Southeast Rockford Groundwater Contamination Superfund Project

Phase I Remedial Investigation Results

Southeast Rockford Groundwater Contamination Superfund Project

October 1992

Rockford, Illinois

Background

In the summer and fall of 1991, the Illinois Environmental Protection Agency (IEPA) conducted Phase I of an environmental investigation as part of the Southeast Rockford Groundwater Contamination Superfund project. The purposes of this investigation included:

1. the preliminary identification of the source or sources of solvents found in southeast Rockford private wells, and
2. the evaluation of the depth and horizontal extent of the solvent contamination within the present study area boundaries.

These solvents are in a class of chemicals called volatile organic compounds.

What are the study area boundaries for the project?

Areas of contamination have not yet been fully defined. The boundaries for the Phase I study were the Rock River on the west, Sandy Hollow Road on the south, Harrison Avenue on the north, and approximately one and a quarter miles east of Alpine Road. These boundaries are study area boundaries only and may change as the investigation progresses. Not all private wells in the study area are contaminated.

How have residences with contaminated private wells been protected?

Based on IEPA, Illinois Department of Public Health and U.S. Environmental Protection Agency (U.S. EPA) sampling, the U.S. EPA Emergency Response section connected over 550 properties to the Rockford public water supply in 1990 and 1991. Wells on these properties had levels of contamination which violated (or potentially could violate) the U.S.EPA public water supply standards. The standards are set to protect people who may drink the water over an average lifetime of 70 years.

What was involved in the environmental investigation?

• Installation and sampling of 33 monitoring wells and sampling of an additional 35 Illinois State Water Survey wells and privately owned monitoring wells for 24 metals, 19 pesticides and 24 semivolatile and 17 volatile organic compounds.
• A soil gas survey of 225 samples in six areas for three volatile organic compounds found in the groundwater. The six areas are only a small portion of the entire study area.

What is a soil gas survey?

The soil gas survey was conducted by driving a hollow tube into the ground to a depth of up to five feet and withdrawing gas (air) from the ground. The gas was analyzed on site for three volatile organic compounds which may have vaporized from the groundwater into the air pockets above the groundwater.

What are the environmental investigation results?

Monitoring Well Sample Results (Total VOC 1991)

• Volatile organic compounds are the prime contaminants of concern.
• Several monitoring wells east of 20th Street showed high concentrations of volatile organic compounds.
• Results indicated several possible sources of contamination. In the eastern area, for example, there may be a plume of contamination originating in the northeastern part and another in the south central part. In addition several southern monitoring wells differed in primary contaminants.
• Water appears to be flowing in a generally westward direction with a significant north/northwest component in the area of Balsam Lane.
• The depth of contamination varies. For example, in the area of Balsam Lane and to the northeast of the study area, contamination is confined to the upper sand and gravel aquifer (water holding geological formation). In the central part of the study area, contamination has penetrated the lower bedrock aquifer.
• The soil gas survey showed only two areas with concentrations high enough to indicate possible soil contamination. One is north of Alton on Marshall Street, and the other is on Kung Street south of Harrison.

Technical Assistance Grants

Citizen groups desiring technical assistance in interpreting data from this investigation may be eligible for a Technical Assistance Grant (TAG). The TAG is a U.S. EPA program which provides up to $50,000 per site to community groups wishing to hire consultants to interpret date generated during a Superfund investigation. Twenty percent of the total funding amount must be provided by the group in cash or by using in?kind services. TAGs cannot be used to duplicate field or lab work. Governmental bodies, potentially responsible parties, academic bodies and headquarters of public interest groups are not eligible to receive TAG's but members of these groups may belong to a community organization requesting a TAG. For more information about TAG, contact the TAG Coordinator, U.S. EPA, P-19J, 77 West Jackson, Chicago, Ill. 60604, phone 1-800-621-8431.

What are the next steps?

The next steps are to gather more information to positively identify contamination sources or to eliminate areas as possible sources. Since groundwater contamination is not easily identifiable at the surface, several phases of investigation may be needed to positively identify all sources. In Phase II, beginning this fall and continuing into 1993, IEPA contractors will sample soil, conduct additional soil gas surveys and install and sample additional monitoring wells. Based on IEPA information of past industrial practices of industries located north of Harrison and information submitted by some of these industries, the study area has been expended northward to Broadway.

In addition, the IEPA contractors will sample private wells on the edge of the contamination plume to see if contamination has spread. If additional private drinking water wells are found to have levels of contamination that violate the U.S. EPA public water supply standards, the IEPA and U.S. EPA will offer the homeowners a connection to the Rockford public water supply. After the sources of groundwater contamination have been identified, the IEPA will prepare a study of possible remedies for the contamination. One remedy will be designated as the IEPA and U.S. EPA preferred remedy. All proposed remedies will be submitted to the public for comment before a final remedy is chosen.

For Additional Information

The full report of Phase I investigation results and other documents on the project are available for public review at the following locations:

Repositories of Information
Rock River Branch
Rockford Public Library
3134 South 11th Street
815/398-7514

Administrative Record
Main Branch
Rockford Public Library
215 North Wyman
815/965-6731

Ken-Rock Community Center
3218 South 11th Street
815/398-8864

The Administrative Record is on microfiche, available for copying at the main library.

For other information, contact: