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Umatilla Army Depot Activity

Summary Information
(last updated on: 12/1/2014 11:13:44 AM)
[Jan. 2009] The Umatilla Army Depot (also known as the Umatilla Chemical Depot) is a 19,728-acre facility formerly used for the storage, maintenance, and demilitarization (deactivation and/or disposal) of conventional munitions and weapons of various types, including the storage of chemical weapons. The Depot opened in 1941. From the 1950s to 1965, approximately 85 million gallons of explosives-contaminated wastewater was discharged into two unlined lagoons. Soil and groundwater beneath the lagoons were contaminated. Explosives residues and lead were found in surface and subsurface soils at other locations throughout the Depot, from past disposal practices. In one 1,750-acre area, unexploded ordnance (bombs, mines, grenades, etc.) was on the surface and in subsurface soil. No contaminants migrated off the Depot property. In July 1987, EPA placed the site on the National Priorities List. In October 1989, a Federal Facilities Agreement was signed by EPA, DEQ and the Army. The agreement required the Army to investigate and clean up the site in accordance with CERCLA and with DEQ's Environmental Cleanup Rules. Eight operable units (study areas) were designated. Units 1 and 2 consisted of the soil and groundwater, respectively, beneath the Explosive Washout Lagoons. Unit 3 was the Explosives Washout Plant. Unit 4 was the soil around the former small arms Deactivation Furnace. Units 5 and 6 consisted of one active and several inactive landfills, respectively. Unit 7 was the 1,750-acre Ammunition Demolition Activity (ADA) Area. Unit 8 was a catch-all unit consisting of 32 distinct sites where hazardous substances may have been disposed of or released. In 2004, under a Hazardous Waste Permit, the Depot began destruction of the chemical stockpile.
General Site Information
Site: Umatilla Army Depot Activity (ECSI Site ID: 514) CERCLIS (EPA) Id6213820917
Project Manager: David Anderson Investigative Status:Listed on the Confirmed Release List or Inventory
PM Phone: (541) 633-2012 NPL(National Priority Listing):Yes
Address: I-84 & Exit 178 Is this site an Orphan?No
Hermiston, 97838 Is this site a brownfield?No
County: UMATILLA Action Underway or Needed: REMEDIAL ACTION
Region: Eastern Region Click for more details ...  
Site Documents
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File NameCategory File Size MB Document Date Upload Date
Draft 2006-2007 EWL Annual Report-no appendices2.pdf Reports 3.1551 1/20/2009
UMAD_OU3_FS_December_1993_text.pdf Reports 3.4606 1/28/2009
UMAD_OU3_FS_December_1993_figures.pdf Reports 1.1980 1/28/2009
UMAD_OU3_FS_December_1993_tbls.pdf Reports 0.8487 1/28/2009
UMAD_OU3_FS_December_1993_Appendices.pdf Reports 2.3689 1/28/2009
UMAD_Misc_OU_RemedialActionReport_text.pdf Reports 2.4467 1/29/2009
UMAD_Misc_OU_RemedialActionReport_Appendices.pdf Reports 1.8574 1/29/2009
UMAD_OU3_Soil_RemedialActionReport_text.pdf Reports 4.0692 1/29/2009
UMAD_OU3_Soil_RemedialActionReport_AppendixI_III.pdf Reports 3.1539 1/29/2009
UMAD_OU3_Soil_RemedialActionReport_Appendix_IV.pdf Reports 3.1936 6/9/2010
Site Links
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LinkDescription
DEQ Umatilla Depot Demilitarization page Additional information on Chemical Demilitarization at Umatilla
Umatilla Army Depot (Lagoons) | Region 10 | US EPA Additional information on the environmental cleanup from EPA
Photographs

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ECSI#514
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Oregon Department of Environmental Quality
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