PUBLIC HEALTH ASSESSMENT
EVERGREEN MANOR GROUNDWATER CONTAMINATION SITE
The Evergreen Manor Groundwater Contamination Site is in a residential area about 1.5 miles northwest of the village of Roscoe, Illinois. The site includes approximately 240 homes with an estimated population of 700 persons. Groundwater currently used by the residents is contaminated with volatile organic compounds. Completed exposure pathways (past and present) include:
- ingestion of contaminated water;
- inhalation of volatilized chemicals during water uses, such as showering and cooking; and
- dermal contact with contaminated water.
The primary chemical of concern at the Evergreen Manor Site is trichloroethene (TCE). Based on the levels of TCE and the possible adverse health effects, the Illinois Department of Public Health (IDPH) concludes that the Evergreen Manor Site poses a public health hazard.
The U.S. Environmental Protection Agency (USEPA) has reached an agreement with the
potentially responsible parties to provide public water to the affected area. Construction of the
water main extension began in November 1999 and is scheduled to be completed in the summer
of 2000. Once public water is available, exposure to contaminated water will be eliminated, and
present and future health hazards should be eliminated. Future actions at the Evergreen Manor Site include groundwater sampling to monitor possible changes in the contamination plume.
The Illinois Department of Public Health (IDPH) prepared this public health assessment under a
cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). Its
purpose is to evaluate any known or future potential human health hazards from exposure to site
contaminants and to recommend actions to reduce or prevent any potential adverse health effects.
The conclusions listed in this public health assessment are based on a review of available environmental information, site visits, and an evaluation of community health concerns.
The Evergreen Manor Site is approximately 1.5 miles northwest of the village of Roscoe, Illinois, in Winnebago County (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 property, 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. Dry Creek flows through a public park, which is within a quarter-mile west of the site.
In 1983, a groundwater contamination plume was discovered in Hononegah Country Estates, a subdivision approximately 0.5 miles east of Evergreen Manor. Chemicals similar to those later detected in Evergreen Manor were identified in that plume, but levels were much higher in Hononegah Country Estates.
During the investigation into the Hononegah Country Estates plume, several samples were collected in the Evergreen Manor area. The sample results showed groundwater contained trace amounts of 1,1,1-trichloroethane, TCE, and other volatile organic compounds (VOCs). At that time, those results were attributed to the Hononegah plume. In retrospect, the detected trace amounts might suggest the beginning of the contaminant plume that was later detected in the Evergreen Manor area. If that is the case, then people might have been exposed to contaminants over an approximately 17-year period.
Public water was made available to the homes in Hononegah Country Estates. Public water is also available to the area under development east and northeast of Evergreen Manor. Public water has not been available to Evergreen Manor [1,2]. In July 1999, residents were given the opportunity to become part of a public water extension into Evergreen Manor.
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 the water contained elevated levels of 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 in December and January. The laboratory results showed the presence of the following chemicals: TCE, 1,1-dichloroethene (DCE), tetrachloroethene (PCE), 1,1,1-trichloroethane, 1,1-dichloroethane, and cis-1,2-dichloroethene .
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 filtering systems 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 concentrations detected for those chemicals were less than USEPA Emergency Removal Action Levels for drinking water supplies. For that reason, USEPA was unable to assist with an emergency removal action .
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). Initial speculation was that this plume was from the same source as the Hononegah Country Estates plume; however, later sample and monitoring well results suggested a separate, very narrow plume running parallel to the first plume .
In 1992, Illinois EPA conducted a Comprehensive Environmental Response Compensation and Liability Act (CERCLA) Screening Site Inspection. Soil gas sampling and additional water samples were collected to identify possible sources of the groundwater contamination . During December 1993 and January 1994, Illinois EPA installed 20 monitoring wells north-northeast of the site. Those wells were installed to help identify possible sources of the groundwater contamination. In addition, Illinois EPA collected approximately 260 private well samples. The results of the monitoring well and private well samples showed the presence of VOCs similar to those found in previous investigations. Four additional monitoring wells were installed in late 1994 in an attempt to determine the source of the groundwater contamination. The source of the groundwater contamination plume has not been definitely identified .
In 1995 and 1996, Illinois EPA contacted the potentially responsible parties for the groundwater contamination plume to discuss voluntary cleanup actions. The discussions were unsuccessful, and in September 1997, the Governor signed a letter of approval supporting Illinois EPA's proposal for the site to be added to the National Priorities List. 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 elevated levels of TCE and PCE. In July 1998, USEPA proposed Evergreen Manor to the Superfund National Priorities List of hazardous waste sites.
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 filters); and 3) point-of-use residential water treatment units (faucet filters). Most of the comments received during the public comment period favored the extension of a public water main .
In the spring of 1999, USEPA reached an agreement with the potentially responsible parties to provide public water to the affected area. Construction of the water main extension began in November 1999 and is scheduled to be completed in the summer of 2000 .
Demographics, Land Use, and Natural Resource Use
The Evergreen Manor Site is in Winnebago County, Roscoe Township, Census Tract 003902, Block Group 2. According to the 1990 U.S. Census, this block group has a total population of 3,632, 3% of whom are minorities. The Evergreen Manor plume currently has the potential for affecting 243 homes and an estimated population of approximately 700 persons.
The Evergreen Manor Site is in an area dominated by a bedrock valley carved through limestone. This bedrock valley has been filled with sand and gravel outwash deposits from the melt waters of several Wisconsin age glacial advances. The sand and gravel deposits overlay the St. Peter Sandstone and are as deep as 250 feet. The shallow sand and gravel aquifer is the major source of groundwater in the area. Well logs indicate that most of the residential wells obtain water from the sand and gravel aquifer approximately 50 feet to 80 feet below the ground surface .