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The former Loring Air Force Base is located in the town of Limestone in northern Aroostook County, Maine. The facility officially closed in September 1994 under the Defense Base Realignment and Closure Act of 1991. Wastes generated by the U.S. Air Force when the facility was an active military installation contaminated soil, groundwater, surface water and sediment at a number of areas across the former base. Despite its closure as an active base, the Air Force is doing the cleanup needed until cleanup goals have been achieved.

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What Is Being Done to Clean Up the Site?

The site is being addressed through federal actions. Since the site’s listing on the NPL, direct contact threats on the base have been eliminated through numerous Air Force cleanup actions. Long-term environmental monitoring continues at many of the sites that have undergone cleanup.

Cleanup work addressed the following areas:

Former Weapons Storage Area: Disposal trenches containing some 1,000 cubic yards of low-level radioactive waste from early-era nuclear weapons maintenance operations were removed and shipped by train to a licensed disposal facility in Utah.

Landfills 2 & 3: The 1994 cleanup plan required the construction of an impermeable cap over each of these two former landfills, which together covered 27 acres. Landfill 2 was capped in the summer of 1996 and Landfill 3 was capped in 1999.

Landfill 1 and Former Coal Yard: Landfill 1 was closed in accordance with state regulations because no Superfund wastes were identified at the landfill. About 180,000 cubic yards of waste from the Coal Ash Yard were excavated and consolidated into Landfill 3 before it was capped.

Debris Disposal Areas: After 17 former disposal areas across the base were evaluated, the only required cleanup was at the Contract Storage Shed site. An excavation and capping was completed there in the summer of 1997.

Landfills Groundwater: Groundwater studies at the former base landfills concluded that no further cleanup was required for groundwater beneath Chapman Pit and Landfill 1. Routine groundwater monitoring for Landfills 2 and 3 evaluates the long-term effectiveness of the caps.

Railroad Maintenance Shop: About 200 cubic yards of contaminated soil was originally going to be excavated and shipped off base for disposal. The remedy was revised and the material was consolidated into Landfills 2 and 3 before they were capped.

Former Quarry: In the summer of 1995, 80,000 cubic yards of sediment and soil were excavated and consolidated in Landfills 2 and 3.

Various Removal Action Areas: About 30,000 cubic yards of contaminated soil were excavated and placed in Landfills 2 and 3 before they were capped.

Base-wide Surface Water and Sediments: Contamination studies included three major watersheds encompassing the former base. Of the 30 square miles studied, only the on-base portion of the East Branch of Greenlaw Brook required cleanup. More than 150,000 cubic yards of contaminated sediments along a 2.25-mile reach of the brook were excavated and placed in Landfill 3 before it was capped. The sediment removal and stream restoration finished in 1998.

Base-wide Groundwater: The cleanup plan for base-wide groundwater was completed in September 1999 and focused on about 2,000 acres in the industrial area of the former base. Cleanup included institutional controls to prevent uncontrolled use and consumption of groundwater, provisional water supplies, long-term groundwater quality monitoring, five-year reviews, and groundwater management zones.

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What Is the Current Site Status?

Department of Environmental Protection and EPA each have assigned roles for investigating the site and doing the cleanup at the former base’s roughly 9,000 acres. All removal and remedial decisions have been made for the 54 sites identified on the former base. All Superfund design and construction activities have also been completed. Operation and maintenance and long-term monitoring activities are done by the Air Force.

Routine groundwater quality monitoring by the Air Force makes sure groundwater contaminant plumes are not migrating and the expected reductions in contaminant concentrations are occurring.

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EPA’s Involvement at the Site

In April 1947, the U.S. Army initiated a directive authorizing land acquisition and construction of Limestone Army Air Field. Before the base was developed, the area primarily consisted of forested lands and farmlands. With the creation of the U.S. Air Force as an independent agency in September 1947, it was established that, once operational, the base would transfer to the U.S. Air Force. The construction period lasted until February 1953. Loring Air Force Base became home to the 42nd Bombardment Wing.

The base was one of the first to be designed and built to accommodate high-speed aircraft, and its layout was different from older, converted Army posts. Many of the industrial, flying and military activities at Loring Air Force Base required the storage and handling of hazardous materials. Several maintenance hangars and aircraft maintenance shops were used almost continuously from 1952 until the base’s closure in 1994. These operations included the maintenance of jet engines, avionic components and vehicles. These industrial operations generated waste oils, recoverable fuels, spent solvents and cleaners.

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Activity and Use Limitations

At this site, activity and use limitations that EPA calls institutional controls are in place. Institutional controls play an important role in site remedies because they reduce exposure to contamination by limiting land or resource use. They also guide human behavior. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup.

For more background, see Institutional Controls.

Institutional controls are required for this site.
This site requires ICs because a decision document, such as a Record of Decision, has documented some level of contamination and/or remedy component at the site that would restrict use of the site. These ICs are required to help ensure the site is used in an appropriate way and that activities at the site do not damage the cleanup components. These ICs will remain in place for as long as the contamination and/or cleanup components stay on site. The matrix below is a general summary of the restrictions at this site at the date of this report. The information in this matrix is a general description of the restrictions at the site only. The site contacts should be consulted if there are questions on the ICs for this site.
The following IC Instruments provide media-specific use restrictions that have been implemented by EPA for protecting human health, the environment and remedial engineering on this site. Instruments are documents used by EPA or other organizations to implement the use restrictions at a site. To know about other media-specific use restrictions that are planned but not implemented at this site, please contact the Regional Office using the Site Contact listed above. Note that where multiple entries occur, it will impact more than one pathway.
Click here for IC Instruments implemented for this site. 

ICs are generally defined as administrative and legal tools that do not involve construction or physically changing the site. Common examples of ICs include site use and excavation restrictions put in place through State and local authorities like zoning, permits and easements. ICs are normally used when waste is left onsite and when there is a limit to the activities that can safely take place at the site (i.e., the site cannot support unlimited use and unrestricted exposure) and/or when cleanup components of the remedy remains onsite (e.g., landfill caps, pumping equipment or pipelines). Effective ICs help ensure that these sites can be returned to safe and beneficial use.
Disclaimer: This information is being provided by EPA as an informational tool to further assist the public in determining the types of restrictions that may be in place at National Priorities List sites being addressed by EPA under the Superfund program. In addition to the areas addressed by the institutional controls identified on this web site there may be other areas on the property that require restrictions on use of the property that are not captured in this EPA database. States and other entities may have implemented laws or restrictions applicable to this site. The information provided herein does not replace a title search or meet "All Appropriate Inquiry" requirements. U.S. EPA encourages users to review the Site files to obtain information regarding remedy components, containment systems and the land use for which cleanup standards were selected for these sites. More information and links can be found in the Institutional Control instrument collection of document, above, and the EPA regional offices may also be contacted.

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