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PUBLIC HEALTH ASSESSMENT

REFUSE HIDEAWAY
MIDDLETON, DANE COUNTY, WISCONSIN


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

This section of the health assessment describes how "chemicals of concern" are distributed in soil, sediment, water, and biota in and near the site. "Chemicals of Concern" are those that occur above a level where the maximum plausible exposure to the contaminated material might affect human health. This assessment addresses only those contaminants that the authors judge to be present at levels of concern. For carcinogenic chemicals, a level of health concern refers to a concentration where a lifetime of exposure to the most contaminated material might result in a upper-level estimated risk of more than one cancer for every one million people exposed. Levels of concern are listed as "health comparison values" in Tables 2 through 7. These values frequently differ from regulatory standards or health advisory levels. Subsequent sections of this health assessment discuss whether chemicals of concern do pose a significant threat to public health. A summary of media sampling appears in Table 1.



Table 1.

Summary of Media Sampling Refuse Hideaway Landfill Middleton, Dane County, Wisconsin

Media Date Sampler Location Parameters

Leachate 1988 RMT53 a VOC, Inorganics, Indicators
Surface Water 1988
1989
RMT53
DNR33
b

b

VOC, Indicators
VOC, Inorganics
Groundwater 1987
1988
1989
1990 & 91
DNR14
RMT53
DNR33
Hydro-Search46
b
b
b
b
VOC, Inorganics, Indicators
VOC, Indicators
VOC
VOC
Private Wells 1986
1988
1988
1989
1989 & 90
1990
1991
1992
1993
DNR19,20
RMT53
DNR23,21
DNR33,24,25
Warzyn64 DNR28,31
DNR32,35
DNR39,38
Hellenbrand44
c
c
c
c
c
c
c
c
c
VOC
VOC
VOC, Inorganics, Indicators
VOC
VOC
VOC
VOC, Inorganics
VOC, Inorganics
VOC

Sampling a-On-Site
Locations b-Off-Site
c - Private Wells

Definitions Indicators: A minimum of pH, Conductivity, Alkalinity, Hardness, Dissolved Solids, and certain inorganic compounds.
Inorganics: Inorganic chemicals including heavy metals (lead, chromium, cadmium, etc).
VOC: Volatile Organic Compounds

A. On-Site Contamination

Landfill Gas

    On-site landfill gas samples were analyzed for constituent VOCs as part of planning and designing a gas extraction system to control migration of gas away from the landfill [67] [49]. The results of this testing are presented in Table 7.

Refuse/Waste

    Refuse Hideaway Landfill received approximately 1.2 million cubic yards of municipal, commercial and industrial waste. The landfill owner reported receipt of hazardous substances including barrels of printing "ink and ink washes from a local newspaper and printing companies, barrels of glue and paint, spray paint booth by-products, paint stripper sludge, and spill residues containing methylene chloride, acetone" and other solvents.



Table 2.

MOn-Site Leachate Sampling Results 1987 & 1988 Refuse Hideaway Landfill Dane County, Wisconsin

Compound Well LH-1 Well LH-2
8/88
(µg/L)
9/88
(µg/L)
8/88
(µg/L)
12/87
(µg/L)

Benzene 5 56 25 11
1,2-Dichloroethylene 2 5 ND 2
Tetrachloroethylene (PCE) ND ND ND ND
Toluene 43 99 280 210
Trichloroethylene (TCE) ND ND ND 5
Vinyl Chloride 8 45 ND 3

Source: RMT, Inc. Remedial Action Report for Refuse Hideaway Landfill, Middleton, Wisconsin. November, 1988, Tables 7-6 & 7-7.
ND - Not Detected in the sample.

Leachate

    Samples were collected from two of the on-site leachate wells (LH-1 and LH-2) in 1987 and 1988, and analyzed for VOCs and inorganic compounds. The results of this testing appear in Table 2. These samples revealed the presence of a number of VOCs (Table 2) [53, TABLES 7-6 & 7-7]. Both leachate wells are less than 60 feet deep, and are screened in waste material situated above the water table [53, TABLE 4-5]. There are no groundwater monitoring wells within the waste boundaries.

Other media

    On-site media sampling was restricted to refuse, landfill gas and leachate. On-site soils and ambient air were not sampled as they are not expected to currently contain contaminants because a clay cap was applied to the site in 1988 and a gas extraction system was installed in 1991. The cap and gas extraction system prevents landfill wastes gases from surfacing on the site.



Table 3.

Off-Site Groundwater Monitoring Results Collected from Shallow Wells Refuse Hideaway Landfill Town of Middleton, Dane County, Wisconsin

Compound June 1987 August 1987  
Minimum
Detected
(µg/L)
Maximum
Detected
(µg/L)
Frequency
of
Detection
Minimum
Detected
(µg/L)
Maximum
Detected
(µg/L)
Frequency
of
Detection
Comparison
Value
(µg/L)

Benzene 10* 24* 4/8 0 5 2/6 1.2 a
1,2-Dichloroethylene 8 600* 6/8 19 620* 3/6 70 b
Tetrachloroethylene (PCE) 34* 530* 7/8 2* 340* 6/6 1 a
Trichloroethylene (TCE) 4* 180* 6/8 2 140* 5/6 3.2 a
Toluene 1 3 3/8 1 2 2/6 343 d
Vinyl Chloride 1* 130* 8/8 20* 200* 3/8 0.7 c

On landfill property, but wells located outside of boundaries of waste/refuse.
* Exceeds Comparison Value.

a Oral Cancer Risk Evaluation Guideline for 1x10-6 excess cancer risk.
b U.S. EPA's Adult LTHA (Lifetime Health Advisory).
c ATSDR's Chronic Oral EMEG (Environmental Media Evaluation Guideline) for an adult.
d Wisconsin Public Health Groundwater Quality Enforcement Standard.

Source: Creative Resource Ventures, Ltd. Infield Conditions Report on Refuse Hideaway Land. Table 6-3. January 14, 1988.

B. Off-Site Contamination

Groundwater - Monitoring Wells

Groundwater around the site was first found to be contaminated in 1987. These results appear in Table 3. A report issued in January 1988 suggested nearby groundwater contained contamination that could be coming from the site [14]. The November 1988 Remedial Action Report also concluded Refuse Hideaway Landfill as the probable source of contamination found in the nearby private wells. This conclusion was made, in part, because the extent of groundwater contamination around the site was much greater than previously suspected. Samples were collected from 15 off-site groundwater monitoring well clusters and analyzed for VOCs and inorganic compounds. The results of this 1988 investigation for chemicals of potential health concern are shown in Table 3.

