Update #2
Illinois EPA’s Crestwood Sampling Summary
June 2009 Investigation of the Potential Source of
Contamination of the Closed Public Water Supply (PWS) Well #1
Village of Crestwood, Cook County
Update #2 - June 30, 2009
During the second week of June 2009, Illinois EPA’s Office of
Site Evaluation performed initial sampling of soil and shallow groundwater
around Playfield Cleaners, a suspected potential source of groundwater
contamination in the tainting of the Crestwood PWS Well #1, and between
the Playfield property and the now sealed well. The purpose of the initial
investigation was to examine and define the extent of contamination and
its potential effects on the general public. Results of this sampling
indicate that there is no current potential for human exposure to the
contamination detected and consequently no health threat to the residents
of Crestwood. However, additional investigation will be needed to attempt
to determine the source and responsibility for the contamination of Crestwood
PWS Well #1.
Investigation Results
The Illinois EPA’s equipment capabilities allow for subsurface
investigations to be performed above the bedrock. Bedrock was found between
approximately 20 and 35 feet below the ground surface across the area.
Four soil and ten shallow groundwater samples were collected for laboratory
analysis. Our sample results indicate:
- At the Playfield Cleaners site, soils beneath the surface remain
contaminated with drycleaner solvent, tetrachloroethene, more commonly
known as perchloroethylene (PCE). At the same location, shallow groundwater
remains contaminated with PCE and some of its breakdown products, including
vinyl chloride.
- Shallow groundwater north of the Playfield Cleaners site is contaminated
with vinyl chloride at one third of the concentration found at the
source location immediately south of Playfield Cleaners. This is the
only groundwater contamination identified beyond the immediate release
area and is confined to under the Playfield Plaza parking lot on the
north side of the shopping center.
- All soil and shallow groundwater samples collected east of Tinley
Creek, between the drycleaner site and the former PWS well, and both
north and south of the former PWS well in Playfield Park and the baseball
fields -- were “non-detect” for all of the volatile organic
chemicals, including vinyl chloride, for which they were analyzed.
- All soil and groundwater samples collected south of the Playfield
Plaza property were “non-detect” for all of the volatile
organic chemicals, including vinyl chloride, for which they were analyzed.
- Based on the concentrations, depth, and limited extent of contaminants
found in the sampling, health impacts from chemical vapors entering
homes is not a concern.
Investigation Goals
IEPA’s primary goal was to find the extent of contamination in
the shallow subsurface from this site and, if possible, try to determine
shallow groundwater flow direction. A primary concern was to determine
if there remains a potential current health threat from the remaining
soil and groundwater contamination.
A secondary goal was to determine if there was a threat to human health
from lead in surface soils under the water tower. Local citizens expressed
concerns that lead-based paints may be present in the shallow soil beneath
the water tower as a result of water tower sandblasting.
The surface soils beneath the water tower and immediate area were investigated
for lead contamination; real-time X-Ray Fluorescence (XRF) imaging revealed
no lead levels exceeding cleanup objectives for residential soils. The
Illinois EPA has sent the XRF results to Illinois Department of Public
Health for further health interpretation. The IDPH’s response will
be posted at the website listed below.
The complete data set and explanations of the sample collection processes,
can be found in the report, “Sampling
Activities at Abandoned Crestwood Well #1” and its
attachments.
Conclusions and Next Steps
Our data indicate shallow groundwater flow direction appears to trend
both northward and toward Tinley Creek. Regional groundwater flow in
the bedrock has been documented as also flowing northward. The Illinois
EPA’s investigations to date have not located any private wells
north of Playfield Cleaners to the Calumet-Sag Channel. Since IEPA has
found no evidence of anyone drinking private well water in the path of
groundwater flow and the PWS well has been sealed, the Agency has concluded
that no one is currently exposed to these contaminants. The Illinois
EPA will assist the state and federal health authorities in their efforts
to identify any potential health impacts from past exposure to tainted
Crestwood PWS water. Although fortunately there is no current exposure
threat from this contamination, the Illinois EPA is evaluating further
investigative options to determine the extent of the historical groundwater
contamination at deeper levels, as well as enforcement activities directed
toward source (soil) cleanup at the Playfield Cleaners site.
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