Castle Air Force Base 6 Areas

⚠ Superfund · Ready for anticipated reuse

The site was originally divided in to three operable units (OUs), two groundwater OUs (OU-1 and OU-2) and one soil OU. The soil OU is referred to as the Source Control Operable Unit (SCOU). The two groundwater OUs were later combined into one groundwater OU.

Location

CityMerced
CountyMerced County
StateCalifornia
Coordinates37.36736, -120.56360

Contaminants of concern

Contaminated media

Cleanup timeline

  1. Initial Assessment Completed — 04/01/1984
  2. Proposed to the National Priorities List — 10/15/1984
  3. Finalized on the National Priorities List — 07/22/1987
  4. Remedial Investigation Started — 07/21/1989
  5. Remedy Selected — 08/12/1991
  6. Final Remedy Selected — 07/03/2006
  7. Remedial Action Started — 03/04/1993
  8. Final Remedial Action Started — 07/03/2006
  9. Construction Completed — 09/21/2006
  10. Deleted from National Priorities List — Not Yet Achieved

EPA references

EPA-regulated facilities nearby

Understanding this Superfund site

Castle Air Force Base 6 Areas is a federal Superfund site in California. The Superfund program, created by Congress in 1980, addresses sites where hazardous substances have been released or threaten release into the environment. EPA scores potential sites using the Hazard Ranking System; those that score high enough are placed on the National Priorities List.

Current status: Ready for anticipated reuse. EPA considers this site ready for anticipated reuse, meaning cleanup has progressed enough for certain land uses. This does not necessarily mean all contamination has been removed — institutional controls like deed restrictions may limit how the land can be used.

EPA has identified 10 contaminants of concern at this site, including 1,1,1-trichloroethane, 1,1-dichloroethane, 1,1-dichloroethene. Contamination has been detected in soil, groundwater.

If you live near this site and have health concerns, your state health department can provide site-specific guidance. EPA maintains a community involvement program for most NPL sites, and site documents — including the Record of Decision, five-year reviews, and public health assessments — are typically available through EPA's Superfund site profile.