PUBLIC HEALTH ASSESSMENT
INTERMOUNTAIN WASTE OIL REFINERY
BOUNTIFUL, DAVIS COUNTY, UTAH
The Intermountain Waste Oil Refinery (IWOR) site was included on the National Priorities List on May 11, 2000, and investigation activities are underway. The Agency for Toxic Substances and Disease Registry (ATSDR) requested that the Environmental Epidemiology Program (EEP) of the Utah Department of Health conduct this public health assessment to identify any public health hazards posed by the IWOR site. The site is currently not a public health hazard.
The IWOR site is in Bountiful, Davis County, Utah, approximately 11 miles north of Salt Lake City. Thirty-six years of refining waste oils from facilities in Utah and neighboring states has resulted in soil and groundwater contamination on-site. During its years of operation, the IWOR facility was cited with several violations for failure to remediate contamination, and in 1993, the facility was closed. Under a cooperative agreement with the Utah Department of Environmental Quality (UDEQ), IWOR owners proceeded with remediation activities. However, because of a lack of funds, remediation was left incomplete.
In August 2001, the Environmental Protection Agency (EPA) removed and disposed of many on-site containers and their contents, including all chemicals located in the laboratory building, 55-gallon drums and 5-gallon containers, two trailer tanks, the contents of an underground storage tank, and the contents of a sump stored above ground in the southeast portion of the site [EPA 2003].
UDEQ is currently preparing institutional controls for future site development and are continuing to monitor groundwater quarterly. UDEQ is also planning to remove the underground storage tank, conduct additional subsurface soil sampling, and possibly install two additional monitoring wells [EEP 2003].
Potential exposure pathways by which people may be exposed to contaminants at the IWOR site include: (1) ingesting contaminated groundwater and (2) ingesting or inhaling contaminated soil. At present, the likelihood of exposure to site contaminants is low because the site is fenced at its perimeter, the entrance gates are locked, and shallow groundwater is not a source of drinking water. Much of the problem surface soil and subsurface soil have been removed. If the contaminants had not been removed or contained, migration of contaminants to the deeper aquifers was possible, and the drinking water supply for more than 70,000 area residents would have been jeopardized.
Trichloroethene and 1,2-dichloroethene are the chemicals of concern at the IWOR site. Those contaminants were detected in the on-site monitoring well at levels that exceed the EPA standards for public drinking water supplies.
The EEP public health action plan, designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment from the IWOR site, consists of the following actions:
The Agency for Toxic Substances and Disease Registry (ATSDR) requested that the Environmental Epidemiology Program (EEP) of the Utah Department of Health conduct this public health assessment to identify any public health hazards posed by the Intermountain Waste Oil Refinery (IWOR) site. For this assessment, EEP evaluated available analytical results for waste, soil, groundwater, surface water, and sediment samples to identify the contaminants of concern. EEP determined how people could come into contact with site contaminants (exposure pathways), evaluated the implications for on public health if exposures occur, and issued recommendations to protect the health of area residents.
The 1986 Superfund Amendments and Reauthorization Act to the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 directs ATSDR to perform specific public health activities associated with actual or potential exposures to hazardous substances released into the environment. Among those activities, ATSDR is mandated to conduct a public health assessment for each site listed or proposed to be listed on the National Priorities List (NPL) within 1 year of the listing. In addition, ATSDR may conduct a public health assessment for a particular facility or release when petitioned by a person or group of persons. IWOR was proposed to the NPL on October 22, 1999, and it was included on the list May 11, 2000 [EPA 2000a].
The IWOR site is located at 995 South 500 West in Bountiful, Davis County, in north-central Utah, about 11 miles north of Salt Lake City (Figure 1). The city of Bountiful is bounded by the city of Centerville to the north, the Wasatch Mountains to the east, the city of North Salt Lake to the south, and the city of Woods Cross to the west. The region is characterized by a semiarid climate, with temperature fluctuations of up to 100°F between winter and summer months. Wind patterns for the region vary according to season and location of storm fronts. The average annual precipitation is 13 to 15 inches, with a 24-hour maximum rainfall of 2.15 inches. The land surface slopes slightly northwest so that runoff from the site could flow into the storm sewers and drains into Mill Creek [UDEQ 1997; EPA 1998a]. The Utah Department of Environmental Quality (UDEQ) later reported that the site's topography had changed so that runoff from the site to Mill Creek was now unlikely.
The site is on the southern portion of the primarily confined East Shore Aquifer system. The East Shore Aquifer system consists of three artesian aquifers: shallow (60-250 feet below ground (bgs)), intermediate (250-500 feet bgs), and deep (greater than 500 feet bgs). The primary recharge area is nearest the mountain front, which is underlain mainly by permeable sands and gravel that enhance the recharge water movement. These aquifers are hydraulically connected; however, little work has been accomplished in defining the boundaries between them. The shallow and deep aquifers likely conjoin into a single aquifer in the recharge area, which lies less than half a mile east of the site. These aquifer systems are composed of mudflow deposits that are poorly sorted and only slightly permeable. The shallow aquifer is currently not used as a drinking water source, but historically it has been used for industrial and irrigation purposes in the area [USGS 1991; USGS 1994].
Groundwater flow direction along the Wasatch front is generally in the direction of the Great Salt Lake; at the IWOR site, the flow is west by northwest. Groundwater investigations at the Phillips Refinery, one mile northwest of IWOR, indicate that groundwater flows in a northwest direction. [USGS 1991; USGS 1994; UDEQ 1997].
A total of 24 municipal wells that serve as a drinking water source for the south Davis County area are within a 4 mile radius of the site; of those, 10 wells are within 0.25 mile from the IWOR facility [UDEQ 1997]. In 1990, more than 67,000 people residing within a 4 mile radius of the IWOR site relied on those water systems for drinking water (Table 4). Projected population estimates for 2000 indicate that the water systems currently supply more than 77,000 residents in Bountiful and surrounding cities [UGOPB 2000]. No known private potable wells are within the 4 mile radius of the IWOR site [EPA 1998a].
The IWOR site occupies approximately 2 acres and can be divided into the western and eastern portions. The western portion consists of a vacant parcel covered with gravel, which is accessible from the driveway through the Aamco Transmission service facility on 500 West. The oil refining processes took place in the eastern portion, which in the year 2000 housed a laboratory, a garage/workshop, several waste piles, and two trailer tanks. In August 2001, EPA removed and disposed of all chemicals found in the laboratory, several 55-gallon drums and 5-gallon containers, the two tankers, the contents of the underground storage tank, and the contents of the sump stored above ground in the southeast portion of the site [EPA 2003].
