Twin Cities Army Ammunition Plant (U.S.)

The Twin Cities Ordnance Plant (TCOP) was established in 1941 as part of the War Department’s government-owned, contractor-operated war materials production program. Federal Cartridge Corporation (FCC) was awarded the contract to construct and operate the plant, which resided in Mounds View Township (later apportioned as the cities of Arden Hills, Mounds View, and New Brighton) and whose mailing address was New Brighton, Minnesota. Construction began August 28, 1941, and production of .30 and .50 caliber cartridges began on February 2, 1942. TCOP produced more than four billion rounds by war’s end and at its peak (July 1943) employed approximately 26,000 people-more than half of whom were women.

Production ceased in July 1945, the Army’s contract with FCC was terminated in March 1946, and TCOP was put on standby. The Army’s Ordnance Department assumed plant management, renaming it the Twin Cities Arsenal on April 1, 1946. In response to the Korean War, the Arsenal resumed production in August 1950 when the federal government again contracted with FCC. In August 1958, the Arsenal was again put on standby.

The Army was reorganized in 1962, and the Ordnance Department was subsumed by the newly created Army Material Command. Consequently, the Arsenal was renamed the Twin Cities Army Ammunition Plant (TCAAP) in 1963. In response to the escalating Vietnamese conflict in Southeast Asia, TCAAP produced small arms (1966-1973) and artillery shells (1967-1976).

Over the years, the plant experienced several work stoppages and strikes, including 1951 (construction workers), 1967 (National Association of Machinists and Aerospace Workers), 1971, and 1972 (People’s Blockade war protestors).

Due to contaminated soil, surface water, and ground water both onsite and in nearby wells, TCAAP underwent significant environmental remediation between 1981 and 1989. The Environmental Protection Agency added the plant to its National Priorities List (also known as a Superfund site), Minnesota's largest at that time. As of 2008, cleanup treatment continues onsite.

In the mid-1990s, the Secretary of the Army and the General Services Administration (GSA) began to consider plans for divesting Army ownership of TCAAP. U.S. Representative Bruce Vento (DFL-Minn.) formed a committee to consider alternatives, whose recommendations were known informally as "The Vento Plan."

Redevelopment of the site has been incremental and ongoing. In 2004 Ramsey County purchased for its regional park system acreage surrounding Rice Creek. In 2007 the city of Arden Hills purchased the site from the GSA and is planning for a mixed-use housing and business development.