 49 - - N.D. 3/15 Contant ve Dry 0 - - N.D. 3/15 Tutu % Dry 2.2 - - N.D. 3/17 Lerkenlund * Dry 2.2 - - N.D. 3/17 Smith Bay * Dry 4.2 - - N.D. 3/21 Lyttons Fancy ¥ Dry 13 - - N.D. 3/21 C.V.I. w Dry 918 3 3 N.D. 3/21 Tutu * Dry 33 - - N.D. 3/22 C. Amalie x Dry 130 - - N.D. 3/24 Nadir * Dry 542 - - N.D. 4/04 Frencliman Bay * Dry 0 - - - 4/07 Marindahl % Dry 130 TNTC TNIC 6 4/09 Bovont * Dry 0 - - - 4/09 Harmony * Dry 240 - 15 2 4/11 Frenchman Bay % Dry 2400 0 25 - 4/12 St. Peter Mt. x Dry 918 - 17 2 4/13 Crown/Hawk * Dry 2400 - TNTC 2 4/13 Crown/Hawk * Dry 2400 - 102 2 4/13 Crown/Hawk Gov. Runoff C Dry 345 - 134 - 4/15 CVT. fe Dry 0 - - - 4/16 Donoe * Dry 1600 - 7 - 4/16 Donoe * Dry 0 - - - 4/16 Donoe * Dry 348 - - 2 4/19 18" 4/22 Nadir * Ave. 240 TNTC TNIC - 4/23 Bovont * Ave. 130 - 7 2 32 ne ees Dene ee ne: ee ne Pes Pin Pe | 3 ] 9 9 (continued...) Date Location P.C,%* P.H.C.* Rainfall Total Coliform Salmonella sp. Shigella Fecal Strep. 4/23 Bovont * Ave. 130 - 7 2 4/23 Bovondt * Ave. 0 - 1 - 4/23 Bovoni w Ave, 0 - 32 - 4/23 Bovoni * Ave. 542 - 10 - 4/26 Hospital Grd. * Ave. 130 - - ~ 4/28 Papaya Hill * Ave. 0 - 1 2 4/28 Papaya Hill ok Ave. 348 - 3 2 4/28 Pearl x Ave 0 - - - 5/03 Esperance Ave. 79 - - 2 5/03 C.V.1. * Ave. 2.2 - 2 - 5/03 C.V.1. * Ave, 2.2 - 6 - 5/03 C.V.I. * Ave. 4 - 2 - 5/03 Hospital Grd. % Ave, 0 - ~ - 5/05 Lindberg Bay x Ave. 0 - - - 5/05 Annas Retreat Ave, 0 - - - 5/07 Bordeaux x Ave. 0 ~ - - 5/07 Bordeaux x Ave. 0 ~ - - 5/07 Bordeaux x Ave. 6 2 17 2 5/07 Bordeaux x Ave. 0 - 3 69 5/07 Bordeaux * Ave. 0 - ] JL 5/07 Bordeaux * Ave. 0 ~ 1 - 5/07 Bordeaux x Ave, 0 - - - 5/07 Bordeaux * Ave. 0 = - - 5/07 Bordeaux * Ave. 79 - 10 - 5/07 Bordeaux * Ave. 79 - 2 10 §/07 Bordeaux rt Ave, 2400 6 240 5/07 Bordeaux * Ave. 0 - - - 5/07 Estate Hope * Ave, 0. - - - 5/09 Nazareth * Ave. 79 - -' 2 5/14 Tutu * * Ave, 2400 - 1 - 33 a er 3 | a) E] E) 3 F E en 3 7 ~"39 79 (continued...) Date Location P.C.* P.H.C.* Rainfall Total Coliform Salmonella sp. Shigella Fecal Strep. | 5/14 Tutu * Ave. 2400 ~ - 2 5/14 Tutu x Ave. 2400 ~ - - 5/14 Tutu * Ave. 542 2 10 ~ 5/14 Tutu * Ave. 918 2 13 79 5/14 Tutu * Ave. 2400 - 1 79 5/14 Tutu * Ave. 2400 3 1 - 5/14 Tutu * Ave. 2400 4 3 - 5/14 Tutu % Ave. 2400 1 8 79 5/14 Tutu * Ave. 2400 12 13 69 5/14 ‘Tutu * Ave. 2400 - - 49 5/14 Tutu * Ave. 109 - - 2 5/14 Tutu * Ave. 2400 - 1 49 5/14 Tutu * Ave. 2400 - - 79 5/17 Pearl * Ave. 0 - - - 5/17 Pearl * Ave. 109 4 10 - 5/21. Smith Bay * Ave. 0 - - 5/21 Smith Bay x Ave. fs) - - 5/21 Smith Bay * Ave. 0 - - - 5/21 Sapphire * Ave. 130 - 13 - 5/21 Veasup Bay x Ave. 0 - - - 5/21 Tutu * Ave. 2400 - - 2 5/21 Mandahl * Ave. 17 ~ - - 5/21 Mandahl Xe Ave. 2400 - - - 5/21 St. Joseph * Ave. 0 - - - 5/21 Rosendahl * Ave. 0. - a - 5/21 Dorothea * Ave. 130 - - 2 5/21 Dorothea * Ave. 240 - 2 240 5/21 Lerkenlund x Ave. 918 - - 2 5/26 Scott Beach * Ave. 2400 - 1 240 5/26 Vessup Bay * Ave. 0 ~ - - 34 | 3 3 3° 79 3 3 3 Fe re nr ne re (continued...) Date Locat ton P.c.* P.H.C.* Rainfall ‘Total Coliform Salmonella sp. Shigella Fecal Strep. 