PUBLIC HEALTH ASSESSMENT
WAUCONDA SAND AND GRAVEL LANDFILL
WAUCONDA, LAKE COUNTY, ILLINOIS
The tables in this section list the contaminants of concern. These contaminants have beenevaluated in the subsequent sections of the health assessment for determination as to whetherexposure to them has public health significance. These contaminants have been selected basedupon the following criteria:
- Concentrations of contaminants on- and off-site.
- Field data quality, laboratory data quality, and sample design.
- Comparison of on- and off-site concentrations with health assessment comparison values fornoncarcinogenic endpoints, and carcinogenic endpoints.
- Community health concerns.
In the data tables that follow under the on-site contamination subsection and the off-sitecontamination subsection, the listed contaminant does not mean that it will cause adverse healtheffects from exposures. Instead, the list indicates which contaminants will be evaluated furtherin the health assessment.
The data tables include the following acronyms:
CREG: Cancer Risk Evaluation Guide EMEG: Environmental Media Evaluation Guide ILGWS: Illinois Groundwater Standards LTHA: Lifetime Drinking Water Health Advisory MCL: Maximum Contaminant Level MCLG: Maximum Contaminant Level Goal ppb: parts per billion ppm: parts per million RfD: Reference Dose RfC: Reference Concentration RMEG: Reference Media Evaluation Guide VOC: Volatile Organic Chemical
Comparison values for health assessment are contaminant concentrations in specific media thatare used to select contaminants for further evaluation. Media levels for each chemical arecompared with these values in the order in which they are explained below. The first valueexceeded becomes the chemical-specific comparison value for the health assessment. Thesevalues include Environmental Media Evaluation Guides (EMEGs), Cancer Risk EvaluationGuides (CREGs), and other relevant guidelines that are commonly used. EMEGs aremedia-specific comparison values developed by ATSDR to select contaminants for furtherevaluation, derived from non-cancer health data. CREGs are estimated contaminantconcentrations based on a one excess cancer in a million persons exposed over a lifetime. CREGs are calculated from USEPA's cancer slope factors. USEPA's Reference Dose (RfD) fornoncarcinogens is an estimate of the daily exposure to contaminant that is unlikely to causeadverse health effects. The RMEG is calculated from the RfD, and is the concentration in water(assuming a person drinks 2 liters a day) that is unlikely to cause adverse health effects. The RfCis the actual concentration in air that is considered "safe" exposure. The USEPA developed theLTHA to provide the level of a contaminant in drinking water at which adverse non-carcinogenichealth effects would not be anticipated with a margin of safety, over a period of 70 years,assuming exposure rate of 2 liters per day. Maximum Contaminant Levels (MCLs) areenforceable drinking water regulations that USEPA deems protective of human health(considering the availability and economics of water treatment technology) over a lifetime (70years) at an exposure rate of 2 liters of water per day. MCLGs are non-enforceable drinkingwater health goals. They are set by USEPA at a level that no adverse health effects areanticipated to occur and which allow an adequate margin of safety. ILGWS are IllinoisGroundwater Standards as set by the Illinois Pollution Control Board, which, if not met, triggercorrective action for potable water supplies. If the concentration of a chemical exceeds any ofthese values, it is selected as a contaminant of concern.
The contaminants of concern associated with this site are VOCs, metals, and a few semi-volatilecompounds. The VOCs of concern are chlorinated solvents (alkanes and alkenes) includingvinyl chloride, and benzene and 2-butanone. PCBs have been detected, only twice, at low levelsin the USEPA/CRA sampling programs since 1983. Several pesticides were detected only oncein 1983 in on-site groundwater, and have not been detected since. There are a number of metalsof concern detected in on- and off-site upper aquifer samples. Antimony and vanadium werealso present above comparison values in residential wells. Antimony is at similar concentrationsin leachate, groundwater (on- and off-site) and in residential well samples. There is, therefore,no discernable concentration gradient linking antimony with the landfill. Vanadium has beendetected at higher levels in leachate than in groundwater or residential wells. However, since itwas also detected in Wauconda municipal wells which have not exhibited any otherlandfill-linked contamination, it is unclear whether vanadium present in the groundwateroriginated from the landfill.
Sixteen samples of leachate were taken by USEPA in 1983 and Conestoga-Rovers Associates(1986-91). Table 1 shows the range of contaminant concentrations found in on-site leachatesamples taken. One PCB (Aroclor 1260) was detected in one of 13 samples tested for PCBs in1990 and one sample was found to have low levels of PCBs in 1992. PCBs were not detected ina duplicate sample taken a month later. In 1983, the USEPA collected samples from leachateseeps; in 1986, CRA collected samples from wells bored into garbage. From 1987 on, sampleswere obtained from the leachate collection system of the landfill. The LCHD sampled oneleachate seep in 1987 for general water quality parameters and selected metals. No chemicalswere found that exceeded health guidelines, although ammonia, iron, and chloride were elevated(LCHD, 1988).
In 1983, Woodward Clyde Consultants obtained three sediment samples next to leachate seeps(USEPA, 1984). Only manganese was found to exceed comparison values.
Groundwater - Upper Aquifer Monitoring Wells
Monitoring wells were sampled by Woodward Clyde Consultants for USEPA in 1983-84. CRAsampled the wells for the WTG until 1987. No on-site upper aquifer samples have been takensince 1987 (CRA, 1990).
During this period, a number of metals were detected above applicable comparison values (Table 2). Total metal concentrations were obtained for all samples; dissolved metal concentrationswere also obtained for a few samples. Four inorganics (boron, lead, antimony, and vanadium)were especially common above comparison values.
|Contaminant||Ranges of levels-ppb|
|Ranges of levels-ppb|
|Volatile Organic Chemicals|
|Semivolatile Organic Chemicals|
-- = Not Analyzed
* One Sample, Aroclor-1260; 13 other leachate samples were ND for PCBs.y
|Contaminant||Range oflevels-ppb(1983-1987)||Frequency of detects||ComparisonValues (ppb)|
|*Tetrachloroethylene||ND-26||6/8 (1984) 0/14(1985-91)||CREG=0.7|
ND = Not Detected
Ammonia and sulfate exceeded the LTHA. Two VOCs (benzene and vinyl chloride) exceededcomparison values when detected, and were detected in at least one-third of samples taken. Bis(2-ethylhexyl)phthalate was detected in four of 22 samples taken. Four pesticides weredetected in one of 22 samples, during the 1983 sampling event.
