mgm brakes


The MGM Brakes Superfund site is an approximately 5-acre area located in Sonoma County in the southern portion of the City of Cloverdale, California. The site is located at the southwest corner of the intersection of Donovan Road and South Cloverdale Boulevard. Cloverdale is an agricultural community of approximately 4,500 residents. Runoff from the site drains into Icaria Creek, which is a tributary to the Russian River. The Russian River is approximately 1 mile east of the site. The groundwater aquifer underlying the site is used as a public drinking water source. Water is provided by the South Cloverdate Water Company and is collected from two wells located one-half to three-quarter miles upgradient and to the east of the Site. No downgradient water supply wells have been identified. From 1962 until operations ceased in 1982, the MGM Brakes facility manufactured and cast aluminum brake components for large motor vehicles. The facility consisited of a casting plant building, seven above ground tanks, a cooling tower, and a storage shed. From 1965 until 1972, hydraulic fluids containing polychlorinated biphenyls (PCBs) were used in the casting machines. These hydraulic fluids leaked from the casting machines in the normal course of plant operations and were then collected, together with water used to cool the dies between castings, in floor drains. Following gravity separation of oils and grease, the wastewater containing PCBs was discharged, via a drain line, to the ground adjacent to the casting plant. The use of hydraulic fluid containing PCBs was gradually discontinued in 1973, but wastewater containing ethylene glycol (the hydraulic fliud later used in the casting machines) continued to be discharged in the same manner until 1981. The practice of discharging wastewater onto the vacant fields surrounding (mostly to the south) of the casting plant building is believed to be the main cause of contamination at the site. On August 11, 1981, the North Coast Regional Water Quality Control Board (NCRWQCB) conducted a site inspection in response to a citizen complaint. During the inspection they noted the presence of oily soil. The soil was found to be contaminated with PCBs. The State ordered the company to stop all discharge activity and to investigate the nature and extent of contamination. The owners of the site, TBG, Inc. and Indian Head Industries, Inc. conducted additional sampling under state oversight from 1981 to 1983. PCB contamination was detected in surface water runoff, surface and subsurface soil, and inside the casting plant building. In 1986, volatile organic compounds (VOCs) were detected in groundwater at the northeastern and southeastern boundary of the MGM Brakes property and in groundwater on parcels 62 and 63 immediately adjacent to the northeastern and southeastern boundary of the property. The detected VOCs were benzene, chlorobenzene, cis-1,2-dichloroethylene, 1,4-dichlorobenzene, 1,1-dichloroethylene, 1,1,1,-trichloroethane, trichloroethylene, and vinyl chloride. EPA assumed lead agency responsibility for oversight of site investigation and cleanup activities in 1983 when the site was added to the National Priorities List. All demolition and cleanup activies described below in the section titled "Cleanup Approach" have been completed. A Voluntary Covenant and Agreement to restrict use of certain portions of the site was recorded in Sonoma County in July 1995. Groundwater was sampled on a semi-annual basis to monitor the progress of natural attenuation until October 2013 when groundwater contamination was below maximum contamination levels (MCLs) for all contaminants of concern.

Hazardous Ranking Score

35 / 100

A score of 28.5 or higher qualifies a site for the Superfund National Priority List.

Regional Contact

Region 9
Phone: (415) 947-4251

Contact Region



Site Inspection
Preliminary Assessment
Final Listing On NPL

Contaminants & Health Effects

      Endocrine Disrupter
      Reproductive Toxin
      Persistent, bioaccumulative and toxic


        African American
        American Indian and Alaska Native
        Native Hawaiian


        People living
        within a 1 mile radius


        Average Income


        Occupied homes

        Potentially Responsible Parties

        Similar Sites

        Add Story


        No stories have been submitted for this site.