5/26 Vessup Bay | X Ave. 240 - - 5/26 Bolongo Bay x Ave. 109 - - 5/26 Compass Point * Ave. 0 - - 5/28 St. Peter Mt. * Ave. 0 - - 5/28 Caret Bay * Ave. .7 - 2 5/28 Caanan ¥e Ave. 918 - 2 5/28 Caanan tt Ave. 918 1 9 5/28 Caanan * Ave. 1600 6 13 5/28 Luisenho] Ave. 0 - - 5/28 Luisenho]} % Ave. 0 - - 5/28 Caret Bay * Ave. 0 - - 5/28 (Tortola) * Ave, 0 ~ - 6/07 Esperance * Ave. 1600 1 TNTC 6/07 Esperance * Ave. 1600 - TNTC 6/07 St. John % Ave. 27 - 7 6/08 Bovonl 1 _ Ave. 7 - 3 6/13 Hidden Valley * Ave. 5 - - P.c. Private Cistern P.U.C. wou Public Housing Cistern 35 | a | Table 3 presents the results of the chemical analyses of the cistern water supplies on St. Thomas. To assess the relative potable and palatable quality of these waters, a compilation of existing U.S. EPA water quality criteria and regulations was developed (Table 4). The sources for the concentration limits presented in Table 4 are the National Academy of Science and National Academy of Engineering (1973) "Blue Book" of water quality criteria, the U.S. EPA (1976a) "Red Book" of water quality criteria, and the U.S. EPA (1980) Water Quality Criteria (toxic chemicals). In general, the most recently revised criterion for each parameter is presented in Table 4. A critical comparison of Tables 2-4 for each of the parameters is presented below, with particular emphasis given to the characteristics of the household cistern water supplies. I. pH. The recommended pH range for domestic water sup- plies, based on welfare characteristics such as minimizing corrosion and scale formation, is 5 to 9. All of the water samples collected had acceptable pH values. Il. Calcium, Magnesium, Sodium, Potassium. The Ca and Mg concentrations (hardness) of the water supply systems were within the acceptable range for domestic water supplies. The cistern water supplies that were not receiving significant amounts of the private water supply well water, as well as the Charlotte Amalie waters, would all be considered soft water Zn, a) Mn Fe 2 Cu Na TONS Mp Ca pl plt AND METAL Rainfall a) TABLE 3: “9 P.HULC.* z] p.c.* Location Date OM OMONAS rae ade SANNNDHAS Hoe NOROMNNH As www NSOONNHoOoSHHe wn Nan CAMO nOTTN NAN AOHNNUSAKRaMmaMm AMOS AHN MS N ~N NoOwMasasrTooon ONnronnrnraoowow Ay HAAAD ew ee wk aAaaAARA oO Gy Seal * oO «Es Cc =] =< a mK RK K DK c oo ms s vw a= ~_ arene = c+ 2Pzt = mer = >aErrmurs Sere OCs eoNntN erecenecrcroce — CEs 22 2 -oao CE bee .-oCCH fees f©oewyunuye' .ogoge -—FeHoOmOenmoULULU A Be ~XADANNMNOMANMHCOwCw CCOOn kek naini nin eo Me TR MR MH Me SR SS wwwrwwwersyseseer wwe Dry Dry Dry Dry Dry Dry 18" /19 = e ee ce ee @ ONTFANHMANAAN A Nai mn FON NONMMANeEARS HeOTON MANN SHE eo ANNANMONANMNRAN a a 4 ze mz KE KY cs Bee CoekK- ec Bee pw Sek of ee DADS ee ~“~ CC OCOCCCOHoa Eek PrprwvrpsSee>GfL4a6¢ 303 Sooooc$ccene CUOUC AHR eB Remremtannk AAFNNMNINMNMNINMTtoMOe NANNNNNANANANRWAANDA m™M™ MR MM me SS wwwwseryssse ers 37 a Ei d p) ) | E a a a a 3 J E 3 a9 (continued...) oe ot ee -- oo od Date Locatton r.c.* P.H.C.* Rainfall pHu2 Ca Mp K Na Cu Fe Mn an. ne eer eee —_ 5/03 Bonne Esp. ” 5/03 * Ave. 7.4 0.7 3.4 0.05 0.15 C.V.T, Ave. 7.8 0.3 2.2 0.02 0.05 0.04 5/03 C.V.4. big Ave. 8.2 4 0.6 4.0 0.02 5/03 C.V.T. bid Ave. 9.0 5/02 llospital Grd. « 0.3 2.1 0.02 0.01 * Ave, 8.4 4 0.2 2.5 0.01 0.46 0.22 5/04 Lindberg Bay Ave. 8.5 4 5.0 0.04 5/04 Annas: Retreat * Ave 8.2 4 2.5 0.02 0.03 5/07 Bordeaux « Ave. 8.2 0.9 5/07 Rordenus * 3.6 0.01 0.06 5/07 Bordenus * Ave. 8.2 4 6.4 0.02 0.05 0.01 ve Ave 8.2 11 5.0 5/07 Noardenux Ave, 8.0 10 6 2.5 0,01 5/07 Rordeauy % Ave. 8.2 16 7.4 0.05 5/07 Bordeaux bd Ave, 8.2 5/07 Bordeaux ag U Ava, 1.9 0.01 0.21 0.03 * 8.4 4, 1.5 3.8 0.01 0.03 0.14 5/07 Bordeaux Ave 8.4 12 2.] 