Phthalates and methylene chloride are common laboratory contaminants. Some detects of thesecompounds in different media may be due to laboratory contamination of samples. Some blanksshowed detectable amounts of these compounds, but not all blanks associated with samplesshowing positive detects for these compounds showed detectable readings.
No PCBs were detected in on-site upper aquifer monitoring wells. Chloride, often used as aplume marker for sanitary landfills, was detected in high concentrations on the landfill and northand east of the landfill (Figure 4) (CRA, 1992a).
Groundwater - Lower Aquifer Monitoring Wells
Two samples were taken in the only on-site lower aquifer well, in 1991 and 1992. Metalconcentrations were similar to off-site lower aquifer wells, as were general water qualityparameters. Trace amounts of two phthalates (total 6 ppb) were found in 1991. Chlorideincreased from 110 ppm in 1991 to 150 ppm in 1992. No VOCs were detected. Onlybis(2-ethylhexyl)phthalate slightly exceeded comparison values. This chemical is known to be acommon laboratory contaminant.
Woodward-Clyde Consultants took on-site air samples using sampling pumps and Tenax tubesfor gas chromatography/mass spectrometry (GC/MS) analysis. Samples were taken at vents andalong traverses across the landfill. Twenty-four organic compounds were identified in the air. However, field blanks taken during sampling showed higher concentrations than most of theambient air samples. In addition, it appears that the air was less contaminated downwind of thesite (USEPA, 1984). The report concluded that the landfill did not materially impact air qualityat the site. Because of these and other inconsistencies in the data, these data will not bediscussed further.
In 1988, Weston-Sper took air samples on-site using Summa Tenax cartridges for GC/MSanalysis. Measurements were taken downwind of gas vents and at the leachate collection house,as well as in gas vents. Readings downwind of gas vents, upwind of the site, and at the tankhouse, were all less than or comparable to field or system blank readings. Therefore, theseresults cannot be interpreted and are not reported here. Table 3 shows the range of 11 readingstaken in five gas vents on the landfill (Weston-Sper, 1988). The values for six compoundsgreatly exceeded comparison values; the nine other compounds detected do not have comparison
|Gas Vents||Range of levels-|
|Comparison Values(ppb)||*ACGIH TLV-TWA,|
|Methane (% by volume)||ND-67%||--||Lower explosive|
-- = Not Analyzed
* = American Conference of Governmental Industrial Hygienists: Threshold Limit Value - TimeWeighted Average = the concentration for a normal 8-hour workday and a 40-hour workweek towhich nearly all workers may be repeatedly exposed, day after day, without adverse effect.
values. To evaluate possible site worker exposure, the highest measured concentrations in gasvents were compared to the Threshold Limit Values (TLVs) established by the AmericanConference of Governmental Industrial Hygienists (ACGIH). TLVs are airborne concentrationsof substances which the ACGIH believes nearly all workers may be repeatedly exposed to, dayafter day, without adverse health effects. Most of the measurements inside the gas vents werebelow the TLV/TWA (ACGIH Threshold Limit Value for the workplace - Time WeightedAverage) for the respective gases. Since these readings were taken in gas vents, this indicatesthat exposure to site workers will be negligible because of dilution of these gases after they arereleased into the atmosphere. A USEPA risk assessment based on these data indicated that thereis insignificant to no increased risk of cancer to local residents from these gases. Total exposureof residents to gases from vents and diffusing into the air through the topsoil cannot bedetermined with the information collected thus far. In 1990-91, CRA measured methane fromgas vents and leachate wells, and found concentrations of methane up to 62% by volume (CRA,1991a), which exceeds the lower explosive limit for methane.
In November 1983, Woodward Clyde Consultants collected eight surface water samples off-site,which were sent to the USEPA contract laboratory program for analysis. They were analyzed forinorganics, pesticides, PCBs, VOCs, and semi-volatile organic chemicals (priority pollutantscan). The samples were taken from Mutton Creek (upstream, downstream, and near the site)and two surface ponds about 400 to 600 feet from the site. These surface ponds were found tohave no chemical concentrations above levels of health concern. The downstream Mutton Creeksample had elevated levels of trichloroethylene and three pesticides: dieldrin, heptachlor, andheptachlor epoxide. Trichloroethylene was also present in leachate in higher concentrations andtherefore may have come from the landfill. The pesticides, however, were not found in anyleachate samples from the landfill. These pesticides may have resulted from agricultural activity(USEPA, 1984).
In 1986, CRA sampled surface water samples in Mutton Creek immediately upstream anddownstream of a major leachate seepage point along the north perimeter of the landfill. Traceamounts of three VOCs (total 3.5 ppb) were detected downstream. No pesticides or PCBs weredetected either upstream or downstream (CRA, 1987). In 1987, the LCHD sampled MuttonCreek upstream, adjacent to, and downstream of the landfill during the construction of theleachate collection system after residual leachate overflowed into the creek during theconstruction of this system. Ammonia, sulfate, and boron were found immediately adjacent tothe landfill in concentrations exceeding comparison values; sulfate was found at levels exceedingthese comparison values upstream of the site. The high sulfate level may have been due toresidual leachate that was spilled in the creek during the construction of the leachate collectionsystem (LCHD, 1988) (Table 4). It must be noted that most of the data in Table 4 was collectedbefore leachate seeps were repaired. In 1990, Mutton Creek was monitored by CRA in responseto a leachate release from the collection system. Trace amounts of chloromethane were foundboth upstream and downstream of the site; no other VOCs were detected. Metals were detectedat similar concentrations upstream and downstream. There were no detections of base-neutralextractables, pesticides, or PCBs (CRA, 1990). The LCHD also sampled Mutton Creek in May,1990. There were elevated levels of phosphorus, nitrate, and several other parameters upstreamand in the north tributary that flows into Mutton Creek. This is thought to be due to fertilizer andlivestock practices, since the north tributary flows through agricultural land. None of thesemeasurements, or other measurements during this sampling round, exceeded comparison values. In April 1991, Mutton Creek was sampled in response to a leachate release from a collectionsump, which did not appear to reach the creek. No VOCs were detected, and metals were atsimilar concentrations upstream and downstream of the site (CRA, 1991). No chemicals werefound that exceeded ATSDR comparison values during this sampling round.
