Background/ History
The General Motors Wentzville Assembly Center (GM-Wentzville) is a division of General Motors - North American Operations. The facility is located on about 440 acres, of which about 75 acres are under roof, at 1500 E. Route A in Wentzville. Operations at the site began in 1983 and include the assembly of vans, extended vans and cut-aways that connect to other units such as mobile homes. The general processes auto assembly, general maintenance, body washing, auto painting, wastewater treatment, storm water management and power generation.
A variety of hazardous wastes were produced as part of the facility operations. GM-Wentzville stored the hazardous waste in a 20,000-gallon bulk waste storage tank and in 55-gallon drums on the covered drum storage pad before shipping off-site for disposal. GM-Wentzville operated the hazardous waste drum and tank storage areas under the “interim status” portions of the federal Resource Conservation and Recovery Act (RCRA).
Cleanup Summary
GM-Wentzville closed the drum storage pad and bulk waste storage tank, which was located within a former tank farm, in November 1992. Both the hazardous waste drum and tank storage areas were clean closed. No groundwater contamination is known to result from these areas. The department accepted the closure certifications for all the regulated hazardous waste management units in 1993. GM-Wentzville built a new hazardous waste container storage area and bulk waste storage area for less than 90-day storage. GM-Wentzville no longer stores hazardous waste at the site for more than 90 days. The storage areas are managed under generator storage requirements in 10 CSR 25-5. GM-Wentzville is not subject to the permitting requirements of the Missouri Hazardous Waste Management Law or federal Hazardous and Solid Waste Amendments for post-closure care because they “clean closed” the interim status hazardous waste areas.
GM-Wentzville is subject to corrective action because they completed closure of the interim status hazardous waste management units after the effective date of the federal Hazardous and Solid Waste Amendments. An Environmental Protection Agency (EPA) Environmental Priorities Initiative Preliminary Assessment Report, completed in March 1992, identified several areas at the site that required further investigation. GM-Wentzville is currently a candidate for an administrative order or Letter of Agreement. GM-Wentzville currently maintains an on-site wastewater treatment system, metals being the main constituents of wastewater that requires treatment. GM-Wentzville completed a RCRA Facility Investigation. The department is working with GM-Wentzville to implement an Environmental Covenant for the facility.
