PUBLIC HEALTH ASSESSMENT
ACKERVILLE AREA GROUNDWATER
[a/k/a TOWN OF POLK LANDFILL (FORMER)]
TOWN OF POLK, WASHINGTON COUNTY, WISCONSIN
The Department of Natural Resources (DNR) asked the Department of Health and FamilyServices (DHFS) to evaluate the health implications of groundwater sampling results in theTown of Polk, and in areas near two landfills in Ackerville, Washington County, Wisconsin. The Washington County Health Department also requested assistance from DHFS in addressingcommunity health concerns regarding drinking water quality and health statistics for the sameareas. This public health assessment addresses requests from both agencies.
Limited groundwater contamination exists in the area of two former landfill sites located westand northwest of Ackerville. The contaminants of concern in the groundwater aretrichloroethylene (TCE) and arsenic. One private drinking water supply well contains a tracelevel of TCE that is not a health concern. Although groundwater contamination is not impactingother nearby private wells, the presence of TCE in this well is an indication that ongoingmonitoring is necessary. Elevated arsenic has been found in a monitoring well, but not in anydrinking water supply wells.
A citizens group, formed to oppose a highway expansion project, including a portion that passesthrough Ackerville, has raised concerns about the rates of cancer in the area. The group has alsosuggested the possibility of a relationship between the cancer rates and contamination from anearby landfill. They have expressed concerns that the bridge construction project would resultin a greater spread of contamination. A DHFS review of the cancer statistics for the Ackerville Zip Code found no statistically significant difference from the expected statewide rates.
A DNR evaluation of nearby groundwater contamination and the bridge construction projectconcluded that groundwater quality and movement would not be affected by the project. InApril, 2002 the Department of Transportation (DOT) installed six monitoring wells and hassampled them quarterly for five quarters. The DOT investigation so far confirms DNR'sconclusion. Sampling of these wells will continue until at least January of 2004.
DHFS, in coordination with the Washington County Health Department, will continue to provide accurate health information to the community.
The purpose of this public health assessment is to describe the existing health issues related toAckerville groundwater quality in the area of two closed landfills. Community health concernsabout a planned bridge construction project and cancer statistics in the area are also addressed. This report includes input from public comments received during the public comment period forthe project and updated information from a DOT groundwater investigation.
Because a public health hazard was not identified during the public health assessment process,the public health action plan for this project focuses on providing information to concernedcitizens (see Attachment A). Additionally, DHFS will provide technical assistance to theWashington County Health Department to address these issues.
The unincorporated Village of Ackerville is in south central Washington County near theintersection of State Highway 164 and State Highway 175, in the Town of Polk. This rural areadoes not have dense residential development. The closed Waste Management of Wisconsin PolkLandfill and the closed Town of Polk Landfill are located about ¾ mile to the northwest and westof Ackerville, respectively. The landfills are separated by the Milwaukee, St. Paul & Pacificrailroad tracks. Groundwater from these sites flows east and southeast in the direction ofAckerville (1). Refer to Figure 1 for the general locations of the landfill sites and Ackerville.
The Town of Polk landfill (Town of Polk) was constructed in a former gravel pit and operated fora short period between 1970 and 1971. This landfill was closed without the installation ofgroundwater monitoring wells.
The Waste Management Polk Landfill (Waste Management) comprises approximately 9 acres,and is 900 feet north of the Town of Polk landfill. Waste Management operated the site fromapproximately 1971 to 1981. In the mid-1980s several monitoring wells were installed as part ofthe long-term monitoring plan for this landfill. As a result of this monitoring plan, two areas ofgroundwater contamination were identified. Petroleum-related contaminants are clearlycontaminating groundwater east of the site. The petroleum contaminants break down a shortdistance from the waste area. Groundwater in an area southeast of the Waste Management siteand northeast of the Town of Polk site contains TCE. This contamination has not been directlylinked to either of the landfills (2).
In response to DNR concerns regarding the amount of leachate (i.e., liquid within the wastematerial) in the landfill, Waste Management has been extracting leachate from the waste masssince 1987. In the fall of 1998, Waste Management improved the efficiency of the leachatecollection system. The leachate from this landfill does not contain TCE. An upgraded landfillgas extraction system was also installed in a series of trenches cut into the landfill (3).