4.8 0.01 0.02 5/07 Rordeauy * Ave. 8.2 12 1.9 10.0 0.01 5/07 Bordeaux * Ave. 8.2 4 1.1 RBordeany big 3.6 5/07 Ave. 8.0 0.6 1.4 6.3 0.01 5/07 Bordeany nid Ave, 8.0 1.2 0.5 4.5 0.01 0.06 5/07 Fst. flape * Ave. 7.7 0.8 0.4 5/08 Nazareth « ), 4.8 0.04 0.01 0.09 Ave. 8.3 1.0 1.0 6.0 0.01 ae ee wee es. eee Pc. = Trivate Cistern Pc. = Public Housing Cistern 38 3 E) a 3 re ee eee: See | rr en i er TABLE 4: DRINKING WATER GUIDELINES AND REGULATIONS Max. Legal Parameter Conc. (*) pH (range) 5-9 1 Specific conductance (umhos/cm) 350 1 (dissolved solids mg/g) (500) Alkalinity (mg/& as CaCO03) >400 1 Hardness (Ca and Mg) >150 ? - (mg/£ as CaC03;) Neé none - k none: - Chloride (mg/£) 250 1 SO. (me SOs/2) 250 1 Total PO, none - NO2 + NO; (mg N/£) 10 3 Ammonia (mg N/Z) 0.5 é Organic N none - F (mg/£) 1.4 3 Zn (mg/2) 5 2 Cu (mg/2) 1 2 Cd (yg/2) 10 2 Pb (g/k) 50 2 Cr (yg/k) 50 2 Ni (ug/2k) 13.4 2 Fe (mg/x) 0.3 1 Mn (pg/s) 50 1 He (vg/£) 2 2 =i = U.S. EPA (1976a); 2 = U.S. EPL (19803; = -S. Pe (1976b); 4= NAS. NAE (1973) (*}From: Lee and Jones, 1982 39 ~~" a3) re rn | 3 | a a and would tend to be somewhat corrosive (c.f. Table 5 Isquith and Winters, 1981; Table 6, Jordan and Cosner, 1973). The well waters, on the other hand, (Table 6), especially the private wells, would be considered hard water. The Na and K concentrations in most waters investigated were satisfactory for domestic water use. IIft. Other Ions. The transition group metals; copper, zinc, iron, and manganese were analyzed for, since they are more soluble than heavy metals and are biologically active. In low concentrations they are active in vitamins and co- enzymes. In higher concentrations they act similar to heavy metals, poisoning proteins and membrance structures. In this study these metals ions were found to be in the accept- able range. 40 “~~ pe “Jj “9 73 | re ee | DISCUSSION For routine examination of most potable water supplies, which are usually disinfected with chlorine, the presence or absence of coliform bacteria is used as the legal measure of water quality. These bacteria are always present in the nor- mal intestinal tract of man and other warm-blooded animals and eliminated in large numbers in fecal wastes. Therefore, the absence of total coliform bacteria is used as an indica- tor of the bacteriologically safe water. In practice, particularly in cisterns with a heavy sedi- ment or organic loam, this may not be the case. The coliform group has included all aerobic and facul- tative anaerobic Gram-negative, non-sporeforming, rod-shaped bacteria that ferment lactose with gas formation within 48 hours at 35°C. Water of "good" quality for drinking will be less than 20 per 100 ml,"very good to excellent" quality 1 per 100 ml. Most of the cistern water samples could be Classified as unacceptable based upon their total coliform count (Table 2). Analyses of the total coliform group through the use of the IMViC