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ANOKA COUNTY
FRIDLEY
Congressional District # 05
NAVAL INDUSTRIAL RESERVE ORDNANCE PLANT
EPA ID# MN3170022914Last Updated: March, 2009
Site Description
The Naval Industrial Reserve Ordnance Plant (NIROP) is an 83-acre site, located 700 feet from the Mississippi River, where the U.S. Navy and its contractors have produced advanced weapons systems since 1940. In 1981, trichloroethylene (TCE) was discovered in NIROP groundwater wells and in the city of Minneapolis's drinking water treatment plant intake, which is located approximately 1,500 feet downstream from the site in the Mississippi River. In 1983, investigations identified pits and trenches in the North 40 area of NIROP, where drummed wastes had been disposed. Contaminated soil and drums were excavated from North 40 and disposed of offsite. A remedial investigation and feasibility study (RI/FS) was completed in August 1988, which indicated that groundwater contaminated primarily with TCE was flowing into the Mississippi River at 37 parts per million (ppm); as of October 2006, compliance wells along the Mississippi have reduced that number with 3 wells between 110 to 380 parts per billion (ppb), 10 wells averaging less than 100 parts per billion (ppb), and 3 wells under Maximum Contaminant Level (MCL) of 5 ppb. The Safe Drinking Water Act set the MCL for TCE at five parts per billion (ppb). Over 200,000 people live within three miles of the site. An estimated 29,000 people obtain drinking water from public wells within three miles of the site. the city of Minneapolis with a population of 500,000 people uses the Mississippi River as its primary drinking water source.Site Responsibility
This site is being addressed through federal and state actionsThreats and Contaminants
Onsite groundwater and soils are contaminated with solvents, including TCE and methylene chloride. Highly permeable sands, conducive to the downward migration of contaminants, lay beneath the facility. Also, polycyclic aromatic hydrocarbons (PAHs) were detected in subsurface soils. Potential health risks exist for individuals who ingest or come into direct contact with contaminated groundwater or soil.Cleanup Progress
A Record of Decision (ROD) for Operable Unit 1 (OU 1) was issued on September 28, 1990, which selected a remedy to hydraulically contain the TCE plume via a groundwater extraction well system. In September 1992, a groundwater extraction well system was started which partially contained TCE contaminated groundwater. In 1995, the groundwater extraction system was modified and hydraulic containment obtained. Under the Phase I treatment, extracted groundwater was being treated at a local wastewater treatment plant. From September 1993 to April 1997, 968,992,857 gallons of contaminated groundwater had been pumped and treated. The Phase II treatment required construction of an onsite treatment system. The Phase II treatment plant construction was completed in November 1998, and treated groundwater is now being discharged to the Mississippi River. Additional modifications to the groundwater extraction system were completed in fall 2001, including the installation of four new extraction wells and the abandonment of three old extraction wells. The groundwater extraction system currently consists of seven wells. As of June, 2008, a total of 2,367,950,000 gallons have been extracted and process through the system. Also, as of June, 2008, effluent sampling from outfall 020 show all analytes are below permit limits. Additional software and hardware upgrades have been made to the system.In September 1993, the U.S. Navy completed an investigation of sources in the North 40 outside of the 57-acre NIROP building, (OU2), which may have contributed to groundwater contamination. During that investigation, 33 drums of chlorinated solvents were removed and disposed of offsite. In 2002, 35 cubic yards of contaminated soil at a depth of 0-3 feet below ground surface was removed from OU2.
During summer 1997, a two-phase remedial investigation of OU3 began. This investigation addressed potential source areas under the 57-acre NIROP building. The first phase of the investigation was completed in October 1997. The second phase of the investigation was completed by spring 1998.
In late summer 2002, the Navy completed a proposed plan to address source contamination both outside of the 57-acre NIROP building (OU2) and under the NIROP building itself (OU3). The proposed plan called for engineering and institutional controls. Subsequently, Institutional Controls (IC) have be placed on OU2. The first prohibits the disturbance of soils deeper than 3 feet below ground surface without prior written approval of the U.S EPA (EPA) and MPCA. The second IC restricts the property to industrial and limited commercial use until and unless EPA and MPCA determine that concentrationsof hazardous substances in the soils have been reduced to levels which allow for a less restrictive use. One Instituational Control was placed on OU3. This prohibits the distubance of soil below the plating shop. An additional Engineering control was place on OU3. This prohibits removal of the concrete floor above the plating shop without written approvalof the EPA and MPCA. A ROD was issued in September 2003 to address these problems.
A draft land use control remedial design (LUC RD) for OU2 and OU3 was issued in spring 2004. The purpose of this document was to provide information on how the remedy selected in the ROD for OU2 and OU3 was to be implemented, maintained, and enforced. This document was finalized in September of 2004. A third five-year review was completed in October, 2008. The site was found to be protective of human health and the environment.
Property Reuse
The property continues to be used as a manufacturing facility.Contacts
Remedial Project Manager, U.S. EPAmary tierney (tierney.mary@epa.gov)
(312) 886-4785
Community Involvement Coordinator, U.S. EPA
cheryl allen
(312) 353-6196
Aliases
NAVAL SEA SYSTEMS COMMAND