Area private wells were sampled for volatile organic compounds (VOCs) in May of 1984. Twoof the wells contained trichloroethylene (TCE). Both wells contained TCE above the state andfederal drinking water standard of 5.0 parts per billion (ppb). The highest level of TCE detectedin either well was 17 ppb. Both wells were abandoned and replaced with deeper wells. Sincetheir installation, these deeper replacement wells have tested clean.
Two monitoring well nests located next to the railroad tracks between the two landfills haveconsistently shown elevated arsenic concentrations. These levels have occasionally exceeded thecurrent Wisconsin Groundwater Enforcement Standard of 50 ppb, as well as the expected lowerfuture threshold of 10 ppb. The state and federal maximum contaminant limit for public watersupplies was recently reduced to 10 ppb. Arsenic concentrations in the leachate for the WasteManagement facility have not been significantly elevated (generally <10 ppb).
DOT has been working on a long-term highway expansion project extending through parts ofWaukesha and Washington counties. On February 10, 2000, a local citizens group opposing theexpansion of State Highway 164 petitioned the Environmental Protection Agency (EPA) toinvestigate Waste Management for possible inclusion on the National Priorities List of SuperfundSites. The highway project in this area involves constructing a bridge overpass over bothHighway 175 and a two-track railroad line. As part of its basis for this request, the groupexpressed concern about the existing groundwater contamination and area cancer rates (1, 7, 8).
In April of 2000, in response to citizen concerns about groundwater quality, DNR sampled fournearby private wells for VOCs, including TCE. No VOCs were detected in those samples. Under a cooperative agreement with the EPA, DNR staff conducted additional investigation ofsoils and groundwater in an attempt to identify a source of the TCE and arsenic contamination. The sampling for this investigation took place during March and April of 2001. As part of thisinvestigation, four additional groundwater monitoring wells were installed and sampled, 15 soilsamples were collected, and seven existing monitoring and private wells were also sampled.
The monitoring well samples collected in 2001 were analyzed for VOCs, semivolatile organiccompounds (SVOCs), pesticides, polychlorinated byphenyls (PCBs), cyanides and metals. Nopesticides, PCBs or cyanides were detected. TCE was detected in samples from three of thewells at concentrations ranging from 0.6 to 0.8 ppb. Bis(2-ethylhexyl)phthalate was found in onewell at 19 ppb. Iron and manganese were elevated in many of the samples. The highest ironconcentration was 1,970 ppb. The highest manganese level was 315 ppb. Arsenic was notdetected in any of the wells. The highest lead level was 2.6 ppb. Only bis(2-ethylhexyl)phthalatewas at a level that would be of health concern if it were in a drinking water supply well. TheWisconsin Groundwater Enforcement Standard for bis(2-ethylhexyl)phthalate, a commonlaboratory contaminant, is 5.0 ppb.
In the spring of 2002, DOT installed three monitoring well nests (total of six wells) in the area ofthe bridge construction project. These wells were sampled in April, July, and October of 2002,and January and April of 2003 as part of a two year, quarterly monitoring program. The resultsof those samples identified low level VOC contamination consistent with the results of previousgroundwater samples for this project. Table 1 contains a summary of those results for the April,July, and October sampling rounds, and Figure 2 shows monitoring well locations.(13)
Trichloroethylene, benzene and chloroform were found in some of the wells. These chemicals were each found below their health based groundwater and drinking water standards. Threeother VOCs found are not chemicals of concern for this project because they are believed to befrom the well installation process itself. Bromodichloromethane and dibromochloromethane arebyproducts of chlorination and likely came from the use of a large volume of water from amunicipal water supply known to contain them. These two chemicals were found in the firstround of samples collected from one well and were not found in any well during the secondround of sampling. Toluene was also found in four of the wells in the first round of samplesfollowing construction. It is common to find low levels of toluene in well water as a result ofmaterials used during well installation. Samples from two of those four wells contained tolueneduring the sampling round conducted in July. The level of toluene in the July sample resultsdecreased significantly from the samples collected in April.
No VOCs were detected in samples collected during the October sampling round. However, adifferent laboratory was used from the previous two sampling rounds for this round. The VOCdetection limits were above some of the trace level detections reported in previous rounds. Theselevels of detection were low enough, however, to be protective of public health. In April of2003, methylene chloride was the only chemical found in any of the well samples. This chemicalwas found in a quality control sample and is a common laboratory contaminant. Methylenechloride is not believed to be in any of the wells.
