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PUBLIC HEALTH ASSESSMENT

INTERMOUNTAIN WASTE OIL REFINERY
BOUNTIFUL, DAVIS COUNTY, UTAH


SUMMARY

The Intermountain Waste Oil Refinery (IWOR) site was included on the National Priorities List onMay 11, 2000, and investigation activities are underway. The Agency for Toxic Substances andDisease Registry (ATSDR) requested that the Environmental Epidemiology Program (EEP) of theUtah Department of Health conduct this public health assessment to identify any public healthhazards 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 insoil and groundwater contamination on-site. During its years of operation, the IWOR facility wascited with several violations for failure to remediate contamination, and in 1993, the facility wasclosed. Under a cooperative agreement with the Utah Department of Environmental Quality(UDEQ), IWOR owners proceeded with remediation activities. However, because of a lack offunds, remediation was left incomplete.

In August 2001, the Environmental Protection Agency (EPA) removed and disposed of many on-sitecontainers and their contents, including all chemicals located in the laboratory building, 55-gallondrums and 5-gallon containers, two trailer tanks, the contents of an underground storage tank, andthe 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 continuingto 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 siteinclude: (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 itsperimeter, 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 hadnot been removed or contained, migration of contaminants to the deeper aquifers was possible, andthe 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. Thosecontaminants were detected in the on-site monitoring well at levels that exceed the EPA standardsfor public drinking water supplies.

The EEP public health action plan, designed to mitigate and prevent adverse human health effectsresulting from exposure to hazardous substances in the environment from the IWOR site, consists of the following actions:

  • To address health concerns of residents, EEP conducted a public availability session inSeptember 2002, in coordination with the Davis County Health Department, EPA, andthe UDEQ. At the session, the agencies addressed public concerns associated with thesite.
  • EEP, in coordination with EPA and the UDEQ, will continue to monitor the progress ofactivities at the site to protect public health during remediation efforts.
  • EEP, in coordination with the Davis County Health Department, will monitor thedevelopment of commercial property near the site and activities on the site that couldfurther facilitate migration of contaminants off-site.
  • EEP, in coordination with UDEQ and the Davis County Health Department will monitor area drinking water supplies until remediation is complete and contaminants are shown not be to be entering drinking water aquifers.

PURPOSE AND HEALTH ISSUES

The Agency for Toxic Substances and Disease Registry (ATSDR) requested that the EnvironmentalEpidemiology Program (EEP) of the Utah Department of Health conduct this public healthassessment 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. EEPdetermined how people could come into contact with site contaminants (exposure pathways),evaluated the implications for on public health if exposures occur, and issued recommendations toprotect the health of area residents.

The 1986 Superfund Amendments and Reauthorization Act to the Comprehensive EnvironmentalResponse, Compensation, and Liability Act of 1980 directs ATSDR to perform specific publichealth activities associated with actual or potential exposures to hazardous substances released intothe environment. Among those activities, ATSDR is mandated to conduct a public healthassessment for each site listed or proposed to be listed on the National Priorities List (NPL) within1 year of the listing. In addition, ATSDR may conduct a public health assessment for a particularfacility 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].


BACKGROUND

Site Characterization

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 ofCenterville 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, withtemperature fluctuations of up to 100F between winter and summer months. Wind patterns for theregion vary according to season and location of storm fronts. The average annual precipitation is 13to 15 inches, with a 24-hour maximum rainfall of 2.15 inches. The land surface slopes slightlynorthwest 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 reportedthat 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 EastShore 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 areais nearest the mountain front, which is underlain mainly by permeable sands and gravel that enhancethe recharge water movement. These aquifers are hydraulically connected; however, little work hasbeen accomplished in defining the boundaries between them. The shallow and deep aquifers likely conjoin into a single aquifer in the recharge area, which lies lessthan half a mile east of the site. These aquifer systems are composed of mudflow deposits that arepoorly sorted and only slightly permeable. The shallow aquifer is currently not used as a drinkingwater 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 SaltLake; at the IWOR site, the flow is west by northwest. Groundwater investigations at the PhillipsRefinery, 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 areaare 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 siterelied on those water systems for drinking water (Table 4). Projected population estimates for 2000indicate that the water systems currently supply more than 77,000 residents in Bountiful andsurrounding cities [UGOPB 2000]. No known private potable wells are within the 4 mile radius ofthe IWOR site [EPA 1998a].