This report suggested an excessive build-up of leachate at the landfill was the primary mechanism for contaminant movement from the site and into groundwater. Monitoring wells with the highest VOC concentrations (P-8, P-9, and P-21) located on the landfill property along the south boundary of the Superfund site [46, p1-2]. For each well the water table was no more than ten feet below the surface [53, TABLE 7-2].

Table 4.

Off-Site Groundwater Monitoring of Shallow Monitoring Wells December 1990 and January 1991 Refuse Hideaway Landfill Town of Middleton, Dane County, Wisconsin

Compound On Landfill Propertya Off Landfill Propertya  
Minimum
Detected
(µg/L)
Maximum
Detected
(µg/L)
Frequency
of
Detection
Minimum
Detected
(µg/L)
Maximum
Detected
(µg/L)
Frequency
of
Detection
Comparison
Value
(µg/L)

1,2-Dichloroethylene 3 32 3/9 - - 0/16 70 c
Tetrachloroethylene (PCE) 3* 16* 5/9 2* 114* 5/16 1 b
Trichloroethylene (TCE) 7* 28* 4/9 2 12* 3/16 3.2 d
Vinyl Chloride 6* 525* 5/9 - 10* 1/16 0.7 d

* Level detected exceeds Comparison Value.

a. Monitoring wells located either off or on the Landfill property, but not on the Superfund Site. No monitoring wells are located on the Superfund Site.
b. Oral Cancer Risk Evaluation Guideline for 1x10-6 excess cancer risk.
c. U.S. EPA's Adult LTHA (Lifetime Health Advisory).
d. ATSDR's Chronic Oral EMEG (Environmental Media Evaluation Guideline) for an adult.

Source: Hydro-Search, Inc. Groundwater Monitoring Study at the Refuse Hideaway Landfill, Middleton, Wisconsin. Table 5-16. Brookfield, Wisconsin: June 24, 1991.

A groundwater investigation was conducted in 1990 and 1991 to determine the extent of off-site groundwater contamination around Refuse Hideaway [46]. This investigation discovered no other private wells showing contamination from the site. During the investigation an additional 27 monitoring wells were installed, increasing the number of monitoring wells around the site to 54. VOC contamination was found in 29 of the 54 monitoring wells, and these results are shown in Table 5. The groundwater investigation reported contaminated groundwater has spread radially at least 1,500 feet around the site [46, p5-18].

This investigation also examined the stratification of groundwater contamination. During drilling of ten monitoring wells, groundwater samples were collected at regular intervals. These samples were analyzed for VOCs. In one well (P-40), VOC contamination was detected in samples collected from 50 to 250 feet. The VOCs detected in this well included tetrachloroethylene and trichloroethylene [46, p5-11].

Table 5.

Groundwater Monitoring of Off-Site Deep WellsaDecember 1990 to January 1991 Refuse Hideaway Landfill Town of Middleton, Dane County, Wisconsin

Compound On Landfill Propertya Off Landfill Propertya  
Minimum
Detected
(µg/L)
Maximum
Detected
(µg/L)
Frequency
of
Detection
Minimum
Detected
(µg/L)
Maximum
Detected
(µg/L)
Frequency
of
Detection
Comparison
Value
(µg/L)

Benzene 1 7* 3/6 - - 0/15 1.2 b
cis 1,2-Dichloroethylene 1 13 2/6 - 1 1/15 70 c
Tetrachloroethylene (PCE) - 3* 1/6 6* 99* 5/15 1 b
Trichloroethylene (TCE) 0 10* 1/6 2 11* 4/15 3.2 b
Toluene 1 7 2/6 1 58 5/15 343 e
Vinyl Chloride 14* 32* 3/6 2* 50* 2/15 0.2 d

* Level detected exceeds Comparison Value.

a. Monitoring wells may be located on the Landfill property, but not on the Superfund Site.
b. Oral Cancer Risk Evaluation Guideline for 1x10-6 excess cancer risk.
c. U.S. EPA's Adult LTHA (Lifetime Health Advisory).
d. ATSDR's Chronic Oral EMEG (Environmental Media Evaluation Guideline).
e. Wisconsin's Public Health Groundwater Quality Enforcement Standard.

Source: Hydro Search, Inc. Groundwater Monitoring Study at the Refuse Hideaway Landfill, Middleton, Wisconsin. Table 5-16. Brookfield, Wisconsin: June 24, 1991.

The 1991 groundwater investigation provided a good characterization of the leading edge of the contaminant plume. The report described the edge of the plume as 3,800 feet southwest from the site. The leading edge of the plume is within the upper 250 feet of the aquifer [46, p7-2]. Figure 2 depicts the approximate boundary of the plume. The three contaminated private wells are found within the southeastern lobe of the plume, and the plume is traveling toward the Deer Run Heights neighborhood. The principle plume constituents described in the 1991 investigation include 1,2-dichloroethylene, tetrachloroethylene, and trichloroethylene [46, TABLE 5-16].

Groundwater - Private Wells

One nearby private well (PW-2) was first sampled for VOCs in July 1986 and no contamination was found. When seven nearby private wells were again sampled in January 1988, VOC contamination was detected in water collected from the PW-1. In February and March 1988 the DNR found three nearby private wells with VOC contamination. Table 6 summarizes the history of contaminant levels in the three private wells. DNR has regularly tested well water samples collected from selected private wells in the vicinity of the site. Private well samples were only tested for VOCs. Other than the three wells there have been no additional private wells near the site showing signs of contamination from the site.

In March 1988, two VOCs were discovered at very low levels in a private well located 1,000 directly south of the site. The two detected trihalomethanes, which were not at levels of health concern, were attributed by the DNR to the chlorine water treatment system installed at the house [22]. However, the owner reported the treatment system was not in operation when the two water samples were collected. The source of contamination is probably not site-related because trihalomethanes have not been detected in any groundwater monitoring wells on or around the site. Furthermore, monitoring wells in the vicinity of the house suggest the contaminant plume is currently to the north and does not threaten this private well. Therefore, the source of this contamination is not known. No other contamination has been found in this private well, which has been tested five other times [43].

The DNR performed inorganic analysis on samples collected from two contaminated private wells (PW-1 & PW-2) in June 1989 [33, TABLE 5]. The DNR also collected one unfiltered sample from one private well (PW-2) in December 1992 [55]. No inorganic chemicals have been detected in these wells at a level of potential health concern. No other private wells have been analyzed for inorganic chemicals. All private wells have not been analyzed for SVOCs, pesticides, or specific organic compounds with a high molecular weight. This represents a potential data gap. The sampling plan of the remedial investigation proposes to test selected private wells around the site for VOCs, SVOCs, inorganic chemicals, pesticides, and specific organic compounds of a high molecular weight (such as PCBs).