test (Indole, Methyl Red, Voges-Proskauer anc Citrate) showed that most of the coliform group isolated were of the Klebsiella-Aerobacter type bacte- ria. This suggested that most cisterns had been contaminated hy or considerable lensth of time anc had not been chlorinatec. ti" bet t aiso points to probable heavy loading with rotting vegeta- tion. 41 TABLE 5: CHEMICAL AND OTHER CHARACTERISTICS OF CISTERN AND OTHER WATER SUPPLIES FOR ST. THOMAS, VIRGIN ISLANDS ALK, NEAVY METALS conouc, AS Ca ta K T-PO, 10, + TYPE OF SUPFLY pit (iiros Ae, Ny C1 S800 asp ong, Meh ORG NF In. Cu Cds PRsdCr ONT OF ng Jem canes vee PLTONG seer er sts rresseeret er (my/t) --cercreee serene etree eee ee eee (mg N/k)osercene cece reece eee ce nee en eee (9/t)----- senceccceneccnce es Fublle Water Supply Charlotte Amalle West Part of Clty 7.6 «610 1h Bt 2.9) 24 0,8) 57.2 «9.8 0.075 <0.05 <0.05 <0.05 <0.05- 10h 3.6 0.2 <b ch 1h 16 <5 2.7 Sovan Street Faucet 8.5 700 11.8 9.2 3.3 28 0.5 5h 8.5 0.28 <0.05 <0.05 0.25 0.1 ' 6.7 <0.2 <1 ch 0.9 110 <§ 3.0 Storoye Tank Savan 7.1 2900 45.6 22.7) Jil gh 3.5 53 8.5 oO.jh 0.27. <0.05 O.1h <0.05 116 5.68 0.6 <1 oh 1.2 GS 0.4 Prlvate Woll Used for Mrtvete Water Supply Kost End of tsland 7.4 1600 hoo 73 43 240 1.5 163 37 0.04 2.5 <0.05 0.14 0.62 4 3.5 0.5 <1 eh <0.5 << 1 <5 WN? Government of Virg dn Tr Doivte Nerethon Sean then Welt & Clatera 8.1 bho 298 19 ? 176 0.7 103 3 0.09 0,92 <0.05 <0.05 0.26 133 0.7? 0.9 ' <h 0.5 ct 5 1.6 turth Side of Islond—Wall Only fu 1150 369 «(15 9.5 208 0.4 58 36 0.08 <0,05 <0.05 <0.05 0.37 19 4.) 0.2 <1 ch 60,5 «1 65 0.8 'rlvatey Home cIstern Supply Wo. 1 200) 21) 28 17 8.2 202 1.6 60 th.2 0.2 Vt 0,08 «0.05 0.25 >150 35 J.2067 2 «eh 0006 «Bh at 2 2.4 110 «2 i 0.9 5.7? 0.2 @.2 §.0 0,07 0.19 <0.98 0.06 <0.05 22 4,0 <0.2 «1 <h 0.5 ch €§ 0.) j 7.0 79 «26.6 lo.t 0.5 4.9 <0.t 10.5 3.1 0.04 O.t <0,05 «0.05 <0.05 54 4.6 0.7 <1! ch 0.5 <1 5 342 4 6.8 60 22 8.5 O.4 3.6 «0.1 9.7 2,6 0.026 <0.05 <0,05 <0.05 <0.05 j 2.2 0.6 <«f <h 069 110 <§ = =60.6 5 6.8 9h 30 5.0 1.6 9.9 <0,1 16,1 2.2 0.008 0.1 £0.05 0.2 <0.05 1156 160 0.6 2.4 «h 0.6 <1 5 2.2 t 7.0 90 35 8.20 of 9.2 0.6 9,8 4.3 0.06 0.15 <0.05 0.2 <0.05 15 iB) 1.6 <) ch 0.6 J <§ U3 ? 6.9 92 4013.4 0.9) 5.2 00238 0.03 0,05 «<0.05 0.09 <0.05 10 7.7 0.6 <1 ch 4.2) 39° 5 0.6 6 7.0 69 27 5.6 0.2 9.2 Jt.h 6.0 3.6 0.04 0.9 £0.05 Oth <0.05 <t <0.§ 0.2 <1 <h 0.5 <l <5) (00) 9 6.7 68 19 6.5 Ie 0.8 <0.9 19.7 4.0 0.06 0.12 «0.05 0.2 £0.05 4 12 OF ef och 42 3 GY 10 7.6 Vhoo AS 38 yh 220 1.700971 36 =: 0.006 1.8 0.05 0.31 0.6 5? 16.7 0,2 <1) ch <0.$ el 65) 0,7 W 7.0 92 3% 74 1.6 10.2 <O.4 13.4 0.6 0.03 0.1 £0.05 0.2 <0.05 15 7.0 OJ <1 ch <0.5 19 <§ 0.5 2 6.2 4S oy 1.5 0.6 Wh <0.) 19.9 9.5 0.04 <0,.05 <0.05 0 2.0.6 41.1 <4 0.6 20 <§ Of 09 <0.05 154 VW, FROM: Isqulth and Winters, 1981 43 ~3 73 739 73 73 73 73 ~ 73 7 3O0U UGU ) E) 2 3 7 79 E] 3 TABLE 6: Analyses of Water of St. Thomas (From: Jordan and Cosner, 1973) reuene wrote 1 2 3 4 5 6 7 8 9 10 11 12 [13 | 14 | 15 atew~--e mmr 9-29 ]11-19 ]10-14] 1-2 [12-22] 6-29]11-24] 7-22 |11-16| 8-22 |12-1711-24 | 12-7 | 5-11] 5-20 Year--<------- 1964 | 1963 | 1963 | 1964 | 1964] 1963] 1963 | 1964 | 1963] 1964 | 1963 ]}1964 | 1963 | 1968S | 1964 Milligrams per