|Location of HighestAmount||Contaminant||Range oflevels-ppb(1983-1990)||Comparison Values(ppb)|
|Mutton Creek Adjacent||Boron||58-16,900||EMEG=100|
|Mutton Creek Adjacent||Ammonia||ND->100,000||EMEG=3,000|
|Mutton Creek Adjacent||Sulfate||70,000-772,000||MCL=400,000|
In 1983, Woodward-Clyde Consultants collected seven off-site sediment samples, five fromMutton Creek and two from nearby surface ponds. There were no elevated levels ofcontaminants at the upstream Mutton Creek site. Trace levels of methylene chloride weredetected at all sampling locations, but is a suspected laboratory contaminant. There were nopesticides or PCBs found adjacent or downstream of the site in Mutton Creek. Trace amounts ofacetone and 2-butanone were found immediately downstream of the site (USEPA, 1984). Nocontaminants were found at levels above comparison values.
CRA sampled sediments associated with surface waters in 1986 and found one VOC: toluene(2.8 ppb downstream and 35 ppb adjacent to the landfill), below comparison values. Metals weresimilar upstream and downstream of the landfill. No PCBs were found in sediments (CRA,1987). In March 1990, Mutton Creek sediment samples were collected in response to a leachaterelease from the collection system. No concentrations of VOCs or metals were detected abovecomparison values; there were no detections of pesticides or PCBs (CRA, 1990). CRA sampledMutton Creek sediments again in April 1991 because of a prior leachate release from the leachatecollection system. No VOCs were detected; metal concentrations were again similar upstreamand downstream of the site (CRA, 1991).
|Contaminant||Ranges of levels-ppm(1983-1990)||Comparison Values-normalchild(ppm)|
CRA analyzed soil from two off-site monitoring well boreholes (OW409 and OW410, Figure 5),for metals, VOCs, pesticides, and PCBs in September-October 1986 (CRA, 1987). Depth of thesamples was unspecified, and is assumed to be of subsurface soil, because these are boreholesamples. Metals were similar to normal values found in soils in Illinois (Kelty, 1983). The soilalso has small amounts of chlorinated hydrocarbons (Table 6).
|Contaminant Organics(ug/kg)||Ranges of levels (ppb),1986||ATSDR ComparisonValues normal child(ppb)|
-- = No Comparison Value
Groundwater - Upper Aquifer Monitoring Wells
There were a number of metals present above comparison values. A number of VOCs, pesticidesand semi-volatiles were also present above comparison values. It is not likely that the pesticidescame from the landfill, because none of them were found in any leachate samples. Their origin islikely from nearby agricultural activities.
The distribution of organics, metals, and chloride (a common marker for sanitary landfill plumes)did not show a clear pattern among the wells during the 1990 and 1991 sampling events. WellOW403 (east of the landfill; Figure 3) consistently had the most detects and highestconcentrations for VOCs. However, wells OW412 and OW416, east and much closer to the site,had fewer hits for VOCs. There was no clear pattern as to metals concentrations among differentwells. The wells (OW408, OW407, OW406, and OW413) close to and north or northeast of thelandfill had the highest concentrations of chloride. This is consistent with an expected chlorideplume that would result from the existing north-northeasterly groundwater flow direction in theupper aquifer.
A number of tentatively identified compounds (TICs) were detected in the 1986 sampling roundoff-site in the upper and lower aquifers (CRA 1987). The identity of these needs to be confirmedby GC/MS before the health effects attributable to these can be assessed.
|Contaminant||Ranges oflevels-ppb(1983-1991)||Ranges oflevels-ppb(1992)||Frequency ofdetects(1983-1992)||ComparisonValues (ppb)|
-- = Not Analyzed
--- = No Comparison Value
Groundwater - Lower Aquifer Monitoring Wells
In 1983, one lower aquifer off-site well (134 feet deep) was monitored by Woodward ClydeConsultants (USEPA, 1984). Acetone and 2-butanone (1300 ppb) were detected, the latter wasabove comparison values. Lead was also detected in an unfiltered sample, but an upgradientbackground well sample contained lead at a similar concentration, so this was not deemed to be acontaminant originating from the landfill. Three lower aquifer off-site wells were sampled byCRA in 1986, 1987, 1988, 1990, and 1991. 2-Butanone was detected once in 14 samples duringthis time at 26 ppb, below comparison values. Several metals and VOCs were detected at levelsabove comparison values (Table 8). Different contaminants were found at relatively low levelsat the three off-site wells at different times. There was no apparent pattern to the detects amongthe three wells (CRA, 1990; CRA, 1992a). It therefore cannot be determined from the data givenwhether these contaminants originated from the landfill. No PCBs were detected in loweraquifer samples.
