EPA proposes cleanup plan for Concord site

The federal Environmental Protection Agency is proposing a plan to complete its cleanup of contaminated soil, sediment, and groundwater at the Nuclear Metals Inc. Superfund site in Concord.

The EPA has scheduled two public meetings on the proposal, both to be held in Concord’s Town House, 22 Monument Square. An informational session to present details on the plan, and allow residents to ask questions, is set for 6:30 to 8:30 p.m. Wednesday. A formal hearing, with opportunities for public comments, is slated for 6:30 p.m. Dec. 10.

Written comments can also be submitted until Dec. 15.

At the information meeting, the EPA will also provide an update about the ongoing cleanup and demolition of the facility’s buildings, said Melissa Taylor, remedial project manager for the EPA.

The agency conducted urgent removal actions, one in 2002 and one in 2008, to address materials that presented immediate risks at the Nuclear Metals site. In 2011, the EPA started the still-ongoing process of dealing with the contaminated buildings.

Taylor said this is the last phase of the cleanup.

“We’ve cleaned up a good portion of the site already,’’ she said. “This is for the soil and groundwater contamination.’’

The Nuclear Metals property is a 46.4-acre parcel at 2229 Main St. In 1958, the company began operating a manufacturing facility on previously undeveloped land where it produced depleted-uranium products, primarily for use in armor-piercing ammunition, according to the EPA. The company also manufactured metal powders for medical applications, photocopiers, and specialty metal products, such as beryllium tubing used in the aerospace industry. Operations at the site resulted in contamination of soils, sediments, and groundwater, the EPA says.

In 2001, the property was added to the agency’s Superfund National Priority List, which includes the country’s most serious hazardous waste sites identified for possible long-term cleanup.

The proposal for the Concord site explains the various cleanup options being considered for the soil and groundwater. EPA’s preferred action includes excavation and off-site disposal of sediments and soils from outside of the holding basin, stabilization of holding basin soils, and containment of those soils. It also includes treatment and monitoring of site groundwater, and ongoing monitoring to ensure the remedy protects human health and the environment by preventing risk of exposure to site contaminants, according to agency documents on the project. The EPA estimates that its preferred cleanup plan would cost approximately $125 million.

Taylor said after the EPA takes comments, it will complete a decision outlining the steps that will be taken.

The agency has not yet entered negotiations to determine who will pay for the next phase of the cleanup.

However, Taylor said, all of the agreements to perform the work at the site have been between the EPA and the US Army, the Department of Energy, and two private parties, Whittaker Corp. and Textron Inc.

The portion allocated to private parties has historically been 2 percent of the costs, and the Army and the Energy Department have covered the remainder, Taylor said.

More details about the project and links to the EPA’s documents are posted on the 2229 Main Street Oversight Committee’s page on the town website, www.concordma.gov.