liter Silica (8102) 33 23 28 36 32 20 27 -- 26 25 29 26 20 33 20 Iron (Fe) 0.00 /0.00 10.04 [0.00 |0.00 /0.13/0.04 | 0.00 [0.00 |0.00 |0.00 {0.00 10.00 |0.09 | 0.32 ' Calcium (Ca) 14{ 48 | s9 | 48 | 38 | 20 | 46 | 30 | 34 | 40 | s2 | 74 | 48 | 94 | 4 Magnesium (Mg) 15 45 $7 46 34 11 61 77 36 39 43 108 39 68 4.9 Sodium-Potassium (Na ond K) 245 | 464 372 293 295 81 477 $19 |363 353 468 718 355 359 25 Bicarbonate (HCO3)] 524 | 726 730 758 666 {186 /1,010]1,0281772 704 935 848 798 772 36 Bulfate (804) 37 90 1133 32 38 17 60 80 8) 86 27 (| 120 37. 142 4 Chloride (C1) 112 | 432 305 200 200 70 360 440 |235 275 40S 962 255 362 36 Fluoride (F) 4 11.2 -9 11.0 8 -3 113.0 1.3 5 7: 8 a) .4 11.0 | Nitrate (NO3) 3 | 17 | 28 |9.4 | 10 | .6 |3.9 | 1.8.}3.8 | 2.3 0 1s | .o 10.3 | .2 Dissolved solids 727 |1,440/1,300 1963 {994 | -- [1,480 {1,700 |1,110)]1,150 1,510 |2,380 |1,080 1,470] 160 Hardness (CaCO3) 96 | 305 382 309 235 95 366 392 4233 260 306 628 280 514 30 Specific conduct- ance (micromhos . at 25°C) 1,220/2,490/2,200 |1,670|1,680]541 |2,500/2,780 1,820]1 ,910 }2,800)4,240]1,870/2, 400] 193 pH 8.1 | 8.0 7.9 7.9 [7.7 {7.4 7.41] 6.1 ) 6.2] 7.9 8.3]7.6 7.8] 7.7 6.8 * Locations of sites listed above are given below : 1. Well 3 in volcanic rock of Loulsenhoj Formation, 9. Bonne Resolution Gut at Bonne Resolution, 2. Well 10 do base-flow discharge 15 gpm. 3, Well 18 do 10. Same as above~base-flow discharge 5 gpm. 4, Well 19 do 11. Well 23 in shallow alluvium, Lower 5. Well 12 do Turpentine Run Valley. 6. Turpentine Run near Mt. Zion storm runoff 12. Well 24 in deep alluvium and bedrock, discharge 1,700 gpm. Lower Turpentine Run Valley. 7. Turpentine Run near Mt. Zion, base-flow 13. Well 2 in shallow alluvium of coastal discharge 9 gpm. embayment. 8. Turpentine Run near Mt. Zion, base-flow 14. Well 16 in Outer Brass Limestone. discharge 1 gpm... 15. Hoffman Pond, Upper Turpentine Run basin. TABLE 6: Analysis of Water of St. Thomas (From: Jordan and Cosner, 1973) *lo w~anwana Oe shrtins 3 4 5 6 7 8 9 10 11 12 13 14 15 iia - 719 110-14] 1-2 |12-22] 6-29) 11-24] 7-22 {113-16] 8-22 |12-1711-24 | en ee ewes - - - 2-7 | S-11 | 5-2 Year 196411963 | 1963 | 1964 | 1964] 1963] 1963] 1964 | 1963| 1964 | 1963 11964 | 1963 | 1965 1964 Milligrams per Iter Silica (S102) 33 | 23 28 36 32 | 20 27 -- | 26 25 29 26 20 33 20 Iron (Fe) 0.00 0.00 0.04 /0.00 {0.00 /0.1310.04 | 0.00 j0.00 [0.00 10.00 |0.00 |0.00 |0.09 | 0.32 nae ; 14 | 48 59 48 38 | 20 46 30 | 34 40 52 74 48 94 4 agnesium (Mg 15 | 45 57 46 34 712 61 77 36 3 Sodium-Potassium ° 8 0e "s °° (Na and K) 248 | 464 | 372 | 293 |295-]81 | 477 519 |363 | 353 | 488 1718 | 355 | 359 25 Bicarbonate (HCO3)| 524 {726 |730 |758 |668 j188 |1,010]1,028/772 | 704 | 935 |e48 |798 1772 36 Sulfate (SO4) 37 | 90 [131 32 35 {17 60 50 | 51 56 27, | 120 37, «| 142 4 Chloride (Cl) 112 | 432 |305 |200 |200 | 70 | 360 440 |235 | 275 | 40S | 962 |255 | 362 36 Fluoride (F) 4 11.2 -9 11.0 6 |] .3 11.0 1.3 5 8 8 5 .4 11.0 1 Nitrate (NO) 3] 17 28 19.4 10 6 13.9 1.8 13.8 | 2.3 0 15 .0 10.3 .2 Dissolved solids 727 |1,440/1,300 | 963 {994 | -- {1,480 {1,700 }1,110]1,150/1,510 |2,380 {1,060 |1 ,470] 160 Herdness (Ceco;) 96/305 |302 | 300 |238 | os | 366 392 |233 | 260 | 306 |628 | 280 | 324 30 Specific conduct- ance (micromhos at 25°C) 1,210/2,490|2,200 |1,670/1,660] 541 |2,500/2,780 |1, 8201/1 ,910 |2,50014,240/1,870|2,400| 193 pH 8.1 |6.0 | 7.9 | 7.9 17.7 ]7.4 | 7.4 | 8.2 8.1 | 7.9 8.3] 7.6 7.8/7.7 16.8 * Locations of sites listed above are given below: 1, Well 3 in Volcanic rock of Loulsenhoj Formation. 