Samples from each of these wells were analyzed for arsenic. Arsenic was detected in samplesfrom each well in the October 2002 sampling round. The level of detection for arsenic used inthis round is considerably lower than it had been in the past and at appropriate screening levels. The arsenic results do not indicate a trend or the presence of a source of contamination.
During the DNR 2001 investigation the four nearest private wells were again sampled. One wellcontained a very low level of TCE (0.16 ppb). Resampling of this well confirmed the detectionof TCE (0.3 ppb). This well had been sampled the previous year and no TCE was detected, atleast with a detection limit of 0.2 ppb. No other VOCs were detected in area private wells. DHFS does not consider drinking water containing TCE below 5.0 ppb (Wisconsin GroundwaterEnforcement Standard, and the Federal Maximum Contaminant Limit) to pose a health hazard. Nevertheless, the presence of TCE in a drinking water supply indicates that the well is vulnerableto contamination. The private wells were also sampled for arsenic to address concerns about thelocalized arsenic found in a landfill monitoring well (9). Three of the four private well samplescontained arsenic between 1.1 and 1.9 ppb. These levels are commonly found in Wisconsingroundwater and do not indicate a contamination source. DHFS does not consider drinkingwater arsenic levels below 10 ppb to pose a public health concern.
Each private well contained high levels of iron ranging between 1,800 and 4,000 ppb. TheWisconsin groundwater standard for iron based on aesthetic quality is 300 ppb. These levels areconsistent with the poor taste and odor of the water reported by area residents, but are not ahealth concern. In addition to elevated iron, a number of nuisance bacteria were identified. Onewell had particularly high counts of common nuisance bacteria. High iron is a naturallyoccurring problem in many wells in this area. Nuisance bacteria is typically related to thecondition of an individual well. The well with the most significant level of bacterialcontamination was itself in poor condition and not in compliance with well construction codes.
The soils collected were taken from soil borings at various depths to identify potentialcontaminant source areas. The samples were analyzed for VOCs, SVOCs, pesticides, PCBs,cyanide, and metals. No odor or staining was noticed at any of the sample locations. None of thesamples contained VOCs, SVOCs, PCBs, or cyanide. Arsenic was consistently detected between0.94 and 3.7 milligrams per kilogram. These levels are within the range of arsenic naturallyoccurring in Wisconsin soils and do not indicate a source of contamination (10). One soil samplecontained the pesticide breakdown product endrin aldehyde at 4.6 micrograms per kilogram. Due to the lack of toxicity testing, there are no health-based soil thresholds for endrin aldehyde. Endrin is a solid, white, almost odorless substance formerly used as a pesticide to control insects,rodents, and birds. Endrin has not been produced or sold for general use in the United States since 1986 (12).
Groundwater samples collected during the 2001 DNR site investigation contained TCE in oneprivate well and three monitoring wells. All of the detected TCE concentrations were below 1.0ppb and are not a health concern. It is clear from historic and current sampling results thatgroundwater near the landfill sites is contaminated. The chlorinated solvent TCE is thecontaminant of concern because it has moved from the area and entered private wells (4). TheDOT wells installed near the bridge project contain low level VOC contamination. Althoughnone of the VOCs were found at levels of health concern, their presence indicates that periodicmonitoring of nearby private wells is appropriate.
One monitoring well sample contained the common laboratory contaminant bis(2-ethylhexyl)phthalate. Previously, this chemical had not been considered a contaminant ofconcern at this site and is likely not present in area groundwater. The level detected would be ofhealth concern if found in a drinking water supply (1).
Residents of the Ackerville area have expressed concerns about the safety of their well water. They have based their concerns on taste and odor problems, as well as rumors of nearbycontamination, which have received considerable local attention.
In the 1980s the residents of two households were exposed to TCE in their well water above safedrinking water standards. If it is conservatively assumed that contamination began immediatelyfollowing waste disposal in the early 1970s, these exposures would not result in a measurablehealth risk.