The eastern portion of the site is fenced at its perimeter, and both gate entrances are locked [EEP 2000a]. The IWOR property is bounded by 11 residences to the north and east, and by commercial properties to the south and west [DCRO 2000].
IWOR began operations in 1957, processing waste oil from facilities in Utah, Nevada, Idaho, and
Wyoming. The waste oil was treated on-site, and the cleaned oil product was distributed to area
cement facilities as fuel for cement kilns. The waste sludge 
from the cleaning process was disposed
in the North Davis County Landfill (UTD980514210) and the Salt Lake County/City Landfill
(UTD981541055). Wastewater from the process was boiled off on-site [UDEQ 1997; EPA 1998a].
During its years of operation, UDEQ, the Utah Department of Natural Resources, and the Utah Attorney General's Office issued several violations to IWOR owners. The Notice of Violations and Orders were issued for failure to remediate contamination resulting from years of spillage at the refinery. The facility had its permit revoked on several occasions because of poor waste management practices [UDEQ 1997]. The Davis County Health Department (DCHD), Environmental Health Division, also issued violations to IWOR owners. Those violations were mainly because of odor complaints. The DCHD reports indicate that on at least two occasions, oil sludge flowed from the site onto 500 West and into a storm drainage leading to Mill Creek on at least two occasions [EEP 2000b].
In 1991, UDEQ did not reissue the operating permit for IWOR, and in May 1993, the facility closed. Under a cooperative agreement with UDEQ, the owners dismantled the refinery and consolidated the waste into a pile of approximately 100 cubic yards in the northeast portion of the site. When the owner claimed lack of funds, remediation activities ceased, and the remainder of the site was covered with gravel and soil backfill [UDEQ 1997].
Over the past 10 years, several agencies have sampled and analyzed media relating to the IWOR facility. These results are summarized in the section titled, "Nature and Extent of Contamination."
The site was proposed for listing on the NPL in October of 1999 and finalized on May 11, 2000. In March 2001, the field investigation began. Samples were taken from tanks and drums remaining on site. Soil-vapor sampling was also conducted on and near the site to help determine the extent of ground-water contamination that resulted from site operations.
In August 2002, the Proposed Plan that outlined the cleanup options for the soils and other sources was made available to the community. A public comment period extended from August 19th to September 17th. A public meeting was held on August 22nd in Bountiful. The Record of Decision, which outlines the selected remedy, taking into consideration public comments, was signed in November 2002 [EPA 2003].
UDEQ is currently preparing institutional controls for future site development. This action will attach a building requirement to the property and/or deed through the County Recorder's office. It will require all future development on site to have a soil vapor mitigation system in place prior to construction. UDEQ is also continuing to monitor ground-water quarterly and are planning to remove the underground storage tank, conduct additional subsurface soil sampling and possibly install two additional monitoring wells [EEP 2003].
According to 1990 US census data, 13,636 people, mainly in the city of Bountiful, live within one mile of the reclaimed IWOR property boundaries [USDC 1990]. Of those residents, 1,919 are children ages six and under, and 1,496 are over the age of 65 (Figure 2). In the past several years, new residential developments that have increased those 1990 population estimates have been built in surrounding communities that have increased those 1990 population estimates. The population of this area has grown since 1990. According to 2000 US census data, Bountiful has a population of 41,301, which is 10% larger than in 1990. The current population of Davis County is estimated at 238,994 [USCB 2000].
The IWOR facility has been closed since 1993, and no workers are on-site. Trespassing at the site is unlikely because the entrance gates are locked and a chain-link fence surrounds the perimeter. There is limited access to the site. The main access from 500 West has been obscured by the Aamco Transmission building [EEP 2000a]. Approximately 80 people work at businesses around the site [UDEQ 1997].
Nature and Extent of Contamination
Between 1992 and 1998, several agencies analyzed waste, surface soil, groundwater, surface water, and sediment samples at the IWOR facility and its vicinity. Following is a summary of the investigations that have been conducted at the IWOR site.
Consultants representing the IWOR owners found 62 parts per billion (ppb(1)) of 1,2-dichloroethene and 991 ppb of trichloroethene in the on-site monitoring well and other volatile organic compounds in the on-site sump in 1992 [Enviro Search 1992]. In 1995, the UDEQ, Division of Solid and Hazardous Waste, collected samples from the on-site sump and detected several contaminants, including tetrachloroethane 23,000 ppb, toluene 151,000 ppb, and trichloroethene 14,000 ppb [UDSHW 1995].
In the 1996 Preliminary Assessment, UDEQ evaluated potential exposure routes and identified exposure targets [UDEQ 1996]. Based on historical data and an on-site reconnaissance visit, UDEQ reported that groundwater, surface water, and soil were potential pathways of exposure, and in 1997, UDEQ began a Site Inspection [UDEQ 1997]. Elevated levels of contaminants associated with the IWOR site were confirmed in the on-site monitoring well (shallow aquifer), on-site surface soils, and waste samples. Surface soil samples collected from Washington Elementary School and two residential yards adjacent to the IWOR facility did not contain elevated levels of contaminants. Low levels of acetone (0.005 ppb) and toluene (0.98 ppb) were detected in two samples and were attributed to residual contamination or laboratory error. Three samples were collected from Mill Creek. The two down-gradient surface water samples did not contain any elevated levels of contaminants. The up-gradient surface water sample contained acetone (48 ppb), chloroform (7 ppb), 1,2-dichloroethene (430 ppb), methylene chloride (340 ppb), 1,1,1-trichloroethane (5 ppb), and trichloroethene (580 ppb). UDEQ determined that there had been a one-time illegal disposal of solvents into Mill Creek by an area resident or a business. Furthermore, UDEQ reported that the site's topography had significantly changed so that runoff from the site to Mill Creek was now unlikely.
URS Operating Services, Inc., was tasked by the EPA to conduct an Expanded Site Inspection in 1998 [EPA 1998a]. URS Operating Services collected waste, soil, and groundwater samples to evaluate the site with regard to the EPA's Hazard Ranking System criteria [EPA 1990]. Seven sources of contamination were identified at the IWOR site and found to contain elevated levels of several volatile organic compounds and lead. Samples collected from the on-site monitoring well contained elevated levels of volatile organic compounds and several inorganic analytes. The off-site soil samples collected from a residential yard northeast of the IWOR facility did not contain any elevated levels of contaminants.
