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The tables in this section list the contaminants selected for further evaluation associated with theLenz Oil site. These contaminants are further evaluated in the remaining sections of this publichealth assessment to determine if they pose a threat to public health. The listing of acontaminant in the following tables does not necessarily mean that the contaminant poses athreat to public health. The selection of these contaminants is based on the following factors:

  1. Concentrations of contaminants found on and off the site.
  2. Data quality, both in the field and in the laboratory, and sampling plan design.
  3. Comparison of contaminant concentrations and background concentrations with environmental media comparison values (discussed further in this section).
  4. Community health concerns.

Comparison values are media-specific chemical concentrations used to select contaminants forfurther evaluation. These values include Environmental Media Evaluation Guides (EMEGs),Cancer Risk Evaluation Guides (CREGs), Reference Dose Media Evaluation Guides (RMEGs),Lifetime Health Advisories (LTHAs), and Maximum Contaminant Levels (MCLs). If a site-related contaminant is found at levels above any of these comparison values or if no comparisonvalue exists for the chemical in that medium (air, water, or soil), the contaminant is evaluatedfurther in the remaining sections of this document to determine if it poses a significant threat,upon exposure, to public health. Known or suspected human carcinogens with no carcinogeniccomparison value are listed as a contaminants of concern and are evaluated in the remainingsections of this public health assessment.

EMEGs are comparison values developed for chemicals that are relatively toxic, frequentlyencountered at NPL sites, and present a potential for human exposure. They are derived toprotect the most sensitive members of the population (e.g., children) and are not cut-off levels,but rather comparison values. As developed, ATSDR did not consider carcinogenic effects,chemical interactions, multiple route exposure, or other media-specific routes of exposure. Theyare very conservative concentration values.

CREGs are estimated contaminant concentrations based on one excess cancer in a millionpersons exposed to a chemical over a lifetime (70 years). These are also very conservativevalues designed to protect sensitive members of the population.

RMEGs are estimates of a daily oral exposure to a particular chemical that are unlikely toproduce any noncarcinogenic adverse health effects over a lifetime. They are based on USEPAreference doses (RfDs) and are conservative values designed to protect sensitive members of thepopulation.

RfCs are estimated air concentrations an individual can breathe for a lifetime (70 years) withoutexperiencing adverse health effects. They are developed by USEPA.

LTHAs are estimated water concentrations an individual can drink for 70 years withoutexperiencing noncarcinogenic health effects. These numbers contain a margin of safety toprotect sensitive members of the population. These values are established by USEPA and areconsidered only if no EMEG, CREG, or RMEG is available for the chemical.

USEPA established MCLs for public water supplies to reduce the chances of adverse healtheffects from drinking contaminated water. These standards reflect the best achievable levelsconsidering the occurrence, relative source contribution factors, monitoring capabilities, cost oftreatment, available technology, and health effects. These are enforceable limits that publicwater supplies must meet. These values are considered only if no EMEG, CREG, RMEG, orLTHA is available for the chemical. Proposed Maximum Contaminant Levels (PMCLs) are alsosometimes used in the absence of MCLs. These are proposed standards under consideration byUSEPA.

USEPA has also established Soil Screening Levels (SSLs), which they use to determine if a siteneeds further characterization. These values are used only for soil and if no other comparisonvalue is available.

Before clean up activities, oils, solvents, asphalts, and metals stored in above-ground and under-ground tanks, 55-gallon drums, and truck tanks were the primary sources of contamination. Themechanisms of release included leaking tanks and drums, nonexistent overflow structures,construction of poorly designed surface impoundments, spills, and poor housekeeping at the siteduring daily operation. Accumulation of these waste oils and solvents spanned 25 years. All ofthe source material in containers, in impoundments, or in badly contaminated soil was removedor incinerated. Therefore, preclean-up contaminant concentration data have not been used todetermine health risks at the site. Instead, sample collection and analyses completed in 1991 and1992 provide the basis for characterizing the health risks found at Lenz Oil in this public healthassessment. Some residual contaminated soils, sediments, and groundwater remain. Themanagement of the residual waste is discussed in the RI/FS published in February 1997 (30) andin the USEPA Proposed Plan of July 1997 (31).

The unremediated, contaminated groundwater remains the primary concern. The highlycontaminated nonaqueous phase liquid at the surface of the site's underlying aquifer has highconcentrations of many contaminants. How quickly contaminants are migrating from thefloating contaminant layer into the underlying groundwater has not yet been determined.

A. On-site Contamination

Waste Source

The contents of storage containers and structures were sampled and analyzed during the summerand fall cleanup of 1986. Many volatile organic compounds (VOCs), semi-volatile organiccompounds (SVOCs), polychlorinated biphenyls (PCBs), and metals are associated with the site-related wastes.

IEPA sampled sludges in the unlined waste ponds in February and May 1985. Table 13 listssome of the contamination concentrations known before the immediate clean up activities. Highconcentrations of many oil- and solvent-based contaminants were identified in this on-site"surface water." Aerial photographs from 1954 to present did not show any permanent naturalsurface water on site (7).

Besides the wastes in the impoundment areas, contamination of environmental media on site wasalso caused by leaking drums, tanks, and poor housekeeping. Once, standing oil covered anestimated 25 percent of the facility. Storage tanks were close to overflowing when the site wasabandoned, and virtually no containment structures for leaks or overflow had been erected.