TCE is a chlorinated solvent and is one of the most common groundwater contaminants inWisconsin. DHFS is concerned about TCE in groundwater because long-term exposures to TCEcan increase a person's risk of developing cancer. At the highest levels of TCE historicallydetected in area groundwater, those risks are relatively low. Still, because these risks areunnecessary and avoidable, steps were taken by the DNR to prevent exposures (11). Moreinformation about TCE, including the full text of the Agency for Toxic Substances and DiseaseRegistry Toxicologic Profile, can be found at the following Web site: http://www.atsdr.cdc.gov/toxprofiles/tp19.html
Arsenic analysis in the four private wells found only those levels of arsenic that occur naturallyin Wisconsin groundwater. The levels detected were below both the existing groundwaterstandard of 50 ppb and below the lower, proposed safe drinking water level of 10 ppb. DHFScurrently issues health advice to well owners with arsenic levels greater than 10 ppb. Arsenic is anaturally occurring element commonly found in Wisconsin groundwater. The area aroundAckerville is not an area considered to be a high risk for naturally occurring arsenic at levels ofhealth concern. There are, however, sporadic occurrences of the bedrock unit that have beenimplicated as a source of high arsenic in this area. For this reason, and because arsenic levels inthe at-risk areas can change over time, well owners might want to sample their wells periodicallyfor arsenic. For more information about arsenic in private well water, please refer to thefollowing Web site: http://www.dhfs.state.wi.us/eh/Water/index.htm or search on Arsenic at thefollowing Web site: www.wi.gov
Although not of health concern, all of the private wells contained naturally occurring chemicalsthat are causing taste and odor problems. Each well contained substantial quantities of iron anddetectable nuisance bacteria; in fact, some wells contained very high nuisance bacteria levels. These bacteria will magnify the aesthetic problems caused by the high iron levels. Conditionsspecific to each well--including improper well construction in some cases--are the causes ofbacterial contamination. The nuisance bacteria identified (Crenothrix, Gallionela, andLeptothrix) are not harmful to humans. That said, however, the condition of a well that allowstheir entry and encourages their growth can also make the well susceptible to organisms that cancause health problems. One of the four wells was found to be constructed in an old frost pit thatis subject to flooding. The well owner was informed of this unsanitary condition and providedwith information on how to correct the problem.
Although, changes in the taste, odor, and clarity of well water can be an indication of a waterquality change that can also include substances of health concern, TCE, coliform bacteria,arsenic, lead and related contaminants do not generally have taste, odor, or clarity warningproperties. More information about these common private well water quality problems, as well as how to address them, can be found on the following Web sites:
DNR web page covering common water quality problems and solutions
USEPA web page addressing common questions about drinking water quality
Water Quality Association web page for diagnosing common water problems
The effect of the roadway expansion on area groundwater has been a central concern expressedby the group opposed to the construction project. In August 2000, DNR concluded that theproposed roadway expansion and bridge construction would not alter the existing flow ofgroundwater, nor would it affect the degree and extent of contamination in the area (4). Thespecific project in question is a bridge overpass intended to reduce a public safety hazard posedby the existing railroad crossing.
The group opposed to the expansion of Highway 164 felt a number of existing private wells werecontaminated, but no sample results were provided at the time to support that belief. Thisresulted in many area residents contacting DNR, DHFS, and the Washington County HealthDepartment to express concerns about water quality. Members of this group later stated thattheir evidence of contamination was the very poor aesthetic quality of some area private wells.
Members of the group requested data on the total number of cancer cases from the CancerReporting System maintained by DHFS. The total number of cancer cases for each year wereprovided for each of two Zip Codes. Zip Code 53086 includes the Ackerville area and theVillage of Slinger. The adjacent 53076 Zip Code includes the Richfield area. The group did notask that an interpretation of the analysis of the data be included in their request for the numbers. Without guidance from an epidemiologist, the group was not able to correctly interpret thenumbers and incorrectly assumed that any cancer in the area was likely caused by contaminationfrom the landfills.(7,8)
First, people cannot be harmed by contaminants present in the environment if they are notexposed to them at high enough levels over long enough time to cause illnesses. DHFS dididentify exposure to contaminants in drinking water, but the levels are far below those levelsknown to cause disease. Furthermore, the population of the Slinger/Ackerville Zip Code isconsiderably larger than that of neighboring Richfield. The Slinger/Ackerville population is alsoproportionally older than that of Richfield. Both of these factors would lead epidemiologists toexpect a greater number of cancer cases in the Slinger/Ackerville Zip Code than the RichfieldZip Code (5,6).
In May of 2000, DHFS Bureau of Environmental Health staff obtained and reviewed the cancerdata used by the roadway opposition group. It was quickly noted that the group was comparingtotal numbers of cancers between the two Zip Codes without considering the significant sizedifference between the two Zip Code populations. Individual cancer types were also notidentified in this data, and no age adjusting of the data was performed. The DHFS review of thisdata did not identify a discrepancy between the Zip Codes or the expected statewide rates. Theconclusion of the DHFS review stated "... that Zip code 53076 experiences an all cancer risk thatis slightly and significantly lower than the state's, while residents in Zip code 53086 have an allcancer risk that is no different from the rest of the state's." A copy of the letter provided to theWashington County Health Department regarding that review is attached. None of the cancerquestions or concerns raised by this group were specific to any of the individuals residing in thehomes with existing or past TCE contamination. For these reasons a more thorough evaluationof health statistics would not be beneficial and is not planned.