Table 6.

Private Well Contamination Selected Samples Collected from March 1988 to August 1993 Refuse Hideaway Landfill Dane County, Wisconsin All Concentrations in µg/L

Private Well Location
and
Chemical Detected
1/88 2/88 3/88 9/88 3/89 9/89 2/90 10/90a 4/91a 10/91a 6/92a 8/93a Comparison Value
(µg/L)

PW-1 (7734 Highway 14)  
cis-1,2-Dichloroethylene 28d 47d 32 33 36 26 27 - 15 16 18 NT 70b
Tetrachloroethylene (PCE) 24* 28* 26* 21* 24* 14* 18* 14* 8* 9* 8* NT 1c
Trichloroethylene (TCE) 8* 8* 9* 9* 10* 8* 8* 5* 4* 5* 4* NT 3.2c
Vinyl Chloride 4* 6* - - - - - - - - - NT 0.7e
PW-2 (7750 Highway 14)  
cis-1,2-Dichloroethylene NT 21d 30 12 12 9 8 - 5 6 5 7 70b
Tetrachloroethylene (PCE) NT 31* 27* 22* 19* 14* 17* 19* 10* 12* 12* 15* 1c
Trichloroethylene (TCE) NT 4 8* 5* 4* 2 3 2 2 2 2 2 3.2c
Vinyl Chloride NT 6* 2* - - - - - - - - - 0.7e
PW-3 (7755 Highway 14)  
cis-1,2-Dichloroethylene NT NT 2 - - - (Testing of well was discontinued)   70b
Tetrachloroethylene (PCE) NT NT 3* - - 1*   1c

* Exceeds or matches Comparison Value.
NT Well Not Tested

a. Point-Of-Entry filtration system in operation and samples drawn from unfiltered water.
b. U.S. EPA's Drinking Water Lifetime Health Advisory
c. Oral Cancer Risk Evaluation Guideline for 1x10-6 excess cancer risk.
d. The results reported are for the "trans" isomer of 1,2-dichloroethylene.
e. ATSDR's Chronic Oral EMEG (Environmental Media Evaluation Guideline) for an adult.

Surface Water

Surface water samples were collected in December 1987 from three off-site points from the drainage way flowing east along the southern edge of the landfill property. A surface water sample was also collected from the off-site catchment basin that receives runoff from the central portion of the site. It is important to note these water samples were collected from the drainage way and sediment basin when it was frozen over.

Contamination was only found in a water sample collected from the catchment basin. The basin was drained and dredged in the fall of 1992. This contamination included 1,2-dichloroethylene (11 µg/L) [53, p7-32]. These concentrations were likely higher than those expected during spring, summer, or fall because frozen conditions would probably restrict volatilization of contaminants. None of contaminants are at levels of potential health concern.

It is unclear whether the contamination found in this basin is from the site. The catchment basin receives runoff not only from the site, but also from the sand and gravel company's staging area, which is immediately east of the site. Maintenance and repairs of heavy equipment and machinery are done in a garage at the sand and gravel business and could contribute to, or be the sole source of, VOCs detected in these surface water samples.

Indoor Air of a Nearby Building

Gas was detected at explosive levels in a building used by the gravel business, which is on the landfill property and immediately east of the site (refer to page 18 for a discussion of this physical hazard). No gas samples were collected for analysis from the building, which represents a data gap. However, landfill gas samples from the site were analyzed for VOC constituents. The gas detected in this building may have contained similar types and levels of contaminants as found in the on-site landfill gas samples. The estimated levels of these contaminants are in Table 7. See page 27 for the possible health effects from these potential chemical exposures.

Other media

Off-site sampling has been restricted to groundwater and surface water from the run-off catchment basin. Samples have not been collected for soil, air, and biota.

C. Toxic Chemical Release Inventory

A Toxic Chemical Release Inventory (TRI) search was conducted by the Division of Health for the Village of Cross Plains and the City of Middleton zip codes (53528 and 53562 respectively). The TRI is searched to investigate any other sources of the same type of environmental contamination as found on the Superfund site. Certain manufacturers are required to report to the U.S. EPA of releases to the environment of over 300 hazardous chemicals. This reported information is entered into the automated TRI system. There were no reports in the TRI of the release of hazardous substances also found at the site for the Village of Cross Plains and the City of Middleton zip codes.

D. Quality Assurance and Quality Control

The Wisconsin Division of Health assumes the DNR and contractors fully met standard sampling protocol, unless stated otherwise, including those cited as appendices in referenced reports. These quality assurance and quality control measures were to be followed during the field sampling and measurements, the chain of custody activities, laboratory analytical procedures, and data reporting. The ability of the Division of Health to make valid conclusions depends on the amount and quality of data provided.

Table 7.

VOC Concentrations of Landfill Gas On-Site Landfill Gas and Estimated Indoor Air of Adjacent Building Refuse Hideaway Landfill Town of Middleton, Dane County, Wisconsin All Values in Parts Per Billion

Compound Highest Level Detected in On-Site Gas
(ppb)
Estimated
Level
in Building
(ppb)
Non-Cancer
Comparison Values
(ppb)

Benzene 2,000 11* 2a
1,2-Dichloroethylene ND n/a n/a
Tetrachloroethylene (PCE) 26,000 142 600a
Toluene 26,000 142 300a
Trichloroethylene (TCE) 23,000 125 n/a
Vinyl Chloride 61,000 320* 2i

* Exceeds Non-Cancer Comparison Value.
ND- Not Detected.
a- ATSDR's acute (<30 days) Environmental Media Evaluation Guideline.
i- ATSDR's intermediate (31 - 365 days) Environmental Media Evaluation Guideline.
s- Threshold Limit Value - Short Term Exposure Limit maximum occupational exposure for 15 minutes.

Sources: Warzyn Engineering, Inc. Gas and Leachate Extraction System. Refuse Hideaway Landfill, Town of Middleton, Dane County, Wisconsin. Engineering Design 13928.48. Prepared for the Wisconsin DNR. Madison, Wisconsin: Warzyn, August 1990.

Mostardi-Platt Associates, Inc. Landfill Gas System Destruction Efficiency Tests. A Gaseous Study Performed for Warzyn Engineering, Inc. Refuse Hideaway landfill. Middleton, Wisconsin. Bensenville, Illinois: Mostardi-Platt: September 30, 1991.