The 1997 UDEQ and 1998 EPA investigations provide the most recent analytical information for the IWOR site. These data were used to evaluate the possible exposure pathways in this public health assessment.
To determine whether nearby residents and workers are exposed to contaminants related to a site, ATSDR evaluates the environmental and human components that lead to human exposure. An exposure pathway consists of five elements [ATSDR 1992]:
(1) A source of contamination;
(2) Transport of the contamination through an environmental medium (such as
soil, water, air);
(3) A point of exposure;
(4) A route of human exposure; and
(5) A receptor population.
ATSDR categorizes an exposure pathway as either completed or potential. Completed exposure pathways have all five elements, and exposure to a contaminant has occurred in the past, is occurring, or will occur in the future. No completed exposure pathways were identified at this site. Potential exposure pathways have at least one of the five elements that has not been identified, but the element(s) could exist. Exposure to a contaminant could have occurred in the past, could be occurring, or could occur in the future. Two potential exposure pathways were identified at this site: groundwater and on-site wastes and surface soil.
An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present. When an exposure pathway is identified, comparison values (CVs) for air, soil, or drinking water are used as health guidelines for selecting contaminants that require further evaluation [ATSDR 1992]. To protect the more susceptible population, the CVs for children are used when available.
Groundwater Pathway
Groundwater qualifies as a potential pathway of exposure at the IWOR site because two pathway elements are identified, and the remaining three elements could exist in the future if site contamination is not addressed (Table 1): Elements of this potential exposure pathway for residents near the site are as follows:
| Exposure element | Intermountain Waste Oil Refinery Site |
| 1) A source of contamination | former site activities |
| 2) Transport through environmental medium | contaminated groundwater |
| 3) A point of exposure | NOT PRESENT: future exposure could be home water taps (on-site monitoring well water is contaminated, but that well is not used for drinking or other purposes); |
| 4) A route of human exposure | NOT PRESENT: future exposure could be ingestion and skin contact. |
| 5) An exposed population | NOT PRESENT: future exposure could be people who use contaminated groundwater for a drinking and domestic water supply. |
Pathway elements three, four, and five do not currently exist. The on-site monitoring well is not a source of drinking water, the municipal wells are not contaminated, and humans have not been exposed to the groundwater contamination. However, the US Geological Survey has reported that the shallow, intermediate, and deep aquifers are hydraulically connected with one another in this region [USGS 1994]. If contaminants in the shallow aquifer are not contained or removed, they may migrate to the deeper aquifers, affecting drinking water supply wells in the future.
Groundwater samples collected during the 1997 UDEQ and 1998 EPA investigations were analyzed for the presence of a total of 159 chemicals (listed in Appendix C). Of the chemicals that were detected, two exceeded comparison value guidelines (Table 2). The on-site monitoring well, which draws water from the shallow aquifer, contained elevated levels of 1,2-dichloroethene and trichloroethene. In 1997, UDEQ sampled the on-site well and reported 435 ppb of 1,2-dichloroethene and 650 ppb of trichloroethene. In the 1998 EPA sampling of the same well, 1,2-dichloroethene (500 ppb) and trichloroethene (855 ppb) were detected. The Maximum Contaminant Levels (MCLs(2)) for 1,2-dichloroethene and trichloroethene are 70 ppb and 5 ppb, respectively [EPA 2000b]. The health effects that might result from exposure to those contaminants are discussed in the "Toxicologic Evaluation" section of this document. Iron, calcium, magnesium, potassium, and sodium levels were elevated in the monitoring well; however, these compounds are relatively non-toxic.
Off-site groundwater samples did not contain elevated levels of contaminants (Table 2). Samples collected from an up-gradient monitoring well completed in the shallow aquifer did not contain detectable levels of 1,2-dichloroethene or trichloroethene [EPA 1998a]. Elevated levels of chemicals were not detected in samples collected from the Bountiful Shop Well, which draws water from a different aquifer [EPA 1998a]. Samples collected from a spigot at the wellhead of the Weber Basin Municipal Well did not contain any contaminants exceeding drinking water standards [UDEQ 1997].
On-site Wastes and On-site Surface Soil Pathway
On-site contaminated waste and soils qualify as a potential pathway of exposure at IWOR because four pathway elements are fulfilled, and the remaining element could exist in the future (Table 1). Elements of this potential exposure pathway for residents near site are as follows:
| Exposure element | Intermountain Waste Oil Refinery Site |
| 1) A source of contamination | former site activities |
| 2) Transport through environmental medium | contaminated surface soils and on-site waste |
| 3) A point of exposure | on-site waste piles and oil seeps |
| 4) A route of human exposure | accidental ingestion of or skin contact with contaminants, and inhalation of soil or vapors. |
| 5) An exposed population | NOT PRESENT: future trespassers that gain access to the site. |
Because the facility is no longer in operation, the site is fenced around its perimeter, its entrance gates are locked, and the main access to the site is obscured by neighboring businesses, no one should be exposed to the contamination. Accidental ingestion, skin contact or inhalation of soil or soil vapors by trespassers could present a health threat over a long period of time. However, this scenario is unlikely. EPA's removal of drums, tanks, and the contents of the underground storage tank has decreased the risk of human exposure that could occur on-site.
On-site waste and soil samples collected during the 1997 UDEQ and the 1998 EPA were analyzed for the presence of 159 chemicals (see Appendix C). Of the chemicals that were detected, four exceeded comparison value guidelines (Table 2). The sources of contamination identified at the IWOR site were tanker 1, tanker 2, the sump, waste piles, and oil seeps. Benzo[a]pyrene was detected in the eastern waste pile at 0.86 parts per million (ppm(3)), exceeding the Cancer Risk Evaluation Guideline (CREG) of 0.1 ppm [ATSDR 2003]. Tanker 1 contained arsenic (43.3 ppm), lead (3560 ppm), and mercury (154 ppm). The comparison value guidelines for arsenic, lead, and mercury are 0.5 ppm (CREG) [ATSDR 2003], 400 ppm [EPA 1998b] and five ppm [EPA 1999], respectively.
Nine chemicals were detected in on-site waste and/or on-site surface soils for which there are no available comparison value guidelines (Table 3): benzo[a]anthracene, benzo(g,h,i)perylene, n-butylbenzene, carbazole, chrysene, phenanthrene, propylbenzene, 1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzene. Of these nine chemicals, the levels of polycyclic aromatic hydrocarbons (benzo[a]anthracene, benzo(g,h,i)perylene chrysene, phenanthrene) were well below their respective background levels in soil [ATSDR 1995].
