PUBLIC HEALTH ASSESSMENT
ISLAND CHEMICAL CORPORATION/VIRGIN ISLAND CHEMICAL CORPORATION
CHRISTIANSTED, ST. CROIX, U.S. VIRGIN ISLANDS
The Island Chemical/Virgin Island Chemical site is an inactive facility in the south central portion of St. Croix, U.S. Virgin Islands. The site, which covers about 3 acres, is located about 1,500 feet north of the Alexander Hamilton Airport. The site was used from the early 1970s to the mid 1980s by several chemical companies for the manufacture of pharmaceuticals, primarily phenacetin, ethoxyquin, and quinidine, and other chemicals, such as benzyl acetate and benzyl salicylate. In the late 1980s, a portion of the site was used for an alcohol (ethanol) dehydration project. Currently, the site is unoccupied and in a state of disrepair.
The site is bordered on the north and east by an intermittent stream known as River Gut; on the west by an undeveloped lot; and on the south and southwest by Route 66. A concrete batch plant, an asphalt paving company, and two automobile repair shops are located east of the site, across River Gut.
Historical operations at the site resulted in contamination by various organic compounds, including
chloroform, pyridine, quinidine gluconate, quinine sulfate, and toluene in the following areas of the
site: 1) soil between above-ground storage tanks (ASTs) #8 and #9; 2) water and sludge 
in the
process pit and associated sludge in the drainage line from the process pit; 3) soil under the concrete
loading dock and in a trench next to the loading dock which had been contaminated by
leakage/drainage from the former lab pit; and 4) soil under concrete slab #3 near the ASTs. Most of
the contaminated materials in these areas have since been either removed or remediated. However,
organic contaminants, primarily chloroform, from past site operations are present in groundwater at
the site and in nearby public supply wells, including the Virgin Islands Water and Power Authority
(VIWAPA) Fairplains wells and the Virgin Islands Port Authority (VIPA) airport wells. In
addition, volatile organic compounds (VOCs), including ethylbenzene and xylenes, are present at
significant levels in subsurface soil and groundwater in the AST area.
ATSDR has classified the Island Chemical/Virgin Island Chemical site a no apparent public health hazard because available environmental sampling data do not indicate that people have been exposed to site contamination at levels that would be expected to cause adverse health effects. Nevertheless, ATSDR believes the site's numerous physical hazards, including miscellaneous debris (e.g., old pipes, pieces of metal, old plant equipment, junk cars, old tires, nails, old lockers, old lab equipment); dilapidated and deteriorating buildings and storage tanks; and unsecured outside stairways could pose a minor safety threat to site trespassers.
ATSDR has identified two completed human exposure pathways associated with contamination from the site: 1) users of the municipal water supply who were likely exposed to low levels of contaminants, such as chloroform, lead, and mercury, in their residential drinking water, and 2) workers and visitors at the Alexander Hamilton Airport who were likely exposed to low levels of contaminants, including bromoform, bromodichloromethane, chloroform, chlorodibromomethane, aluminum, iron, lead, mercury, and vanadium, in the airport's drinking water. These past exposures are no longer occurring because the municipal and airport wells that were impacted by contamination are no longer in use. In addition, some of the contaminants detected in the municipal and airport water supplies may not be directly related to contamination at the site. ATSDR's toxicological evaluation indicates that no adverse health effects, either carcinogenic or noncarcinogenic, will result from past exposures to contaminants in the municipal and airport drinking water supplies.
ATSDR has also identified the following potential human exposure pathways: 1) residents in the site area who use private well water for their household water needs (e.g., drinking, bathing, showering); 2) former plant employees, site investigators, and trespassers who may have come into contact with chemicals in raw materials, finished products, and wastes associated with former site operations, or contaminated soils and sediments resulting from former site operations; and 3) persons who may have come into contact with surface water (while the plant was in operation) or sediments in the River Gut stream channel downstream of the site. ATSDR believes that the public health significance of these potential exposures is likely to be minimal; however, additional information regarding the use and quality of private well water in the site area is necessary to fully evaluate this potential exposure pathway.
No community health concerns about the Island Chemical/Virgin Island Chemical site have been expressed by the citizens of St. Croix.
Health outcome data for the population surrounding the site was not identified during the gathering of information and data for this public health.
Data inadequacies include 1) limited sampling data for the VIWAPA Fairplains wells and the VIPA airport supply wells; 2) no sampling data for other VIWAPA wells near the site, such as the Bethlehem, Negro Bay, Golden Grove wells; and 3) no sampling data or water use information for private wells in the site area.
ATSDR has determined that no follow-up health activities are indicated for the site at this time. However, ATSDR will reevaluate the site for appropriate follow-up health activities if future data or information indicates that human exposure to site contaminants is occurring at levels of public health concern.
The Agency for Toxic Substances and Disease Registry (ATSDR), whose headquarters are in Atlanta, Georgia, is a federal agency within the U.S. Department of Health and Human Services and is authorized by the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) to conduct public health assessments of hazardous waste sites. As part of that mandate, ATSDR has evaluated the public health significance of the Island Chemical/Virgin Island Chemical site (e.g., Are health effects possible?) and has recommended actions to reduce or prevent possible health effects.
A. Site Description and History
The Island Chemical/Virgin Island Chemical site is an inactive facility on Route 66 (Melvin Evans Highway) in the south central portion of St. Croix, U.S. Virgin Islands (Figure 1). The site, which covers about 3 acres, is located about 1,500 feet north of the Alexander Hamilton Airport. The site was used from the early 1970s to the mid 1980s by several chemical companies for the manufacture of pharmaceuticals, primarily phenacetin, ethoxyquin, and quinidine, and other chemicals, such as benzyl acetate and benzyl salicylate. The site is bordered on the north and east by an intermittent stream knows as River Gut, on the west by an undeveloped lot, and on the south and southwest by Route 66. A concrete batch plant, an asphalt paving company, and two automobile repair shops are located east of the site, across River Gut (1,2,3). The location of these and other facilities within a quarter mile of the site is shown in Figure 2 (3).
The site property is owned by the Charles H. Steffey Holding Corporation (CHS) (4). In May 1969, CHS leased the site to Houston Chemical Industries, Inc. (Houston) on a 30-year lease. In March 1972, Houston assigned the lease to Caribe Chemical Company, Inc, which was subsequently known as Pierrel America, Inc. Houston and Caribe reportedly used the facility to produce phenacetin and ethoxyquin. In June 1978, Pierrel America assigned the lease to Cooper Laboratories, Inc. (Cooper). In July 1978, Cooper incorporated Island Chemical Company as its subsidiary to assume production activities at the facility. Cooper used the facility to convert quinine to quinidine using toluene and pyridine. In November 1979, Cooper Laboratories sold all of its stock in Island Chemical Company to Berlex Laboratories, Inc. (Berlex). Berlex, operating under the name Island Chemical Company, produced quinidine gluconate from quinine sulfate, toluene, and methanol. In October 1982, Berlex shut down the Island Chemical operations, and between November 1982 and February 1983, removed several thousand gallons of toluene and xylenes from the facility's above ground storage tanks (ASTs) for off-site disposal. In September 1984, Berlex sold its Island Chemical Company assets to Virgin Island Chemical Company (VI Chemical). VI Chemical operated the plant until late 1985, initially producing benzyl acetate from benzyl chloride and acetic acid and later producing benzyl salicylate (1,2,3,5,6).