E. Physical and Other Hazards

Landfill Gas

Landfill gas generated at Refuse Hideaway Landfill is a potential explosive hazard to persons living and/or working in buildings found near the site. In 1989, landfill gas was found in soil outside of the site perimeter [65, p2]. Monitoring throughout 1990 did not reveal landfill gas in nearby homes, though it was detected in a commercial building adjacent to the site [61, p4] [68].

Landfill gas has been detected at elevated levels in Refuse Hideaway Landfill and is reported to have a high potential for migrating away from the site in the ground [65, p4]. Methane, a primary constituent of landfill gas, is generated from the anaerobic decomposition of organic waste material found at the site. The fractured dolomite bedrock found under the site provides a permeable pathway for landfill gas to move away from the site [65, p6]. Landfill gas could then flow into nearby buildings and homes and accumulate in these structures up to an explosive level. A spark from a furnace, water heater, or other mechanical source could ignite the gas.

In 1990, gas was detected three times at high levels (once at 80% and twice at 100% of the Lower Explosive Limit) in a commercial building located east of the site, but on the landfill property. These explosive levels were found around the base of a toilet in an office of the sand and gravel business. It is possible the septic holding tank was the source of a portion or all of the gas detected in the building, as suggested by the owner/operator of the sand and gravel business [41]. This hazardous situation was corrected when cracks in the floor of the restroom were filled with grout, thus halting the infiltration of gas into the building [68]. Since this time explosive gas has not been detected in this building as a monitoring system continues to operate. When gas was detected in the building it was recommended the business proprietor adequately ventilate the building and place signs on the building warning of the explosive hazard. These temporary measures were recommended until the installation and operation of a gas extraction system, which was expected to reduce the levels of off-site landfill gas [65, p6 & Appendix B].

The gas detected in this building was not tested for constituent chemicals, which is a potential data gap as VOC contamination found in on-site landfill gas samples were at elevated levels. Only landfill gas samples from the site were analyzed for any hazardous constituents. If landfill gas were coming into this building, it could contain chemicals, such as benzene or vinyl chloride, which could pose a health hazard to people even if gas concentrations occurred below 100 percent of the Lower Explosive Level (refer to page 21 for a discussion of this potential pathway). Any future gas samples collected from nearby buildings should be analyzed for constituent chemicals.

A combination landfill gas and leachate extraction system was installed at the site on July 1991 to reduce landfill gas migration away from the site [27]. The extraction system has significantly reduced or eliminated off-site migration of landfill gas.

PATHWAYS ANALYSES

There are several ways people are exposed to contamination from a site. This section of the health assessment describes how people may become exposed to site-related contaminants.

A "Completed Exposure Pathway" are those pathways where there are clear indications people were exposed to contaminants from the site and when there is sufficient information to evaluate such an exposure. All five of the pathway elements must exist for there to be a "Completed Exposure Pathway" (a description of these five elements is found in Appendix D). This considers exposures likely occurred in the past and these exposures are currently occurring. A "Potential Completed Pathway" is when there is insufficient information to link a contaminant or chemical to a known level of exposure among an identified population. A "Potential Completed Pathway" refers to when an exposure may have occurred in the past, is probably occurring, or may occur in the future. An exposure pathway can be eliminated from consideration if at least one of the five elements is missing and will never be present.

A. Completed Human Exposure Pathways

Past: Groundwater - Private Wells

    An estimated eight people living in three households southwest of the site apparently were exposed to contaminated groundwater. Additionally, three employees at the seed business probably were exposed to contaminated groundwater during their working hours. The exposure routes from the domestic use of contaminated groundwater includes ingestion, inhalation, and dermal absorption.

    Once contamination of these private wells was found, actions were taken to reduce and eliminate human exposure to contaminants. A supply of bottled drinking water was provided to the three households and business in early 1988. However, contaminated water was still being used for other domestic purposes. In October 1988 representatives of the Wisconsin Division of Health (DOH) advised these people of methods to reduce their inhalation and dermal exposure to contaminants.

    To halt all exposures to contaminated groundwater the DNR installed a carbon-activated filtration system in July 1989 at two of these homes (the third home was no longer occupied) [62, p1-3]. Initially all contamination was removed, but post-filter sampling later found this filtration system was beginning to fail [26]. This system was replaced by the DNR in May 1990 with a POE (Point-of-Entry) water filtration system [29].

    Subsequent monitoring has shown the POE system effectively removes all detectable VOCs. VOCs are still being found in unfiltered water. The POE treatment systems have become permanent water systems for these homes [36]. The household sharing the well with the business (PW-3) was eventually vacated by the tenant in late 1989, and the owner did not rent out the home. One employee at the business (7755 Highway 14) stated the well is no longer used. The DNR continues to provide bottled water to the business.

    This health assessment assumes people living in these households were exposed to contaminated groundwater for no more than four years. When private well contamination was first found in January 1988 these residents probably were not exposed to contaminated well water for more than two years. A water sample collected in July 1986 from one private well west of the site (PW-2) which did not reveal signs of contamination [19]. Despite a bottled water supply and efforts to reduce dermal and inhalation exposure, it was not until May 1990, four years later, the installed filtration system was shown to be removing all detectable contaminants from their water.

    The assumption that people who lived in nearby households with contaminated groundwater, and were exposed for no more than four years, is based on a single August 1986 water sample collected from one well (PW-2) that showed no contamination. This water sample was collected by the DNR. While one water sample may not completely depict VOC contamination of an aquifer, there is no information which suggests this water sample was improperly collected and analyzed, nor is evidence available that shows contamination was present prior to the sampling date. Therefore, the authors interpret This sample as accurate in showing VOC contamination was not present in these private wells at levels above the method detection limits before August 1986.

    As stated under Quality Assurance and Quality Control (page 17), the Division of Health expects all groundwater samples collected and tested fully met standard sampling protocols, unless otherwise stated. The ability to make valid conclusions depends on the quality of data provided.

B. Potential Human Exposure Pathways

Future: Groundwater - Private Wells

    Contaminated groundwater coming from the site has not been detected in other nearby private wells. DNR is conducting an ongoing program to monitor the movement of the contaminant plume. Selected private wells in the Deer Run Heights neighborhood are sampled every six months. This monitoring program will alert the DNR to any changes in the location of groundwater contamination and provide advance warning of potential threats to nearby residents.

    If the site was not cleaned-up and the contaminant plume continued moving away from the site, contaminated groundwater might reach Deer Run Heights neighborhood at sometime in the future. This represents a future potential pathway. Deer Run Heights neighborhood is approximately one mile west-southwest of the site and is in the apparent path of the contaminant plume, which is less than 1,300 feet from the nearest home. There are an estimated 80 people living in 25 homes in this neighborhood.