Some area residents have reported that in the past, their children played in "tanks" at the IWOR site [EEP 2000b]. One resident reported seeing employees climb into the tanks when the site was in operation [EEP 2000b]. The tanks have been removed from the site, and the contents were never sampled. The tanks reportedly held waste oil and cleaned oil, but there is no documentation to determine if children and workers were seen in the tanks before or after they had been emptied. For that reason, this possible exposure pathway was not evaluated further.
Levels of contaminants that exceed comparison values (CVs) will not necessarily cause adverse health effects upon exposure. The potential for exposed persons to experience adverse health effects depends on many factors, including:
1,2-Dichloroethene
1,2-dichloroethene (also called 1,2-dichloroethylene) is a highly flammable, colorless liquid with a sharp odor that is noticeable in very small amounts, beginning at a level of about 17 ppm. The chemical exists in two structurally different forms or as a mixture of both: one form is called cis -1,2-dichloroethene; and the other form is called trans -1,2-dichloroethene. The chemical is commonly released into the environment from industries involved in solvent production, pharmaceutical manufacturing, and rubber extraction. When 1,2-dichloroethene is released into air, it takes 5-12 days for half of any amount to break down. When it is released into groundwater, it takes 13-48 weeks for half of a given amount to break down because of less opportunity for evaporation. Small amounts of 1,2-dichloroethene may break down into vinyl chloride, a more toxic chemical. Also, 1,2-dichloroethene is a breakdown product of other volatile compounds such as trichloroethene [ATSDR 1993b, 1996].
People can be exposed to 1,2-dichloroethene by breathing contaminated air, by drinking contaminated water, or by bathing in contaminated water. Animal testing has confirmed that once 1,2-dichloroethene is in the body, it is absorbed by the blood and other tissues and is eventually broken down by the liver [ATSDR 1993b, 1996].
The EPA has determined that the MCL for the cis-form is 70 ppb and for the trans-form is 100 ppb [EPA 2000c]. The trans form is approximately twice as potent as the cis form in its ability to depress the central nervous system [EPA 2000c]. On the basis of animal studies, ATSDR established an oral Minimal Risk Level (MRL(4)) for intermediate exposures of 0.3 milligrams per kilogram per day (mg/kg/day) and 0.2 mg/kg/day for the cis and trans forms, respectively. If residents were to drink the contaminated water at levels found on site, exposure would be estimated at 0.014-0.05 mg/kg/day, which is 10 times lower than the MRLs (see Appendix B for calculations). Breathing highlevels (1,200-2,220 ppm) of 1,2-dichloroethene for 5 to 10 minutes can cause nausea, drowsiness, and fatigue in humans. Those levels are almost 10,000 times greater than those found in the monitoring well at the site. In animals, damage to the liver and lungs has been noted after exposures to 200 ppm trans-1,2-dichloroethene for 8 hours per day, 5 days per week, for either 8 or 16 weeks [ATSDR 1993b, 1996]. That level is about 1,000 times more than what is present in the monitoring well water.
Cis -1,2-dichloroethene does not cause cancer in humans; no studies have been conducted to assess whether trans -1,2-dichloroethene can cause cancer in humans [ATSDR 1993b, 1996; EPA 2000c].
Trichloroethene
Trichloroethene (also called trichloroethylene, Triclene7, or Vitran7) is a non-flammable, colorless liquid with a sweet taste. It has a sweet odor that is noticeable beginning at a level of about 100 ppm. The largest source of trichloroethene (TCE) in the environment exists through the process of evaporation primarily from factories that use TCE as a solvent to remove grease from metals. TCE can also be found in typewriter correction fluid, paint removers, and adhesives. When TCE is released into air, it takes 7 days for half of any amount to break down. When TCE is released into groundwater, it takes much longer to break down because of less opportunity for evaporation [ATSDR 1993a, 1997].
People can be exposed to TCE by breathing contaminated air, by drinking contaminated water, or by bathing in contaminated water. When a person breathes air containing TCE, about half the amount inhaled will be absorbed by the blood and other organs; the rest will be exhaled. If a person drinks water containing TCE, the majority of the contaminant will be absorbed directly into the bloodstream. If TCE comes in contact with human skin, some of it will enter the body, although not as much as from inhalation or ingestion.
Once TCE is in the body, the liver converts it to other chemicals that are excreted in the urine within a day. If exposure continues, TCE and its breakdown products can build up in body fat [ATSDR 1993a, 1997].
The EPA established the MCL of TCE that is permissible in community water systems at 5 ppb. Some studies in humans exposed to TCE in drinking water reported impaired fetal development in pregnant women [ATSDR 1997]. A New Jersey survey suggested an association between TCE exposure at levels averaging about 55 ppb in water (levels greater than 10 ppb) to oral clefts, central nervous system defects, neural tube defects, and major cardiac defects [ATSDR 1997]. Interpretation of the findings of that study were limited by the small case numbers and exposure classification. If residents were to drink the contaminated water on-site daily, exposure would be estimated at 0.03-0.085 mg/kg/day, which is 10 times lower than the acute MRL [see Appendix B for calculations]. No MRLs have been derived for chronic exposure.
People who breathe between 38-172 ppm of TCE may experience headaches or dizziness. Those levels are about 100 to 1,000 times the amount found in the monitoring well water. TCE is a mild irritant to the lungs and respiratory tract; however, it breaks down in air to produce phosgene and hydrogen chloride, which are severe lung irritants [Cooper 1997]. No air monitoring data were collected to assess the amount of TCE in the air, but levels would be expected to dissipate quickly as TCE moved from the site.
Skin contact with TCE may lead to the development of rashes and skin irritations. However, dermal effects are usually due to direct skin contact with concentrated solutions of TCE. Because the concentration of TCE found in the on-site monitoring well is considered dilute at 650-855 ppb, this concentration is unlikely to cause dermal irritation [ATSDR 1993a, 1997].
The International Agency for Research on Cancer has determined that, according to extensive animal research and limited human data, TCE likely causes cancer in humans [ATSDR 1993a, 1997]. However, more studies need to be conducted to establish the relationship between TCE exposure and cancer.
ATSDR and EEP recognize that the unique vulnerabilities of infants and children require special emphasis in communities faced with contamination of their water, soil, air, or food. Children are at greater risk than adults from some environmental hazards. Children are more likely to be exposed to contaminants because they play outdoors, often bring food into contaminated areas, and are more likely to come into contact with dust and soil. Also, because children's bodies are still developing, children can sustain permanent damage if toxic exposures to some contaminants occur during critical growth stages.