In 1984, U.S. Resources and Chemicals, Inc. began leasing a portion of the property from VI Chemical, and shortly thereafter began an alcohol dehydration operation at the site. U.S. Resource transferred the lease and ownership of the alcohol dehydration equipment to VIAG Fuels, Inc. By early 1991, the alcohol dehydration operation was no longer active although several of the facility's ASTs were still being used to store ethanol. VIAG later removed the ethanol and the alcohol dehydration equipment from the site. Currently, the site is unoccupied and in a state of disrepair (2,4,7).
In 1984, in conjunction with the sale of assets of Island Chemical Company to Virgin Island Chemical Company, Enviro-Sciences, Inc. (ESI) was hired to conduct an environmental investigation of the site. As a result of the ESI investigation, which was conducted from October 1984 to March 1986, four areas of contamination were identified and characterized through environmental sampling. The four areas (Figures 3 and 4) consisted of 1) soil between above-ground storage tanks (ASTs) #8 and #9 (Area B); 2) water and sludge in the process pit (Area C) and associated sludge in the drainage line from the process pit; 3) soil under the concrete loading dock (Area D) and in a trench next to the loading dock which had been contaminated by leakage/drainage from the former lab pit; and 4) soil under concrete slab #3 near the ASTs (Area E) (2,6).
Soil samples collected by ESI between October 1984 and March 1986 indicated the presence of
various organic compounds, including toluene and pyridine, in the areas of concern described above.
Toluene-contaminated soil in Areas B and E was excavated, heat treated in the plant's drying oven,
and later shipped off the island for final disposal. Soil contaminated by pyridine in the loading dock
area (Area D) was treated in-place (after removal of the overlying concrete surface) by aeration and
biodegradation through periodic tilling of the soil. Sludge and wastewater in the process pit, an
underground 8,000-gallon concrete tank, were removed and placed in drums for later disposal. At a
later date, the process pit was sealed with concrete (2,4,6).
During the ESI investigation, the central storm drain, which conveyed stormwater and wastewater from the process pit to River Gut, was found to consist of 55-gallon drums, with their ends removed, welded end-to-end. The drain line drums were badly corroded and contained an oily sludge. ESI excavated the drain line and contaminated soil beneath the drain line and placed the drums, oily sludge, and contaminated soil in containers for later disposal. The excavated drain line was then replaced with a 10-inch polyvinyl chloride (PVC) pipe. Waste materials from the various ESI site activities, including treated soil from the dying oven, water and sludge from the process pit, and drums and sludge from the excavated central drainage line, were removed from the site and shipped off the island in late 1985 (2,4,6).
In September 1985 and March 1986, EPA conducted two enforcement inspections under authority of the Resource Conservation and Recovery Act (RCRA) to verify the effectiveness of ESI's soil remediation activities and to determine compliance with applicable RCRA regulations. Samples collected during the RCRA inspections indicated the presence of toluene, phthalates, benzene, chloroform, polynuclear aromatic hydrocarbons (PAHs), chromium, and zinc in site soils and sediments, including sediments in the River Gut steam channel (2,4,5,6,8).
In January and February 1989, EPA's Response and Prevention Branch conducted a Preliminary Assessment and Removal Evaluation at the site. At that time, EPA found approximately 400 drums, in various conditions, inside the warehouse building (Area A, Figure 4). The drums contained a variety of substances including ethyl alcohol, methanol, benzyl acetate, benzyl chloride, toluene, methyl isobutyl carbinol, sodium hydroxide, paints, and unidentified substances. EPA also discovered leaking cylinders of chlorine and hydrogen chloride, and over 800 containers of laboratory reagents including sodium, potassium cyanide, phosphorus pentoxide, and ethyl ether in the lab building. Between February 1989 and October 1991, EPA removed more than 250 drums of the various chemicals, and more than 8,000 pounds of lab pack chemicals from the laboratory/warehouse building for off site disposal. In January 1990, during the site removal activities, EPA collected groundwater samples which showed chloroform to be present in an on-site production well and nearby municipal wells (2,4,7).
In February 1991, EPA's Field Investigation Team (FIT) conducted a sampling site inspection at the site during which groundwater, sediment, and soil samples were collected. Chloroform was found in on-site and off-site wells, and various organic and inorganic contaminants were present in the sediment samples from the facility's storm drains. Low level of several pesticides were also detected in the site soil and sediment samples (2,4).
In January 1994, the site was proposed to EPA's National Priorities List (NPL). The NPL is the
national list of hazardous waste sites that qualify for cleanup under the federal Superfund program.
The site was listed as final on the NPL in June 1996 (2).
In January and February 1995, EPA conducted an initial (Phase I) remedial investigation (RI) of the Island Chemical/Virgin Island Chemical site. The purpose of the RI was to characterize the nature and extent of contamination at the site and to evaluate whether such contamination posed a risk to human health and the environment. The initial RI field activities included site clearing, installation of four monitoring wells, completion of 11 soil borings, rehabilitation of two on-site productions wells, and collection of numerous soil and groundwater samples. In May 1995, EPA revisited the site and collected an additional round of groundwater samples. The results of the initial RI activities indicated significant soil and groundwater contamination in the tank farm area due to leaks and/or spills from one or more of the ASTs. The RI data also showed some residual soil and groundwater contamination in other areas of the site from past site operations (3).
In May and June 1996, EPA conducted supplemental (Phase II) RI field activities to further characterize the extent of groundwater and soil contamination in the AST area and to evaluate groundwater quality near the former process pit (near the center of the site). The supplemental field activities included installation of two monitoring wells, completion of seven soil borings, and collection of groundwater and soil samples. The results of the supplemental investigation helped define the extent of VOC soil and groundwater contamination near AST tank #8 and indicated some residual groundwater contamination (primarily chloroform) near the former process pit (9).
Phase III of the RI is currently in the planning stages. The Phase III field activities will include additional soil and groundwater sampling to further characterize the extent of VOC contamination in the AST area, to evaluate the presence of VOC contamination in shallow and deep groundwater, and to determine the levels of contaminants in the River Gut stream channel. In addition, the field activities will include measurement of groundwater levels in order to evaluate the flow characteristics of the deep aquifer in the immediate site area (10).
In December 1994, Steve Richardson and Deborah Boling, ATSDR headquarters staff, and Steven Jones, ATSDR Region II representative, visited the Island Chemical/Virgin Island Chemical site. The following site conditions were observed during the site visit:
In April 1997, Steve Richardson, Deborah Boling, and Brian von Gunten, ATSDR Region II representative, conducted a follow-up site visit. Most of the site conditions were similar to those observed during the December 1994 site visit. Access to the site was still unrestricted because sections of the perimeter fence were missing and the site entrance gate was broken. The site was still overgrown by vegetation although some areas had obviously been cleared during the previous RI field activities. The site was still littered with debris, and the site's buildings and other structures (e.g., pipes, tanks, catwalks, stairways) had become more dilapidated and deteriorated since the previous site visit. The granular orange and black substances and grey pellet-like materials observed on the floor of the lab/warehouse building during the previous site visit were still present.
Other observations made during the April 1997 site visit included the following:
C. Demographics, Land Use, and Natural Resource Use
Demographics
The population of St. Croix is approximately 50,000, based on 1990 census data. The racial distribution of the U.S. Virgin Islands' population, which includes St. Croix, St. John, and St. Thomas, is about 80% black, 15% white, and 5% other. The Virgin Island population can be further classified according to the following ethnic groups: 74% West Indian (45% born in the Virgin Islands and 29% born elsewhere in the West Indies); 13% U.S. mainland; 5% Puerto Rican; and 8% other. In addition, 14% of the population is reported to be of Hispanic origin (0, 11). The specific demographic makeup of the population living near the Island Chemical/Virgin Island Chemical site cannot be determined based on currently available information.
