Twin Cities Army Ammunition Plant
New Brighton, MN (Anoka County)
- EPA ID# MN7213820908
- NPL Factsheet
- Superfund Site Progress Profile
- Alias(es): New Brighton/Arden Hills; Ramsey County ;TCAAP; US Army Twin Cities Amo Plant
Community Involvement Coordinator
Nefertiti DiCosmo (firstname.lastname@example.org)
312-886-6148 or 800-621-8431, ext. 66148
Remedial Project ManagerThomas Barounis
312-353-5577 or 800-621-8431, ext. 35577
U.S. Army Offices
470 West Highway 96
Suite 100 Shoreview, MN
Access can be arranged by contacting:
Mike Fix (email@example.com) (651) 294-4930.
The New Brighton/Arden Hills Superfund Site consists of the Twin Cities Army Ammunition Plant (TCAAP) and all other areas of the surrounding communities historically contaminated by the migration of hazardous substances or contaminants from TCAAP. Between 1941 and 1981, wastes were disposed at 14 areas, or sites, within TCAAP. The U.S. Army is the responsible party for the New Brighton/Arden Hills Superfund Site.
The wastes disposed at TCAAP included volatile organic compounds (VOCs), semi-VOCs, metals, polychlorinated biphenyls (PCBs), cyanide, pesticides, and explosives. The primary impact to the surrounding communities has resulted from VOC contamination of the regional groundwater resource, which is used for municipal and private water supplies.
The construction of a granular activated carbon (GAC) treatment system for the Village of St. Anthony by U.S. EPA and MPCA was completed in 1991, pursuant to a September 1986 Record of Decision. The remedy for the site was addressed in three stages or operable units. Operable Unit 1 (OU1) addresses the North Plume of contaminated groundwater, which has migrated off-TCAAP; Operable Unit 3 (OU-3) addresses the smaller, South Plume.
The OU1 and OU3 RODs provide for containment pump-and-treat systems comprised of wells, which serve the dual purposes of containment and municipal water supply for the city of New Brighton. Temporary treatment (GAC) was installed for the New Brighton system in 1983. The permanent GAC facility for OU 1 was constructed in 1990, with two additional extraction wells added into the OU 1 system in 1996 and 1998, completing the OU 1 ground water extraction system. The OU 3 groundwater extraction and GAC treatment system was completed in 1994. For a number of years, VOC levels in monitoring wells in the South Plume extraction well vicinity were consistently non-detect, and the system was shut off in 2001. An amendment to the OU3 ROD removes groundwater extraction and associated remedy components and retains the alternate water supply, groundwater monitoring and institutional control components of the original remedy.
The last component of the final remedy for the site was for Operable Unit 2 (OU2). The remedy addressed the contaminated soil and groundwater within the TCAAP boundary. By summer 1999, major components of the soils remediation component of the OU2 remedy were begun. By summer 2002, the TCAAP remedial and removal actions were largely complete, though additional soil removal and other small removal actions occurred since 2002 (and will yet occur). The installation of soil covers was completed in 2008. An extensive long-term monitoring program for groundwater and surface water is currently in place and will continue well into the future. In 2011, a sediment investigation was completed for Round Lake. The results of the investigation will support the development of a final feasibility study for Round Lake, to be completed in 2013.
The City of New Brighton has been an integral partner with the Army in the successful implementation and operation of the OU1 and OU3 groundwater extraction and cleanup remedies because it is the City's municipal wells, which serve as the extraction wells for these remedies. Of the approximately 2400 acres of the original TCAAP area, control over 1500 acres has been transferred to the U.S. Army Reserve and the Minnesota National Guard. Smaller portions have been transferred to Ramsey County for a public works facility and a wildlife corridor, and the City of Arden Hills for a new City Hall.
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- Record of Decision (PDF) June 1983
- Appendix G - Rice Creek Sampling Locations and Analytical Measurement
Results (PDF) (12pp, 411K)