Reports from parents in the area indicate that children might have come into contact with some soil or waste on the site in the past, before site access was restricted. Any exposure that might have occurred if children played in tanks is difficult to estimate. Currently, limited access to the site should mean that no children are exposed to site-related contaminants. Future exposure could occur if contaminants enter nearby drinking water supplies. Children might be expected to have an enhanced response to these contaminants as compared to adults. Because children have immature and developing organs, their bodies will likely have a decreased ability to detoxify or clear the contaminants. The chemicals remain in the body for a longer period of time and have a greater opportunity to cause damage to other developing organs.
COMMUNITY HEALTH CONCERNS AND COMMENTS
On July 11, 2000, EEP staff accompanied the community involvement coordinators for EPA and UDEQ on interviews with Bountiful City officials and several residents whose homes are adjacent to the IWOR site. City officials and residents provided EEP, EPA, and UDEQ staff with historical information and personal experiences regarding the site. Residents reported seeing rats on the site [EEP 2000b]. The rats reportedly encroached residential yards and destroyed fruit trees. Other residents complained that the cut, dried weeds on-site were a fire hazard [EEP 2000b]. The following summary reflects residents' specific health concerns related to the IWOR facility and the accompanying EEP responses.
| Comment: | (a) How long does it take for solvents to degrade? (b) Will the clean-up occur before the degradation to vinyl chloride? |
| Response: |
(a) When 1,2-dichloroethene is in groundwater, it takes 13-48 weeks for half of a given amount to break down because of less opportunity for evaporation. However, when 1,2-dichloroethene is released from tap water into the air, it takes 5-12 days for half of any amount to break down in air. For the same reason, it takes much longer for TCE to break down in groundwater as compared to air. When TCE is released from water into air, it takes seven days for half of any amount to break down. (b) In August 2001, EPA removed and disposed of many on-site containers and their contents, including all chemicals located in the laboratory building, 55-gallon drums and 5-gallon containers of various chemical or oily mixtures, two trailer tanks and their contents, the contents of an underground storage tank found during the investigation, and contents of the sump stored above ground in the southeast portion of the site [EPA 2003]. The IWOR facility has not operated since 1993, and subsequent UDEQ (1997) and EPA (1998) groundwater investigations have not reported finding elevated levels of vinyl chloride on- or off-site [UDEQ 2002]. |
| Comment: | I have asthma. Although I don't think it was caused by the IWOR site, could the smell from the site be a trigger for asthma? |
| Response: | Offensive odors, including those not associated with hazardous waste sites, can affect asthma attacks. Although both 1,2-dichloroethene and trichloroethene, the major contaminants detected at the IWOR site, have been linked to respiratory irritation, no evidence was found indicating that those contaminants would be at levels sufficient to cause or trigger adverse health effects. Those contaminants were detected in the on-site monitoring well, in groundwater, which helps slow evaporation. Therefore, the small amounts of the contaminants that evaporate into air are likely to be dispersed before reaching nearby homes. |
| Comment: | Can the odors emanating from the site cause the following conditions: seizures, developmental problems, genetic problems, nausea, tumors? |
| Response: | Before contaminants can cause any kind of health effect, you must come into contact with the contaminant. Because of the access restrictions, it is unlikely that anyone will come in contact with the primary contaminants of concern at the site. In general, the contaminants detected at the IWOR site are not believed to be associated with seizures. Breathing high levels (1,200-2,200ppm) of both 1,2-dichloroethene and trichloroethene can cause nausea in humans; however, the levels detected at the site are well below that concentration and were detected in the monitoring well, not in the air. Some very limited studies suggest that some developmental problems might occur in children whose mothers were exposed to chemical mixtures that included TCE. On the basis of animal research, TCE likely causes cancer, but further studies are needed to determine if that is the case in humans. Cis-1,2-dichloroethene does not cause cancer in humans; however, no studies have been done to assess whether trans-1,2-dichloroethene can cause cancer. |
This public health assessment was released for public comment on September 17, 2002. No comments were received during the public comment period ending on October 17, 2002.
The IWOR site poses no public health hazard under current conditions. Most of the problem soil and subsurface soil has been removed by the EPA, as well as tanks, drums, and the contents of the underground storage tank. UDEQ is currently preparing institutional controls for future site development and is continuing to monitor ground-water quarterly. UDEQ is also planning to remove the underground storage tank, conduct additional subsurface soil sampling and possibly install two additional monitoring wells [EEP 2003].
Thirty-six years of refining waste oil at IWOR resulted in contamination of on-site soils and groundwater (shallow aquifer). The chemicals, 1,2-dichloroethene and trichloroethene, were detected in the on-site monitoring well at levels that exceed the EPA MCLs. Levels of arsenic, benzo[a]pyrene, lead, and mercury exceeded comparison value guidelines in samples collected from waste piles and tankers. Since removal activities, the existing levels do not exceed screening guidelines in on-site surface soil. Potential exposure pathways by which people may be exposed to contaminants from the IWOR site include: (1) ingesting contaminated groundwater and (2) ingesting or inhaling contaminated soil on the property. At present, the likelihood of exposure through these pathways is low; the site is fenced at its perimeter, and the shallow groundwater is not a source of drinking water.
The following public health action plan is to be implemented by Environmental Epidemiology Program staff members and other government agencies at and near the vicinity of the Intermountain Waste Oil Refinery site. The purpose of the public health action plan is to ensure that this public health assessment provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment from the Intermountain Waste Oil Refinery National Priorities List site.
Tamra Jewkes, Health Hazard Assessor
Environmental Epidemiology Program
Office of Epidemiology
Utah Department of Health
(801) 538-6191
M. Gambrelli Layco, M.F.S., Health Program Manager
Environmental Epidemiology Program
Office of Epidemiology
Utah Department of Health
John Contreras, Epidemiologist
Environmental Epidemiology Program
Office of Epidemiology
Utah Department of Health
(801) 538-6191
Designated Reviewer
R. Wayne Ball, Ph.D., D.A.B.T., Program Manager / Toxicologist
Environmental Epidemiology Program
Office of Epidemiology
Utah Department of Health
(801) 538-6191
This Public Health Assessment, Intermountain Waste Oil Refinery, Bountiful, Utah, was prepared by the Utah Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the public health assessment was begun.