|Contaminant||Ranges oflevels (ppb)(1983-1991)||Ranges oflevels (ppb)1992||Comparison Values(ppb)||Frequency ofdetects1983-1991|
-- = Not Analyzed
--- = No Comparison Value
Groundwater - Residential Wells
Woodward-Clyde Consultants sampled 21 nearby residential wells in 1983. They found one thatwas contaminated with a number of substances above comparison values (203A, Figure 6; Table 9). Two other wells had cadmium levels exceeding the EMEG for cadmium (G213 and G224). Both G203 and G250 had vinyl chloride above comparison values. Both of these wells were nolonger used for residential water after 1984; G203 was subsequently used as an off-sitemonitoring well. In subsequent sampling (1986-91 by CRA), organic compounds were notfrequently detected, and usually at values close to the lower detection limit (CRA, 1992a). TheLCHD also sampled residential wells for water quality parameters and selected metals (M. Kuhnet al., 1986; LCHD, 1988; Olsen et al., 1989, 1990, 1991).
|Contaminant||Range oflevels-ppb(1983-1991)||Range oflevels-ppb1992||Comparison values(ppb)|
|Vinyl chloride *||ND-3.8||ND-1.6||EMEG=0.2|
-- = Not Analyzed
+ = Maximum concentrations found in well G203A in 1983 round one sampling (USEPA,1984). This well also had trace quantities of a number of pesticides and two PCBs. Noconcentrations exceeding comparison values were found for these chemicals after 1983.
* = This was found in two wells in 1983. After 1985, two detects found in two samples, out of33 samples analyzed (2 ppb and 1.6 ppb; CRA, 1990; CRA, 1992b)
** = No readings exceeding comparison values found after 1985 (CRA, 1990 and 1992b).
The number of compounds and the frequency of detections was considerably lower than forupper or lower aquifer off-site monitoring wells (Table 9). Metals results were less variablecompared to monitoring wells since residential wells generally provide less turbid samples. Onlythree metals (antimony, vanadium, and boron) exceeded comparison values in sampling after1984. Vinyl chloride was the only VOC to exceed comparison values after this sampling, and itwas detected once (1989). Contamination of residential wells appears to be minimal from thelandfill except for vanadium, since this element has appeared several times in residential andmonitoring wells and is present at higher concentrations in the leachate. Antimony is presentthroughout the groundwater and leachate, but its level is not elevated in the leachate.
Groundwater - Municipal Wells
The Village of Wauconda has six municipal wells. Well #4, closest to the landfill (about 1000feet southeast) gets its water from a deep (Cambrian-Ordovician) aquifer. The other five wellsare 1 to 1.5 miles from the landfill (southeast to southwest of the site) and are screened in thebedrock aquifer. In 1988-89, all six wells were tested for VOCs as well as general water qualityparameters. No VOCs were detected except toluene at one well (1.5 ppb) and chloroform at twowells (0.8 and 2 ppb). They were all below comparison values. There were no VOCs detected atwell #4, the closest to the landfill. It is very unlikely that the landfill will impact the municipalwells screened in the bedrock aquifer because of their distance from the landfill, and because theupper aquifer flows in a north-northeasterly direction, away from these wells. Also, well #4 willnot likely be affected because it is in a deeper aquifer and is not in the direction of flow fromeither aquifer.
In preparing this health assessment, the IDPH relied on the information provided in thereferenced documents and assumed that adequate quality assurance and quality control measureswere followed with respect to chain-of-custody, laboratory procedures, and data reporting. Sampling in 1983 through January 1985 was conducted by USEPA using their own qualityassurance procedures. March and May 1985 sampling was conducted according to a qualityassurance project plan (QAPP) written by CRA that was not reviewed by USEPA. Samplingfrom September 1986 through April 1991 was done according to a QAPP written by CRA andapproved by USEPA. The CRA 1986 and August-December 1991 sampling was done accordingto a revised QAPP (CRA, 1991b), which was also approved by USEPA. The validity of theanalyses and conclusions drawn for this health assessment is determined by the completeness andreliability of the referenced information.
At the time of this health assessment, site access was restricted by a chain link fence surroundingthe whole site, with a locked gate at the northeast corner for vehicle access to the leachatecollection tank area. The gap observed underneath the fence during the February 29, 1992 sitevisit has since been repaired. The only physical hazards on-site were the steep terrain of thesouthwest corner of the landfill. The area immediately southwest of the landfill is an off-sitedemolition dumping area with unrestricted access. Piles of large pipes, culverts, and otherconstruction materials present a physical hazard to children or others trespassing in this area. Methane gas buildup, resulting in a potential for fire and explosion, occurs at some sanitarylandfills. In 1988, USEPA took soil gas samples around the landfill and found this not to be ofsignificant concern.
Since the reporting of toxic chemical releases began in 1987, the USEPA has collectedinformation on estimated annual releases of toxic chemicals by industry to the environment (air,water, land, or underground injection). These data are compiled and are retrievable through theon-line database, Toxic Chemical Release Inventory (TRI). The reporting years of 1987 to 1992are currently available for review.
These TRI records were reviewed for reporting industries in the vicinity of the site. Noindustries near the site (Village of Wauconda, zip code 60084 or within a one mile radius of thesite) reported releases of chemicals to the environment.
To determine whether nearby residents are exposed to contaminants migrating from the site,IDPH evaluated the environmental and human components that lead to human exposure. Thispathways analysis consists of five elements: source of contamination, transport through anenvironmental medium, a point of exposure, a route of human exposure, and an exposedpopulation.
Exposure pathways are identified as completed, potential, or eliminated. Completed pathwaysrequire that the five elements exist and indicate that exposure to a contaminant has occurred inthe past, is currently occurring, or will occur in the future. Potential pathways, however, requirethat at least one of the five elements is missing, but could exist. Potential pathways indicate thatexposure to a contaminant could have occurred in the past, could be occurring now, or couldoccur in the future. Eliminated pathways require that at least one of the five elements is missingand will never be present.
One completed pathway has been identified at this site to date: groundwater contamination oftwo residential wells prior to 1984. These wells were not used after 1984 for residentialpurposes.