Table 13 lists the identified contaminants found in surface and subsurface soils before IEPAclean up efforts. The analytical results of sampling from the 1992 RI report provided data for acurrent soil characterization (13). Tables 4, 5, and 6 summarize the RI data for soilcontamination on site. January and February 1991 sampling did not meet QA/QC requirementsfor several results reported simply as "unknown volatiles" or "unknown semi-volatiles." Onlythe known contaminants are listed. Additional soil and sediment samples were collected in 1992. Surface and subsurface borings were collected and analyzed for VOCs, SVOCs, pesticides,PCBs, and metals.

Generally, surface soil borings had lower VOC concentrations than subsurface samples. Thedetected VOCs of concern in the on-site soils include aromatic solvents (benzene, toluene,ethylbenzene, and xylene) and chlorinated solvents (1,1-dichloroethane, 1,2-dichloroethane,trichloroethene, 1,1,1-trichloroethane, and tetrachloroethene).

No pattern of distribution was evident for detected SVOCs in on-site soils. The detected SVOCsof concern include naphthalene, 2-methylnaphthalene, benzo(a)anthracene, chrysene,benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene,benzo(g,h,i)perylene, dibenzofuran, and di-n-butylphthalate. The SVOCs were numerous andfrequently found, but at low concentrations. This is not unexpected since burning carbon-containing compounds generates some SVOCs. Polychlorinated biphenyls or PCBs (e.g.Aroclor-1248 and Aroclor-1254) were also found. The on-site soil concentrations that exceededan environmental media comparison value include benzo(a)pyrene and PCBs.

The results of on-site soil and sediment inorganic chemical analyses are summarized in Table 6. Antimony and arsenic were detected in concentrations above environmental media comparisonvalues for a child's exposure. However, other metals could be considered contaminants ofconcern if compared to values determined for a child with a propensity to eat dirt (a pica child). Most children with pica are very young and not likely to venture onto a site unobserved. Nocomparison values have been set for aluminum, cobalt, copper, iron, lead, or mercury.


The aquifer immediately under the site is contaminated because of its close proximity to thesurface and because it is not naturally protected from contaminants leaching directly into it. Infact, the site is considered part of the aquifer's natural recharge zone. Regional groundwater flowis generally south-southeast, toward the Des Plaines River (13). However, seasonalmeteorological factors, the slight northwest slope of the site, and the drainage ditch to the northmay influence this principle. Hydrogeologic data reveal some variation in the groundwater flowdirection at the site.

After monitoring wells were installed at Lenz Oil, water samples collected in June 1982 by STSand in May 1984 by IEPA staff were observed to be very oily and dirty. Eleven wells wereinstalled by the state in 1986, and additional wells were installed for an investigation in 1991. The wells that were still in use at that time are illustrated in Figure 5.

Data from on-site monitoring wells (sampled May 1991) with confirmed concentration valuesinclude toluene (6 parts per billion or ppb) and chloroethane (53 ppb). Compounds identifiedwith estimated concentrations include total xylenes (920 ppb), ethylbenzene (370 ppb), 1,2-dichloroethane (31 ppb), 1,1-dichloroethane (28 ppb), chloroform (14 ppb), total 1,2-dichloroethene (3 ppb), and trichloroethene (2 ppb).

Many organic compounds have been found at high concentrations in the nonaqueous liquid fromon-site wells. They are listed in the first column of Table 2. The maximum thickness of thenonaqueous liquid has been estimated to be 1.3 feet. Sampling to date does not show whetherthe nonaqueous layer covers the entire surface of the underlying aquifer. Because the analysesfor these contaminants were different than analyses for water, the detection limits were muchhigher than those normally used for drinking water, and the substance is likely to containadditional chemicals. In addition, many tentatively identified compounds were found in thefloating contaminant layer, and the total organic concentration was very high.

Contaminants in the groundwater are also listed in Table 2. Of the detected organic compoundsin on-site groundwater, benzene, vinyl chloride, 1,1-dichloroethene, 1,2-dichloroethane,tetrachloroethene, naphthalene, fluorene, and PCBs were detected at concentrations above theirdrinking water comparison values.

The inorganic contaminants detected in on-site groundwater (Table 3) monitoring wells at levelsabove comparison values include arsenic, barium, chromium, lead, and selenium.

B. Off-site Contamination


Three background soil samples from the area north of the railroad tracks, upgradient of the site,were checked for VOCs, SVOCs, pesticides, and PCBs. Only one VOC was detected at a lowconcentration (1,1,1-trichloroethane at 5 ppb). Note that 1,1,1-trichloroethane was reportedreleased into the environment (Table 12).

Surface samples were collected around the northern drainage ditch. Samples from thesoutheastern side of this ditch contained some detectable concentrations of aromatic andchlorinated solvents, including trichloroethane, tetrachloroethane, toluene, ethylbenzene, andxylenes. All these compounds were detected at levels below comparison values.

Soil Gas Survey

Lighter weight (or low molecular weight) organic compounds are often called volatile organiccompounds or VOCs. Heavier complex organic compounds are often called semi-volatile(sometimes called SVOCs), which means they are less likely to evaporate than VOCs. Apossibility exists that low molecular weight contaminants can be released into the air fromsubsurface soils during excavation. Once released, the VOCs will quickly move off site in thedirection of the prevailing wind. A soil gas analysis conducted on site before clean up operationsin May 1987 (Table 10) revealed five VOCs present in significant concentrations.