Site Description

The IWOR site occupies approximately 2 acres and can be divided into the western and easternportions. The western portion consists of a vacant parcel covered with gravel, which is accessiblefrom the driveway through the Aamco Transmission service facility on 500 West. The oil refiningprocesses took place in the eastern portion, which in the year 2000 housed a laboratory, agarage/workshop, several waste piles, and two trailer tanks. In August 2001, EPA removed anddisposed 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 storedabove 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 [EEP2000a]. The IWOR property is bounded by 11 residences to the north and east, and by commercialproperties to the south and west [DCRO 2000].

Site History

IWOR began operations in 1957, processing waste oil from facilities in Utah, Nevada, Idaho, andWyoming. The waste oil was treated on-site, and the cleaned oil product was distributed to areacement facilities as fuel for cement kilns. The waste sludge from the cleaning process was disposedin 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 UtahAttorney General's Office issued several violations to IWOR owners. The Notice of Violations andOrders were issued for failure to remediate contamination resulting from years of spillage at therefinery. The facility had its permit revoked on several occasions because of poor wastemanagement practices [UDEQ 1997]. The Davis County Health Department (DCHD),Environmental Health Division, also issued violations to IWOR owners. Those violations weremainly because of odor complaints. The DCHD reports indicate that on at least two occasions, oilsludge flowed from the site onto 500 West and into a storm drainage leading to Mill Creek on atleast 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 consolidatedthe waste into a pile of approximately 100 cubic yards in the northeast portion of the site. When theowner claimed lack of funds, remediation activities ceased, and the remainder of the site wascovered with gravel and soil backfill [UDEQ 1997].

Over the past 10 years, several agencies have sampled and analyzed media relating to the IWORfacility. 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. InMarch 2001, the field investigation began. Samples were taken from tanks and drums remaining onsite. Soil-vapor sampling was also conducted on and near the site to help determine the extent ofground-water contamination that resulted from site operations.

In August 2002, the Proposed Plan that outlined the cleanup options for the soils and othersources was made available to the community. A public comment period extended from August19th to September 17th. A public meeting was held on August 22nd in Bountiful. The Record ofDecision, which outlines the selected remedy, taking into consideration public comments, wassigned in November 2002 [EPA 2003].

UDEQ is currently preparing institutional controls for future site development. This action willattach 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 priorto construction. UDEQ is also continuing to monitor ground-water quarterly and are planning toremove the underground storage tank, conduct additional subsurface soil sampling and possibly install two additional monitoring wells [EEP 2003].

Demographics and Land Use

According to 1990 US census data, 13,636 people, mainly in the city of Bountiful, live within onemile of the reclaimed IWOR property boundaries [USDC 1990]. Of those residents, 1,919 arechildren 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 builtin 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 apopulation of 41,301, which is 10% larger than in 1990. The current population of Davis Countyis estimated at 238,994 [USCB 2000].

The IWOR facility has been closed since 1993, and no workers are on-site. Trespassing at the siteis 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 AamcoTransmission building [EEP 2000a]. Approximately 80 people work at businesses around the site [UDEQ 1997].


DISCUSSION

Nature and Extent of Contamination

Between 1992 and 1998, several agencies analyzed waste, surface soil, groundwater, surfacewater, and sediment samples at the IWOR facility and its vicinity. Following is a summary of theinvestigations that have been conducted at the IWOR site.

Consultants representing the IWOR owners found 62 parts per billion (ppb(1)) of 1,2-dichloroetheneand 991 ppb of trichloroethene in the on-site monitoring well and other volatile organic compoundsin the on-site sump in 1992 [Enviro Search 1992]. In 1995, the UDEQ, Division of Solid andHazardous 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.

Exposure Pathways Analysis

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.