Concerns were also raised by a local health care professional who believed more than a usualamount of aggressive and unusual cancer was occurring in the young adult population. DHFSpointed out that Zip Code-wide cancer statistics would not identify the subtle observations thatmight be seen in a localized clinic setting. The clinic was encouraged to gather the data on thecases believed to be unusual and to pursue follow up if the data so warranted.
Staff from DHFS and the Washington County Health Department have met with communitymembers in the past and continue to respond to numerous questions from the public regardingthe health implications of the bridge project. The issue has been discussed during severalmeetings of the Washington County Board of Health including two joint meetings withcommunity members interested in the project. A general fact sheet was created to answer anumber of the common questions raised about the project.
Children are often more sensitive to the impacts of chemical exposures for a number of reasonsrelated to their development and behavior. Parents of small children are naturally concernedabout environmental hazards. DHFS has not identified a public health hazard related to thisproject. The one chemical contaminant (TCE) identified in an existing private well was found below levels of health concern for children or adults.
- Although one private well has tested positive for a trace level of TCE, none of the private wells in this area contain contamination at levels of health concern. At this time, the groundwater contamination does not pose a public health hazard to people in the area.
- There is limited groundwater contamination in the Ackerville area west of the intersection of Highways 164 and 175.
- Concerns about taste and odors in private well water are the result of aesthetic problems from naturally occurring iron levels as well as the presence of nuisance bacteria.
- Cancer rates for the Ackerville Zip Code are not elevated when compared to statewiderates or the neighboring Richfield Zip Code.
- Because there has been very little human exposure to contaminants of concern at this site a more thorough evaluation of health outcome data is not warranted.
- The private wells nearest to the area of TCE-contaminated groundwater should bemonitored periodically for VOCs.
- Accurate information about the health and environmental conditions in this area shouldbe provided to the community.
DNR will make decisions about periodic monitoring for TCE in groundwater near private wells.
DHFS will continue to provide accurate health information to the community. DHFS has workedwith DNR to develop a fact sheet answering some common questions about this site. This factsheet has been provided to community members. If needed, the fact sheet will be updated toaddress changing conditions, questions and concerns related to the site.
In the past, DHFS has participated in public meetings with the Washington County Board ofHealth on this topic. DHFS will continue to provide technical support to the Washington County Health Department as requested.
DHFS, Division of Public Health
This public health assessment for Ackerville Area Groundwater was prepared by the WisconsinDepartment of Health and Family Services under a cooperative agreement with the Agency forToxic Substances and Disease Registry (ATSDR). It is in accordance with approvedmethodology and procedures existing at the time the public health assessment was begun.
Gail D. Godfrey
Technical Project Officer, S.P.S., SAAB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment and concurs with the findings.
Chief, State Program Section, DHAC, ATSDR
This section contains a summary of the public comments received regarding the content of thePublic Health Assessment along with an explanation of how those comments are addressed in thefinal health assessment. The responses are preceded by the comments, restated to removepersonal identifiers and statements not related to the content of the public health assessment. Statements not directly related to the public health assessment were forwarded to other agenciesfor their response. Only comments that suggest changing the document are included.
Comment: A request was made to include the results from the round of groundwater monitoring wells installed by the Department of Transportation near the bridge project site in the final Public Health Assessment.
Response: Information from five quarters of sampling of those wells has been evaluated and included in the document as requested.
Comment: A concern has been raised that DHFS did not collect environmental data independently from the data collected by other parties involved in the project. The concern was expressed that DHFS should have conducted a separate "independent analysis to either verify or disclaim the information stated from other reports."
Response: DHFS can collect a limited number of samples to fill information gaps when absolutely necessary. However, we do not have the resources that would be needed to duplicate the efforts of others. The State of Wisconsin has strict professional requirements for contractors and laboratories to ensure the validity of the information provided from those sources. DHFS staff believe that the existing data available are valid for evaluation of the conditions at this site.
Comment: The report identifies that lab contaminants were found in the water samples. This raises concerns about the usefulness of all of the data.