Nearby Well Users/Groundwater (Upper Aquifer) Pathway
The groundwater pathway is complete for wells for two residences that had elevated levels ofseveral contaminants in 1983-4, including vinyl chloride and benzene (3.8 ppb and 4.6 ppb,respectively) (Table 9). Residential use was discontinued for these wells after 1984. Since thesewells are located 200-300 feet east and downgradient of the landfill and were tapped into theupper aquifer, they are likely to get some contamination from the landfill. Upper aquifergroundwater, which flows in a north-northeasterly direction, has shown a consistent pattern ofelevated chloride in monitoring wells 1000 feet east-northeast of the landfill (Well OW414,Figure 4), and almost as far north of the landfill. Scattered detects of VOCs and elevated levelsof some metals have also occurred in off-site monitoring wells in this area. Since there is noclear gradient of these compounds as distance increases from the landfill, it is unclear whetherthe chemicals originated there. Residents living in the houses serviced by these wells were likelyexposed to these chemicals in water via ingestion (drinking water), skin contact (washing handsand showering), and inhalation (as a result of the chemicals volatilizing into the air duringshowers and general water use). Presently, two other wells tapped into the upper aquifer arecurrently being used as residential wells, about 1600 feet northwest of the landfill. Six otherwells (of the approximately 35 located within 1/4 mile of the landfill) are of unknown depth, andtherefore could be tapped into the upper aquifer. There is potential for residents using shallowaquifer wells north or northeast of the landfill to be exposed to a number of different chemicalsthat have been detected in off-site upper aquifer groundwater.
Nearby Well Users/Groundwater (Lower Aquifer) Pathway
There are about 35 residential wells located within 1/4 mile of the landfill. All but eight areknown to be screened in the lower aquifer. The lower aquifer has had scattered readings ofelevated levels of some contaminants (Table 8). This groundwater flows southwest (Figure 5) atan average velocity of 72 feet/year (CRA, 1992a). Occurrence of chemicals at the three off-sitelower aquifer wells do not show the expected pattern related to the landfill, since the two wellsthat were upgradient had higher readings for more chemicals than the one downgradient off-sitewell and one down-gradient on-site well (Figure 5). A clay aquitard lies between the upper andlower aquifer. It separates the upper and lower aquifer throughout the vicinity of the landfillexcept for an area north of the landfill (around well OW418, Figure 3), where the upper andlower aquifers are interconnected. This is attributed to glacial erosion of the clay layer andappears to be local to this well. Soil data from neighboring wells (OW415 and OW419) foundthis clay aquitard to be present. The east-west extent of this interconnection is estimated to be550 feet (CRA, 1992a). Except for this area, groundwater flow from the upper aquifer to thelower aquifer is supposedly retarded by the aquitard. However, the observed pattern of chemical"hits" in the lower aquitard may be the result of upper aquifer water seeping through the aquitardinto the lower aquifer. If that were the case, then the people living in houses served by wellstapped into the lower aquifer could potentially be exposed via ingestion (drinking), skin contact(e.g. dish washing, taking showers), and inhalation (volatilization of organic compounds duringshowers). The potential receptor population in this case is 30-35 families living near the landfill.
Nearby Houses/Dust Pathway
Exposure of nearby residents or businesses to windblown dust is another potential path of humanexposure. Before the cap was put on the landfill, there were areas of uncovered garbage. Thiswas a potential pathway of human exposure to contaminants from the landfill via inhalation ofdust particles. However, since the cap was installed, garbage has been covered and the cap wellcovered with grass and other vegetation. This makes windblown dispersal of contaminated fillfrom the landfill extremely unlikely in the present or future, though it may have occurred in thepast.
Nearby Houses/Landfill Gases Pathway
Past, current, and future exposure pathways are possible from contamination of ambient air bythe landfill. This may occur from on-site vents or from gases escaping from buried garbagedirectly through the topsoil on the landfill. Measurements have been taken in on-site vents(Table 3), but the volume of gases escaping from them or directly through the topsoil of thelandfill is unknown. Nearby homes downwind of the landfill are the likely point of exposure tolandfill gases in ambient air. Exposure to gases, if occurring, would be through inhalation. Thereceptor population are the families living in houses downwind of the landfill, primarily to theeast of the landfill. It is not known how many people, if any, may be affected because theamount of gases escaping is unknown. The USEPA monitored ambient air in 1988, as did theWTG in 1993. Both air evaluations indicated no adverse health risk to nearby residents fromlandfill gas and found this potential pathway to be unlikely.
Subsurface migration of gases from the landfill to the basements of nearby homes is anotherpotential pathway. This has been documented at many landfills, with loss of life due to fire andexplosion. The potentially affected people are the residents of nearby houses and businesses. The potential routes of exposure for this pathway are inhalation and heat transfer (fire orexplosion). In 1988, USEPA conducted soil gas sampling and next to the landfill and found thispotential pathway also to be unlikely.
Recreational Waters/Users Pathway
In the past, leachate from the landfill has on occasion flowed into Mutton Creek along thesurface of the ground. There also existed the possibility of leachate flowing through an erodedravine on the north side of the landfill into Mutton Creek. However, no persistent contaminationof either surface water or sediment downstream of the landfill have been indicated (Tables 4 and5). Receptor populations may have been exposed through dermal exposure (such as the possibleplaying of kids in Mutton Creek). It is not known how big these receptor populations were, butthey probably involved very few people. Present and future via this pathway is not likelybecause the present operation of a leachate collection system, inspections, and control. Theeroded ravine, mentioned previously, has been rebuilt as Swale #1 and was designed to preventleachate migration.
Site Workers/Trespassers Pathway
It is possible for workers or trespassers to inhale landfill gases coming from vents on-site or upthrough the topsoil while they are present at the landfill. It is also possible for workers ortrespassers to have skin contact with soil or surface water on-site. In the past, leachate seepswere another source of contamination available for skin contact or inhalation of vaporized gasesfrom the leachate. This pathway is unlikely to be completed now or in the future because (1)there is a security fence around the site; (2) site workers at Superfund sites are trained in use ofappropriate protective clothing; (3) gas concentration in ambient air have not been measuredabove background, and is therefore probably very low except in the immediate vicinity of the gasvents.
