EVERGREEN MANOR GROUNDWATER CONTAMINATION
(a/k/a EVERGREEN MANOR GROUND WATER CONTAMINATION)
WINNEBAGO COUNTY, ILLINOIS
The purpose of this health consultation is to provide an update of the activities at the Evergreen Manor Groundwater Contamination Site (Evergreen Manor). The Illinois Department of Public Health (IDPH) completed a public health assessment for Evergreen Manor in December 1999. At that time, IDPH concluded that exposure to groundwater at Evergreen Manor posed a public health hazard .
The Evergreen Manor Groundwater Contamination Site is approximately 1.5 miles northwest of the Village of Roscoe in Winnebago County, Illinois (Attachment 1). The site consists of the residential areas of Evergreen Manor Subdivision, Hononegah Heights Subdivision, and Olde Farm Subdivision (Attachment 2).
The area surrounding the site is a mixture of residential and agricultural land and some commercial properties. Tresemer Subdivision is to the west, the Rock River is to the south, Hononegah Country Estates Subdivision is to the east, and agricultural land and Dry Creek are to the north. A public park through which Dry Creek flows is about 0.25 miles west of the site.
The initial discovery of contamination in Evergreen Manor occurred in November 1990 when a lending institution required a local homeowner to sample a residential water supply. Analysis of the well water showed elevated levels of volatile organic chemicals (VOCs). As a result, IDPH was asked to investigate.
In December 1990, IDPH initiated a sampling program of the private wells in the area to determine the initial extent of contamination. Approximately 100 residential well samples were collected. The laboratory results showed the presence of the following chemicals: trichloroethylene (TCE), 1,1-dichloroethylene, tetrachloroethylene (PCE), 1,1,1-trichloroethane, 1,1-dichloroethane, and cis-1,2-dichloroethene. The highest level of TCE detected was 91 micrograms per liter (µg/L) and the highest level of PCE detected was 5.8 µg/L. The maximum contaminant level (MCL) for each chemical is 5 µg/L. The MCL is a U.S. Environmental Protection Agency (USEPA) standard for these chemicals in public water supplies that is safe for human consumption.
Based on the initial results, IDPH issued advisory fact sheets in February 1991 to the residents of the area describing the sample results, the location of the contaminant plume, and recommendations concerning domestic use of groundwater. At that time, several residents installed some type of water treatment unit or switched to bottled water for drinking and cooking purposes. The filtering systems ranged from whole house filters to faucet filters. The Illinois Environmental Protection Agency (Illinois EPA) and USEPA were contacted for assistance; however, the maximum levels detected for these chemicals were less than USEPA Emergency Removal Action Levels for drinking water supplies.
The initial sampling program identified a narrow contaminant plume extending south-southwest through the Hononegah Heights Subdivision into the Evergreen Manor and Olde Farm Subdivisions (Attachment 2).
In 1995 and 1996, Illinois EPA contacted the potentially responsible parties for the groundwater contamination plume to discuss voluntary clean-up actions. The discussions were unsuccessful, and in September 1997 Governor Edgar signed a letter of approval supporting Illinois EPA's proposal for the site to be added to the Superfund National Priorities List of hazardous waste sites. In December 1997, Illinois EPA referred the site to USEPA for federal enforcement action.
USEPA collected 12 residential well water samples in May 1998. Several wells had levels of TCE and PCE greater than the MCL. In July 1998, USEPA proposed the Evergreen Manor site for the National Priorities List.
USEPA completed an Engineering Evaluation/Cost Analysis (EE/CA) and opened a public comment period for the EE/CA in November 1998. The evaluation covered three options to reduce or eliminate the threat to human health from exposure to contaminated drinking water: (1) the extension of a public water main from the North Park Water District; (2) point-of-entry residential water treatment units (whole-house units); (3) point-of-use residential water treatment units (faucet units). Most of the comments received during the public comment period favored the extension of a public water main.
In early 1999, USEPA entered into an agreement with the potentially responsible parties to provide public water to the affected area. Construction of the water main extensions began in November 1999 with plans to connect 262 homes. In July 2000, USEPA decided to expand the site area to include an additional 21 homes as a precaution. The project was completed in September 2000 with all of the initial 262 homes being connected to public water. Of the additional 21 homes, 19 connected to public water . The two homes that did not connect are next to each other east of the contamination plume. In May 2001, IDPH collected a water sample from the home closest to the plume. Sample results showed that the well remains unaffected by the contamination plume. All of the homes that connected to public water had their existing water wells properly abandoned.
As part of the public health action plan described in the December 1999 public health assessment, in May 2001 IDPH collected five water samples from private wells adjacent to the project area. Three samples were collected from the west edge of the plume and two from the east edge. The purpose of these samples was to make sure that the homes outside the project area (and still connected to private wells) continue to be unaffected by the contamination plume. The sample results showed no VOCs in the five wells .
Currently no one is exposed to VOCs in the groundwater. Although it is possible for future exposure to occur, this is unlikely. The contamination plume is well defined and has remained stable for more than 10 years.
IDPH has determined that no children are currently exposed to the VOCs in the groundwater. Future exposure is unlikely given the stability of the groundwater plume and continued monitoring.
IDPH concludes that this site currently poses no public health hazard because no one is exposed to the VOCs in the groundwater. Although future exposure to contaminated groundwater is possible, continued monitoring of the plume makes identification of any change in conditions likely before anyone is exposed to levels that could harm them.
IDPH recommends that Illinois EPA continue monitoring the groundwater to detect any changes in the contamination plume, which is part of the plan for monitoring this site in the future.
IDPH will continue to collect and analyze a small number of private well samples near the site to monitor any future changes in the contamination plume. IDPH also will continue to review water sample results and provide residents with information regarding those results.
Steven J. Johnson
Illinois Department of Public Health
- Illinois Department of Public Health. Public health assessment for Evergreen Manor Groundwater Contamination Plume, Roscoe, Winnebago County, Illinois. Springfield, Illinois: Illinois Department of Public Health; 1999 Dec 28.
- US Environmental Protection Agency Region 5. Memorandum from Ken Theisen concerning Evergreen Manor Alternative Water Supply Project, Roscoe, Illinois. Chicago. August 8, 2000.
- Illinois Department of Public Health. Evergreen Manor Groundwater Contamination Site water sample results data. Springfield, Illinois. December 28,1999.
This Evergreen Manor health consultation was prepared by the Illinois Department of Public Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the public health consultation was begun.
Gail D. Godfrey
Technical Project Officer, SPS, SSAB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health consultation and concurs with the findings.
Lisa C. Hayes
for Chief, SSAB, DHAC, ATSDR