Land Use
The area surrounding the Island Chemical/Virgin Island Chemical site is predominately agricultural and commercial. Several businesses are adjacent to the site (as shown in Figure 2) including (1) an unknown business inside a small, fenced area next to the southwest corner of the site (near the AST area); (2) a redi-mix concrete plant about 100 feet east of the site; (3) an asphalt paving company about 300 feet north of the site; (4) two auto repair shops about 400 feet north-northeast of the site; (5) an engineering company about 600 feet northwest of the site; and (6) an asphalt manufacturing plant about 700 feet northwest of the site. Other facilities in the site area include the Golden Grove Correctional Institute, located about 1,100 feet northwest of the site; a construction materials and equipment company, located approximately 1,300 feet southeast of the site; and an old quarry next to the construction company. In addition, the Alexander Hamilton Airport is less than half a mile south of the site (3).
A number of agricultural areas surround the site. These areas are used primarily to raise cattle and goats.
The nearest residences to the site are reportedly located about one-tenth of a mile south or east of the site. However, the existence of these residences cannot be confirmed. The nearest known residences are located about one-third of a mile north-northeast of the site in the Upper Bethlehem area. Other residences, including the mobile homes of the Golden Grove Trailer Park, are located about three-quarters of a mile northwest of the site in the Golden Grove area (2,4,7)
Natural Resource Use
Fresh water is a scarce commodity in the U.S. Virgin Islands. To meet the demand for fresh water on St. Croix, all available sources of fresh water are used, including desalinated seawater, groundwater, and rooftop rainfall catchment systems (cisterns).
Groundwater is used as a source of potable water supply for both private and public water systems on the island of St. Croix. The Virgin Islands Water and Power Authority (VIWAPA) has at least 60 public supply wells in about nine well fields across the island. However, less than half of these are believed to be currently active. Water from the active VIWAPA supply wells is used to supplement desalinated seawater from VIWAPA's four large desalination units near Christiansted. Water from the desalination units is mixed with water from the municipal supply wells and distributed in the same water lines. In the past, approximately 70% of the water distributed by VIWAPA was obtained from the desalination units while the remaining 30% was supplied by the municipal supply wells. Recently, the capacity of the desalination units was increased such that desalinated seawater now makes up nearly all of VIWAPA's water supply under normal conditions. During extremely heavy periods of demand, such as those that occur in the summer when rainfall is scarce, a greater portion of the municipal water is provided by the VIWAPA water supply wells (4,12).
The municipal well fields closest to the site are the VIWAPA Fairplains well field, located about 900 to 1,800 feet southeast of the site, and the Bethlehem well field, located about 1,000 to 1,200 feet northeast of the site. Other VIWAPA well fields near the site are the Golden Grove well field, which is about 3,000 to 4,500 feet west-northwest of the site, and the Negro Bay well field, located about 3,500 to 4,000 feet west and southwest of the site. The locations of the VIWAPA well fields in the site area are shown in Figure 5. Until recently, water from the individual wells in these well fields was pumped into a 100,000-gallon storage tank at the Fairplains well field where it mixed with desalinated seawater from the Christiansted treatment units. The combined water in the Fairplains storage tank was withdrawn, chlorinated, and distributed through the municipal distribution system to VIWAPA's water users. Over the past several years, some of the Fairplains wells were taken out of service, and, recently, the remaining Fairplains wells were shut down. According to VIWAPA authorities, there are no plans to use the Fairplains wells in the future. Currently, water from the other well fields--Bethlehem, Golden Grove, and Negro Bay--is pumped through a filtration system to remove particulates, and a reverse osmosis unit to reduce salinity, prior to entering the Fairplains storage tank. As before, the combined well water and desalinated seawater in the Fairplains tank is withdrawn, chlorinated, and distributed. As discussed above, the VIWAPA supply wells are used primarily when the availability of desalinated seawater from the Christiansted plant is insufficient to meet user demand (3,4).
The principle aquifer for the Fairplains and Golden Grove well fields is the alluvium which is composed mostly of low permeability clay. The thickness of this deposit in the site vicinity is reported to range from about 55 to 100 feet. Imbedded in the clay are isolated, high permeability lenses of sand and gravel, ranging from 1 to 8 feet in thickness. Reported depth from ground surface to the water table in the site vicinity vary from 9 feet to 107 feet. For example, water levels in the Fairplains wells near the site reportedly range from 16 to 20 feet below ground surface. In the site area, the direction of shallow groundwater flow has not been adequately defined (2,3,4).
The soil structure beneath the Island Chemical/Virgin Island Chemical site is generally consistent with the alluvial deposits found in the site area. Boring logs indicate that the site is underlain by at least 25 feet of sandy clay and silty clay with discontinuous lenses of gravelly sand and silty sand. The lowermost lens, which is encountered at a depth of 24 to 33 feet below ground surface, is a silty sand that appears to be continuous across the site. At the site, depth from the ground surface to the water table varies from about 21 feet to 28 feet. In addition, two different shallow groundwater flow patterns have been reported at the site. Under typical (dry) conditions, a shallow groundwater divide exists, such that west of a line between MW-3 and MW-4, groundwater flows to the west and northwest, while east of a line between MW-3 and MW-4, groundwater flows to the east and northeast. In contrast, during and immediately after significant rainfalls, a reversal of flow direction occurs so that shallow groundwater flows to the west and northwest across the entire site. These periods of flow reversal are reported to last for a period of 1 to 2 weeks (2,3,4,9).
Underlying the alluvium in some areas of St. Croix, and exposed at the surface in other areas, is the Kingshill Limestone aquifer, which, in the site vicinity, is composed primarily of chalks and marls. The Kingshill aquifer has a maximum saturated thickness of approximately 200 feet, and is reported to be the most productive aquifer on the island. However, because of salt water intrusion, much of the groundwater in this aquifer has a high chloride content and, therefore, is not generally suitable for human consumption. The Kingshill aquifer is the principal aquifer for both the Bethlehem and Negro Bay well fields. The direction of groundwater flow in the deep Kingshill aquifer at the site has not been determined. In addition, the shallow alluvial and the deep Kingshill aquifers in the site area are believed to be interconnected, because of the presence of numerous old abandoned wells that are screened, perforated, or open across both aquifers (2,4).
The Kingshill aquifer is also tapped by two public wells near the site that are not part of the VIWAPA municipal water system. These two wells are located about 900 to 1,200 feet west of the site (Figure 2), and are about 110 feet deep. Until recently, the two wells, which are owned by the Virgin Islands Port Authority (VIPA), were used to supply water to the nearby Alexander Hamilton Airport. Water from the wells was pumped to a large storage tank on top of a hill near the airport. Water in the storage tank was distributed to the airport terminal and a number of businesses associated with the airport for various uses, including drinking water. VIPA officials indicate that powdered chlorine was periodically added to water in the storage tank for disinfection. Recently, the airport was connected to the VIWAPA's water distribution system, thereby eliminating the need to use the two airport supply wells except in cases of emergency (2,3,4).