Response: DHFS does look closer at the results when common laboratory contaminants are found in samples. None of the contaminants of concern for the case are among the laboratory contaminants found and re-sampling of the wells has consistently confirmed our understanding of actual groundwater quality in the area.
Comment: The public health assessment does not recommend additional investigation of petroleum contamination found near the Waste Management landfill site.
Response: Petroleum contaminants found in groundwater have not been found at levels of public health concern. This comment has been forwarded to DNR for their consideration because it relates to the ongoing monitoring of the waste disposal facilities in the area.
Comment: Add the date of sampling to the statement in the last sentence of the third paragraph on page three.
Response: This has been added as requested.
Comment: The arsenic contamination poses a major health risk because it is close to a landfill.
Response: The elevated arsenic is a cause for concern in a location between a landfill and railroad tracks, but it does not appear to be moving from this area. In this case the arsenic does not pose a health risk because it is not found in or near a drinking water well.
Comment: Since the Town of Polk Landfill was closed without monitoring wells, why not make a recommendation to monitor the leachate in the landfill.
Response: Groundwater sampling information in the area near this landfill is sufficient to make a public health determination. DNR may choose to recommend additional investigation of this landfill based on additional factors. This suggestion has been forwarded to DNR for their consideration.
Comment: The presence of VOC's may not only impact the drinking water but also the air quality of homes that have with VOC's in their water.
Response: This statement is true. However, at this site private wells are not impacted at a level that poses a health hazard for exposure through any use of the water.
Comment: DHFS should immediately order the WisDOT to stop all construction on the Ackerville Bridge/Lovers Lane Reconstruction Project.
Response: DHFS does not believe there is public health justification for intervening in this project.
Comment: The groundwater contamination issues are much more serious than this public health assessment is leading people to believe.
Response: This public health assessment is written to present the chemical exposures and health implications in a fair and balanced manner.
Comment: Arsenic was found in [a residential well] at a level about twice the U.S. EPA Health Advisory Level.
Response: The arsenic level in this well was found to be 1.9 parts per billion. This value is actually more than five times lower than EPA's Health Advisory Level of 10 parts per billion. Wells in Wisconsin commonly contain arsenic at this level and it does not indicate a contamination problem.
Comment: The existence of taste, odor and color problems with the private well water in Ackerville should raise "red-flags" that there are serious problems with this water which need to be immediately addressed to protect the health and safety of the people of this area.
Response: The presence of taste, odor, and color problems are indications of problems with the water. However, the problems indicated do not relate to the contamination in this area. Each well owner was provided with information and specific recommendations on how to address these problems.
Comment: The public health assessment has improperly dismissed the valid citizen concerns about the elevated individual cancer rates among residents of the Ackerville area without first doing further cancer studies of this area. The public health assessment has also ignored the health concerns expressed by [local pathologist], who asked that the DHFS conduct further health and medical studies to determine the cause of the elevated cancer rates in the Ackerville area population. The DHFS has the resources (i.e., our tax dollars) and expertise to collect data from Ackerville's residents who have been affected by cancer and then conduct these studies. The DHFS should immediately begin collecting detailed data directly from the Ackerville area residents about their families' experiences with cancer while living in this area. This data should be used be used to determine the frequency and types of cancer cases occurring in the Ackerville area, and this site-specific data then should be compare with data collected from other areas farther away from Ackerville. We are confident that this type of comparative data analysis would prove that cancer rates are significantly higher for Ackerville area residents and their families.
Response: Unfortunately, DHFS does not have unlimited resources for conducting detailed epidemiological investigations. Instead, DHFS makes the decision to conduct an investigation when there is either an indication of widespread chemical exposure that could plausibly result in elevated rates of disease within the population, or if an unusually large number of a specific type of disease is identified within a geographic area. In this case neither condition exists. There has been very limited exposure to chemical contaminants related to this project area. None of those exposures would be expected to result in a measurable increased level of illness. The pathologist referred to in this comment expressed concerns about cancer statistics summarized for two Zip-codes. A review of these statistics by a DHFS epidemiologist found that cancer rates for the area are not different from what we would expect to see in other parts of Wisconsin. Pathologists and other medical professionals who can document unusually high rates of a specific disease in a population should report that information to DHFS. The pathologist involved with this project has been informed of this process. No specific reports that suggest there are elevated disease rates in the Ackerville area have been made to DHFS.
|Parameter VOCs - all units micrograms per liter (µg/L)||MW-1||PZ-1||MW-2||PZ-2||MW-3||PZ-3||Health Advisory Level|
* Methylene chloride is a common laboratory contaminant and is not believed to be in the actual samples for thesewells. It was detected in only the last round of samples. It was also found in the quality control sample (trip blank)sent to the lab for the sam round.
