Solid State Circuits, Inc. is a Superfund site in downtown Republic, Missouri. The company made printed circuit boards there from 1968 to 1973, using trichloroethene (TCE) and related solvents. TCE turned up in the city's municipal well in 1982. The site was added to the National Priorities List (NPL), the federal list of priority cleanup sites, in June 1986. It remains on the NPL today.
Seven contaminants have been found in groundwater at the site. They are 1,1,1-trichloroethane, 1,1-dichloroethane, 1,1-dichloroethene, vinyl chloride, methylene chloride, trans-1,2-dichloroethene, and trichloroethene. All are volatile organic compounds (VOCs). EPA determined that each one poses unacceptable risk to human health or the environment at the levels present.
Early cleanup work in the mid-1980s removed contaminated soil from the basement and surrounding area. A groundwater extraction and treatment system was later installed. A fire destroyed that treatment system on December 8, 2011, and it is no longer operating. The remedy was organized into two operable units (OUs). The main remedial unit, OU 01, had its original cleanup plan set in a Record of Decision from September 1989. A 2004 update shifted the approach from surface water discharge to reinjection into the contaminated aquifer. A new feasibility study for OU 01 began in July 2020 and is estimated to wrap up between August and October 2028. A third round of injection treatment targeting source material was scheduled for the week of July 22, 2024. Three new monitoring wells were installed in December 2024 to support ongoing groundwater assessment.
The Missouri Department of Natural Resources leads the cleanup, with EPA in a support role. The responsible party is operating under a Force Majeure agreement. The seventh such agreement was signed on December 18, 2024. The most recent five-year review was completed on September 2, 2022. The next is estimated between September and November 2027. Current conditions show no one is being exposed to contaminants at unacceptable levels, and groundwater migration is under control. However, not all cleanup goals have been met, and the site is not yet ready for all anticipated uses.
Community members with questions can contact the Community Involvement Coordinator or the Remedial Project Manager. For state-related questions, contact the Missouri Department of Natural Resources.