During state clean up efforts, contractors covered soil that was waiting to be incinerated and usedfoam to reduce dust and emissions during excavation. Therefore, off-site emissions were likelykept to a minimum. Ambient off-site air monitored during July 1987 (Table 11) detected onlyslight concentrations of ambient VOCs while incineration was underway.

A second soil gas survey revealed the presence of lower concentrations of volatile organiccompounds. Of 32 soil gas samples collected south of the Lenz Oil site during a post-cleanupsoil gas investigation conducted in January 1991, only two had detectable values of VOCs. Thelow temperatures during January may have reduced volatilization of some of the contaminants. However, this information was useful in estimating the extent to which undergroundcontamination has migrated. Trichloroethene (0.1 parts per million or ppm), 1,1,1-trichloroethane (0.05 ppm), and 1,2-dichloroethane (0.23 ppm) were identified in samplescollected across Jeans Road. That suggests that the groundwater contamination has migrated toat least as far as these sample locations.

VOCs are part of the subterranean, non-aqueous liquid layer and subsurface soils, and they couldpotentially be released if the ground is disturbed or if the non-aqueous liquid layer migratescloser to residential basements or to the surface.


IEPA collected six drainage ditch sediment samples during the RI. No VOCs, PCBs, orpesticides were detected that could be attributed to contamination from the site. However, thefollowing SVOCs were detected: benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene, benzo(g,h,i)perylene, anthracene, phenanthrene, and 2-methylnaphthalene. The SVOC that exceeded the comparison value was benzo(a)pyrene.

Inorganic contaminants were also detected in sediments of the drainage ditch (Table 6), but theyhave not been conclusively attributed to past activities at the site.

Surface Water

When IEPA conducted an investigation in February 1985, contaminated surface water flowingoff-site was sampled. The sample was collected immediately north of the Lenz Oil site propertyline, south of the railroad right-of-way. IEPA personnel observed that this liquid materialappeared to be flowing through a berm into an unnamed drainage ditch to the north, which flowsinto a tributary of the Des Plaines River. Six samples were collected for the recent RIinvestigation and were analyzed for VOCs, SVOCs, metals, PCBs, and pesticides. Severaltentatively identified SVOCs compounds were found, which were not evaluated for this publichealth assessment. No VOCs, PCBs, or pesticides were detected. The inorganic analyses resultsare included in Table 7. The elevated metals detected in this drainage ditch have not beenconclusively attributed to the Lenz Oil site.


Three off-site wells are considered background wells because they were installed upgradient andnorth of the site (G101M, G101L, and G101D). The data from the background wells areincluded in groundwater tables for comparison purposes. The information is especiallyimportant for inorganic compounds that do not have comparison values or for which comparisonvalues are much less than naturally occurring values for the area. Chlorinated solvents have beenfound in the deep background well.

In March 1985, IEPA sampled five private wells located near the site. VOCs were detected intwo wells, and acetone was tentatively identified in one well. Later, analytical results of samplescollected from some downgradient private wells in 1986 identified the presence of low levels ofVOCs.

The Lenz residence well (Figure 3), 100 feet northeast of the site, was screened for VOCs,SVOCs, PCBs, and pesticides, and inorganics during the RI. No compounds attributed to the sitewere found in the sample. Samples from this well have historically never contained anycontamination. Samples from the bait shop well, approximately 100 feet south of the site, acrossJeans Road, have contained some contamination in the past, but this well was not resampled inthe recent investigation. The owner refused to have the well sealed.

Much of the data from samples collected between May 6 and May 9, 1991, regardinggroundwater contamination were qualified or rejected during data validation activities (18). Only the VOC results were considered usable. The SVOCs, PCBs, pesticides, and inorganicresults were rejected. Background groundwater samples in one upgradient location, north of thesite, beyond the railroad tracks, contained trace concentrations (estimated to be 2 to 3 ppb) of1,1-dichloroethene, chloroform, 1,1,1-trichloroethane, carbon tetrachloride, andtetrachloroethene.

The organic contaminants found in off-site wells at levels above their comparison values includevinyl chloride, 1,1-dichloroethene, trichloroethene, carbon tetrachloride, and tetrachloroethene. The inorganic contaminants detected in off-site wells at levels above comparison values includearsenic and lead.

Many chlorinated solvents have been detected at low concentrations in the monitoring wellssouth of the site. Soil gas results, however, suggest that the groundwater plume has migratedsince the past characterization efforts. Additional groundwater sampling has been conducted toprovide guidance for remediation plans (30 and 31).


In June 1987, during site incineration activities, ambient air sampling was conducted downwindof the site. Downwind sampling results showed only slight increases of VOCs over air samplingconducted upwind. The results of this air monitoring are summarized in Table 11 (22). The VOC levels were similar to those detected in Chicago during the same period.

Besides the review of currently available data concerning off-site contamination, the USEPAToxic Chemical Release Inventory (TRI) was searched for the site and local area for 1987through 1991 (27). This database contains information on environmental releases from activeindustrial facilities. Table 12 summarizes environmental releases from a variety of industries inthe area. Most of these industries are in Lemont, 3.5 miles southwest and downgradient from thesite. This information can give a general idea regarding the volume and types of emissions frommanufacturing facilities that may be contributing an additional environmental burden to apotential population of concern. Many site-related contaminants are also reported on thisdatabase.