This section discusses the available data about the chemicals that are in human exposurepathways at the Wauconda landfill. There is often little information about the health effectscaused by low level environmental exposure. Most human exposure studies use informationfrom industrial exposures, where the doses are much higher than exposure to contaminants fromthe Wauconda landfill. Industrial exposure data normally do not include precise informationabout the dose, the purity of the chemicals, their interactions with other substances, and theduration of the exposure. With these limitations, human exposure data will be used in thefollowing toxicology section. Although animals do not necessarily have the same responses thathumans show when exposed to toxic substances, animal experiments can be conducted undercarefully controlled dosages and time periods. Accordingly, when human information isunavailable or limited, pertinent animal data will be incorporated into this section. Chemicalsconsidered in this section were found in residential wells or were often detected in lower aquiferoff-site monitoring wells, the main source for drinking water for private wells near the landfill.
I. Volatile Organic Chemicals (VOCs)
Benzene has been detected in leachate, on- and off-site groundwater, and residential wells (in1983 sampling only) above comparison values. Benzene is a known human carcinogen;leukemia is associated with long-term benzene exposure. The maximum reading for a residentialwell was 4.6 ppb (obtained in 1983, and not detected since in any residential wells). A persondrinking water with this level of benzene over a 70 year lifetime would experience no apparentincreased risk of contracting cancer. Long-term exposure to benzene at higher levels can alsodisrupt normal blood production and cause a decrease in important blood components.
b. Methylene Chloride
Methylene chloride was detected in off-site lower aquifer wells at concentrations of up to 50 ppb. It has been shown to cause liver and lung cancer in laboratory animals, but there is little or nodata indicating that it does likewise in humans. Therefore, it is suspected, but not known, to be ahuman carcinogen. The highest concentration measured would pose no apparent increased riskof cancer if one drinks water with the highest concentration found every day for a lifetime of 70years. Animals exposed to methylene chloride in food or water at much higher concentrationsexperienced changes in liver function.
Trichloroethylene (TCE) has been detected in off-site lower aquifer monitoring wells at levelsabout twice the USEPA Maximum Contaminant Limit (MCL) of 5 ppb. The maximum leveldetected would not exceed ATSDR's intermediate oral Minimal Risk Level (MRL) whichindicates that noncarcinogenic health effects are unlikely to occur at the that level of TCE foundin the lower aquifer. Animal studies of intermediate length (14 to 365 days) with much higherlevels of TCE have shown some liver toxicity; long-term animal studies with very high levelshave also shown some kidney toxicity. At that same TCE concentration, exposure would poseno apparent increase in cancer risk.
d. Vinyl Chloride
Vinyl chloride has been detected at low levels (up to 10 ppb) in off-site groundwater, in tworesidential wells in 1983 (subsequently not used), and once after that (of 28 samples collected) inother residential wells. The highest concentration found in any residential well was 3.8 ppb. Itwas also detected inside a landfill vent as gas, slightly above the American Conference ofGovernmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) of 5,000 ppb. Vinyl chloride is a known human carcinogen. This has been determined through studies of vinylchloride workers exposed to much higher levels than present in groundwater or ambient air nearthe landfill. Long-term cancer studies have shown vinyl chloride to cause liver tumors in ratsand mice. A level of 3.8 ppb in groundwater, the highest reading obtained there, would result ina low increased risk of contracting liver cancer, if one drank water from the residential well withthe highest concentration over a lifetime of 70 years. Exposure estimates based on the highestlevel found in groundwater exceeds ATSDR's chronic oral MRL for children and adults. TheMRL for vinyl chloride is based on the lowest-observed-adverse-effect level of 0.018 mg/kg/day,which caused an increase in certain types of cellular nuclei in animals. At slightly higher doses,animals have been shown to experience increased blood coagulation and an increase in bloodcollagen.
II. Semi-Volatile Organic Chemicals
This compound was found above comparison values only in residential wells during the 1983sampling round. It has not been found since in any groundwater, residential well, or leachatesamples. Therefore, the "detection" of this compound may have been an artifact resulting frompoor laboratory technique in 1983. This compound can cause liver cancer in mice, so it may alsobe able to cause it in people. Exposure to 7 ppb, which was the highest level detected inresidential wells, would result in a moderate increase in the risk of cancer, roughly twice the riskexperienced from drinking from a municipal water supply. However, this risk estimate is veryconservative, and the actual risk is much lower, since the chemical has not been detected in anymedia after 1983.
b. Bis(2-ethylhexyl) phthalate (DEHP)
DEHP has been detected in leachate and off-site monitoring wells, and also occasionally at lowlevels (up to 7 ppb) in residential wells. The average intake of DEHP from water supplies in theU.S. is 0.02 mg/day. Assuming that an average person drinks two liters of water a day, thismeans that people, on the average, get an equivalent dose that would be obtained from drinkingwater that contains 10 ppb of DEHP, if DEHP was not ingested at all from food. This chemicalis known to be a carcinogen in animals, but there is inadequate evidence or no evidence ofcarcinogenicity in humans. The maximum concentration found in residential wells would posean insignificant or no increased risk of contracting cancer from exposure to DEHP at this level. Long-term exposure of animals to much higher levels of DEHP has resulted in structural andfunctional changes in the kidney, similar to those seen in the kidneys of long-term dialysispatients.
III. Inorganic Chemicals
This metal has been detected in leachate, groundwater (on- and off-site) and in residential wells. Maximum concentrations found have been similar among all these media. It is thereforequestionable whether the landfill is the source of antimony in the area. It has been detected inresidential wells at levels (up to 58 ppb) which is 20 times the USEPA Lifetime Health Advisory(LTHA). It is not known what effects, if any, that antimony exposure at these levels has onhumans or animals. Rats that drank a much higher level, 2000 ppb, for 600 days, died soonerthan rats not exposed. Humans who drank 19000 ppb of antimony, once, vomited.