9. Bonne Resolution Gut st Bonne Resolution, 2. Well 10 do base-flow discharge 15 gpm. 3, Well 18 do 10. Bame as above—base-flow discharge S gpm. 4. Well 19 do 11. Well 23 in shallow alluvium, Lower 5. Well 12 do ‘Turpentine Run Valley. 6. Turpentine Run near Mt. Zlon storm runoff 12, Well 24 in deep alluvium and bedrock, discharge 1,700 gpm. Lower Turpentine Run Valley. 7. Turpentine Run near Mt. Zion, base-flow 13. Well 2 in shallow alluvium of coastal discharge 9 gpm. embayment. 8, Turpentine Run near Mt. Zion, base-flow 14, Well 16 in Outer Brass Limestone. discharge 1 gpm..- 15. Hoffman Pond, Upper Turpentine Run basin. 43 “3 739 79 73 73 a | J Pie a The normal habitat of fecal streptococci is intestines of man and animals, therefore, these organisms can also be used as an indicator of fecal pollution. The data in Table 2 become contaminated with 1 the cisterns ha Laahy (). Show that many o fecal streptococci. Some of the cistern waters showed the presence of coliform bacteria, but not the presence of fecal streptococci, while others were positive for fecal streptococci and negative for coliform. This may well be due to the long time of coliform bacteria (Klebsiella sp. and survival Aerobacter sp-) in the dark and in association with organic sediments. The presence of coliform bacteria and fecal streptococci in cistern waters was only an indicator of fecal pollution and suggests the possible presence of pathogenic bacteria. Many of the cistern waters showed the presence of Salmonella spp. and Shigella spp- in great numbers. Salmonella sp. may have long survival times and some can cause a variety of diseases, such as typhoid, in humans. These findings con- firm those of Isquith and Winters, 1981(Table 6 Phase I). The high level of coliform bacteria, fecal streptococci and Salmonella spp- in many of the cisterns suggested the possible presence of pathogens in these waters. In addition to Salmonella and Shigella spp., these waters also contained species of Proteus, Aerobacter, Serratia, and Pseudomonas, which were noted but not counted. These are secondary 44 [ = pathogens,which means that they may initiate an infection if fm a person has been weakened or exposed to a primary pathogen, a = disease, ‘au which has caused rm 0) al wl Ga om r ia) cm ta] (ou ra] -e P 45 [ “~3 ~ "> CONCLUSIONS 1. The level of major ions in cistern water on St. Thomas is within acceptable safe drinking water standards. 2 The majority of cisterns tested failed to meet minimum safe drinking water standards in terms of coliforms. 3. The majority of the cisterns tested showed potential pathogens whether or not E. coli was present. These pathogens were most often fecal streptococci, Salmonella spp., Shigella spp., Proteus spp-, Klebsiella spp., Aerobacter spp., etc. 4. Most of the cistern water in public housing or in Bovoni and Tutu fails to meet EPA and USPHA bacterial stan- dards. S. The current situation in the Virgin Islands is critical with a high potential for disease. Existing laws, standards, and methods of treatment and/or enforcement are inadequate and need review, and in some cases, changing. 