A large number of private water supply wells are located throughout the island of St. Croix, especially in areas that are not served by the VIWAPA municipal water system. Records containing specific information about private wells on the island are scarce and generally incomplete. Most private wells on the island are reported to be screened in the shallow alluvial aquifer or in the upper portion of the deeper Kingshill aquifer. These wells are believed to be used primarily for drinking water supply, irrigation, and commercial/industrial operations. The closest private wells to the site are two wells at the concrete plant about 150 feet east of the site, and two wells at the asphalt plant about 700 feet northwest of the site (Figure 2). These four wells are located across River Gut from the site, and are used for industrial/commercial purposes only--not for potable water supply. The closest private wells used for drinking water are not known for certain, but may be the wells at the Golden Grove Trailer Park located approximately three-quarters of a mile northwest of the site (2,3,4).
Most private dwellings on St. Croix have cisterns which are used to store rainwater from rooftop catchment systems. Cisterns provide almost 10% of the freshwater supplies on the island. Some residences depend on cisterns as their principle source of potable water, while others use cisterns to supplement their private well water. In addition, when rainfall is adequate, many residences use water from their cisterns instead of the municipal water supply to reduce their water costs (2,12).
The nearest surface water to the site is River Gut, an intermittent stream that borders the site on the north and east. The gut originates northwest of the site, flows past the site and then, about 800 feet to the southeast, flows under Highway 66 where it is joined by another intermittent stream, Bethlehem Gut. About 4,500 feet southeast of the site the combined streams discharge to the Caribbean Sea. River Gut is an intermittent stream that generally flows only during the island's rainy season (September to December). Although the gut is not likely to be heavily used for recreational activities such as boating or fishing, in the past children were reported to have used the gut for swimming downstream of the site (13). On the north and northeastern sides of the site, the gut is about 12 to 15 feet deep with steeply sloped, heavily vegetated sides. Rainfall runoff from the site reportedly drains to the gut either by sheet flow, generally from southwest to northeast, or by one of two storm drains which discharge to the gut on the southeast side of the site (2,3).
During the December 1994 site visit, ATSDR staff contacted officials of the Virgin Islands Department of Health, the Virgin Islands Department of Planning and Natural Resources, the Virgin Islands Water and Power Authority, and the Virgin Islands Port Authority to gather information regarding health concerns about the site. These officials were not aware of any complaints from the public related to contamination at the Island Chemical/Virgin Island Chemical site. However, a representative of the Virgin Island Port Authority expressed concern about the possibility of site groundwater contamination affecting the two airport water supply wells located just west of the site.
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
This section of the public health assessment identifies contaminants of concern found in specific environmental media at the Island Chemical/Virgin Island Chemical site. The contaminants of concern will be evaluated later in the health assessment to determine if exposure to them will affect the public's health.
ATSDR selects and discusses contaminants of concern using the following information:
It is emphasized that the listing of a contaminant in the following tables does not mean it will cause adverse health effects if people are exposed at the reported concentrations. Rather, the listing of a contaminant indicates that the contaminant will be evaluated further in this public health assessment. When a contaminant is selected as a contaminant of concern in one medium, its presence or absence in all media sampled will be discussed.
The data tables presented in this section include the following abbreviations and/or acronyms:
Comparison Values (CVs) • CREG = Cancer Risk Evaluation Guide • EMEG = Environmental Media Evaluation Guide • RMEG = Reference Dose Media Evaluation Guide • LTHA = Lifetime Health Advisory • MCLG = Maximum Contaminant Level Goal • MCL = Maximum Contaminant Level • PMCLG = Proposed Maximum Contaminant Level Goal Data Clarifiers • ppb = parts per billion • ppm = parts per million • ND = not detected • N/A = not analyzed or not available • N/R = not reported • J = associated numerical value is an estimated quantity
EMEGs are media-specific values developed by ATSDR for use in selecting environmental contaminants of potential health concern. EMEGs are calculated using noncancer health endpoints and do not consider potential carcinogenic effects. RMEGs are media-specific values developed by ATSDR from EPA Reference Doses (RfDs). RfDs are EPA's estimates of the daily exposure to a contaminant that is unlikely to cause adverse health effects. CREGs are estimated contaminant concentrations expected to cause no more than one excess cancer in a million persons exposed over a lifetime (70 years). Maximum Contaminant Level Goals (MCLGs) are EPA-developed drinking water health goals. EPA believes that MCLGs represent levels at which no known or anticipated adverse effect on the health of persons should occur (allowing for an adequate margin of safety.) Proposed Maximum Contaminant Level Goals (PMCLGs) are MCLGs that are being proposed. Maximum Contaminant Levels (MCLs) represent contaminant concentrations that EPA deems protective of public health (considering the availability and economics of water treatment technology) over a lifetime (70 years) at an exposure rate of 2 liters of water per day. EPA's Lifetime Health Advisories (LTHAs) represent the level of a contaminant in drinking water (with a margin of safety) at which adverse noncancer health effects would not be anticipated during a lifetime (70 years) exposure. While MCLs are regulatory concentrations, PMCLGs, MCLGs, and LTHAs are not.
As previously discussed, sampling data have been collected since 1984 from various environmental media at the Island Chemical/Virgin Island Chemical site. Most data were collected during the ESI site investigations and the EPA Remedial Investigation. Relevant contaminant data from these and other sampling events, which were described previously in the Background section, are discussed and evaluated below.
For the purpose of this public health assessment, "on-site" refers to those areas within the general site boundary shown in Figure 6. All areas outside of the site boundary, including the River Gut stream channel, are considered to be "off-site".
Bulk Chemicals
Twenty, 8,500-gallon above-ground storage tanks (ASTs) were originally located in a tank farm (Area B, Figure 4) along the western site boundary. In the 1980s, six of the tanks were sold and removed from the site. The ASTs were used by the various site operators to store bulk chemicals for use in the plant's manufacturing operations.
In October and November 1982, four of the ASTs were sampled and found to contain toluene, xylene, para-phenetidine and 9-fluorenone. These chemicals were later removed from the site for off-site disposal. In March 1986, nine of the ASTs were sampled and the following liquids were found: 1) a solution of benzoquinone and fluorenone; 2) solutions of benzophenone and fluorenone with traces of VOCs; 3) p-phenetidine; 4) p-phenetidine with aromatics; 5) hydroxyfuranocoumarin; and 6) a mixture of hydroxyfuranocoumarin and p-phenetidine. In January 1989, four of the ASTs were found to be filled with ethanol, which was used by one of the site's operators in an alcohol dehydration project, while the other 10 were empty. In May 1989, ethanol was again found in the first four tanks while diesel fuel was discovered in the fifth tank. In April 1995, field investigators detected a black, petroleum-like liquid leaking from the drain valve on Tank #5 and a small area of stained soil beneath the leaking valve. In addition, at that time only 10 of the ASTs tanks were present; apparently, four of the tanks were removed from the site sometime between 1990 and 1994.
Sludge
In June 1985, ESI sampled sludge inside the process pit (Area C, Figure 4) for organics and inorganics. The sampling data showed high levels of several organic contaminants, such as benzyl acetate, benzene methanol, diphenyl methanone; low levels of other organics, such as chloroform; and elevated levels of several inorganic contaminants, including chromium, lead, and zinc. Sampling data for contaminants of concern, (i.e., contaminants whose concentration exceeded an applicable ATSDR comparison value and those for which there is no applicable comparison value) in the process pit sludge samples are shown in Table 1.
Wastewater
In July 1985, ESI sampled wastewater inside the process pit and found detectable levels of several organic and inorganic contaminants. However, most of the inorganic contaminant concentrations did not exceed applicable ATSDR comparison values. The contaminants detected in the July 1995 process pit wastewater samples were generally consistent with the contaminants found in the June 1995 process pit sludge samples. Sampling data for contaminants found at levels exceeding an applicable ATSDR comparison value and for contaminants which have no comparison value are presented in Table 2. After the July 1985 sampling event, the process pit tank was cleaned out and filled with concrete.
