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Background: To address Tetrachloroethylene (Perc) contamination identified in the area of a former dry cleaner (tenant spaces addressed as 2410-2412 10th Avenue) at the Sunrise Shopping Center facility, chemical treatment was conducted between May 2019 and January 2020, and a sub-slab depressurization system was installed/operated in the 2410 and 2412 tenant spaces beginning in 2020. No additional remedial actions are planned for this Site at this time.
Quarterly Monitoring Well Sampling: Quarterly groundwater sampling for Perc was conducted on MW-5 on January 24 and April 11, 2022, with results provided in Quarterly Groundwater Sampling Reports dated March 1, 2022, and May 31, 2022. The quarterly sampling results continue to show Perc in MW-5 at concentrations above the Enforcement Standard. The most recent results (April 2022) show a decrease in concentration to a level consistent with the relatively stable concentrations previously observed between September 2019 and May 2021. (There was a short period of higher concentrations observed between August 2021 and January 2022.) Quarterly sampling will continue until a Case Close Out Letter is issued for the Site.
PFAS Sampling: In addition to conducting quarterly groundwater sampling activities, four (4) new monitoring wells (MW-600 to MW-603) were installed in January 2022 and groundwater sampling for per- and polyfluoroalkyl substances (PFAS) was performed in February 2022. (PFAS sampling of previously existing monitoring wells had been previously completed in 2021.) The well installation and groundwater sampling procedures and results were discussed in the Emerging Contaminant Evaluation Report Addendum dated March 28, 2022. The report showed that only the most upgradient monitoring well (MW-603) was reported with any PFAS constituents above the applicable standards, indicative of an upgradient, off-site source of the PFAS contamination observed on-site. In a response email of April 7, 2022, WDNR requested another complete round of PFAS sampling to further evaluate concentrations and trends.
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