Tammie McRae, MS
Technical Project Officer, SPS, SSAB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment and concurs with the findings.
Roberta Erlwein
Chief, State Program Section, DHAC, ATSDR
Agency for Toxic Substances and Disease Registry, ATSDR 1992. Public health assessment guidance manual. Chelsea, Michigan: Lewis Publishers. 1992.
Agency for Toxic Substances and Disease Registry, ATSDR 1993a. Toxicological profiles on CD-ROM. Atlanta: the US Department of Health and Human Services, CRC netBASE, 1999. Toxicological profile for trichloroethylene. Prepared by Life Systems, Inc., April 1993.
Agency for Toxic Substances and Disease Registry, ATSDR 1993b. Toxicological profiles on CD-ROM. Atlanta: US Department of Health and Human Services, CRC netBASE, 1999. Toxicological profile for 1,2-Dichloroethylene. Prepared by Life Systems, Inc., April 1993.
Agency for Toxic Substances and Disease Registry, ATSDR 1995. Toxicological profile for polycyclic aromatic hydrocarbons (update). Atlanta: US Department of Health and Human Services. Prepared by Research Triangle Institute. August 1995.
Agency for Toxic Substances and Disease Registry, ATSDR 1996. Toxicological profile for 1,2-dichloroethylene (update). Atlanta: US Department of Health and Human Services. Prepared by Research Triangle Institute. August 1996.
Agency for Toxic Substances and Disease Registry, ATSDR 1997. Toxicological profile for trichloroethylene (update). Atlanta: US Department of Health and Human Services. Prepared by Research Triangle Institute. September 1997.
Agency for Toxic Substances and Disease Registry, ATSDR 2003. Soil comparison values (update). Atlanta: US Department of Health and Human Services, Public Health Service.
Cooper AR. 1997. Cooper's toxic exposures desk reference, trichloroethylene. Boca Raton, FL: CRC Press Lewis Publishers. 1997.
Davis County Recorder's Office, Plats: Prefix 03-072 and Prefix 03-035, Section 30, Township 2N Range IE. Records as of July 2000.
Environmental Epidemiology Program, EEP 2000a. Memorandum for the record, EEP staff site visit to Intermountain Waste Oil Refinery, Davis County, Utah. Office of Epidemiology, Utah Department of Health. August 8, 2000.
Environmental Epidemiology Program, EEP 2000b. Memorandum for the record, notes on interviews with Bountiful residents and city officials regarding Intermountain Waste Oil Refinery, Davis County, Utah. Office of Epidemiology, Utah Department of Health. 2000 July 11 2000.
Environmental Epidemiology Program, EEP 2003. Memorandum for the record, email from Tony Howes, UDEQ, regarding Intermountain Waste Oil Refinery, Davis County, Utah. Office of Epidemiology, Utah Department of Health. September 15, 2003.
Enviro Search 1992. Initial soil and groundwater results at the Intermountain Oil Facility. May 20, 1992.
Environmental Protection Agency, EPA 1990. 40 CFR Part 300, Hazard Ranking System (HRS). December 14, 1990
Environmental Protection Agency, EPA 1998a. Site inspection report for expanded site inspection, Intermountain Waste Oil Refinery, Bountiful, Utah. CERCLIS # UTD093117844. December 1998.
Environmental Protection Agency, EPA 1998b. Solid waste and emergency response. Clarification to the 1994 Revised Interim Soil Guidance for CERCLA Sites and RCRA Corrective Action Facilities. EPA 540-F-98-030, NTIS: PB98-9630244.
Environmental Protection Agency, EPA 1999. Integrated Risk Information Systems (IRIS). Online.
The National Library of Medicine: Specialized Information Services - TOXNET (Toxicology
Data Network). Available at http://sis.nlm.nih.gov/cgi-bin/sis/htmlgen?IRIS accessed
November, 1999.
Environmental Protection Agency, EPA 2000a. U.S. Environmental Protection Agency (EPA) On-Line. CERCLIS Query results for Intermountain Waste Oil Refinery, CERCLIS #
UTD093117844 . Available at: http://www.epa.gov/superfund/sites/cursites/ . Accessed June, 2000.
Environmental Protection Agency, EPA 2000b. Office of Water. Office of Ground Water and
Drinking Water. Online. Current drinking water standards. National primary and
secondary drinking water regulations. Available at: http://www.epa.gov/OGWDW/mcl.html . Accessed February 2000.
Environmental Protection Agency, EPA 2000c. Office of Water. Office of Ground Water and
Drinking Water. Drinking water and health, technical fact sheet on 1,2-dichloroethylene.
Available at http://www.epa.gov/OGWDW/dwh/t-voc/12-dich2.html . Accessed September, 2000.
Environmental Protection Agency, EPA 2000d. Office of Water. Office of Ground Water and
Drinking Water. Drinking water and health, technical fact sheet on Trichloroethylene.
Available at http://www.epa.gov/OGWDW/dwh/t-voc/trichlor.html . Accessed September, 2000.
Environmental Protection Agency, EPA 2003. Intermountain Waste Oil Refinery. November
2002. http://www.epa.gov/region08/superfund/sites/ut/intmtnref.html . Accessed
September 15, 2003.
Utah Department of Environmental Quality, UDEQ 1996. Preliminary Assessment for Intermountain Oil, Bountiful, Utah, by Jim Thiros. Final Report, March 13, 1996.
Utah Department of Environmental Quality, UDEQ 1997. Analytical Results Report for Intermountain Waste Oil Refinery, Bountiful, Davis County, Utah. Final Report, September 30, 1997.
Utah Department of Environmental Quality, UDEQ 2002. Utah Department of Environmental
Quality 1,000-Day Plan Milestones. Available at:
http://www.deq.utah.gov/EQOAS/PROJECTS/milestones.htm . Accessed September 18,
2003.
Utah Division of Solid and Hazardous Waste, UDSHW 1995. Analytical results report for Intermountain Waste Oil Refinery, Bountiful, Davis County, Utah. Referenced in UDEQ, Analytical Results Report for Intermountain Waste Oil Refinery, Bountiful, Davis County, Utah. Final Report, September 30, 1997, page 9.
Utah Governor's Office of Planning and Budget On-Line. UGOPB 2000. Demographic and
Economic Analysis, State of Utah Long-Term Economic and Demographic Projections,
State, Counties, and Multi-County Districts. Available at: http://www.governor.state.ut.us/dea/CustomDataTables.html . Accessed
August 2000.