C. Quality Assurance and Quality Control

In preparing this public health assessment, IDPH relies on the information provided in thereferenced documents and assumes that adequate quality assurance and quality control measureswere followed with regard to chain-of-custody of samples, laboratory procedures, and datareporting. The analyses and conclusions in this public health assessment are valid only if thereferenced information is complete and reliable.

Validation of data from the Lenz Oil site has ensured that the data meet quality assurances. Several deficiencies have been identified throughout these investigations, and some data havebeen rejected. In some instances, entire sampling rounds were dismissed as unusable.

D. Physical and Other Hazards

Fire and explosive conditions existed when large volumes of solvents were stored at the site. Presently, no fire or explosive hazards are present on the site. The site has been graded, andaccess is restricted from Jeans Road by a chain-link fence with several locked gates. This chain-link fence connects to a wooden privacy fence at the northeast border between the Lenz Oil siteand the nearest residential property. Gaps in the fence do exist under the Illinois Route 83overpass and along the railroad right-of-way to the north. Three nonfunctional monitoring wellswere sealed. Some underground utilities exist and must be considered during boring and drillingactivities. The underground plastic liner surrounding the incinerated soil has been reported tohave been punctured during some sampling activities.


Chemicals disposed on site can migrate into other media such as soil, sediment, surface water,groundwater, and air. During rain storms, soil contaminants can migrate in surface water runoffto ditches, roads, channels, and rivers. Once in these waterways, contaminants can betransported downstream until they are either deposited as sediment, degraded by bacteria,translocated through evaporation into the air, or percolated into groundwater. In addition, rainwater may percolate through soil and leach contaminants into groundwater beneath. Once ingroundwater, contaminants will migrate in the direction of groundwater flow until degraded bybacteria, removed through a manmade structure, or released into a low-lying surface water body. Contaminants that are adsorbed to surface soils may be carried by the wind to nearby areas. Ifcontaminants in surface soils are volatile or are uncovered, they may evaporate and move off sitein air.

Once people are exposed to a chemical present in the environment, their bodies may absorb thechemical by inhalation, skin absorption, and ingestion. At the Lenz Oil site, before remediation,the hazardous materials stored on site and released into the environment became the source forcontamination of several media including air, soil, groundwater, surface water, and sediments.

A hazardous material can affect people only if they contact it at a sufficient concentration tocause a toxic effect. This requires a source of exposure, an environmental transport medium, aroute of exposure, and an exposed population at the point of exposure. A pathway is complete ifall of its components are present and people were exposed in the past, are currently exposed, orwill be exposed in the future. If (1) parts of a pathway are absent, (2) data are insufficient todetermine if the pathway is complete, or (3) exposure may occur at some time (past, present,future), then it is a potential exposure pathway. If a part of a pathway is not present and willnever exist, the pathway is considered incomplete and can be eliminated from furtherconsideration. The site-specific completed and potential exposure pathways are discussed in thissection and presented in Tables 14 and 15. No current completed exposure pathway has beenverified.

A. Completed Exposure Pathways


Workers and nearby residents were exposed in the past to the wastes handled and stored on siteduring the years the site was in operation. However, data are insufficient to evaluate anypossible health effects that may have been caused by such exposure.


Surface waste formerly stored on site leached through the soil and easily entered the groundwaterbecause the water table is high and the aquifer is naturally unprotected. Private wells becamecontaminated, and residents living downgradient from the site, between the site and the DesPlaines River, likely ingested some contaminants before their homes were connected to thecommunity drinking water supply lines. Residents likely also inhaled low levels of volatilecontaminants when using water from their private wells. Until all the private wells are sealed,such exposure may continue.

Surface Water

Although no receptors have been specifically identified, people likely used nearby surface waterfor recreation or other purposes at some time. Runoff from the site during precipitation eventshas historically carried contamination from the site surface into nearby ditches and streams and,ultimately, to the Des Plaines River. No storm sewers are in the area; therefore, thecontamination has remained accessible to nearby residents. The contaminated groundwaterlikely discharges to the Des Plaines River, especially during periods of high water table. However, exposures to contaminated surface water would likely be infrequent and of shortduration. The contaminant levels are low in the surface water, and exposure would not expectedto result in adverse health effects.

B. Potential Exposure Pathways


The groundwater remains unremediated and is currently the contaminated environmentalmedium of greatest concern. The non-aqueous phase liquid at the surface of the aquifer has veryhigh concentrations of contaminants, whereas the underlying groundwater has only a lowfrequency of detectable organic compounds. The groundwater contamination plume has beenestimated to be approximately 31 feet below the surface and may extend 60 feet off site (7). Aspreviously stated, VOCs have been identified in the downgradient private well across Jeans Roadto the south. If the contaminant plume migrates to more distant private wells, community watersupplies, or discharges into surface waters, people could be exposed to the contaminants if theyuse their drinking water wells; however, no receptors have been identified to date. If wells aredrilled into this plume or the river becomes a drinking water source for people closer to thesource of contamination, the number of individuals exposed to this contamination may increase.

