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Background: Polynuclear Aromatic Hydrocarbon (PAH) contamination was identified within two (2) areas at the Sunrise Shopping Center facility: within the area of a former heating oil UST behind the 2414B 10th Avenue tenant space (location of monitoring well MW-4) and within the southern extent of the site (location of MW-3). The PAH contamination continues to be monitored during quarterly groundwater monitoring.
Quarterly Monitoring Well Sampling: Two (2) quarterly groundwater sampling events were conducted during the first semi-annual 2023 reporting period. Quarterly groundwater sampling for PAHs was conducted at MW-3 and MW-4 on January 6 and April 21, 2023, with results provided in Quarterly Groundwater Sampling Reports dated February 7 and May 19, 2023. The most recent quarterly sampling results indicate that the PAH constituents of concern include Benzo(a)pyrene, Benzo(b)fluoranthene, and Chrysene. The site-wide presence of fill material (including coal and cinders remaining from the historical use of the property) likely contributes to the observed PAH groundwater concentrations. The April 2023 sampling results of MW-3 indicate stable concentrations consistent with the concentrations observed between July 2019 and May 2021. The sampling results from MW-4 are also stable and consistent with the earlier results observed from April through October 2022. No free-product petroleum has been noted in MW-4.
No active remediation is currently being conducted, nor is any proposed. Quarterly sampling will continue until a Case Closure Letter is issued for the Site. A Case Closure Report is to be submitted in August 2023. The Case Closure Report will be proposing exclusion from the requirement to reduce concentrations based upon an incomplete exposure pathway. Drinking water is provided by the municipality via Lake Michigan and there are no potable groundwater wells on-site.
PFAS Sampling: WDNR approved the completion of per- and polyfluoroalkyl substances (PFAS) sampling in an email dated November 7, 2022. No additional PFAS groundwater sampling activities were conducted during the January-June 2023 semi-annual period.
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