Umatilla Army Depot Lagoons

⚠ Superfund · Cleanup underway

EPA and the Army divided the site into eight areas, referred to as operable units, or OUs. EPA and the Army selected long-term remedies for seven of the eight OUs between 1992 and 1994. The remedy for the eighth OU, Site 39, was selected in 2008.

Location

CityHermiston
CountyMorrow County
StateOregon
Coordinates45.83611, -119.45000

Contaminants of concern

Contaminated media

Cleanup timeline

  1. Initial Assessment Completed — 12/01/1982
  2. Proposed to the National Priorities List — 10/15/1984
  3. Finalized on the National Priorities List — 07/22/1987
  4. Remedial Investigation Started — 01/26/1990
  5. Remedy Selected — 09/25/1992
  6. Final Remedy Selected — 06/01/2005
  7. Remedial Action Started — 02/15/1994
  8. Final Remedial Action Started — Estimated Oct - Dec 2027
  9. Construction Completed — Not Yet Achieved
  10. Deleted from National Priorities List — Not Yet Achieved

EPA references

EPA-regulated facilities nearby

Understanding this Superfund site

Umatilla Army Depot Lagoons is a federal Superfund site in Oregon. 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: Cleanup underway. Active cleanup is underway, meaning EPA has approved a remediation plan and work is in progress. Cleanup timelines vary widely — some sites take decades depending on contamination depth, groundwater involvement, and funding availability.

EPA has identified 10 contaminants of concern at this site, including 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (hmx), 1,3,5-trinitrobenzene, 1,3-dinitrobenzene. Contamination has been detected in liquid waste, sludge, groundwater, debris, soil, sediment.

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.