- Wisconsin Department of Natural Resources. Preliminary assessment/site inspection-former Town of Polk Landfill. Washington County, WI. September 7, 2001.
- Washington County Board of Supervisors. Letter to Ken Miller from Michael Peterson, Waste Management Closed Sites Group. February 23, 2000.
- Wisconsin Department of Natural Resources. Memorandum to Chad Czarkowski from Philip Fauble concerning recent groundwater quality data, WMWI-Polk Sanitary Landfill, Washington County, WI, DNR License #0307. March 16, 2000.
- Wisconsin Department of Natural Resources. Memorandum to Jay Waldschmidt from ChadCzarkowski and Phillip Fauble concerning Ackerville Area Road Project / groundwater concerns. August 8, 2000.
- Rank D. Report on dump in Ackerville to be delivered. West Bend Daily News.May 30, 2000.
- CACI. The sourcebook of zip code demographics-1990 Census Edition. 1991.
- Rank D. Agencies see no extra health risks in Ackerville. West Bend Daily News. June 5, 2000.
- Gonyo JM. "Why is Thompson ignoring the people of Ackerville?" The Capital Times (editorial). November 16, 2000.
- Wisconsin Department of Natural Resources. Letter to Phillip Faublefrom John E. Thresher, Jr. concerning additional arsenic related data for an analysis of the groundwater contamination at the WMWI-Polk Landfill and environs, Town of Polk, Washington County, WI. February 21st, 2001.
- Wisconsin Department of Health and Family Services. Memorandum to DNR/DATCP concerning public health implications of residual lead and arsenic in orchard soils. March 28, 2000.
- Agency for Toxic Substances and Disease Registry. Toxicological profile for trichloroethylene (TCE) (update). Atlanta: US Department of Health and Human Services; September 1997.
- Agency for Toxic Substances and Disease Registry. Toxicological profile for endrin and endrin aldehyde. Atlanta: US Department of Health and Human Services; August 1996.
- STS Consultants, Inc. "Well Installation and Groundwater Sampling Documentation for STH 164 (Lover's Land Road) in Ackerville, Wisconsin." May 2, 2002 - Table 1 Updated, June 6, 2003.
Residents in the Ackerville area have raised questions about the quality of their drinking water. This fact sheetanswers some of the commonly asked questions.
Q. What do we know about drinking water quality in this area? Is our water safe to drink?
R. All available sample results from private wells in this area indicate that the water is currently safe to drink. Some groundwater contamination has been found in the area near two old landfills. Two shallow drinking water wells were replaced with deeper, bedrock wells in the late 1980s because of this contamination. The replacement wells have been clean ever since. Recently, a private well near the two landfills was found to contain a trace level of the same contamination. This well did not contain the chemical when tested last year.
Q. What is the chemical that was found, and what does it mean to find it?
R. This chemical is a chlorinated solvent called trichloroethylene, or TCE. It is one of the most commonlyfound groundwater contaminants in Wisconsin. This is the same chemical that was found in the late 1980s inthe private wells that were replaced. The recently reported contaminant was found at more than 30 timesbelow the unsafe drinking water level for that chemical. Although water from that well continues to be safe todrink, it is an indication that there is more work to be done.
Q. My water tastes and smells bad, does that mean our groundwater is contaminated?
R. No. Taste and odor problems in well water often indicate that there is a naturally occurring iron problemor the growth of nuisance bacteria. Recent tests of a nearby well with severe taste and odor complaints founda significant nuisance bacteria problem. These bacteria do not travel in groundwater; rather, they grow in thewell itself because of problems with well construction and unsanitary conditions around the well. Unfortunately, most chemical contaminants do not have taste and odor warning properties. For this reason,the Department of Natural Resources (DNR) sampled many private wells last year and again this year, andfound them all to be chemically safe.
Q. What do we know about groundwater contamination near the old Town of Polk landfill?
R. The DNR is currently sampling soils and groundwater at the old Town of Polk Landfill to determine ifthis area is a possible source of the groundwater contamination. Initial test results indicate that any TCE thatmay be present is extremely low level and is not originating from either of the two landfills. In fact, theresults confirm previous conclusions that the presence of low level TCE that could be related to past railroadactivities (engine degreaser) and not the landfills.