Potential Exposure Pathways

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:

Potential Exposure Pathways
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 analyzedfor the presence of a total of 159 chemicals (listed in Appendix C). Of the chemicals that weredetected, two exceeded comparison value guidelines (Table 2). The on-site monitoring well, whichdraws water from the shallow aquifer, contained elevated levels of 1,2-dichloroethene andtrichloroethene. 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 ContaminantLevels (MCLs(2)) for 1,2-dichloroethene and trichloroethene are 70 ppb and 5 ppb, respectively [EPA2000b]. The health effects that might result from exposure to those contaminants are discussed inthe "Toxicologic Evaluation" section of this document. Iron, calcium, magnesium, potassium, andsodium 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). Samplescollected from an up-gradient monitoring well completed in the shallow aquifer did not containdetectable levels of 1,2-dichloroethene or trichloroethene [EPA 1998a]. Elevated levels ofchemicals were not detected in samples collected from the Bountiful Shop Well, which draws waterfrom a different aquifer [EPA 1998a]. Samples collected from a spigot at the wellhead of the WeberBasin 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 IWORbecause 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:

On-site Wastes and On-site Surface Soil Pathway
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 analyzedfor the presence of 159 chemicals (see Appendix C). Of the chemicals that were detected, fourexceeded comparison value guidelines (Table 2). The sources of contamination identified at theIWOR site were tanker 1, tanker 2, the sump, waste piles, and oil seeps. Benzo[a]pyrene wasdetected in the eastern waste pile at 0.86 parts per million (ppm(3)), exceeding the Cancer RiskEvaluation 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, andmercury 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 noavailable 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 theirrespective 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 inoperation [EEP 2000b]. The tanks have been removed from the site, and the contents were neversampled. The tanks reportedly held waste oil and cleaned oil, but there is no documentation todetermine 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.

Public Health Implications

Levels of contaminants that exceed comparison values (CVs) will not necessarily cause adversehealth effects upon exposure. The potential for exposed persons to experience adverse health effects depends on many factors, including:

  • The amount of each chemical to which a person is or has been exposed;
  • How long a person is exposed;
  • The route by which a person is exposed (breathing, drinking, skin contact);
  • The health condition of the person;
  • The nutritional status of the person; and
  • Exposure to other chemicals (such as cigarette smoke).

Toxicologic Evaluation

1,2-Dichloroethene

1,2-dichloroethene (also called 1,2-dichloroethylene) is a highly flammable, colorless liquid witha sharp odor that is noticeable in very small amounts, beginning at a level of about 17 ppm. Thechemical 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 iscommonly 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, ittakes 13-48 weeks for half of a given amount to break down because of less opportunity forevaporation. Small amounts of 1,2-dichloroethene may break down into vinyl chloride, a more toxicchemical. Also, 1,2-dichloroethene is a breakdown product of other volatile compounds such astrichloroethene [ATSDR 1993b, 1996].

People can be exposed to 1,2-dichloroethene by breathing contaminated air, by drinkingcontaminated water, or by bathing in contaminated water. Animal testing has confirmed thatonce 1,2-dichloroethene is in the body, it is absorbed by the blood and other tissues and iseventually 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 todepress the central nervous system [EPA 2000c]. On the basis of animal studies, ATSDR establishedan oral Minimal Risk Level (MRL(4)) for intermediate exposures of 0.3 milligrams per kilogram perday (mg/kg/day) and 0.2 mg/kg/day for the cis and trans forms, respectively. If residents were todrink the contaminated water at levels found on site, exposure would be estimated at 0.014-0.05mg/kg/day, which is 10 times lower than the MRLs (see Appendix B for calculations). Breathinghighlevels (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 foundin the monitoring well at the site. In animals, damage to the liver and lungs has been noted afterexposures to 200 ppm trans-1,2-dichloroethene for 8 hours per day, 5 days per week, for either 8 or16 weeks [ATSDR 1993b, 1996]. That level is about 1,000 times more than what is present in themonitoring 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, colorlessliquid with a sweet taste. It has a sweet odor that is noticeable beginning at a level of about 100ppm. The largest source of trichloroethene (TCE) in the environment exists through the process ofevaporation primarily from factories that use TCE as a solvent to remove grease from metals. TCEcan also be found in typewriter correction fluid, paint removers, and adhesives. When TCE isreleased into air, it takes 7 days for half of any amount to break down. When TCE is released intogroundwater, 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, orby bathing in contaminated water. When a person breathes air containing TCE, about half theamount inhaled will be absorbed by the blood and other organs; the rest will be exhaled. If a persondrinks water containing TCE, the majority of the contaminant will be absorbed directly into thebloodstream. If TCE comes in contact with human skin, some of it will enter the body, although notas 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 withina 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 developmentin pregnant women [ATSDR 1997]. A New Jersey survey suggested an association betweenTCE exposure at levels averaging about 55 ppb in water (levels greater than 10 ppb) to oralclefts, central nervous system defects, neural tube defects, and major cardiac defects [ATSDR1997]. Interpretation of the findings of that study were limited by the small case numbers andexposure classification. If residents were to drink the contaminated water on-site daily, exposurewould be estimated at 0.03-0.085 mg/kg/day, which is 10 times lower than the acute MRL [seeAppendix 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. Thoselevels are about 100 to 1,000 times the amount found in the monitoring well water. TCE is a mildirritant to the lungs and respiratory tract; however, it breaks down in air to produce phosgene andhydrogen chloride, which are severe lung irritants [Cooper 1997]. No air monitoring data werecollected 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, dermaleffects are usually due to direct skin contact with concentrated solutions of TCE. Because theconcentration of TCE found in the on-site monitoring well is considered dilute at 650-855 ppb, thisconcentration is unlikely to cause dermal irritation [ATSDR 1993a, 1997].