Homes of nearby residents living downgradient of the site have been connected to a municipalwater supply, but wells that are not sealed may be used for general household purposes. Domestic use of this contaminated water could expose residents, either through skin contact orinhalation, to contaminants in their well water. Inhalation is the most likely exposure routebecause most of the contaminants readily evaporate. If the non-aqueous liquid migrates nearhomes having basements, the potential for inhalation exposure becomes greater.


Sediments that have and are continuing to accumulate contaminants could be a source ofexposure to recreational users of area waterways. The northern drainage ditch has always beenand remains unsecured. In addition, exposures may occur if the northern drainage ditch isdisturbed or if any sediments migrate to areas that are known to be used.


The incineration used in the immediate clean up of the site did not destroy all of thecontaminants in surface and subsurface soils. Also, the incinerator ash may have containedheavy metals and some nondegraded contaminants. Direct contact with remaining contaminatedsoils or ash can occur to individuals working on the site or trespassing. Trespassers can easilygain access through gaps in the fence. Soil contaminants from the site could be carried or tracked into homes (on shoes or clothing) by children or other site trespassers. Contaminants may even be tracked into a home by a family pet that wanders on site. Such homecontamination may put toddlers at risk.

In the past, during facility operations and during soil excavation by IEPA, VOCs released toambient air were a potential source of exposure. However, air data collected during clean upactivities showed that air concentrations of contaminants did not reach levels that exceededcomparison values.

If future development occurs on this site, on-site visitors or residents could be exposed to hazardous substances still present in soil.


This section includes discussions on the possible health effects experienced by people exposed tospecific site-related contaminants, on any applicable state and local health databases, and onspecific community health concerns.

A. Toxicological Evaluation

To evaluate health effects, Minimal Risk Levels (MRLs) have been developed for compoundscommonly found at hazardous waste sites. The MRL is an estimate of the daily human exposureto a contaminant below which adverse, non-cancer, health effects are not likely to occur. MRLsare developed for different routes of exposure, including ingestion and inhalation, and for threedifferent exposure periods, acute (less than 14 days), intermediate (15-365 days), and chronic(more than 365 days).

ATSDR has developed Toxicological Profiles for contaminants that are common at hazardouswaste sites. The Toxicological Profiles are specific for individual chemicals. The ToxicologicalProfiles referenced for this discussion are: benzene, toluene, ethylbenzene, xylene, vinylchloride, polycyclic aromatic hydrocarbons (PAHs), PCBs, aluminum, arsenic, barium,cadmium, chromium, lead, manganese, nickel, selenium, and zinc. The profiles containinformation on health effects, environmental transport, human exposure, and regulatory status ofeach chemical.

Most of the toxicological information presented in this section focuses on site-related exposures. Usually, adverse health effects are known only as a result of occupational exposure situationswhere individuals were exposed to very high chemical concentrations. In all cases, theprobability an adverse effect will occur is dependant upon the exposure concentration and theamount of time an individual is exposed.

Chlorinated Solvents

This group of VOCs is commonly used in industry and has been found to be prevalent at theLenz Oil site. Local industries reported releases of many chlorinated solvents on the TRI (Table 12). These compounds consist of chlorine, carbon, and hydrogen. Following incineration, mostof the soil concentrations of these compounds were reduced to levels below comparison values. Many chlorinated solvents continue to be detected frequently in several environmental media butat low concentrations. Some have been selected only because they are so commonly found, notbecause they exist at levels above comparison values. Chlorinated solvents detected at Lenz Oiland selected for further evaluation include chloroethane, vinyl chloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1-dichloroethene, trichloroethene, 1,1,1-trichloroethane, carbon tetrachloride,and tetrachloroethene. Table 8 lists the environmental medium where solvents containing chlorine were found.

IDPH found an abundance of information regarding health effects resulting from high-doseexposures to chlorinated solvents in animals and man. In humans, most of these data are a resultof occupational exposures. More information is needed regarding long-term, low-dose exposuresto these common contaminants. However, the main health effects associated with this type ofexposure are believed to include elevated cancer risk, adverse reproductive outcome, and adverseeffects to the nervous system. Many chlorinated solvents can cause cancers in laboratory animalsexposed to high doses.

Studies have shown that one chlorinated solvent, vinyl chloride, increases the risk of liver cancerin workers who have been occupationally exposed. However, studies of human populationsexposed to these compounds through drinking water have not provided strong evidence for anincreased risk of developing cancer (2). Because of the uncertainty, chlorinated solvents areconsidered possible or potential human carcinogens. Vinyl chloride was detected in two samplesof off-site groundwater.

Aromatic Solvents

This group of VOCs has also been found at this site; however, these solvents do not havechlorine associated with them. They easily volatilize into the air. High concentrations ofxylenes have been found at Lenz Oil. Studies show that long-term inhalation at concentrationsof 230 to 800 parts per million (ppm) in animals has caused heart rate changes and abnormalblood flow. At levels of 100 to 299 ppm, eye, nose, and throat irritation occurs and breathingbecomes difficult. Impaired memory, headaches, and decreased coordination are nervous systemdisorders associated with long-term exposures to relatively high concentrations of xylenes. Inwaste sites where xylenes are present, it is typical to also find related chemicals, benzene,toluene, and ethylbenzene. All four of these solvents have been detected in on-site soils butbelow levels of concern. Toluene, ethylbenzene, and xylenes have been found in the nonaqueousliquid at Lenz Oil at high concentrations.