Q. Is it true that the bridge construction project will make groundwater contamination worse in our area?
R. No. There is no relationship between the proposed bridge construction project and area groundwaterquality. The groundwater is 30 feet below the ground surface, and will not be affected by the bridge or roadconstruction.
Q. There are rumors that cancer statistics show unusually high cancer rates in this area. Is this true?
R. No. This is not true. Some individuals, however, have been misrepresenting the actual cancer statistics inthat way. The rates of cancer in this area are not higher than the neighboring zipcode or cancer ratesstatewide.
Q. I have been experiencing health problems. Should I be concerned about the quality of my drinking water?
R. If you are having health problems you should contact your physician. The information currently availableabout groundwater quality in the Ackerville area has not identified any groundwater quality problemsexpected to cause health effects.
Q. How can I get my well tested?
A. Contact a private commercial laboratory or environmental consulting firm from your local directory. Werecommend an annual test for coliform bacteria as an indicator of the general sanitary condition of your well. If you would like a test for chemical solvents, ask for a VOC test for drinking water. This typically costs$150-$200 by an EPA-certified method. Either Method 524.2 or method 8260 is appropriate. Some labs dononcertified testing for less, but the results may not be as reliable. If you are concerned about arsenic or othercontaminants you must specifically ask for that to be tested. More information about well testing can be foundon the DNR internet site, or by calling the Drinking Water Specialist in your local DNR office.
Q. Who can I contact for more information.
R. For more information about the following topics please contact:
| Groundwater Quality |
DNR - Milwaukee
| Landfill Investigation |
DNR - Milwaukee
|Health Questions |
DHFS - Madison
This information was developed by the Departments of Natural Resources and Health and Family Services.
May 31, 2000
Ms. Linda Walter, Director
Washington County Health Department
333 E. Washington Street
West Bend, WI 53095
Dear Ms. Walter,
Our Department recently provided you with a count of cancer incident cases for two Zip Codes: 53076 and53086. The data described newly diagnosed (incident) cancer cases for the years 1980 through 1997.
I would like to provide you with an additional perspective on the counts. There were 147 cases in Zip code53076, and 351 cases in Zip code 53086. During the same time period, the state as a whole experienced398,653 incident cancer cases (see Table 1).
Unfortunately the counts themselves do not describe risk. In looking at Table 1, we cannot determine thatresidents in Zip code 53086 experience a higher cancer rate than do residents in Zip code 53076. To ascertainrisk, we need to calculate incidence rates for both groups. We then customarily compare cancer rates to thestate as a whole.
I have calculated cancer incidence rates for males and females (Tables 2 and 3). Using Poisson regression, Ihave compared the two Zip codes to the statewide rates. Poisson regression was used to control for age andyear of diagnosis. The relative risk (RR) tells us if the Zip code rate is higher or lower than what has beenexperienced statewide. A number greater than one (1) indicates a higher rate, while a number less than oneindicates a rate lower than the state's.
Table 2 shows that, for females in Zip code 53076, the all cancer risk was significantly lower than the state'srate (RR = 0.668, P Value = 0.0006) while for Zip code 53086, the rate was not significantly different fromthe state's (RR = 1.07, P Value = 0.315). Upper (U95CI) and lower (L95CI) confidence intervals at the 95%level are also provided for the relative risk estimate.
Table 3 shows that, for males residing in Zip code 53076, the all cancer risk was significantly lower than the state's rate (RR = 0.68, P Value = 0.0011). For Zip code 53086, the rate was not significantly different from the state's (RR = 0.86, P Value = 0.0796).
From this analysis, it would appear that Zip code 53076 experiences an all cancer risk that is slightly andsignificantly lower than the state's, while residents in Zip code 53086 have an all cancer risk that is nodifferent from the rest of the state's.
I hope that these analyses have provided you will a more complete perspective on the cancer counts. Pleasecontact me if have any questions on these analyses.
[original signed by Lawrence Hanrahan - 5/31/00]
Lawrence P. Hanrahan PhD MS
Senior Epidemiologist & Chief
Section of Epidemiology and Toxicology
Bureau of Environmental Health
Wisconsin Division of Public Health
1414 E. Washington Ave, Room 96
Madison, WI 53703
CC Laura Stephenson-Vine