The International Agency for Research on Cancer has determined that, according to extensiveanimal 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.


CHILD'S HEALTH CONSIDERATIONS

ATSDR and EEP recognize that the unique vulnerabilities of infants and children require specialemphasis in communities faced with contamination of their water, soil, air, or food. Children areat greater risk than adults from some environmental hazards. Children are more likely to be exposedto contaminants because they play outdoors, often bring food into contaminated areas, and are morelikely 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 criticalgrowth stages.

Reports from parents in the area indicate that children might have come into contact with somesoil or waste on the site in the past, before site access was restricted. Any exposure that mighthave occurred if children played in tanks is difficult to estimate. Currently, limited access to thesite should mean that no children are exposed to site-related contaminants. Future exposurecould occur if contaminants enter nearby drinking water supplies. Children might be expected tohave 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 orclear 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 andUDEQ on interviews with Bountiful City officials and several residents whose homes are adjacentto the IWOR site. City officials and residents provided EEP, EPA, and UDEQ staff with historicalinformation 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. Otherresidents complained that the cut, dried weeds on-site were a fire hazard [EEP 2000b]. Thefollowing summary reflects residents' specific health concerns related to the IWOR facility and theaccompanying 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.


CONCLUSIONS

The IWOR site poses no public health hazard under current conditions. Most of the problem soiland subsurface soil has been removed by the EPA, as well as tanks, drums, and the contents ofthe underground storage tank. UDEQ is currently preparing institutional controls for future sitedevelopment and is continuing to monitor ground-water quarterly. UDEQ is also planning toremove the underground storage tank, conduct additional subsurface soil sampling and possiblyinstall two additional monitoring wells [EEP 2003].

Thirty-six years of refining waste oil at IWOR resulted in contamination of on-site soils andgroundwater (shallow aquifer). The chemicals, 1,2-dichloroethene and trichloroethene, weredetected 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 collectedfrom waste piles and tankers. Since removal activities, the existing levels do not exceedscreening guidelines in on-site surface soil. Potential exposure pathways by which people maybe exposed to contaminants from the IWOR site include: (1) ingesting contaminatedgroundwater and (2) ingesting or inhaling contaminated soil on the property. At present, thelikelihood 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.


RECOMMENDATIONS

  1. The Environmental Epidemiology Program will continue to provide community healtheducation to communities near the IWOR site about the possible health effects from sitecontaminants to ensure that residents continue to avoid exposure on-site.
  2. The Environmental Epidemiology Program, in coordination with the Davis CountyHealth Department and the Utah Department of Environmental Quality will monitor areadrinking water supplies until remediation is complete and contaminants are shown not tobe entering drinking water aquifers.

PUBLIC HEALTH ACTION PLAN

The following public health action plan is to be implemented by Environmental EpidemiologyProgram staff members and other government agencies at and near the vicinity of the IntermountainWaste Oil Refinery site. The purpose of the public health action plan is to ensure that this publichealth assessment provides a plan of action designed to mitigate and prevent adverse human healtheffects resulting from exposure to hazardous substances in the environment from the Intermountain Waste Oil Refinery National Priorities List site.