Boron has been detected in leachate, groundwater (on- and off-site) and in residential wells at theWauconda landfill. In residential wells, it has been found at levels up to 1,340 ppb, which isslightly more than twice the U.S. EPA's Lifetime Health Advisory (LTHA) of 600 ppb. It is notknown what effects, if any, that long-term exposure to boron at these levels can cause. The onlyinformation available on long-term exposure to boron by the oral route is the following: rats thatwere given water with 880,000 ppb of boron for 70 days experienced changes in sperm count. Boron sometimes occurs naturally in groundwater at levels of up to 5,000 ppb.
Cadmium has been detected in leachate and in groundwater (both on- and off-site). In 1983,cadmium was found in three of 21 samples taken from residential wells, at levels up to 8 ppb. Ithas not been detected in residential wells since then. Two of the three wells where cadmium hadbeen detected were taken out of service. Exposure to this concentration is four times the chronicoral MRL for cadmium. There is no information on what health effects, if any, result fromdrinking water with this level of cadmium for a long period of time. Eating or drinking higherlevels of cadmium over a long time can lead to a buildup of cadmium in the kidneys. Thiscauses kidney damage, and also causes bones to become fragile and break easily. Animals thateat or drink high levels of cadmium sometimes get high blood pressure, iron poor blood, liverdisease, and nerve or brain damage.
Chromium has been detected in leachate and groundwater above comparison values. The highestobserved reading for off-site lower aquifer monitoring wells is 71 ppb. Exposure to thisconcentration exceeds the USEPA chronic oral RfD for the hexavalent (VI) oxidative state ofchromium, which is the most toxic. In fact, total chromium was measured, of which only a partis the (VI) form; the other common form is the trivalent (III) oxidative state, which is believed tobe an essential nutrient. Therefore, there are unlikely to be any health effects associated withexposure to chromium, even at the highest level found in the lower aquifer. Ingestion of muchhigher amounts can result in stomach upsets, ulcers, and kidney and liver damage.
Lead has been detected in leachate, on- and off-site groundwater, and once above comparisonvalues in a residential well (in 1983; 153 ppb) near the Wauconda landfill. Lead is considered tobe a no-threshold toxin, which means that it is considered toxic at any level. The most sensitivepopulation for lead exposure is the developing fetus and young children up to 6 years of age. The most detrimental effects are on the developing nervous system, which can result inbehavioral effects, learning problems, and decreased IQ at low doses. Lead is also detrimental tothe hematopoietic, cardiovascular, kidney, and immune systems. Health effects from leadtoxicity from wells around the landfill is slight because 38 of 40 readings since 1983 have beenbelow the Illinois Groundwater Standard of 7.5 g/L. These two readings were found in twodifferent wells at different times, and are judged to be isolated occurrences.
Vanadium has been frequently detected in leachate, groundwater (both on- and off-site),residential wells, and once in the Wauconda municipal water supply, at concentrations exceedingcomparison values. Since it appears to be ubiquitous in all these media and is not moreconcentrated in leachate, it does not appear to originate from the landfill. Vanadium has beendetected in residential wells at up to 39 ppb, which is twice the USEPA Lifetime HealthAdvisory of 20 ppb. There is no information on what health effects, if any, exposure tovanadium at these levels may cause. Small amounts of vanadium normally occur in food andwater. Most of this is poorly absorbed by the digestive tract. Animals that drink water with highlevels of vanadium did not have an excess of tumors, but some minor birth defects occurred inthe fetuses of female rats fed vanadium in water when they were pregnant. It is not known ifthese birth defects would occur in people. Minor effects on the kidney were seen in rats afterexposure to high levels of vanadium for three months. Humans given 0.47 to 1.3 mgvanadium/kg body weight (the equivalent of 16,450 to 45,000 ppb of vanadium in water,assuming a daily intake of two liters per day and a body weight of 70 kilograms) did not showany altered kidney parameters.
Zinc has been detected in leachate, off-site monitoring wells, and in residential wells (1983sampling only) at levels exceeding comparison values. It was not detected in on-site upperaquifer monitoring wells. In residential wells, the highest reading was 7,140 ppb in one well in1983, which is almost four times the USEPA Lifetime Health Advisory (LTHA). After 1983,there were no readings exceeding the LTHA. There is no data on what health effects thatlong-term exposure to this level of zinc in drinking water may cause, if any. Zinc is a naturalmineral in many drinking waters, and average zinc intake in the diet ranges from 7-16 mg perday. Zinc is an essential nutrient, with a Recommended Daily Allowance (RDA) of 15 mg perday, and it is in many mineral supplements. If one obtained all of the RDA from water and dranktwo liters per day, the water would contain 7,500 ppb of zinc. Therefore, it is unlikely that anyhealth effects would result from drinking water that had levels contained in the residential wellwith the highest concentration. If large doses of zinc (10 to 15 times the RDA) are ingested for ashort time, stomach and digestive problems may occur.
Cancer Incidence data
The Division of Epidemiologic Studies of the Illinois Department of Public Health compared theobserved number of cancer cases for the two zip codes nearest to the Wauconda landfill(Wauconda 60084 and Island Lake 60042) to the expected number of cancer cases. The expectednumber of cases is based on the cancer rate in a population similar in size and age distribution tothese two zip codes.
In the 1985 to 1987 time period, 174 cases were observed (expected number 102). A statisticallysignificant excess was identified in the age group 45 to 74 in both zip codes. In zip code 60042,this excess was attributable to males with lung or bladder cancer and to females with liver(hepatocellular carcinoma) or breast cancer. In zip code 60084, the increase was attributable tomales with bladder cancer and females with cancer of the oral cavity.
None of these cancers has been shown to be associated with environmental exposure tochemicals detected at the landfill. Lung cancer is the leading form of cancer in the United States. Cigarette smoking may contribute to at least 80% of lung cancers in males. The remainingincidence may be due to occupational exposure by inhalation of asbestos, radon, mustard gas,polycyclic aromatic hydrocarbons, and other chemicals. Cigarette smoking also increases aperson's risk of bladder cancer, as does occupational exposure to benzidine, 2-napthylamine andother aromatic amines used in dyestuffs. Rubber workers and tire makers have also exhibited anexcess of bladder cancer; excessive use of analgesic drugs containing phenacetin has also beenshown to increase risk. Eight of the 10 bladder cancer cases had a prior history of smoking; onehad an occupational history with potential exposure to materials known to cause bladder cancer.
