United States Environmental Protection Agency OLEM/OSRTI Washington, DC 20460 ***NPL Site*** March 2024 LOT 46 VALLEY GARDENS TCE Des Moines, Iowa Polk County (f) Site Location: The Lot 46 Valley Gardens TCE site encompasses approximately a half-mile-long plume of contaminated groundwater containing chlorinated volatile organic compounds (CVOC) in an area south of downtown Des Moines and the Raccoon River in Polk County, Iowa. The area is zoned as mixed use, light industrial, and heavier commercial uses, and hosts a variety of manufacturing businesses, commercial properties, and scattered residential properties. xl Site History: In 2004, the Iowa Department of Natural Resources (IDNR) began investigating contamination. In 2020, IDNR sent a Request for Federal Action (RFA) to the EPA. IDNR has been unsuccessful at compelling the potentially responsible party to take remedial actions to mitigate the plume, which extends from the facility. The search for additional potentially responsible parties is ongoing. xl Site Contamination/Contaminants: CVOC contamination, including tetrachloroethene (PCE), trichloroethylene, (TCE), and degradation products, are exceeding the Safe Drinking Water Act Maximum Contaminant Levels (MCLs) in groundwater. xl Potential Impacts on Surrounding Community/Environment: A half-mile-long plume of contaminated groundwater containing chlorinated volatile organic compounds is approaching the groundwater infiltration intake for the city of Des Moines Water Works (DMWW), which serves a population of approximately 550,000 individuals as the primary municipal water supply source. ^ Response Activities (to date): From 2004 until 2020, IDNR installed 200 temporary and 24 permanent monitoring wells to characterize the aquifer. Between 2021 and 2023, EPA's Superfund Removal program performed integrated assessments at the site to explore removal options that can be completed within regulatory limitations. Need for NPL Listing: The state of Iowa referred the site to the EPA because no other viable options for investigation and potential long-term remediation were available. Other federal and state cleanup programs were evaluated but are not viable at this time. The EPA received a letter of support for placing this site on the NPL from the state. [The description of the site (release) is based on information available at the time the site was evaluated with the HRS. The description may change as additional information is gathered on the sources and extent of contamination. See 56 FR 5600, February 11, 1991, or subsequent FR notices.] For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet at https://www.atsdr.cdc.gov/toxfaqs/index.asp or by telephone at 1-800-CDC-INFO or 1-800-232-4636. ------- |