Table 1. Sampling Data for Contaminants of Concern in Sludge Samples from the Process Pit1
| CONTAMINANT | CONCENTRATION RANGE (ppm) | BACKGROUND CONCENTRATION (ppm) | COMPARISON VALUE | |
| ppm | SOURCE | |||
| BENZENE METHANOL(t) | 15,000J | N/A | NONE | |
| BENZYL ACETATE(t) | 170,000 | N/A | NONE | |
| CHLOROFORM(x) | 220 | N/A | 500 | cEMEG |
| CHLOROMETHYLBENZENE(t) | 4,400J | N/A | NONE | |
| 1-CHLORO-2-METHYLBENZENE(t) | 40J | N/A | NONE | |
| DIPHENYL METHANONE(t) | 30,000J | N/A | NONE | |
| 9H-FLUORENE-9-ONE(t) | 3,000J | N/A | NONE | |
| METHYLENE CHLORIDE | 125 | N/A | 90 | CREG |
| 1,1'-(OXYBIS(METHYLENE))BIS-BENZENE(t) | 4,000J | N/A | NONE | |
| TOLUENE | 1,560 | N/A | 1,000 | ciEMEG |
| ARSENIC | 40 | <0.1 - 7382 | 0.5 | CREG |
| CHROMIUM | 592 | 10 - 3003 | 60 | CREG (Cr+6) |
| COPPER | 327 | 30 - 1003 | NONE | |
| LEAD | 688 | 10 - 3003 | NONE | |
| ZINC(x) | 3,594 | ND - 2003 | 20,000 | cEMEG |
Table 2. Sampling Data for Contaminants of Concern in Wastewater
Samples from the Process Pit1
| CONTAMINANT | CONCENTRATION RANGE (ppb) | COMPARISON VALUE | |
| ppb | SOURCE | ||
| BENZALDEHYDE(t) | 3,000J | 1,000 | cRMEG |
| BENZENE | 40 | 1 | CREG |
| BENZENE METHANOL(t) | 24,000J | NONE | |
| CHLOROMETHYL BENZENE(t) | 300J | NONE | |
| DIPHENYL METHANE(t) | 400J | NONE | |
| 1,1'-(OXYBIS(METHYLENE))BIS-BENZENE(t) | 400J | NONE | |
| PHENYL ACETATE(t) | 26,000J | NONE | |
| TOLUENE | 380 | 200 | ciEMEG |
| ZINC | 4,850 | 3,000 | cEMEG |
Soil/Sediment
Between September 1984 and February 1991, numerous soil and sediment samples were collected at the site from several areas of concern, including the AST area (Area B), the central and southern storm drain, the concrete slabs near the AST area (Area E), and the loading dock/lab pit area (Area D) (Figure 4). These data showed high levels of several organic compounds (such as benzophenone, phenol, pyridine, quinidine gluconate, quinine sulfate, and toluene), and slightly elevated levels of some inorganics (including antimony, iron, lead, and zinc) in site soils from the areas of concern. Sampling data for contaminants found at levels exceeding an applicable ATSDR comparison value, and for contaminants which have no comparison value are presented in Table 3. The highest contaminant concentrations were generally found in the AST area soils, which were reportedly contaminated due to a toluene spill from Tank #8, and in the loading dock/lab pit area soils, which were believed to have been contaminated due to leaks and/or drainage of liquids from the lab pit. The contaminants found in site soils were generally consistent with chemicals known to have been used as raw materials or manufactured as products during the plant's operating history. All contaminated soil in the AST area, the loading dock/pit area, and the area near the concrete slabs was reportedly remediated through excavation, heat treatment, and off-site disposal or through in-situ aeration and biodegradation.
Table 3. Historical (Pre-RI) Sampling Data for Contaminants of Concern in On-Site Soil/Sediment Samples (various depths)1
| CONTAMINANT | CONCENTRATION RANGE (ppm) | BACKGROUND CONCENTRATION (ppm) | COMPARISON VALUE (ppm) | |
| ALDRIN | 0.012J - 30J | N/A | 0.04 | CREG |
| BENZOPHENONE | 2,600 - 15,000 | N/A | NONE | |
| d-BHC | 0.0077J | N/A | NONE | |
| BIS(2-ETHYLHEXYL)- PHTHALATE |
1.9J - 51 | N/A | 50 | CREG |
| CARBON TETRACHLORIDE | 10 | N/A | 5 | CREG |
| a-CHLORDANE | 0.0035J - 4J | N/A | 0.5 | CREG |
| g-CHLORDANE | 0.0061 - 7.5J | N/A | 0.5 | CREG |
| CHLOROFORM(x) | 0.0014J - 340 | N/A | 500 | cEMEG |
| 1,1-DCA | 0.02 | N/A | NONE | |
| 4,4'-DDE (1,1-DICHLORO-2,2-BIS(p-CHLOROPHENYL)ETHYLENE) | 0.024J - 5.8J | N/A | 2 | CREG |
| DI-N-OCTYLPHTHALATE | 0.5J - 9 | N/A | NONE | |
| HEPTACHLOR EPOXIDE | 0.0048J - 10J | N/A | 0.08 | CREG |
| METHYLENE CHLORIDE | 0.0015J - 1,240 | N/A | 90 | CREG |
| 2- METHYLNAPHTHALENE | 0.63J | N/A | NONE | |
| PYRIDINE | 0.02 - 3,014 | N/A | 50 | cRMEG |
| QUINIDINE GLUCONATE | 47 - 8,227 | N/A | NONE | |
| QUININE SULFATE | 82 - 2,594 | N/A | NONE | |
| TOLUENE | 0.007 - 13,880 | N/A | 1,000 | ciEMEG |
| 1,1,1-TRICHLOROETHANE | 0.0008J - 0.011 | N/A | NONE | |
| ALUMINUM | 9,400 - 27,000 | 7,000 - 100,0002 | NONE | |
| ANTIMONY | 8.4 - 26.6 | <1 - 8.82 | 20 | cRMEG |
| ARSENIC | 1J - 9.1J | <0.1 - 7382 | 0.5 | CREG |
| BERYLLIUM | 7J | ND - 1.53 | 0.2 | CREG |
| CALCIUM | 23,300 - 69,300 | 1,500 - 70,0003 | NONE | |
| CHROMIUM | 19.8J - 110J | 10 - 3003 | 60 | CREG (Cr+6) |
| COBALT | 13.4 - 22.3 | ND - 1003 | NONE | |
| COPPER | 45 - 367 | 30 - 1003 | NONE | |
| IRON | 21,500 - 183,000 | 30,000 - 50,0003 | NONE | |
| LEAD | 9 - 466 | 10 - 3003 | NONE | |
| MAGNESIUM | 3,630 - 7,800 | 7,000 - 15,0003 | NONE | |
| MANGANESE | 735 - 1,420 | 700 - 10,0003 | NONE | |
| POTASSIUM | 2,170 - 2,990 | 50 - 37,0002 | NONE | |
| SODIUM | N/R | 3,000 - 10,0003 | NONE | |
| ZINC(x) | 63 - 1,710J | ND - 2003 | 20,000 | cEMEG |
During the RI field activities in January 1995, soil samples were collected from soil borings in the following areas of the site: the AST area (Area B), the process pit area (Area C), the loading dock/lab pit/lab drain area (Area D), the area in front of the concrete slabs (Area E), and the fenced storage area (Area F). Soil samples were also collected from borings used in the installation of the RI monitoring wells (Figure 7). Depth-discrete soil samples for the shallow monitoring well borings were collected from depths of 0-1 foot and 4-5 feet, while samples for the deep monitoring well borings were collected at various depth intervals ranging from 0-1.5 feet to 25.0-26.5 feet. All RI soil samples were analyzed for organic and inorganic contaminants.
