The U.S. Army Corps of Engineers has been conducting ongoing investigations into potential chemical contamination stemming from a decommissioned Titan-1 missile site in Placer County, California. This Cold War-era relic, situated near the Sun City Lincoln Hills development, has been a source of environmental concern due to its history of chemical leakage. The most recent data collected from the site has revealed some unexpected findings, shedding new light on the extent and nature of the contamination.
The Titan-1 missile site, operational for only three years during the Cold War, was part of a network of nuclear missile bases across the United States. The Lincoln site, one of three in California, encompassed dozens of acres and featured an extensive underground complex, including three 160-foot-deep silos and miles of tunnels. During its brief period of operation, trichloroethylene, a toxic chemical, was used for cleaning purposes. Over time, TCE leaked into the surrounding soil and groundwater, creating a plume that has been slowly moving towards the Sun City Lincoln Hills community, home to approximately 11,000 residents aged 55 and older.
Recent data collected by the Army Corps of Engineers has provided some reassurance to nearby residents. New soil vapor monitoring probes installed closest to the Sun City homes have not detected any signs of TCE, which had been the primary chemical of concern. This finding suggests that the TCE plume may not have reached as close to the residential area as previously feared. However, the investigation did uncover the presence of low levels of benzene in the wells nearest to the homes. Benzene, a known carcinogen, was detected in two soil vapor probes near Sun City homes and three near the neighboring St. Joseph Catholic Church.
The source of the benzene contamination remains unclear, as it is not typically associated with the operations of Titan-1 missile sites. Experts suggest that the benzene may have originated from other sources, given the long period since the site's decommissioning. A toxicologist present at a recent Restoration Advisory Board meeting stated that the measured levels of benzene would pose no greater risk than that encountered when filling up a car at a gas station. This comparison aims to provide context and alleviate immediate health concerns among residents.
The Army Corps of Engineers has been working on cleanup efforts at the site since the early 2000s. Initial attempts involved using extraction trenches and wells, which successfully removed 10 pounds of TCE from the groundwater. However, these efforts were paused in 2009 due to questions about responsibility for the cleanup between the Army Corps and the county. Between 2000 and 2022, the TCE-contaminated groundwater plume spread at an average rate of 87 inches per year, moving a total of 150 feet towards Sun City Lincoln Hills.
To address community concerns and improve transparency, the Army Corps formed a Restoration Advisory Board consisting of 11 volunteer residents. This board serves multiple functions, including communicating updates to the neighborhood, providing oversight of the Army Corps' processes, and helping to dispel fears and misunderstandings about the site's dangers. The board is working on creating fact sheets and meeting with real estate agents to ensure accurate information is disseminated to the public.
As the investigation continues, the Army Corps is following the federal Comprehensive Environmental Response, Compensation, and Liability Act process, which requires thorough internal review and comments before the final report can be released to the public. This report, expected in the coming weeks, will provide a more comprehensive analysis of the latest findings and their implications for the surrounding community. The ongoing monitoring and cleanup efforts at the former Titan-1 missile site underscore the long-lasting environmental impacts of Cold War-era military installations and the importance of continued vigilance in addressing potential health risks to nearby populations.