6. Cisterns represent a unique ecosystem with their own colonization patterns, energy contamination vectors, sources, internal niches, and population dynamics that require detailed study. 46 ~~9 RECOMMENDATIONS Based on this study, a number of practices for the use of household cistern water supplies are recommended and enumerated below. 1. Paint used for rooftop collection systems snould have as low a level of heavy metals, such as mercury and lead, as possible. During the time of painting, and until the paint is thoroughly dry, any rainwater. that should fall on the collec- tion surface should be diverted to the ground. 2. Local health authorities should carefully evaluate the sanitary and chemical contaminant quality of all alternate water supplies which are used to supplement cistern supplies, especially private supplies,to ensure that they meet U.S. EPA drinking water guidelines and regulations. 3. Initially at quarterly intervals, and eventually at semiannual to annual intervals, the local health authorities should provide low-cost testing of the sanitary quality of each cistern supply. If the cistern supply is found to contain fecal coliform in excess of one fecal coliform organ- ism per 100 mi of water, the amount of chlorine added to the system each night should be increased so that the total re- sidue each morning is about 1 mg Cl ’/L- The local health authorities should also provide users of household cistern 47 r water suppiies with low-cost analytical services, at annual to biannual intervals, to analyse the cistern supplies for lr : heavy metals and other contaminants of potential concern. Parti- _ : cular emphasis should be given to those contaminants included ' in the U.S. EPA National Interim Drinking Water Regulations lr 4. Every household with a cistern water supply should prac- tice chlorination of their cistern Storage water; sufficiently Strong solutions of chlorine such as "Clorox", should be added to the cistern each night so that the residual total chlorine the next morning is on the order of 0.5 mg Cl /L or greater, based on measurements with a DPD chlorine colorimetric test kit. New cistern water supply systems should be required to be constructed to filter debris and to facilitate the addition of chlorine to the storage tanks. One way to accomplish this would be to provide plastic Piping which would allow the addi- tion of chlorine from the main part of the house, and which would preferably distribute the chlorine to several locations within the tank. A water depth indicator in the cistern supply tank would also be desirable to aid in determining how much - er ee ee ne chlorine is needed. It is realized that the addition of ~9 chlorine in this manner will increase the chlorinated organics content of the cistern water supply. However, in the opinion of the authors, the health risk of the increased concentrations is small when compared to the risk of promoting entric disease if the chlorine were