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Remediation System Evaluation, Modesto Groundwater Contamination Superfund Site

The Modesto Groundwater Contamination Site is located in a commercial area on McHenry Avenue south of West Fairmont Avenue in the City of Modesto, Stanislaus County, California. The remedy at the site addresses tetrachloroethylene (PCE) contamination primarily from Halford’s Cleaners, located at 941 McHenry Avenue. Contamination originally was discovered in municipal water supply Well 11 in 1984. The well was shut down until 1991 when granular activated carbon units were added to treat the water. However, in 1995 uranium concentrations above the maximum contaminant levels (due to naturally occurring uranium) were detected in the extracted water, and the well was shut down.

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