Benzene is a known human carcinogen. Individuals exposed in occupational settings for longperiods of time have experienced changes in blood forming tissues and blood disorders. Thetype of cancer associated with long-term, high-dose benzene exposure is cancer of tissues thatform white blood cells or leukemia (2). Benzene has been detected at levels of concern in twogroundwater samples from on-site monitoring wells. Benzene was not detected in any otherenvironmental samples and has not been found in private wells.

Semivolatile Organic Compounds

Most of the semivolatile organic compounds of concern at the Lenz Oil site are a class of relatedcompounds called polycyclic aromatic hydrocarbons or PAHs. The PAHs detected in more thanone medium at the Lenz Oil site include: naphthalene, 2-methylnaphthalene, anthracene,benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene,indeno(1,2,3-cd)pyrene, benzo(g,h,i)perylene, fluorene, dibenzofuran, phenanthrene, andacenaphthene. They were most frequently found in on-site soil samples at low concentrations. The PAHs detected above comparison values include naphthalene, benzo(a)pyrene, fluorene, andacenaphthene.

Naphthalene and 2-methylnaphthalene are examples of substances that have been associatedwith hemolytic anemia (the breakdown of red blood cells). In addition, ingestion has beenknown to cause nausea, vomiting, and diarrhea (2).

Naphthalene was detected in the nonaqueous liquid, on-site groundwater, and on-site soilsamples. The concentration of all the contaminants in the nonaqueous liquid was much higherthan in any other water sample. Naphthalene was found in 18 on-site soil samples, and thehighest concentration detected was 10 ppm. Naphthalene has the highest vapor pressure of thePAHs, which means that it will volatilize more readily than others. The combustion of fossil fuelis the major source of airborne naphthalene (2).

Naphthalene exposure in humans at levels well above those levels found at the site have causedhemolytic anemia, nausea, vomiting, diarrhea, kidney damage, jaundice, and liver damage. Theeffects are seen from both inhalation and ingestion (2). These effects would not be expected tobe exhibited from exposure to naphthalene-containing soils at Lenz Oil. There is not enoughanimal or human data to classify the carcinogenicity of naphthalene.

Phenanthrene was the most frequently detected SVOC in the on-site soil and the north drainageditch sediments. The highest concentration of phenanthrene was 12 ppm in the sediment. Phenanthrene was not detected in any water samples. No comparison values are available forphenanthrene.

Benzo(a)pyrene was found above a level of concern in 25 soil samples. The highestconcentration was 4.5 ppm. Benzo(a)pyrene is classified by USEPA as a probable humancarcinogen, which means there is adequate animal data but insufficient human data to classify itas a known carcinogen. The non-carcinogenic effects of PAHs are based primarily on animalstudies where the animals were exposed to much higher levels than those associated withpossible exposures at this site. Benzo(a)pyrene caused reproductive difficulties in mice and theiroffspring. These offspring also exhibited birth defects and decreased body weight. Animalstudies with other PAHs produced a variety of health effects, including adverse effects to skin,body fluids, and the immune system (2).

Other carcinogenic PAHs found at Lenz Oil include benzo(a)anthracene, chrysene,benzo(b)fluoranthene, benzo(k)fluoranthene, and indeno(cd)pyrene. Studies indicate they werecarcinogenic to animals when ingested, through skin contact, or inhaled. All of the listed PAHsare listed as B2 carcinogens by USEPA. No carcinogenic comparison values were available forany of these PAHs (2).

Polychlorinated Biphenyls (PCBs)

PCBs were detected in the nonaqueous liquid, in on-site groundwater, and in on-site soils. Exposure to PCBs in and around the site would be by inhalation, ingestion, and dermal contact. The amount of absorption by each route is not known in humans. Since absorbed PCBs aredistributed to fat, the fat in breast milk is a source of exposure in infants. PCBs may betransferred from the mother to the fetus through the placenta (2).

The health effects of PCB exposure in humans may include chloracne and possible learningdifficulties in children whose mothers were exposed during pregnancy. Health effects associatedwith PCB exposures in animals include liver, stomach, and thyroid gland effects, anemia, acne,and reproductive system damage. The effects have been seen in offspring of animals exposed toPCBs. There is limited evidence that PCBs are a liver carcinogen in animals (2).

The exposure to PCBs from either soil or groundwater would not be expected to cause chloracnein either trespassers or nearby residents. The health effects that have been seen in animals havenot been observed in humans. PCBs are considered to be a probable human carcinogen byUSEPA. PCBs are no longer being manufactured; however those present in the environment arevery long lasting (2).



This element was detected in all background and environmental soil samples. Aluminum is themost concentrated element in soils following oxygen and silicon. Naturally occurringconcentrations in soils have been reported as high as 300,000 ppm. Aluminum has been found inall environmental media analyzed at this site. USEPA has proposed a Secondary MaximumContaminant Level (SMCL) of 50 ppb for drinking water. An SMCL is not determined by anyadverse health effects but is set for taste and aesthetic purposes (2).

Few adverse health effects have been attributed to aluminum exposure, and no health guidelinevalues have been established. Some occupational inhalation exposures have contributed toworker respiratory disorders. However, inhalation exposures to these high air concentrations areunlikely at this site. Ingested elemental aluminum is not well absorbed (2).


