Tetrachloroethylene (PCE) and trichloroethylene (TCE) contaminate groundwater and soil gas beneath and around the former Chrysler plant on Leo Street in Dayton, Ohio, now owned by MAHLE Behr Dayton LLC. The plume has migrated south and southwest into the McCook Field and Old North Dayton neighborhoods. EPA added the site to the Superfund National Priorities List in April 2009. The main cleanup focus is Operable Unit 01 (OU-01), which targets the VOC plume directly.
The primary health concern is vapor intrusion, where PCE and TCE vapors rise from contaminated groundwater into the indoor air of homes and businesses. Between 2006 and 2009, investigations found nearly half the homes in the affected area had indoor air contamination from the site. Over 250 vapor abatement systems were installed to bring TCE levels down to safe levels. MAHLE has been required since 2009 to operate, maintain, and monitor these systems and add new ones where needed. In January 2018, MAHLE started running an air sparging and soil vapor extraction system at the southern edge of its facility to treat the most heavily contaminated part of the plume. The Ohio Department of Health conducted a cancer incidence assessment in the neighborhood. Total cancer rates were elevated, but high lung cancer rates driven largely by smoking accounted for the spike. Cancers potentially linked to TCE, including kidney cancer, liver cancer, and Non-Hodgkin Lymphoma, were not found at significantly elevated rates.
EPA issued an interim Record of Decision in September 2019 selecting air sparging and soil vapor extraction to treat the broader plume, along with continued vapor intrusion monitoring, active depressurization in buildings, and institutional controls such as zoning restrictions. In 2021, MAHLE and Aramark agreed to design this expanded cleanup. As of 2024, contractors are completing additional environmental investigations to finalize the cleanup design. Remedial design is estimated to wrap up between November 2026 and January 2027, with full remedial action expected to begin between November 2027 and January 2028. Current performance data show insufficient information to confirm that human exposure and groundwater migration are under control. All properties in the area receive municipal water, and no contaminated private drinking water wells have been found.
Community members can engage through the Behr, Valleycrest and Valley Pike Community Advisory Group, which has hosted public education sessions with EPA covering vapor intrusion, the cleanup process, and remedy selection. Materials are available in English and Spanish. Residents are encouraged to allow free vapor intrusion sampling at their properties and to maintain any installed mitigation systems. For site-specific questions, EPA project contacts are available, and Public Health Dayton and Montgomery County or the Ohio Department of Health can address broader health concerns.