Analysis of the RI soil samples indicated very low levels of VOCs, semi-volatile organics, and/or pesticides at all locations except the AST area, which contained significantly higher levels of three VOCs--acetone, ethylbenzene and xylene. The VOC soil contamination found in the AST area is believed to have been associated with leaks and/or spills of volatile chemicals and possibly diesel fuel from one or more of the ASTs. Soil levels of inorganic compounds across the site were similar to normal background levels except for zinc, which was significantly elevated. Sampling data for contaminants with concentrations that exceeded an applicable ATSDR comparison value are presented in Table 4 along with those contaminants which have no comparison value.
In May 1996, EPA collected additional soil samples in the AST area to better define the extent of the VOC contamination near Tanks #8 and #9. The soil sampling locations are shown in Figure 8. The sampling data showed higher levels of acetone, ethylbenzene and xylene than in the June 1985 samples. The soil samples also contained methylene chloride and toluene, which were not detected in the earlier samples. Contaminants of concern from the June 1985 soil samples are included in Table 4.
Table 4. RI Sampling Data for Contaminants of Concern in On-Site Soils1
|
Contaminant |
Concentration Range (ppm) |
# Detects / # Samples |
# Detects Above Comparison Values |
Comparison Values (ppm) |
Comparison Value Reference |
Background Concentration Range (ppm) |
Maximum Detection |
||
|
Sample ID #2 |
Sample Date |
Data Qualifier |
|||||||
| Volatile Organic Compounds | |||||||||
| 4-Methyl-2-pentanone | 0.008 | 1/49 | NA | NA | NA | NA | SBB11B/14-16 | 5/30/96 | J |
| Semivolatile Organic Compounds | |||||||||
| Di-n-octylphthalate | 0.120 | 1/27 | NA | NA | NA | NA | SBD3/0-2/012095 | 1/20/95 | J |
| Pesticides | |||||||||
| Endrin aldehyde | 0.004 | 2/27 | NA | NA | NA | NA | SBC2/0-1/013095 | 1/30/95 | J |
| Metals | |||||||||
| Aluminum | 9,350 - 28,200 | 31/31 | NA | NA | NA | 7,000 -100,0003 | SBB1/ 0-1/013195D | 1/31/95 | *J |
| Arsenic | 0.950 - 1.5 | 4/31 | 4 | 0.5 | CREG | ND - ND4 | SBF1A/13-15/020395 | 2/3/95 | BJ |
| 20 | EMEG (C) Child | ||||||||
| 200 | EMEG (C) Adult | ||||||||
| Beryllium | 0.15 - 0.58 | 27/31 | 26 | 0.2 | CREG | ND - 1.54 | SBB1/ 0-1/013195D | 1/31/95 | |
| 300 | RMEG Child | ||||||||
| 4,000 | RMEG Adult | ||||||||
| Calcium | 4,640 - 133,000 | 31/31 | NA | NA | NA | 1,00 - 70,0004 | SBC1/20-22/012795 | 1/27/95 | |
| Cobalt | 8.1 - 31.7 | 31/31 | NA | NA | NA | ND - 1004 | SBB1/ 0-1/013195D | 1/31/95 | |
| Copper | 27.9 - 141 | 31/31 | NA | NA | NA | 30 - 1004 | SBF3/0-1/012495 | 1/24/95 | N*J |
| Iron | 18,100 - 63,400 | 31/31 | NA | NA | NA | 30,000 - 50,0004 | SBF3/0-1/012495 | 1/24/95 | *J |
| Lead | 1.9 - 89.9 | 24/31 | NA | NA | NA | 10 -3004 | SBE1/0-2/011895 | 1/18/95 | |
| Magnesium | 4,340 - 13,900 | 31/31 | NA | NA | NA | 7,000 - 15,0004 | SBD4/0-1/012795 | 1/27/95 | |
| Manganese | 216 - 2,100 | 31/31 | NA | NA | NA | 700 - 10,0004 | SBB1/ 0-1/013195D | 1/31/95 | |
| Potassium | 597 - 4,330 | 31/31 | NA | NA | NA | 50 - 37,0003 | SBB1/ 0-1/013195D | 1/31/95 | |
| Sodium | 358 - 2,430 | 31/31 | NA | NA | NA | 3,000 - 10,0004 | SBC1/0-1/012795 | 1/27/95 | |
Groundwater--Monitoring Wells
In January and February 1995 four shallow monitoring wells (MW-1, MW-3, MW-4, and MW-5) were installed at the site, during the RI field activities. The monitoring well locations are shown in Figure 9. The well depths ranged from 27 feet to 33 feet below ground surface. A fifth monitoring well (MW-2) was planned near the process pit, but was not installed because installation of a well in that area could have allowed soil contaminants, if present, to migrate into site groundwater.
In mid February 1995, the four monitoring wells were sampled for VOCs, semi-volatile organic compounds (SVOCs), pyridine, pesticides, polychlorinated biphenyls (PCBs), and inorganics. In May 1995, a second round of groundwater samples was collected from the wells. Analysis of the groundwater samples revealed the presence of several VOCs, SVOCs, pesticides, and inorganics in the groundwater samples. The highest contaminant concentrations, especially for VOCs and SVOCs, were generally found in samples from MW-1 in the AST area. Groundwater contamination in the AST area is believed to have resulted from leaks and/or spills of volatile chemicals and possibly diesel fuel from one or more of the ASTs.
Analytical data for contaminants found in the February 1995 or May 1995 samples at levels exceeding an applicable ATSDR comparison value, and for contaminants which have no comparison value are presented in Table 5.
In May 1996, two additional shallow monitoring wells were installed to further characterize groundwater quality at the site--MW-2 near the old process pit, and MW-6 between tanks #8 and #9 in the AST area (Figure 9). MW-2 and MW-6 were 29 feet and 27 feet in depth, respectively. In June 1996, groundwater samples were collected from the two new monitoring wells. Samples from MW-2 were analyzed for VOCs, SVOCs, pesticides, PCBs, cyanide, pyridine, and inorganics, while the MW-6 samples were analyzed for VOCs only. At MW-2, several organic compounds were detected, most notably: carbon disulfide, chloroform, and methylene chloride, and a number of inorganics (similar to those found in the 1995 samples from the other monitoring wells). At MW-6, high levels of ethylbenzene and xylenes were found, indicating significant VOC contamination beneath the AST area. Contaminants of concern from the May 1996 monitoring well samples are included in Table 5.