U.S. Department of Commerce, USDC 1990. Census of population and housing, CPH-1-46: Summary population and housing characteristics, Utah. Issued by Bureau of Census. August 1991.
U.S. Geological Survey, USGS 1991. David W. Clark. Ground-water resources and simulated effects of withdrawals in the Bountiful Area, Utah, technical publication No. 95, 1991.
U.S. Geological Survey, USGS 1994., PB Anderson, DD Susong, SR Wold, VM Heilweil, and RL Baskin., Hydrogeology of recharge areas and water quality of the principal aquifers along the Wasatch Front and adjacent areas, Utah, Water-Resources Investigations Report 93-4221, 1994.
Table 1. Potential Exposure Pathways.
| Pathway Name | Exposure Pathway Elements | Time Frame | Chemical(s) | ||||
|
Source |
Environmental Medium |
Point of Exposure |
Route of Exposure |
Receptor Populations |
|||
| On-site Groundwater | IWOR | Groundwater | Home Taps (Future) | Ingestion, Inhalation, Dermal Contact | Community Residents | Future | 1,2-Dichloroethene, Trichloroethene |
| On-site Wastes and Surface Soil | IWOR | Soil and Water | Waste Piles, Sump, Groundwater (future) | Ingestion, Inhalation, Dermal Contact | Community Residents | Future | Arsenic, benzo[a]pyrene, Lead, Mercury |
Table 2. Chemical Levels in Groundwater Samples.
|
Chemical |
Chemical Levels Detected in Groundwater (ppb) | Drinking Water Comparison Values (CV) for Children | |||||
| UDEQ 1997 | EPA 1998 | ||||||
| On-Site Monitoring Well | Weber Basin Municipal Well | On-Site Monitoring Well | Up gradient Monitoring Well | Bountiful Shop Well | CV (ppb) | CV Source H | |
| Chemicals which exceeded comparison value guidelines | |||||||
| 1,2-Dichloroethene | 435* | U | 500* | U | U | 70‡ | MCL |
| Trichloroethene | 650* | U | 855* | U | U | 5‡ | MCL |
| Iron | 9860 | 23.5 | 2275 | NT | 213 | 300 | NSDWR |
| Chemicals with no available comparison value guidelines | |||||||
| Calcium | 189000 | 62400 | 198000 | NT | 91400 | N/A | N/A |
| Magnesium | 59000 | 20500 | 61500 | NT | 28200 | N/A | N/A |
| Potassium | 7980 | 1590 | [5865] | NT | [1860] | N/A | N/A |
| Sodium | 131000 | 35200 | 137500 | NT | 42800 | N/A | N/A |
| Entries in bold indicate contaminant
concentrations that exceed the CV. * Values given are the mean of duplicate samples. H For an explanation of terms used for CV sources, see Appendix A. ‡ Because the available ATSDR CV is only for intermediate exposures (2 weeks to less than 1 year), the EPA MCL is used as the guideline in this assessment. U = Undetected. NT = Not tested. The analyte was not tested in that particular investigation. NA = No available CV for this compound. |
|||||||
Table 3. Chemical Levels in On-site Waste and On-Site Surface
Soil Samples.
|
Chemical |
Maximum Level Detected |
Soil Comparison Values (CV) |
|||
| (ppm) | Sample Location | Source | (ppm) | CV Source* | |
| Chemicals which exceeded comparison value guidelines | |||||
| Arsenic |
43.3 |
Tanker 1 |
UDEQ, 1997 |
0.5 |
CREG |
| Benzo(a)pyrene |
0.86 |
Eastern Waste Pile |
EPA, 1998 |
0.1 |
CREG |
| Lead |
3560 |
Tanker 1 |
UDEQ, 1997 |
400 |
EPA 540-F-98-030† |
| Mercury |
154 |
Tanker 1 |
UDEQ, 1997 |
5 |
EPA RfD‡ |
| Chemicals with no available comparison value guidelines | |||||
| Benzo[a]anthracene |
0.83 |
Eastern Waste Pile |
EPA, 1998 |
5-20 |
Background levels |
| Benzo(g,h,i)perylene |
1.7 |
NE Waste Pile |
EPA, 1998 |
10-70 |
Background levels |
| n-butylbenzene |
1.13 |
Tanker 1 |
UDEQ, 1997 |
N/A |
N/A |
| Carbazole |
0.67 |
Western Waste Pile |
EPA, 1998 |
N/A |
N/A |
| Chrysene |
2.9 |
NE Waste Pile |
EPA, 1998 |
38.3 |
Background levels |
| Phenanthrene |
0.78 |
South Impoundment |
EPA, 1998 |
30 |
Background levels |
| Propylbenzene |
2.335 |
Oil Seeps |
UDEQ, 1997 |
N/A |
N/A |
| 1,2,4-trimethylbenzene |
3.296 |
Tanker 1 |
UDEQ, 1997 |
N/A |
N/A |
| 1,3,5-trimethylbenzene |
1.532 |
Tanker 1 |
UDEQ, 1997 |
N/A |
N/A |
| Entries in bold indicate contaminant
concentrations that exceed the CV. * For explanation of the terms used for CV sources, see Appendix A. † EPA 540-F-98-030 reports an EPA action level for soil [EPA 1998b] ‡ EPA RfD = EPA Reference Dose [EPA 1999] For calculations, see Appendix B. N/A Not available. |
|||||
Table 4. Distribution of Groundwater Users By Distance from
the IWOR site.
|
City |
0 - 3 |
3 - 2 |
2 - 1 |
1 - 2 |
2 - 3 |
3 - 4 |
Total Population Served 1990 |
Projected Population 2000(5) |
|
Bountiful |
4,794 |
0 |
4,794 |
14,382 |
0 |
0 |
23,970 |
41,471 |
|
Centerville |
0 |
0 |
0 |
0 |
9,885 |
3,954 |
13,840 |
16,048 |
|
North Salt Lake |
0 |
0 |
0 |
4,855 |
1,619 |
0 |
6,474 |
8,808 |
|
South Davis |
0 |
0 |
0 |
9,277 |
0 |
0 |
9,277 |
not available |
|
Weber Basin |
7,029 |
0 |
0 |
0 |
0 |
0 |
7,029 |
not available |
|
West Bountiful |
0 |
0 |
0 |
5,000 |
0 |
0 |
5,000 |
4,822 |
|
Woods Cross |
0 |
1,582 |
1,180 |
2,733 |
0 |
0 |
5,495 |
6,207 |
|
Totals |
11,823 |
1,582 |
5,974 |
36,247 |
8,539 |
3,460 |
67,625 |
at least 77,356 |
APPENDIX A: ACRONYMS AND TERMS DEFINED
Examples of Comparison Values
EMEG = Environmental Media Evaluation Guide.