not added. a re Pr | 48 “9 ee ene 3 ne ee ee ne ne | “9 5. At about yearly interyals, and more frequently if necesSary, a subStantial part of the leaf debris Sludge present in the bottom of the cisterns should be carefully siphoned off or pumped out with a flexible hose so as not to drain the tank. If excessive amounts of debris accumulate, neccessita- ing frequent cleaning, then all trees and shrubbery -that over- hang the rooftop collection area should be removed from that area. If leaves are a problem, it may be appropriate to place screens on the intakes. These screens would have to be cleaned. at frequent intervals to make certain that they did not impair water collection. 49 Ww J Us ~l . References American Public Health Association, American Water Works Association, and Water Pollution Control Federation. 19835 Standards Methods for the Examination of Water and Waste Water, 15th ed., Wasnington, D.C.: American Public Health Association. "Atomic Absorption Analysis for Heavy Metals in the Air". Fausto J. Monoz-Ribadeneira and M.J. Canoy in: Atmospheric Heavy Metals, Vol I, PRNC Publ. 1974, #186. Fishman, M.J., and Midgett, M.R., 1968. Extraction techni - ques for the determination of cobalt, nickel and lead in fresh water by atomic absorption. In Trace inorganics in Water, ed. R.A. Baker, Advances in Chemistry Series 73, pp. 230-235. Washington, D.C.: American Chemical Society. Isquith, Irwin, and Winters, H., "Microbial Analysis of Domestic Cistern Water in the U.S. Virgin Islands," Caribbean Research Institute, College of the Virgin Islands, St. Thomas, 1981. Jordan, D.G. and Cosner, O.J., "A Survey of the Water Resources of St. Thomas, V.I.", U.S. Department of the Interior, Geological Survey, 1973. League of Women Voters, St. Thomas, St. John, 1970. A Study of our Virgin Island Government Structure and Function. Lee, G.F., and Jones, R.A., 1982. Quality of the St. Thomas, U.S. Virgin Islands Household Cistern Water Supplies. Proceedings, International Conference on Rainwater Cistern Systems. Water Research Center, University of Hawaii, 1982. National Academy of Science and National Academy of Engineer- ing, 1973. Water Quality Criteria - 1972. A report by the Committee on Water Quality Criteria Environmental Studies Board for the U.S. Environmental Protection Agency. Washington, D.C.: U.S. Government Printing . Office, $94 p. 50 ‘oO 10. bas | oad . b+ to 14, 15. Robinson, Tully M. et al., "Water Records of the U.S. Virgin Islands, 1962-69", U.S. Department of the Interior, Geological Survey, 1973. U.S. Environmental Protection Agency, 1974. Safe Drinking Water Act. PL 92-523, 42 U.S. Code 300 g-1l. , 1976a. Interim Primary Drinking Water Regulations. Federal Register. Pt 141, 40:59566-88, (40CFR 141). , 1976b. Quality criteria for water. EPA 400/9-76-025. Washington, D.C.: U.S. Government Printing Office. , 1980. Water quality criteria (toxic chemicals). Federal Register 45 (231), November 28. U.S. Geological Survey, 1965. Test Drilling and Ground Water Supplies St. Thomas and St. John, U.S. Virgin Islands. Information Release V1I019, St. Thomas and St. John. Virgin Islands Interim Primary Drinking Water Standards, Chapter 51, Subchapter 1303, VI Code. 51