  1. To address health concerns of residents, Environmental Epidemiology Programconducted a public availability session in September 2002, in coordination with the DavisCounty Health Department, the US Environmental Protection Agency, and the UtahDepartment of Environmental Quality. At the session, Environmental EpidemiologyProgram provided residents with information on the contaminants associated with theIntermountain Waste Oil Refinery.
  2. The Environmental Epidemiology Program, in coordination with the US EnvironmentalProtection Agency and the Utah Department of Environmental Quality, will continue tomonitor the progress of activities at the Intermountain Waste Oil Refinery site in order to protect public health during ongoing remediation efforts.
  3. The Environmental Epidemiology Program, in coordination with the Davis CountyHealth Department, will monitor the development of commercial property near the siteand activities on the site that could further facilitate migration of contaminants off-site.
  4. The Environmental Epidemiology Program, in coordination with the Davis CountyHealth Department and the Utah Department of Environmental Quality, will monitor areadrinking water supplies until remediation is complete and contaminants are shown not beto be entering drinking water aquifers.

AUTHORS

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


CERTIFICATION

This Public Health Assessment, Intermountain Waste Oil Refinery, Bountiful, Utah, wasprepared by the Utah Department of Health under a cooperative agreement with the Agency forToxic 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


REFERENCES

Agency for Toxic Substances and Disease Registry, ATSDR 1992. Public health assessmentguidance manual. Chelsea, Michigan: Lewis Publishers. 1992.

Agency for Toxic Substances and Disease Registry, ATSDR 1993a. Toxicological profiles onCD-ROM. Atlanta: the US Department of Health and Human Services, CRC netBASE,1999. Toxicological profile for trichloroethylene. Prepared by Life Systems, Inc., April1993.

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 forpolycyclic aromatic hydrocarbons (update). Atlanta: US Department of Health and HumanServices. 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. Preparedby Research Triangle Institute. August 1996.

Agency for Toxic Substances and Disease Registry, ATSDR 1997. Toxicological profile fortrichloroethylene (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 2NRange IE. Records as of July 2000.

Environmental Epidemiology Program, EEP 2000a. Memorandum for the record, EEP staff sitevisit 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 oninterviews with Bountiful residents and city officials regarding Intermountain Waste OilRefinery, Davis County, Utah. Office of Epidemiology, Utah Department of Health. 2000July 11 2000.

Environmental Epidemiology Program, EEP 2003. Memorandum for the record, email fromTony 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. December1998.

Environmental Protection Agency, EPA 1998b. Solid waste and emergency response. Clarification to the 1994 Revised Interim Soil Guidance for CERCLA Sites and RCRACorrective 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 (ToxicologyData Network). Available at http://sis.nlm.nih.gov/cgi-bin/sis/htmlgen?IRIS accessedNovember, 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 andDrinking Water. Online. Current drinking water standards. National primary andsecondary 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 andDrinking 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 andDrinking 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. November2002. http://www.epa.gov/region08/superfund/sites/ut/intmtnref.html. AccessedSeptember 15, 2003.

Utah Department of Environmental Quality, UDEQ 1996. Preliminary Assessment forIntermountain Oil, Bountiful, Utah, by Jim Thiros. Final Report, March 13, 1996.

Utah Department of Environmental Quality, UDEQ 1997. Analytical Results Report forIntermountain Waste Oil Refinery, Bountiful, Davis County, Utah. Final Report,September 30, 1997.

Utah Department of Environmental Quality, UDEQ 2002. Utah Department of EnvironmentalQuality 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 forIntermountain 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 andEconomic 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. AccessedAugust 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. August1991.

U.S. Geological Survey, USGS 1991. David W. Clark. Ground-water resources and simulatedeffects 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, andRL Baskin., Hydrogeology of recharge areas and water quality of the principal aquifersalong the Wasatch Front and adjacent areas, Utah, Water-Resources InvestigationsReport 93-4221, 1994.


FIGURES AND TABLES

Map Showing Location of Intermountain Waste Oil Refinery in Relation to Surrounding Communities in Davis County, Utah
Figure 1. Map Showing Location of Intermountain Waste Oil Refinery in Relation to Surrounding Communities in Davis County, Utah.

Map of One Mile Buffer and Demographics Information for Intermountain Waste Oil Refinery in Davis County, Utah
Figure 2. Map of One Mile Buffer and Demographics Information for Intermountain Waste Oil Refinery in Davis County, Utah.