    In March 1992 the DNR received a report from a contractor which used a mathematical model to analyze and predict future movement of the contaminant plume. This study was conducted, in part, to evaluate the possibility of the plume reaching residential areas in the vicinity of the site. Using conservative assumptions (low degradation, low dispersion, no source remediation and other variables) one scenario predicted a low level of tetrachloroethylene (1 µg/L) might be detected in those Deer Run Heights homes closest to the site in as little five years. However, the report states such information is not conclusive because of "inherent uncertainties in model input parameters" [47].

Past: On-Site Waste

    When the landfill was operational, people who regularly went on the site and came in contact with waste material may have been exposed to hazardous substances. However it is difficult to estimate and evaluate such potential exposures because many details of are unavailable. No data were collected about ambient air quality, the constituents of surface leachate, nor the quality of surface water runoff.

    It is not known if workers at Refuse Hideaway were exposed to any hazardous substances at levels that exceeded levels established by the U.S. Occupational Safety and Health Administration (OSHA). Consequently, it is difficult to estimate the types and levels of contaminants these individuals may have been exposed to. Workers may have inhaled or come in contact with hazardous materials as a normal part of receiving and handling waste.

    There are reports of nearby residents who frequently went onto the site to inspect the landfill and retrieve samples of waste. When these residents came onto the site, they may have received an exposure similar to workers. In 1991, a 71 year-old resident, who regularly went on the site, died of adenocarcinoma of the pancreas. Contaminated groundwater from the site has not reached the private well at this person's home. The many unknowns make it difficult to attribute this cancer to potential exposures received during site visits. Furthermore, there may have been non-site related factors that predisposed this individual to cancer.

Past: Indoor Air of a Nearby Building

    People who worked in a building adjacent to the landfill may have breathed air containing site-related VOCs, but no air sampling data are available. Consequently, this represents a data gap. Estimates of indoor air contaminant concentrations can be made only by making several assumptions.

    On three occasions in 1990 gas was detected at explosive or near explosive levels around the base of a toilet in this nearby building, which is used by a sand and gravel business (see page 18). Though this gas is suspected of originating from the landfill, part or all of the gas found around the toilet could have come from the septic holding tank, which is less than 6 feet away and connected to the toilet.

    While the gas entering the building was tested for a potential to explode, samples were not collected and tested for chemical analysis. Gas samples collected from the landfill were analyzed and showed elevated levels of a number of VOCs. Gas found in the building may also have contained a similar mixture of VOCs as the gas found in the landfill. Gas entering the building may have contained as much as 15 percent methane by volume, while methane levels in gas from the landfill were measured at 55 percent by volume [49] [67]. Any landfill gas entering the building would quickly mix with the air, diluting the levels of VOCs and methane. Consequently, any VOCs present in the gas detected in the building the concentrations were probably lower than the levels measured in on-site landfill gas.

    The lack of data on gas constituents make it difficult to draw conclusions about a potential worker exposure without relying on a number of assumptions. A potential exposure for workers, presented in Table 7, can be estimated by assuming: 1) all gas entering the building originated entirely from the landfill; 2) the gas had a VOC mixture similar to that measured in landfill gas; 3) VOC concentrations in the gas entering the building was 15/55ths of that measured in gas samples taken from the landfill; 4) once landfill gas entered the building the levels of VOCs and methane would be diluted by air in the building such that air containing an average of two percent landfill gas by volume; 6) workers were in the building for no more than eight hours per day; 7) and landfill gas was present in the building for a period no longer than 30 working days.


PUBLIC HEALTH IMPLICATIONS

A. Toxicological Evaluation

The chemicals in groundwater of potential health concern at Refuse Hideaway Landfill include cis-1,2-dichloroethylene, tetrachloroethylene, trichloroethylene, and vinyl chloride (Table 6). Chemicals of potential health concern in indoor air include benzene, tetrachloroethylene, toluene, trichloroethylene, and vinyl chloride.

Groundwater

    cis-1,2-Dichloroethylene (DCE)

    People apparently were exposed to groundwater contaminated with cis-1,2-dichloroethylene (DCE) at three homes and one private business near Refuse Hideaway Landfill. These people probably ingested DCE when drinking contaminated water, inhaled DCE vapors released from domestic use of contaminated water, and absorbed DCE through their skin while bathing in contaminated water. DCE continues to be present in unfiltered water samples collected from two of these homes (PW-1 & PW-2), but the installation of the POE filters removes the all measurable levels of contaminants from the water.

    People living in the homes and working at the seed business probably were exposed to DCE for no more than four years. The highest detected levels of DCE were found in private wells during 1988 and 1989, and were 36 µg/L (PW-1), 30 µg/L (PW-2), and 2 µg/L (PW-3).

    Past exposure to cis-1,2-dichloroethylene is not likely to affect the health of people who live in nearby homes with contaminated well water. The highest level of DCE found in a private well (36 µg/L) is not known to be detrimental to human or animal health [6] [59]. Refer to Appendix E for supporting information.

    If Refuse Hideaway Landfill were not cleaned-up the higher levels of DCE-contaminated groundwater could move away from the site and possibly increase DCE contamination in found in the unfiltered water of private wells or reach other private wells that are not currently contaminated. One shallow monitoring well on the landfill property and adjacent to the site (P-8), had DCE levels over 600 µg/L (Table 3). It is unknown how a person's health would be affected if they were exposed long-term to 300 µg/L of DCE in drinking water (assuming there was a 50 percent dispersion and degradation of the 600 µg/L concentration). There is a little information about the possible health effects from a chronic exposure to such low levels of DCE.

    Tetrachloroethylene (PCE)

    People living in three households and working at the private business near the site evidently were exposed to groundwater contaminated with tetrachloroethylene (PCE). These people probably ingested PCE when drinking contaminated water, inhaled PCE vapors released from the domestic use of contaminated water, and absorbed PCE through their skin while bathing in contaminated water.

    Tetrachloroethylene was detected in the three private wells at the highest levels during March 1988: 26 µg/L (PW-1), 24 µg/L (PW-2), and 3 µg/L (PW-3). PCE continues to be present in unfiltered water samples collected from two of these homes (PW-1 & PW-2), but POE filtration system, installed in May 1990, removes all measurable levels of PCE. People living in these households and working at the seed business were probably not exposed to contaminated well water for more than four years.

    Past exposure to tetrachloroethylene in well water poses "no apparent increased cancer risk" to people who used water from contaminated wells. The highest level of PCE detected in a private well (26 µg/L) is not expected to cause any other adverse health effects.

