Placer County, Northern California

December 2023 Update

Background:

In the 1950s and 1960s, the United States Air Force operated a missile site in Placer County, Northern California. The site was used to store and launch intercontinental ballistic missiles (ICBMs). During this time, various chemicals, including propellants, solvents, and fuels, were used and stored at the site.

In the 1980s, the Air Force began to decommission the missile site. As part of the decommissioning process, the Air Force conducted an environmental assessment of the site. The assessment found that several areas of the site had been contaminated with chemicals, including volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), and heavy metals.

Recent Investigation:

In 2023, the California Department of Toxic Substances Control (DTSC) conducted a new investigation of the former missile site. The investigation included the collection of soil and groundwater samples from several areas of the site. The samples were analyzed for a variety of chemicals, including VOCs, SVOCs, and heavy metals.

Results:

The results of the DTSC investigation showed that several chemicals are still present in the soil and groundwater at the former missile site. The most commonly detected chemicals were:

- Trichloroethene (TCE)

- Tetrachloroethene (PCE)

- Benzene

- Toluene

- Ethylbenzene

- Xylene

These chemicals are all known carcinogens and can cause a variety of health problems, including:

- Cancer

- Nervous system damage

- Reproductive problems

- Developmental disorders

Extent of Contamination:

The DTSC investigation found that the chemicals are present in the soil and groundwater at various depths and concentrations. The highest levels of contamination were found in the areas where the chemicals were stored and used.

The contamination has also spread to nearby surface water bodies, including a stream that runs through the site. The contamination has not yet reached any drinking water wells, but it is a potential threat to groundwater resources.

Cleanup Efforts:

The DTSC is currently working with the Air Force to develop a plan to clean up the contamination at the former missile site. The cleanup plan will involve removing the contaminated soil and groundwater and treating the contaminated surface water.

The cleanup is expected to take several years to complete. In the meantime, the DTSC is taking steps to prevent the contamination from spreading and to protect public health. These steps include:

- Restricting access to the site

- Posting warning signs

- Providing bottled water to residents who live near the site

Conclusion:

The recent DTSC investigation has confirmed that several chemicals are still present in the soil and groundwater at the former missile site in Placer County, Northern California. The chemicals are all known carcinogens and can cause a variety of health problems. The DTSC is working with the Air Force to develop a plan to clean up the contamination.