I-EMEG = Intermediate Environmental Media Evaluation Guide.
RMEG = Reference Dose Media Evaluation Guide.
CREG = Cancer Risk Evaluation Guide for 1x10-6 excess cancer risk.
Urgent Public Health Hazard
Public Health Hazard
Indeterminate Public Health Hazard
No apparent health hazard
No Public Health Hazard
Calculations
(A) Calculation for Water Ingestion Exposure Doses:
IDw = C x IR x EF / BW
| Where: | IDw | = ingestion exposure dose (mg/kg/day) |
| C | = contaminant concentration (mg/L) | |
| IR | = Ingestion rate (L/day); 2 L/day for an adult and 1L/day for a child | |
| EF | = exposure factor | |
| BW | = Body Weight (kg); 70 kg for an adult and 10kg for a child |
To compute human exposure to a water supply that is contaminated with 500 ppb (0.5 mg/L) of 1,2-dichloroethene and 855 ppb (0.85 mg/L) of trichloroethene:
| 1,2-dichloroethene: | Trichloroethene: | ||
| Adult: IDw | = C x IR x EF / BW | Adult: IDw | = C x IR x EF / BW |
| = 0.5 mg/L x 2L/day x 1 / 70kg | = 0.855 mg/L x 2L/day x 1 / 70kg | ||
| = 0.014 mg/kg/day | = 0.03 mg/kg/day | ||
| Child: IDw | = C x IR x EF / BW | Child: IDw | = C x IR x EF / BW |
| = 0.5 mg/L x 1L/day x 1 / 10kg | = 0.855 mg/L x 1L/day x 1 / 10kg | ||
| = 0.085 mg/kg/day = 0.05 g/kg/day | |||
(B) Calculating RMEG for Mercury in soil:
Of the mercury compounds, Amethylmercury is the compound of greatest concern for human health"
| RfD [EPA 1999] | = 1E-4 (ppm)/day |
| RMEGadult | = RfD (BW)/IR |
| = 1 x 10-4 mg methylmercury/kg/day(70 kg)/100 mg soil/day) | |
| = 7 x 10-5 (mg methylmercury/day)/(mg soil/day) | |
| = 70 (mg methylmercury/day)/(kg soil/day) | |
| = 70 ppm | |
| RMEGchild | = RfD (BW)/IR |
| = 1 x10-4mg methylmercury/kg/day(10 kg)/200 mg soil/day) | |
| = 5 x 10-6 (mg methylmercury/day)/(mg soil/day) | |
| = 5 (mg methylmercury/day)/(kg soil/day) | |
| = 5 ppm | |
APPENDIX C: LIST OF CHEMICALS ANALYZED IN GROUNDWATER, WASTE, AND ON-SITE SURFACE SOIL SAMPLES AT THE INTERMOUNTAIN WASTE OIL REFINERY, BOUNTIFUL, UTAH
|
Chemicals Not Detected or Not Exceeding Comparison Value Guidelines |
|||
| 1,1,2,2-Tetrachloroethane 1,1,1,-Trichloroethane 1,1,2-Trichloroethane 1,1-Dichloroethane 1,2-Dichloroethane 1,1-Dichloroethene 1,2-Dichloroethene 1,2-Dichloroethene (total) 1,2-Dichloromethane 1,2-Dichloropropene 2-Butanone 2-Hexanone 4-methyl-2-Pentanone Acetone Benzene Bromodichloromethane Bromoform Bromomethane Carbon Disulfide Carbon Tetrachloride Chlorobenzene Chloroform Chloroethane Chloromethane Dibromodichloromethane cis-1,3-Dichloropropene Dimethyl Sulfide Ethylbenzene Methylene Chloride Styrene Tetracloroethene Toluene trans-1,3-dichloropropene Vinyl Chloride Xylenes Aluminum Antimony Arsenic |
Barium Beryllium Cadmium Chromium Cobalt Copper Lead Manganese Mercury Nickel Selenium Silver Thallium Vanadium Zinc 1,2,4-trichlorobenzene 1,2-dichlorobenzene 1,3-dichlorobenzene 1,4-dichlorobenzene 2,2-oxibis(1-chloropropane) 2,4,5-trichlorophenol 2,4,6-trichlorophenol 2,4-dichlorophenol 2,4-dimethylphenol 2,4-dinitrophenol 2,4-dinitrotoluene 2,6-dinitrotoluene 2-chloronapthalene 2-chlorophenol 2-methylnapthalene 2-methylphenol 2-nitroaniline 2-nitrophenol 3,3-dichlorobenzidine 3-methyl-2-thiophenecarboxyl 3-nitroaniline 4,6-dinitro-2-methylphenol |
4-bromophenyl-phenylether 4-chloro-3-methyphenol 4-chloroaniline 4-chlorophenyl-phenylether 4-methylphenol 4-nitroaniline 4-nitrophenol acenapthalene acenapthene anthracene benzene benzo(a)anthracene benzo(a)pyrene benzo(b)fluoroanthene benzo(g,h,i)perylene benzo(k)fluoroanthene bis(2-chloroethoxy)methane bis(2-chloroethyl)ether bis(2-ethylhexyl)phthalate butalbenzylphthalate carbazole chrysene dibenz(a,h)anthracene dibenzofuran diethylphthalate di-n-butylphthalate fluorene fluoroanthene hexachlorobenzene hexachlorobutadiene hexachlorocyclopentadiene hexachloroethane indeno(1,2,3-cd)pyrene isophorone naphthalene nitrobenzene n-nitrosodiphenylamine (1) n-nitroso-di-propylamine |
pentachlorophenol phenanthrene phenol pyrene pyrrolidinedione trimethylbenzene 4,4-DDD 4,4-DDE 4,4-DDT Aldrin alpha-BHC alpha-chlordane Aroclor 1254 Aroclor-1016 Aroclor-1221 Aroclor-1232. Aroclor-1242 Aroclor-1248 Aroclor-1260 beta-BHC delta-BHC Dieldrin Endosulfan I Endosulfan II Endosulfan sulfate Endrin Endrin aldehyde Endrin Ketone gamma-BHC (Lindane) gamma-chlordane Heptachlor Heptachlor epoxide Methoxychlor Toxaphene |
