RADFORD, Va. — The inspector general for the U.S. Department of Defense has launched an investigation into the open burning of ammunition and explosives at military sites across the country, including at a sprawling Army ammunition plant in Virginia.

The inquiry announced last week was prompted by a congressional request and comes about a year after a lengthy investigation by ProPublica into the military’s practice of open burning.

The inspector general's office said in a memo that the inquiry will evaluate Defense Department compliance with "relevant environmental and related laws, inter-agency and municipal agreements, and policy." The investigation will also evaluate oversight of contractors performing open burning.

The Radford Army Ammunition Plant is located on thousands of acres in southwest Virginia and is the main propellant-manufacturing facility for the Department of Defense. It regularly uses open burns to dispose of hazardous waste. The practice is legally permitted but has raised concerns about impacts on the environment and human health.

U.S. Rep. Carol Shea-Porter, a Democrat from New Hampshire, told ProPublica she requested the investigation and said it was spurred in part by the news organization’s reporting.

Justine Barati, director of public and congressional affairs for the Army's Joint Munitions Command, said Wednesday that the plant had been contacted by the inspector general's office and asked for a copy of its permit and open burning ground standard operating procedures.

Officials are working to schedule a teleconference and possible site visit, she said.

Earlier this year the plant's commander, Lt. Col. James Scott, announced an effort to reduce waste from open burning or detonations 50 percent by the year 2023.

Plans are also underway to install a new $100 million contained incinerator that the Army says will handle about 95 percent of plant’s munitions waste. Construction is expected to be complete in the summer or fall of 2022, as long as necessary permits are approved, Barati said.