    EPA formerly categorized PCE as probable human carcinogen, but this classification is currently being re-evaluated. The Department of Health and Social Services indicates PCE may reasonably be anticipated to be a carcinogen because it causes cancer in laboratory animals. Assuming PCE is a carcinogen a person would have "no apparent increased risk" of cancer if they were exposed for four years to drinking water contaminated with PCE at a level of 26 µg/l. Some studies have suggested a potential relationship between exposure to PCE and some forms of cancer, but these human and laboratory animal studies are inconclusive [8, p60]. There is no conclusive evidence that shows PCE causes cancer in humans. Laboratory mice have shown increases in liver cancer when exposed to much higher levels of PCE than what was found at the site (386 mg/kg/day or the drinking water equivalent of 13,510 µµg/L) [8, p28]. See Appendix E for supporting information.

    If the site were not cleaned-up PCE-contaminated groundwater could reach residential wells farther away from the site. One shallow monitoring well on the landfill property and adjacent to the site (P-8), had a PCE concentration of 530 µg/L. Taking this hypothetical situation one step further and assuming PCE is a carcinogen (as previously classified by the U.S. EPA), a person exposed to one-half of this concentration of PCE (265 µg/L) for thirty years, they would have a moderate increased cancer risk. Refer to Appendix E for supporting information.

    Certain individuals are suspected of being more susceptible to adverse health effects from a PCE exposure than most people. The reasons for a person's increased susceptibility may include genetic makeup, age or developmental stage, health and nutritional status, and a history of previous chemical exposures. A PCE exposure might have a greater affect on an individual with a chronic liver or kidney function problems. Children or unborn babies may be particularly susceptible to the toxic effects of PCE [8, p56]. There are no known non-cancer health effects people would experience if they were exposed to 265 µg/L (half of this concentration assuming a 50 percent dispersion and degradation of the 530 µg/L concentration in P-8).

    Trichloroethylene (TCE)

    People living in two nearby households were probably exposed to drinking water contaminated with trichloroethylene (TCE). These people probably ingested TCE when drinking contaminated water, inhaled TCE vapors released from domestic use of contaminated water, and absorbed TCE through their skin while bathing in contaminated water.

    The highest levels of trichloroethylene found in the private wells levels were 8 µg/L (PW-2) and 10 µg/L (PW-1), which was during 1988 & 1989. TCE continues to be present in unfiltered water samples collected at two of the homes, but a POE filter system installed in May 1990 removes all measurable levels of TCE. It is estimated people in these households probably were exposed to TCE for no more than four years.

    Past exposure to TCE in private well water around the site poses "no apparent increased cancer risk" to people who used water from the contaminated wells. The highest level of TCE detected in a private well (10 µg/L) is not known to have any adverse, non-cancer health effects.

    The EPA formerly categorized trichloroethylene as probable human carcinogen, but this classification is currently being re-evaluated. There is no definitive evidence that shows TCE causes cancer in humans, but some studies suggest higher concentrations of chemical may cause cancer in laboratory animals. An increase in liver cancer was found in laboratory mice when exposed to a high level of TCE (the drinking water equivalent of 35,000 mg/L), but the results are not conclusive [7, p27]. If it is assumed TCE is a carcinogen, as previously defined, a person would have no increased risk of cancer if they were exposed for four years to drinking water contaminated with TCE at a level of 10µg/L. Refer to Appendix E for supporting information.

    Some people are more susceptible to adverse health effects from TCE exposure than most of the population. People who drink alcohol or are treated with disulfiram (Antabuse), may have problems with excreting TCE. The presence of alcohol and/or disulfiram limits the effectiveness of the liver and inhibits the removal of TCE and its by-products. The net effect could be a lengthening of TCE exposure by a delay of its removal from the body. Individuals who smoke may increase their risk of gene damage with an exposure to TCE [7, p58].

    If the site was not cleaned-up higher levels of TCE-contaminated groundwater might migrate away from the site and possibly increase TCE contamination found in private wells or reach currently uncontaminated private wells. The highest level of TCE detected in groundwater was 180 µg/L (Table 2), which was sampled from a monitoring well located on the landfill property, but not on the site. Taking this hypothetical situation one step further and assuming TCE is a carcinogen, a person exposed to 90 µg/L of TCE for thirty years (assuming there was a 50 percent dispersion and degradation of the 180 µg/L concentration) would have a low increased risk of cancer. There are no other known adverse health effects people would experience if they were exposed to such a TCE concentration in their domestic water supply. Refer to Appendix E for supporting information.

    Vinyl Chloride

    People were evidently exposed to groundwater contaminated with vinyl chloride at two homes near Refuse Hideaway Landfill. These people may have ingested vinyl chloride when drinking contaminated water, inhaled vinyl chloride vapors released from domestic use of contaminated water, and absorbed vinyl chloride through their skin while bathing in contaminated water. Vinyl chloride was reported to be found in these two wells only in early 1988. The highest vinyl chloride concentration found in each private well was 6 µg/L (February 1988). Vinyl chloride was not detected again in any private well samples, although other VOCs continued to be found.

    It is assumed vinyl chloride was not present in well water for more than two years. This two-year exposure to vinyl chloride in private well water poses "no apparent increased cancer risk" to people who used water from the contaminated wells. (Refer to Appendix E for supporting information). Also, exposure to such a level of vinyl chloride in drinking water for two years is not known to cause any adverse, non-cancer health effects.

    Most of what is known about how vinyl chloride affects human health is from studies of people exposed in the workplace. Such occupational exposures to vinyl chloride are well above that seen in these private wells. Vinyl chloride is identified as a known human carcinogen because people who inhaled very high concentrations in the workplace and over a number of years were shown to have a significantly increased risk of developing liver cancer [10].

    If the site were not cleaned-up groundwater contaminated with vinyl chloride could move away from the site and possibly reach residential wells farther away from the site. One shallow monitoring well on the landfill property and adjacent to the site (P-21), had a vinyl chloride concentration of 525 µg/L. A person exposed to one-half of this concentration of vinyl chloride (263 µg/L) for thirty years, they would have a "high increased cancer risk." Refer to Appendix E for supporting information.

Indoor Air

The indoor air of a building used by the nearby sand and gravel business may have contained volatile organic compounds. If VOCs were present, people who worked in the building may have breathed these contaminants. We do not know if this indoor air contained VOCs because indoor air was not tested for contaminants, which represents a data gap (see page 21). An estimate of worker exposure can be made only by relying on a number of assumptions. Consequently, it is difficult to evaluate the validity of these estimated levels. However, using these assumptions workers are not expected to experience adverse health effects because they were probably exposed to relatively low levels of contaminants for no more than 30 working days.

