The next round of Department of Defense funding will come with an important requirement: Congress wants the Pentagon’s outmoded and highly toxic practice of burning old munitions and other explosives in the open air to finally come to a stop.

The language of the 2019 National Defense Authorization Act made public this week, which proposes $717 billion in spending, also demands that the Pentagon report back to Congress with a specific plan for ending the centurylong burning of munitions.

ProPublica investigated the Pentagon’s open burn program as part of a series of reports on Department of Defense pollution last year. We highlighted a little-known program to incinerate millions of pounds of materials containing dangerous contaminants in the open air at more than 60 sites across the country, often without common-sense protections. The burns posed a substantial risk to service members and nearby civilians, including schoolchildren.

“The Pentagon will have to tell us what it plans to do to stop this practice,” wrote U.S. Rep. Carol Shea-Porter, a Democrat from New Hampshire, in an emailed statement to ProPublica. Shea-Porter, a member of the House Armed Services Committee, introduced the amendment to the spending bill that deals with open burns. Shea-Porter earlier led efforts to curb the Pentagon’s use of open burn pits at overseas bases — a practice believed by medical experts to have sickened thousands of U.S. soldiers — and she has often pressed for action against other defense-related pollution risks at home.

“If these answers aren’t satisfactory, I am hopeful that the Armed Services Committee will require the Defense Department to take appropriate action to curb this disturbing practice,” she wrote.

Shea-Porter told New Hampshire Public Radio that she and the Armed Services Committee took up the burn issue this year after reading ProPublica’s reporting.

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Neither a spokesperson for the office of the Secretary of Defense nor for the Army’s munitions department immediately responded to requests for comment. But in previous statements to ProPublica, the Department of Defense has maintained that its open burn practices have already been vastly curtailed over the past decade, and where they still take place today, they are both safer and far less expensive than alternatives.

Congress has pressed the Pentagon to phase out open burning for more than a quarter-century. This past year, the National Academies of Science, Engineering and Medicine began studying the risks and impacts of the Pentagon’s burn practices.

The new bill would force the Defense Department to report back to Congress on the findings of this study and set out exactly what it will do to implement any recommendations made by the National Academies. The measure appears designed to spur the Pentagon to propose its own solutions, but could well lead to a law requiring regulatory action.

If the Defense Department cannot lay out a specific course of action, “it is essentially telling the Committee that it won’t do anything after the Committee explicitly said it was concerned about the practice,” a Congressional staff person with knowledge of the bill told ProPublica. “That typically doesn’t go over well. The intent here is to get DoD to take this seriously.”