Table 5. Sampling Data for Contaminants of Concern in On-Site Groundwater Monitoring Wells1
|
Contaminant |
Concentration Range (ppb) |
# Detects / # Samples |
# Detects Above Comparison Values |
Comparison Value (ppb) |
Comparison Value Reference |
Maximum Detection |
||
|
Sample ID # |
Sample Date |
Data Qualifier |
||||||
| Volatile Organic Compounds | ||||||||
| Chloroform | 590 | 1/10 |
1 |
6 | CREG | MW-2/6/17/96D | 6/17/96 | |
|
1 |
100 | EMEG (C) Child | ||||||
|
1 |
400 | EMEG (C) Adult | ||||||
| Ethyl benzene | 2 - 23,000 | 4/10 |
2 |
700 | MCL | MW-6/06/17/96 | 6/17/96 | |
|
1 |
1000 | RMEG Child | ||||||
|
1 |
4000 | RMEG Adult | ||||||
| Methylene chloride | 0.4 - 6,400 | 4/10 | 2 | 5 | CREG | MW-6/06/17/96 | 6/17/96 | BJ |
| 1 | 600 | EMEG (C) Child | ||||||
| 1 | 2,000 | EMEG (C) Adult | ||||||
| Xylene (total) | 0.9 - 27,000 | 5/10 |
2 |
2000 | EMEG (I) Child | MW-6/06/17/96 | 6/17/96 | |
|
1 |
7000 | EMEG (I) Adult | ||||||
| Semivolatile Organic Compounds | ||||||||
| 4-Methylphenol | 48 | 1/8 |
NA |
NA | NA | MW-1/021695D | 2/16/95 | |
| Pesticides | ||||||||
| Aldrin | 0.013 | 1/8 |
1 |
0.002 | CREG | MW-3/021595RE | 2/15/95 | J |
| 0.3 | EMEG (C) Child | |||||||
| 1 | EMEG (C) Adult | |||||||
| alpha-BHC | 0.039 - 0.083 | 2/8 |
2 |
0.006 | CREG | MW-3/051195RE | 5/11/95 | |
| beta-BHC | 0.017 - 0.18 | 2/8 |
1 |
0.02 | CREG | MW-1/021695DRE | 2/16/95 | PJ |
| delta-BHC | 0.057 | 1/8 |
1 |
0.02 | CREG | MW-1/050995D | 5/9/95 | P |
| Endosulfan sulfate | 0.035 | 1/8 |
NA |
NA | NA | MW-1/021695DRE | 2/16/95 | PJ |
| Endrin aldehyde | 0.025 - 0.041 | 3/8 |
NA |
NA | NA | MW-1/021695DRE | 2/16/95 | PJ |
| Endrin ketone | 0.025 | 1/8 |
NA |
NA | NA | MW-1/021695DRE | 2/16/95 | J |
| Heptachlor | 0.025 | 1/8 |
1 |
0.008 | CREG | MW-1/050995D | 5/9/95 | P |
| 5 | RMEG Child | |||||||
| 20 | RMEG Adult | |||||||
| Heptachlor epoxide | 0.014 | 1/8 |
1 |
0.004 | CREG | MW-1/050995D | 5/9/95 | P |
| 0.1 | RMEG Child | |||||||
| 0.5 | RMEG Adult | |||||||
| Metals (total) | ||||||||
| Aluminum | 306 - 18,500 | 9/9 |
NA |
NA | NA | MW-5/021595 | 2/15/95 | EN*J |
| Arsenic | 1.8 - 5.4 | 6/9 |
6 |
0.02 | CREG | MW-3/021595 | 2/15/95 | B |
|
4 |
3 | EMEG (C) Child | ||||||
| 10 | EMEG (C) Adult | |||||||
| 50 | MCL | |||||||
| Beryllium | 0.12 - 1.6 | 5/9 |
5 |
0.008 | CREG | MW-1/050995D | 5/9/95 | N |
| 50 | RMEG Child | |||||||
| 2,000 | RMEG Adult | |||||||
| 4 | MCL | |||||||
| Calcium | 44,900 - 211,000 | 9/9 |
NA |
NA | NA | MW-3/051195 | 5/11/95 | |
| Cobalt | 6.7 - 82.5 | 3/9 |
NA |
NA | NA | MW-5/021595 | 2/15/95 | |
| Iron | 339 - 28,400 | 9/9 |
NA |
NA | NA | MW-5/021595 | 2/15/95 | N*J |
| Lead | 1.6 - 20.3 | 6/9 |
2 |
15 | EPA Action Level | MW-5/051095 | 5/10/95 | S |
| Magnesium | 31,200 - 90,500 | 9/9 |
NA |
NA | NA | MW-3/051195 | 5/11/95 | |
| Manganese | 108 - 14,100 | 9/9 |
NA |
NA | NA | MW-5/021595 | 2/15/95 | ENJ |
| Potassium | 1,260 - 26,400 | 9/9 |
NA |
NA | NA | MW-3/051195 | 5/11/95 | |
| Selenium | 2.2 - 24.2 | 3/9 |
2 |
20 | EMEG (C) Child | MW-1/021695D | 2/16/95 | BJNW |
| Sodium | 314,000 - 928,000 | 9/9 |
NA |
NA | NA | MW-2/6/17/96D | 6/17/96 | E |
| Vanadium | 15.3 - 456 | 9/9 |
8 |
30 | RMEG Child | MW-5/021595 | 2/15/95 | |
|
1 |
100 | RMEG Adult | ||||||
Groundwater--Private Wells
Two water supply wells are located at the site. These wells were used while the plant was active to supply process water for the plant's operations and for fire protection. The north supply well (P-2) was sampled in March 1986 and the southwest supply well (P-1), in February 1991. The locations of the two process wells are shown in Figure 9. The 250,000-gallon on-site water tank, formerly used to store water from the two supply wells, was sampled in January 1990. Sampling data for contaminants found at levels exceeding an applicable ATSDR comparison value, and for contaminants having no comparison value, are presented in Table 6. These data showed that chloroform was present in samples from both wells and the water tank, while two other organics--bis(2-ethylhexyl)phthalate and di-n-octyl phthalate--were found only in supply well P-2. In addition, a number of inorganic compounds were detected in samples from both P-1 and P-2.
Table 6. Sampling Data for Contaminants of Concern in On-Site Production Wells1
| CONTAMINANT | CONCENTRATION RANGE (ppb) | SAMPLING DATE | COMPARISON VALUE | |
| ppb | Source | |||
| BIS(2-ETHYLHEXYL)- PHTHALATE | 280 | 3/86 | 3 | CREG |
| CHLOROFORM | 23.9 - 130 | 3/86, 1/90, 2/91 | 6 | CREG |
| DI-N-OCTYLPHTHALATE | 2.4J - 3.9 | 3/86 | NONE | |
| ARSENIC | 2J - 7 | 3/86, 2/91 | 0.02 | CREG |
| BERYLLIUM | 5J | 3/86, 2/91 | 0.008 | CREG |
| CALCIUM | 68,800 | 3/86, 2/91 | NONE | |
| IRON | 121 | 3/86, 2/91 | NONE | |
| LEAD | 3.1 - 5 | 3/86, 2/91 | NONE | |
| MAGNESIUM | 43,500 | 3/86, 2/91 | NONE | |
| SODIUM | 548,000 | 3/86, 2/91 | NONE | |
Ambient Air
No sampling data for VOCs in ambient air at the site were available during the development of this public health assessment. In addition, data from air sampling conducted inside the lab and warehouse building during previous site investigations and removal activities could not be found.
Groundwater--Public Water Supply Wells
VIWAPA Municipal Wells
Samples from three Virgin Islands Water and Power Authority (VIWAPA) supply wells near the site were collected several times between March 1988 and February 1991. The three wells, Fairplains Wells #6, #8, #9, are located about 900 to 1300 feet southeast of the site. Until recently, water from the VIWAPA Fairplains wells was pumped into the Fairplains water tank where it mixed with desalinated seawater from VIWAPA's Christiansted treatment units, and water from other VIWAPA municipal well fields, prior to being chlorinated and pumped into the municipal water distribution system. The VIWAPA Fairplains wells are no longer active.