    Benzene

    Workers at the business adjacent to the landfill may have breathed the air inside of a building that contained benzene. The highest estimated benzene concentration in the air was calculated at 55 ppb (parts per billion)(Table 7). We assume workers were not exposed for a period longer than 30 days. Though this is above the protective comparison value of 2 ppb, no adverse health effects are expected from such an exposure [4].

    Tetrachloroethylene (PCE)

    People who worked at the sand and gravel business next to the landfill and breathed air inside of one building may have inhaled tetrachloroethylene. These workers probably were not exposed to PCE for longer than 30 days. The highest estimated level of PCE in indoor air was 760 ppb, which is above the comparison value of 600 ppb. However, no adverse health effects are expected from such an exposure to PCE for a 30-day period [7].

    Toluene

    Workers at the business operating possibly breathed indoor air for no more than 30 working days which contained toluene. The highest level of toluene in this air was calculated to be 709 ppb, which is above the comparison value of 300 ppb. Yet, there is no evidence the health of people or laboratory animals are adversely affected by such a level of toluene [9].

    Trichloroethylene (TCE)

    People who worked in a building at the sand and gravel business may have breathed air containing trichloroethylene (TCE). It is estimated the highest level of TCE in the indoor air of the building was 627 ppb, and TCE was present in this air for no more than 30 working days. There are no expected human health effects from this exposure [7].

    Vinyl Chloride

    People who worked at the nearby building may have breathed indoor air that was contaminated with vinyl chloride. Vinyl chloride in air of the building was estimated to have reached a level as high as 1,600 ppb, or 1.6 ppm (parts per million), which is above the comparison value of 2 ppb. This value is based on a laboratory study of rats which had an intermediate inhalation exposure (for 6 hours per day over six months) to 10 ppm of vinyl chloride [10]. We do not expect the health of workers to be adversely affected from a vinyl chloride exposure at 1,600 ppb for thirty days.

B. Health Outcome Data Evaluation

A review of health outcome data is appropriate when there is evidence of people who have been exposed to contaminants at levels that might plausibly lead to an increase in rates of death or illness. "Health Outcome Data" refers to records of death and/or illness. A review of health outcome data might also be appropriate if there are reports of unusual clusters or higher-than-expected levels of specific diseases or illness near a site, or due to a specific community health concern.

A single individual who lived in a nearby house with contaminated groundwater (PW-2) was diagnosed in 1990 with basal cell carcinoma, a form of skin cancer. The Division of Health has not received additional reports of this cancer type among people living near Refuse Hideaway Landfill who may have been exposed to contaminants from the site. See page 30 for further discussion of this community health concern.

The Division of Health received reports of three cases of prostate cancer among males living within three miles of the site. One of these cancers occurred in an individual who lived in one of the households that was later found to have a contaminated well. Refer to page 31 for a discussion of this community health concern.

The estimated levels of exposure to contaminants from the landfill are not expected to affect people's health. Therefore, further analysis of health outcome data is not appropriate. This conclusion is based on existing data from the investigations on and around Refuse Hideaway Landfill and current information on diseases caused by contaminants detected at the site. Such a study may be desirable if additional data become available showing that people living around Refuse Hideaway Landfill were exposed to a much higher level of contaminants than has been shown.

C. Community Health Concerns Evaluation

  • When we hear about how chemicals in groundwater might affect our health we are only told about the adverse health effects from an individual chemical. What are the health effects a person might have when they are exposed to combinations of chemicals detected in the private wells around Refuse Hideaway?

    People who drink groundwater contaminated from a nearby hazardous waste site usually have simultaneous exposures to a number of chemicals. There is limited information available about how each of one these chemicals can affect human health. Even less is known about how pairs or combinations of these chemicals might produce a more powerful adverse health effect than is expected from simply adding the individual known health effects. An amplified health effect from two or more chemicals is called synergy. Synergism is when two or more substances cause an effect that is greater than what is expected from adding the effects of the individual substances.

    Certain combinations of chemicals are known to have a synergistic effect on human health, but no such combinations of these substances have been found in groundwater or contaminated private wells near Refuse Hideaway. The contaminants detected in groundwater, at levels exceeding the Wisconsin Groundwater Enforcement Standard, include benzene, tetrachloroethylene (PCE), trichloroethylene (TCE), and vinyl chloride. Groundwater carrying these contaminants is moving to the southwest and away from the site. The contaminants 1,2-dichloroethylene, PCE, TCE, and vinyl chloride have been found in nearby private wells and are chemicals of concern.

    Human and laboratory animal studies have suggested some contaminants found at the site may interact with each other or with other chemicals. Consumption of alcoholic beverages can reduce how quickly the body excretes TCE and vinyl chloride. The presence of other VOCs may suppress the removal of TCE from the body [10] [7].

    Some people may be unusually susceptible to an exposure from trichloroethylene or tetrachloroethylene. Refer to the toxicological evaluation of PCE and TCE for a discussion of these unusual susceptibilities.

  • How often should people living near the site test their wells, particularly private wells that are not in the plume and have not shown any contamination?

    The DNR is conducting regular private well sampling of selected homes in the Deer Run Heights neighborhood, which is evidently in the path of the contaminant plume. The ongoing testing of groundwater collected from monitoring wells around the site should show if contamination is moving toward any other nearby homes.

  • What impact will the health assessment have on the remedial investigation and the clean-up process?

    A health assessment evaluates how a Superfund site may be affecting the health of people living near the site. In preparing the health assessment, the Division of Health can make recommendations that could affect the remedial investigation and/or the clean-up process. The Division of Health could recommend more information be collected if the remedial investigation is not adequate to evaluate how people are affected by the site. The Division of Health could also recommend an additional clean-up action be undertaken if those being considered for a Superfund site do not adequately protect public health.

  • An individual who lived in a home with contaminated water was recently diagnosed with skin cancer (basal cell carcinoma). Was this cancer caused from exposure to contaminated groundwater coming from the site?

    It is very difficult to show a single episode or cluster of cancer was caused by an exposure to a known cancer-causing substance. People who have a long-term or lifetime exposure to the specific chemicals found in two private wells may have an increased cancer risk. Because residents of the households with contaminated water were probably exposed to these chemicals for no more than four years, these residents are expected to have no apparent increased risk of contracting cancer.

