Remedial Investigation
Southeast Rockford Groundwater Contamination Superfund
Project
June 1991
Rockford, Illinois
Introduction.
The Illinois Environmental Protection Agency (IEPA) is conducting a remedial (environmental)
investigation as part of the Southeast Rockford Groundwater Contamination Superfund project. This
investigation will be carried out by IEPA contractor, Camp, Dresser, and McKee.
What is the purpose of the investigation?
The purpose of the investigation includes two goals:
1. to identify the source or sources of industrial solvents found in southeast Rockford private wells,
and
2. to evaluate the depth and horizontal extent of this solvent contamination.
The industrial solvents are a class of chemicals called volatile organic compounds.
What has been done to protect residents with contaminated private wells?
In the summer and fall of 1990, the United States Environmental Protection Agency (USEPA) connected
over 280 southeast Rockford homes to the Rockford public water supply system, because levels of
industrial solvents in the private wells of these homes posed a possible threat from short?term
exposure. In the spring of 1991, the IEPA completed a study that identified approximately 240
additional private wells with lower levels of contamination that may pose a health threat from long?term
exposure. This summer, the USEPA will connect these additional homes to the Rockford public water
supply system also. Wells sampled are located between the Rock River and 24th Street in an area
approximately bounded by Harrison Avenue and Sandy Hollow Road. Not all wells in this area, however,
are contaminated.
Where will the environmental investigation take place?
Based on private well sample results, the IEPA defined an expanded area for investigation bounded by
the Rock River, Harrison Avenue, Sandy Hollow Road and approximately one and a quarter miles east of
Alpine Road. These boundaries do not indicate areas of known contamination but represent the
geographical area of study which must include uncontaminated as well as contaminated segments. By
comparing groundwater flow in contaminated and uncontaminated segments in the study area, one can
begin to focus on possible sources.
How will the investigation be carried out?
The investigation includes a soil gas survey in six neighborhoods and the installation and sampling of 11
sets of monitoring wells. In addition, the contractor will sample industrial and Illinois State Water
Survey monitoring wells already in place.
What is a soil gas survey?
The soil gas survey is a relatively quick method of evaluating approximate concentrations of volatile
organic compounds in the groundwater (underground water). The soil gas survey is conducted by
driving a hollow tube into the ground to a depth of up to five feet and withdrawing gas (air) from the
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