Arsenic has been detected in samples from both on- and off-site monitoring wells, one upgradient background well, on-site soils, and north ditch sediments. No arsenic was detected inresidential wells. There is mounting evidence from human and animal data that arsenic causescancer by the oral route and is considered by USEPA to be a known human carcinogen by theinhalation route. Inhalation may produce lung cancer, respiratory irritation, nausea, and skinproblems. USEPA has not calculated a cancer slope factor by which to estimate the increasedrisk of developing cancer from arsenic exposure. ATSDR has developed a chronic oral MRL of0.0003 mg/kg/day for ingestion of inorganic arsenic but has not developed an acute orintermediate oral MRL. Since the arsenic levels of concern were in on-site soil, chronic exposureis unlikely. If soil is ingested at low concentrations over an extended period of time, the non-carcinogenic effects that may be associated with inorganic arsenic exposure include irritation ofthe stomach and intestines with symptoms including nausea, vomiting, diarrhea, a decrease in theproduction of red and white blood cells, abnormal heart function, blood vessel damage, andimpaired nerve function causing a "pins and needles" sensation in the hands and feet (2).

Long-term ingestion may also lead to a pattern of skin changes, including a darkening of the skinand the appearance of small "corns" or "warts" on the palms, soles, and torso. These skinchanges are not a health concern by themselves; however, they may later develop into skincancer. Ingestion of arsenic has also been reported to increase the risk of liver, bladder, kidney,and lung cancers (2).


Barium was detected in most of the soil samples analyzed and frequently in groundwater andsurface water samples. Exposure to site-related barium could occur through ingestion andinhalation of barium-contaminated media. Little is known about the health effects of low level,short-term exposure of humans to barium. Health effects of people with chronic exposure tobarium include difficulties in breathing and increased blood pressure, changes in heart rhythm,stomach irritation, changes in blood, muscle weakness, changes in nerve reflexes, swelling of thebrain, and damage to liver, kidney, heart, and spleen. However, daily exposure to on-site soils,sediment, and surface water is unlikely. No MRLs have been established for barium exposure (2).


This trace metal is naturally occurring in soils at levels ranging from 0.01 to 7 ppm. In soils thathave been conditioned with sewage sludge or phosphate fertilizers, the concentration of cadmiumwould likely be on the higher end of the normal range. Unlike some heavy metals, cadmium isnot an essential nutrient and has no known beneficial effect on human health. Workers breathingair with high levels of cadmium over a short time have experienced lung damage and death. Cadmium inhaled over a longer period has been linked to skeletal disorders and lung cancer. However, most cadmium levels encountered in the environment are not high enough to cause thiseffect. Lower levels inhaled or ingested over a long period result in an accumulation of cadmiumin the kidneys and liver and may lead to kidney disorders. In laboratory animals, exposure tocadmium has also resulted in adverse pregnancy outcome and other cancers (2).

The population exposed to cadmium would be the same as for the other inorganic compounds. Exposure would occur by ingestion and inhalation of contaminated soil and inhalation of fugitivedusts from the site. The data on cadmium inhalation and cancer in humans is limited. Nocurrent air data exist for this site.

Non-carcinogenic health effects that may be associated with oral cadmium exposure are a build-up of cadmium in the kidney, which may cause kidney damage, and fragile bones. The chronicoral MRL for cadmium is 0.0007 mg/kg/day (2). Cadmium concentrations of 0.4 ppm for a picachild (a child who regularly eats nonfood items such as dirt), 10 ppm for a child, and 140 ppmfor an adult are estimated to result in a daily exposure equal to 0.0002 mg/kg/day, which is belowthe levels associated with non-cancer, adverse health effects.


Chromium is a metal that exists in several forms in the environment including chromium III andchromium VI. Chromium III is the naturally occurring form and is an essential nutrient. Chromium VI is usually associated with industrial activities. Chromium analysis in both air andsoil samples did not differentiate between chromium III and chromium VI (2).

No adverse health effects associated with chromium exposure through ingestion or inhalation offugitive dust or on-site soils would be expected at this site at the levels detected; however,allergic individuals may have redness and swelling of skin if they contact the chromium (2).

Long-term exposure to elevated chromium levels in the work place have been associated withlung cancer. Chromium VI seems to be at least one form of chromium associated with lungcancer, but chromium III has not been associated with cancer (2).


Lead is a metal found naturally in soil. It has no beneficial biological function once absorbedinto the human body. It is especially harmful to developing nervous systems in unborn babiesand small children. Lead effects on nervous system development were recognized early in thiscentury but were assumed to be reversible until the 1940s when researchers reported permanenteffects on learning and behavior in children exposed to lead (2).

Lead has been found at the Lenz Oil site in the nonaqueous liquid, the groundwater, and the soil. Although it is not appreciably absorbed through the skin, oral and inhalation exposure remains aconcern. ATSDR has no MRLs and USEPA has no RfDs for lead; however the Centers forDisease Control lowered the acceptable blood lead levels. Because it has been linked to centralnervous system disorders in young children, ATSDR and IDPH recommend that environmentallead exposures be limited to those that do not result in blood lead levels more than 10micrograms of lead per deciliter of blood (2).

Most of the health effects associated with lead are the result of chronic low-level exposures. Acute adverse effects of lead intoxication are similar to chronic effects but occur rarely. Acuteeffects can be severe and include mental retardation and death. Chronic effects of leadintoxication vary depending on exposure levels. Some health effects attributed to lead exposureare interference with Vitamin D production, neurobehavioral toxicity, renal dysfunction, and athigher exposures, dysfunction of cardiovascular, hepatic, gastrointestinal, and endocrine systems (2).

The population affected by the site would include workers on site and residents in areassurrounding the site. On-site workers and adjacent populations could be exposed by bothinhalation and ingestion. Inhalation of lead would occur by breathing suspended contaminateddirt and waste pile particles. Workers could accidentally ingest lead if they do not washcontaminated soil from their hands before they smoke or eat; inadvertent ingestion may have alsooccurred indirectly through inhalation contaminated dust and swallowing what did not get intolungs.

Currently, no comparison values have been developed for lead except the MCL action level (15ppb) for community drinking water supplies. The concentration of lead found in eight on-sitemonitoring wells exceeded this MCL; however, these wells are not being used for drinkingwater.


All site soil, sediment, and groundwater samples analyzed contained manganese. Manganese canbe absorbed after ingestion or inhalation, but only 3 to 5 percent of ingested manganese isabsorbed. The amount absorbed after inhalation is not known. Scientists believe the smallamounts consumed by people in a typical diet are important to their health, but highconcentrations can be harmful (2). Children who consume groundwater from the on-site shallowwells with the highest manganese concentrations would not receive a dose that exceeds theUSEPA oral RfD for drinking water. The health effects associated with the ingestion ofmanganese may include weakness, stiff muscles, and trembling of hands. It is not known tocause cancer if ingested (2). Daily ingestion or inhalation of manganese from site soils,sediments, and groundwater is unlikely. Therefore, no adverse health effects are expected ifpeople are exposed to manganese at the site.


Nickel was detected at levels above comparison values in on-site monitoring wells and in on-sitesoils but below comparison values in off-site wells and soils. This element can be absorbed afteringestion or inhalation, and a small amount can be absorbed after dermal contact. Most ingestednickel is not absorbed but is eliminated in the feces. After absorption, most nickel is transportedto the kidneys and is eliminated in the urine. Nickel in the form of refinery dust and the sulfidecompounds are known human carcinogens by inhalation; however, in these occupationalexposures the employees were exposed to nickel levels much higher than those on site. Only afew soil samples exceeded the comparison value. No air data for nickel exist for this site. Insome individuals who are sensitive to nickel, skin contact with nickel may cause a skin rash (2).


Although selenium was below detection limits in most of the samples analyzed, it was found inthe north drainage ditch sediment and in the nonaqueous liquid samples at levels abovecomparison values. Selenium is an essential nutrient. The effects of selenium inhalation inhumans are not known. Ingestion of selenium at concentrations above those necessary for thenutritional requirements can cause brittle hair, deformed nails, and in extreme cases numbnessand incoordination of the limbs (2). Other than the few samples listed in this document , theenvironmental samples did not exceed comparison values. No adverse health effects areexpected to occur if people do sometimes come into contact with selenium at the site.


No comparison values could be found for zinc concentrations in soil or air. The nonaqueousliquid contains a high concentration of zinc. Zinc is an essential nutrient. The health effectsassociated with zinc are non-carcinogenic. The health effects from breathing high levels of zincin the work place include breathing difficulties and may cause a brief sickness called metal fumefever. At very high levels, breathing zinc dust or fumes may be life threatening. Ingestion of toomuch zinc can cause anemia and digestive problems. Excessive zinc intake may also beassociated with an increased risk of heart disease and trouble in fighting disease or infection (2). None of these health effects due to zinc exposure would be expected at this site.

B. Health Outcome Data Evaluation

People living in the small neighborhood community south of the site were likely exposed to site-related contamination until municipal water was made available in 1988. This small population,however, would not be large enough to provide any statistically significant data on whether anyadverse health effects were caused by exposure or occurred by chance. Therefore, no healthoutcome data have been generated or analyzed. There have been no reports of excessive cancerfrom residents who may have previously been exposed to site-related contamination in theirdrinking water. One resident living up gradient of the site reported that her son was diagnosedwith cancer.

C. Community Health Concerns Evaluation
Question 1: What health effects are associated with chlorinated solvents?

Response: There are some chlorinated solvents associated with adverse health effects following long-term exposures. For example, methylene chloride is a chlorinated solvent that is a possible human pancreatic or liver carcinogen. Other chronic effects following methylene chloride exposure may include cardiovascular disorders (arrhythmia) or increased liver enzymes.

Question 2:

Will wells on top of the bluffs become contaminated?

Response: There is a potential for the contaminated groundwater to continue to move further off-site to the south. At this time, we believe the wells on the bluff north of the site are naturally protected because they are up gradient from the site and the groundwater flows in the opposite direction. In December of 1990, IDPH collected a sample of well water from a residence where the resident was concerned about potential contamination of the well and who was experiencing skin rashes. The well in question was north of the site on top of the bluff. The well sample was thoroughly analyzed for all site-related chemicals known to cause skin rashes. The sample analysis did not detect any chemicals at levels above the detection limits of the laboratory equipment. We conclude that the private wells in this neighborhood north of the site are geologically protected from well contamination.

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