Breast cancer is associated with increasing age, family history of breast cancer, and a number ofother factors. No scientific evidence exists between any environmental exposure and risk forbreast cancer. Liver cancer is linked with cirrhosis (linked with excessive alcohol consumption). Angiosarcoma is a rare type of primary liver cancer linked to workplace exposure to vinylchloride. Low levels of vinyl chloride were found in groundwater at the site and off-site. However, the one case of liver cancer found was hepatocellular carcinoma, not angiosarcoma. Known risk factors for cancer of the oral cavity include tobacco use, alcohol use, and nutritionaldeficiencies (iron and vitamins). Of the four female cases of cancer of the oral cavity, one usedalcohol, one did not, and two had unknown histories of alcohol and tobacco use.
We have addressed each of the community concerns about health as follows:
- Will food grown on land fertilized with sewage sludge from Village of Wauconda withlandfill leachate be harmful to health if eaten?
The disposal site for sewage sludge has been permitted by IEPA (as per communication withVillage of Wauconda officials). IEPA will monitor soil concentrations of metals. Of particularconcern is cadmium, which is known to bioconcentrate in the food chain. Barium is also knownto bioaccumulate in plants. Vanadium may bioaccumulate in some root crops; lead is also takenup by some plants, particularly leafy green vegetables. It is recommended that soils at thereceiving site be tested before sludge is added and periodically thereafter, to determine if anymetal buildup is occurring.
- Some toxic chemicals might be overlooked in the annual survey of residential wells.
Continued monitoring of off-site monitoring wells is planned, and should detect pollutants beforethey reach residential wells. There is an extensive database on the area around the site now, andit is very unlikely that new chemicals will appear that have not been detected already.
- Monitoring wells might not be placed correctly to detect progress of contaminants intothe lower aquifer.
Wells have been placed in both Upper and Lower Aquifers to monitor water quality. Monitoringhas not shown the migration of a VOC plume into the Lower Aquifer. The present wells monitorthe groundwater in the interconnection area between the Upper and Lower Aquifers andupgradient of the interconnection area. Adding more monitoring wells would likely onlygenerate redundant data.
- The gate was sometimes left open at the landfill.
This situation was part of the operating procedure of the landfill. The operating procedurespecified that an attendant be present when the gate was left open.
- There seems to be an elevated cancer rate in the area, and there is also concern about theincidence of other diseases.
The IDPH conducted a cancer incidence study of the two zip codes adjacent to the Waucondasite which has been discussed under the Health Outcome Data Evaluation section of this healthassessment. There was an elevated level of cancer found. However, there is no evidence that thetypes of cancer encountered are linked to environmental contamination.
- The leachate collection system may be collecting only a small portion of the leachateactually being generated at the landfill.
The intent of the system was not to collect all leachate generated at the landfill. Rather, it wasdesigned to keep leachate from flowing into Mutton Creek. An upgrade of the cap of the landfillwill reduce the amount of leachate that is formed due to precipitation. The groundwater aroundthe site will continue to be monitored.
- There was concern about the low number of borings on the landfill and the possibilitythat contaminants not detected yet might leach into the groundwater.
The purpose of the long term monitoring program that will continue to operate is to determine ifthis happens in the future. If it does, contaminants should be detected in the monitoring wellsclose to the landfill before they reach residential wells.
- There is concern that Bangs Lake, Mutton Creek, Island Lake, and Creek Marsh arebeing contaminated with heavy metals from the landfill.
Bangs Lake is not in the watershed that receives water draining from the landfill area. Samplingof surface water and sediments at Mutton Creek has not shown a buildup of heavy metals orother contaminants. Island Lake is even less likely to be affected because it is three milesdownstream of the landfill.
- There is concern about vinyl chloride found beyond the perimeter of the landfill.
There have been minor excursions above the MCL in off-site monitoring wells. The long termsampling program will continue to monitor this. There were no detects of vinyl chloride inresidential wells in 1991.
- What measures are being taken to protect the public health of local well owners?
Off-site monitoring wells will continue to be monitored. Most wells are screened to the loweraquifer, which has shown negligible contamination form the landfill. Selected residential wellsare also monitored. If a problem is seen, the USEPA Record of Decision specifies that analternate water supply will be provided.
- Concern was raised that the clay cap might fail, and that cracks were developing in thecap.
A cap upgrade was completed in 1992.
- Concern was raised about air quality, particularly vinyl chloride emissions.
No detectable concentrations of any contaminants were found on-site at the landfill, except in thegas vents themselves. Gas concentrations are expected to be reduced even further as one movesoff-site.
- There is concern that gas generated by the landfill might travel to basements ofneighboring residences.
USEPA found, through soil gas measurements, that this is unlikely to occur now. Passive gasvents were installed on the landfill as part of the cap upgrade completed in 1992.
- There is concern that the groundwater plume will reach a residential area currentlybeing developed about one-half mile northeast of the landfill.
A plume from the landfill could theoretically reach this subdivision in 90 years, given an averageupper aquifer groundwater speed of 28 feet per year. As the plume spreads, additional dilution isexpected to occur, as well as other attenuation and degradation of chemicals. The long termmonitoring program will track this situation. A consistent gradient of hazardous substances hasnot been observed emanating from the landfill. Instead, at wells downgradient of the landfill,there have been some readings that are above comparison values. Non-detects are often obtainedat the same well during the next sampling round.
- There is concern about the health effects of exposure to a small water retention areacollecting surface water from the southwest corner of the landfill.
It is unlikely that this pond will be a health hazard. Water running off the clay cap of the landfillinto this pond will not filter through garbage, and therefore is unlikely to contain elevated levelsof chemicals from the landfill.