    There is no information suggesting any of the VOC contaminants found in groundwater may cause basal cell carcinoma. A literature search did not reveal any information about a potential relationship between basal cell carcinoma and any of the eight contaminants detected in groundwater known or suspected to cause cancers (benzene, 1,2-dichloroethane, 1,1-dichloroethylene, 1,2-dichloropropane, methylene chloride, tetrachloroethylene, trichloroethylene, and vinyl chloride). Please note only four of these contaminants were found in water samples collected from nearby private wells.

    Non-melanoma skin cancers are the most common forms of cancers found in the fair-skinned population of the United States [50, p11]. State cancer registries, including the Wisconsin Cancer Reporting System, do not collect information from hospitals and health care providers about occurrences of non-melanoma skin cancers. Therefore, the incidence of basal cell carcinoma in Wisconsin must be calculated based on national studies and census information. An estimated 500,000 new cases of non-melanoma skin cancers occur in the U.S. each year, of which 80 percent are basal cell carcinoma. Extrapolating this, an estimated 6,400 cases of basal cell carcinoma occur annually in Wisconsin [50], with approximately 150 cases diagnosed in people 24 to 35 years old (the age group of the diagnosed individual). Most cases of skin cancer are thought to be sun-related. People who work with coal tar, pitch, creosote, or radium are also thought to have an increased risk of skin cancer [2].

    There is strong evidence that people ingesting low levels of inorganic arsenic may have an increased risk of skin cancer [3, p50]. Arsenic is classified as a known human carcinogen by the U.S. EPA and the U.S. Public Health Service [58] [3, p65]. A very low level of arsenic was found in one groundwater monitoring on the landfill property, but it was below the Wisconsin Groundwater Enforcement Standard of 50 µg/L [53, TABLE 7-9]. Arsenic was not detected in water samples collected in June 1989 from two private wells, including the well where the individual with this cancer lived [33, TABLE 5]. Results of water testing also in December 1992 and May 1993, from the private well at this home, did not show a detectable level of arsenic [55].

  • A number of nearby residents expressed concerns about illnesses in their families, though most acknowledged no obvious ways their family was exposed to contamination from the site .

    Extensive sampling has shown groundwater is the only significant pathway that transports contaminants away from the site. Among all of the private wells near Refuse Hideaway only three private wells are known to be contaminated. It is unlikely nearby residents came in contact with contaminants by other pathways, unless they came onto the site or worked at the sand and gravel business, where they may have inhaled landfill gas. There are no other pathways which are shown to transport contaminants away from the site.

  • The Division of Health received reports of three cases of prostate cancer among males living within three miles of the site. One of these cancers occurred in an individual who lived in one of the households that was later found to have contaminated well water. Would someone exposed to contamination from the site have an increased risk of prostate cancer? Is there an elevated number of prostate cancers in the vicinity of the site?

    Prostate cancer is receiving increased attention by the American public. Each year the number of prostate cancer cases steadily grows. Prostate cancer is the second most common cancer in men and an estimated one in eleven men will develop prostate cancer at sometime in their life [2].

    A number of factors are suspected of increasing a person's risk of prostate cancer, but much about its causes remain unknown. The incidence of prostate cancer increases with age more rapidly than any other cancer. Other factors which increase the risk of prostate cancer include eating high amounts of fat, use of tobacco products, and practice of certain sexual activities. Men who live in industrialized countries have much higher rates of prostate cancer compared with men from nonindustrialized countries. Some studies found an association between occupational exposures to certain heavy metals (such as cadmium) and an increased risk of prostate cancer, but this remains controversial (39). These heavy metals have not been found at elevated levels in the environment on or around Refuse Hideaway Landfill. There have been no studies that suggest a relationship between increased prostate cancer risk and exposure to VOCs, such as those detected in contaminated groundwater from the site.

    An individual with prostate cancer lived at a household (7734 Highway 14) that was later found in 1988 to have contaminated groundwater. This individual died of an unrelated cause in 1984. It is not likely this person was exposed to contaminated groundwater and there are no reports that he went onto the site.

    Data from the Wisconsin Cancer Reporting System (CRS) were used to evaluate the incidence of reported prostate cancers among people in the vicinity of Refuse Hideaway Landfill. CRS data are readily available at the greatest resolution for ZIP code areas, and were obtained for Cross Plains (53528), Middleton (53562), and Verona (53593). Prostate cancer data from the CRS were sorted by ten-year age groups for the period 1980 to 1990. For each ZIP code and ten-year age group, the differences between the number of cancers observed and the number expected were tested for statistical significance (p<0.05). The number of prostate cancers diagnosed from 1980 to 1990 for most ten-year age groups codes were not elevated, and in a some of cases were less than expected. There were four age groups with a slightly elevated number of prostate cancers, but none were significantly different than what was expected.

  • Some nearby residents expressed concern about contamination from the site affecting the health of a child, who lives nearby and was born with an immune system disorder.

    A nine-year old child with an immune system disorder, was born and currently lives in a home 1,000 feet south of the site. This house is the closest house to the landfill. Twice in March 1988, two VOCs were detected at this private well. The source of these contaminants is uncertain, but they were not found at levels of a potential health concern (see page 13). We know of no association between chemical exposure and the development of the immune illnesses diagnosed in this child [43].

  • During the DNR interviews, a number of people living in the vicinity of the site stated they were worried about groundwater contamination from farm products (pesticides, fertilizer, etc.).

    Contamination of groundwater by pesticides and fertilizers is a growing concern in Wisconsin. One study found aldicarb present in 25 percent of sampled wells and atrazine present in 20 percent around the state. Approximately 10 percent of wells in south-central Wisconsin had levels of atrazine above Wisconsin's preventive action limit groundwater standard of 0.35 µg/L. Generally, nitrates (a by-product of fertilizers) are the most common groundwater contaminant in Wisconsin [45].

    Pesticides typically contaminate groundwater by two routes: point and nonpoint sources. Improper handling, storage, and disposal (including landfills) account for point sources. Nonpoint sources include seepage of chemicals into groundwater after application to fields. Preliminary results of groundwater testing around Refuse Hideaway suggests the site is probably not a significant point source of pesticides. In May 1993 five pesticides were detected in three monitoring wells at very low levels that are not a health concern. Conversely, the nonpoint sources are probably the most significant pesticide contributors to groundwater in the Black Earth Creek valley.

    People who are concerned about private well contamination from pesticides and nitrates may want to test having their well water. Relatively inexpensive test kits for nitrates and atrazine are available from the Wisconsin State Laboratory of Hygiene, (1-800-442-4618 or 608-262-1641). The University of Wisconsin - Extension has an informative publication titled "Home Water Safety", which is available from county extension offices [56]


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