As shown in Table 7, chloroform had been found in the past in the Fairplains municipal wells at levels exceeding ATSDR's comparison value, but not EPA's MCL. Several inorganic compounds commonly found in groundwater aquifers (such as calcium, magnesium, and manganese) were also detected in the well samples, along with low levels of lead and mercury. In addition, the well samples contained high levels of sodium, indicating that groundwater near the site is very saline.
Table 7. Sampling Data for Contaminants of Concern in Municipal Supply Wells1,2
| CONTAMINANT | CONCENTRATION RANGE (ppb) | SAMPLING DATE | COMPARISON VALUE | |
| ppb | SOURCE | |||
| CHLOROFORM | 5 - 75 | (3) | 6 100 |
CREG MCL |
| CALCIUM | 69,900 - 127,000 | 2/91 | NONE | |
| LEAD | 3.9 - 4.2 | 2/91 | NONE | |
| MAGNESIUM | 48,600 - 71,600 | 2/91 | NONE | |
| MANGANESE | 17.7 - 400 | 2/91 | NONE | |
| MERCURY | 3.3 | 2/91 | 2 | MCL/ MCLG |
| SODIUM | 363,000 - 590,000 | 2/91 | NONE | |
VIPA Airport Wells
Two airport supply wells, operated by the Virgin Islands Port Authority (VIPA), are located about 900 to 1200 feet west of the site (Figure 2). Until recently, these two wells were used as the Alexander Hamilton Airport's primary water supply source. Between March 1988 and October 1995, the airport wells and the airport water supply were sampled on numerous occasions by site investigators and the VIPA. The only organic compounds detected in the airport well water samples were trihalomethanes (bromoform, bromodichloromethane, chloroform, and chlorodibromomethane). Several commonly occurring inorganics were also detected in the airport water samples, along with high levels of sodium. Sampling data for contaminants found in the airport wells at levels exceeding an applicable ATSDR comparison value, and for contaminants having no comparison value, are presented in Table 8.
Table 8. Sampling Data for Contaminants of Concern in Airport Supply Wells1,2
| CONTAMINANT | CONCENTRATION RANGE (ppb) | SAMPLING DATE | COMPARISON VALUE | |
| ppb | SOURCE | |||
| BROMOFORM | 68 - 121 | (3) | 4 | CREG |
| BROMODICHLORO-METHANE | 2 | (3) | 0.6 | CREG |
| CHLOROFORM | 2J - 11.5 | (4) | 6 | CREG |
| CHLORODIBROMO-METHANE | 6 - 8 | (3) | 0.4 | CREG |
| ALUMINUM | 60 - 70 | (5) | NONE | |
| CALCIUM | 61,300 - 75,800 | 2/91 | NONE | |
| IRON | 36 | (5) | NONE | |
| LEAD | 2 - 18 | (6) | NONE | |
| MAGNESIUM | 40,100 - 58,000 | (5) | NONE | |
| POTASSIUM | 2,100 - 2,200 | (5) | NONE | |
| SODIUM | 237,000 - 572,000 | (5) | NONE | |
| VANADIUM | 50.3J | 2/91 | 30 | ciEMEG |
Groundwater--Private Water Supply Wells
Sampling data for off-site private wells were not available to ATSDR during the development of this public health assessment. ATSDR considers this a significant data gap because area private wells near the site could be affected by site-related groundwater contaminants now, or sometime in the future.
Surface Water
The only surface-water body at the site is River Gut, an intermittent stream along the north and east boundary of the site. The gut is normally dry, except after heavy rains. When the Island Chemical/Virgin Island Chemical facility was active, the gut received wastewater from the plant's lab pit, process water from the plant's process pit, and stormwater runoff from the plant property. No sampling data for surface water in the gut were available to ATSDR during the development of this public health assessment.
Sediment
Sediments in the River Gut stream channel were sampled in February 1986, March 1986, and February 1991. Samples were collected at various locations, including the point where the lab pit discharges to the gut and the point where the central storm drain discharges to the gut.
The sampling data showed low to moderate concentrations of several VOCs and SVOCs in the gut sediments; however, none of the contaminant levels exceeded ATSDR's comparison values. The greatest number of contaminants and the highest contaminant concentrations were generally found at the point where drainage from the process pit entered the gut via the central storm drain. A number of inorganics were also detected in the sediment samples. Again, the highest levels of contaminants, including chromium, lead, and zinc, were found at the central storm drain discharge point. Most of the inorganic concentrations (as shown in Table 9) were similar to normal background soil levels, and only a few--arsenic, beryllium, and chromium--exceeded an applicable ATSDR comparison value. Zinc levels in the gut sample, although elevated, did not exceed ATSDR comparison values.
Table 9. Sampling Data for Contaminants of Concern in River Gut Sediments1
| CONTAMINANT | CONCENTRATION RANGE (ppm) | BACKGROUND CONCENTRATION (ppm) | COMPARISON VALUE | |
| ppm | SOURCE | |||
| DI-N-OCTYLPHTHALATE | 7.7 - 17 | N/A | NONE | |
| ALUMINUM | 15,700 - 32,400 | 7,000 - 100,0002 | NONE | |
| ARSENIC | 0.8J - 4.1J | <0.1 - 7382 | 0.5 | CREG |
| BERYLLIUM | 7 - 8 | ND - 1.53 | 0.2 | CREG |
| CALCIUM | 45,600 - 82,100 | 1,500 - 70,0003 | NONE | |
| CHROMIUM | 10 - 71.1 | 10 - 3003 | 60 | CREG (Cr+6) |
| COBALT | 14.7 - 25.4 | ND - 1003 | NONE | |
| COPPER | 25.3 - 69.7 | 30 - 1003 | NONE | |
| IRON | 25,700 - 39,200 | 30,000 - 50,0003 | NONE | |
| LEAD | 7.5 - 46.4 | 10 - 3003 | NONE | |
| MAGNESIUM | 7,600 - 11,800 | 7,000 - 15,0003 | NONE | |
| MANGANESE | 954 - 1,430 | 700 - 10,0003 | NONE | |
| POTASSIUM | 1,490 - 1,600 | 50 - 37,0002 | NONE | |
| SODIUM | 1,640J - 1,750 | 3,000 - 10,0003 | NONE | |
C. Toxic Chemical Release Inventory (TRI) Review
ATSDR conducted a search of the EPA Toxic Chemical Release Inventory (TRI) database for facilities in St. Croix, U.S. Virgin Islands. The search showed that some facilities in the area have released various organic and inorganic compounds to the air, water, and land. However, it should be noted that information in the TRI database is reported only by large companies that handle certain quantities of hazardous chemicals. Therefore, it is not possible to determine from the TRI records whether any small businesses have released contaminants in the site area.
D. Quality Assurance and Quality Control
The reports and laboratory data sheets ATSDR reviewed indicate laboratory procedures used to analyze samples from the site included quality control measures. ATSDR presumes that appropriate protocols were followed, and that analytical data are accurate. The validity of ATSDR's evaluations, conclusions, and recommendations is contingent upon the completeness and reliability of the available site data and information.
The Island Chemical/Virgin Island Chemical site is littered with debris (e.g., old pipes, pieces of metal, wooden pallets, empty drums, old plant equipment, junk cars, semi-truck trailer, old tires, nails) which could pose a threat to site trespassers. Other potential physical hazards include the site's dilapidated and deteriorating buildings and tanks and the unsecured outside stairway from which persons could accidentally fall and be injured. Access to these hazards by trespassers, such as the one observed during the April 1997 site visit, is possible because the site entrance gate is broken and some sections of the site fence are missing.
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