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-Dichloroethene435*U500*UU70MCL
Trichloroethene650*U855*UU5MCL
Iron986023.52275NT213300NSDWR
Chemicals with no available comparison value guidelines
Calcium18900062400198000NT91400N/AN/A
Magnesium590002050061500NT28200N/AN/A
Potassium79801590[5865]NT[1860]N/AN/A
Sodium13100035200137500NT42800N/AN/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
56-110
169-59000

Background levels
Rural Soil
Agricultural Soil
Urban Soil

Benzo(g,h,i)perylene

1.7

NE Waste Pile

EPA, 1998

10-70
66
900-47000

Background levels
Rural Soil
Agricultural Soil
Urban Soil

n-butylbenzene

1.13

Tanker 1

UDEQ, 1997

N/A

N/A

Carbazole

0.67

Western WastePile

EPA, 1998

N/A

N/A

Chrysene

2.9

NE Waste Pile

EPA, 1998

38.3
78-120
251-640

Background levels
Rural Soil
Agricultural Soil
Urban Soil

Phenanthrene

0.78

SouthImpoundment

EPA, 1998

30
48-140

Background levels
Rural Soil
Agricultural Soil

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

Background Level:
The amount of a chemical that occurs naturally in a specific environment.


Comparison Values:
Concentrations in an environmental medium (air, soil, water) that are used to select environmental contaminants for further evaluation. The values are not valid for other types of environmental media, nor do actual concentrations above these values indicate that a health risk actually exists.

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.

CREG:
Cancer Risk Evaluation Guides are based on a contaminant concentration estimated to increase the cancer risk in a population by one individual in one million people over a lifetime's exposure.


EMEG:
Environmental Media Evaluation Guides are comparison values used to select contaminants of concern in specific environmental media (air, water, soil) at hazardous waste sites. EMEGs are derived from Minimal Risk Levels (MRLs), developed by the Agency for Toxic Substances and Disease Registry (ATSDR). They are used only as screening values.


EPA:
The U.S. Environmental Protection Agency (EPA) is the federal agency that develops and enforces environmental laws to protect environmental and public health.


MCL:
Maximum Contaminant Level (MCL) is the maximum permissible level of a contaminant in water that is delivered to any user of a public water system. MCLs are enforceable standards.


MRL:
Minimal Risk Level (MRL) is an estimate of human exposure to a compound that is not expected to cause noncancerous health effects at that level for a specified period. They are intended to protect the most sensitive individuals, including children. MRLs are guidelines and are not used to predict adverse health affects. MRLs do not take into account carcinogenic effects, chemical interactions, or multiple routes of exposure.


NSDWR:
National Secondary Drinking Water Regulations are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary standards to water systems but does not require systems to comply. However, states may choose to adopt them as enforceable standards.


NPL site:
The National Priorities List (NPL) is a list published by EPA ranking all the Superfund sites. Superfund is the common name for the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), a federal law enacted in 1980. This law was preauthorized in 1986 as the Superfund Amendments and Reauthorization Act. CERCLA enables EPA to respond to hazardous waste sites that threaten public health and the environment.


Public Health Hazard:
The category ATSDR assigns to sites that pose a health hazard to the public as the result of long-term exposures to hazardous substances. See "Public Health Hazard Categories".


Public Health Hazard Categories:
Categories defined by ATSDR and used in Public Health Assessments that define if people could be harmed by conditions present at a site. One of the following categories is assigned to each site:

Urgent Public Health Hazard
Public Health Hazard
Indeterminate Public Health Hazard
No apparent health hazard
No Public Health Hazard


APPENDIX B: CALCULATIONS

Calculations

(A) Calculation for Water Ingestion Exposure Doses:

IDw = C x IR x EF / BW

(A) Calculation for Water Ingestion Exposure Doses:
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"

(B) Calculating RMEG for Mercury in soil:
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



1 Parts per billion is comparable to one teaspoon of chemical in one million gallons of water.
2 Maximum Contaminant Level (MCL) - The maximum permissible level of a contaminant in water that which is delivered to any user of a public water system. MCLs are enforceable standards set by EPA.
3 Parts per million is comparable to one teaspoon of chemical per 1,000 gallons of water.
4 Minimal Risk Level (MRL) is an estimate of daily exposure of a human being to a chemical that is likely to be without an appreciable risk of adverse non-cancer effects over a specified duration of exposure.
5 Source: Associations of Government; Governor's Office of Planning and Budget [UGOPB 2000]


Table of Contents

  
 
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