US President Donald Trump said on Monday that the federal government will step in to protect the Potomac River following the collapse of a major sewer pipe in the Washington, DC, region last month.

“I am directing Federal Authorities to immediately provide all necessary Management, Direction, and Coordination to protect the Potomac, the Water Supply in the Capital Region, and our treasured National Resources in our Nation’s Capital City,” Trump, who has attempted to assert federal control over cities and states governed by Democrats, said in a social media post.

Maryland’s Democratic Governor Wes Moore accused the Republican administration of not acting on this issue and said the US Environmental Protection Agency has not participated in a Friday legislative hearing on the cleanup.

“Apparently, the Trump administration hadn’t gotten the memo that they’re actually supposed to be in charge here,” the governor’s spokesperson said, adding the federal government is responsible for the Potomac Interceptor sewer line, which was the origin of the sewage leak.

A sewer line in Montgomery County, Maryland, collapsed on January 19, causing an overflow of more than 240 million gallons (909 million litres) of wastewater into the Potomac River.

The University of Maryland has called it one of the largest sewage spills in US history.

Its researchers have detected high levels of faecal-related bacteria and disease-causing pathogens in the river, which the university said raised urgent public health concerns and underscored the risks posed by ageing sewer infrastructure.

The EPA said it had deferred an invitation to brief Maryland state lawmakers on the spill as the response to the leak had been led by the District of Columbia Water and Sewer Authority (DC Water) and the state of Maryland.

The EPA added that it will perform its oversight role, coordinate with DC Water and update Congress.

PRESIDENT SAYS FEMA WILL STEP IN

Trump said the Federal Emergency Management Agency, which has seen significant staff cuts since he took office in early 2025, will coordinate the response.

Climate advocates have criticised Trump’s cuts to domestic climate regulations and the U.S. withdrawal from global environmental accords.

The office of Washington, DC, Mayor Muriel Bowser said it had no comment on Trump’s announcement but pointed to a page on the local government’s website that noted drinking water in the area was safe and not impacted by the sewage release.

The website said DC Water is currently working on measures to contain the spill and repair the pipeline.

Since returning to the White House, Trump has attempted to assert control over Democratic-led areas, including the nation’s capital, through the use of National Guard troops, armed immigration agents and threats to cut federal funding.

More than 2,000 National Guard troops have been in Washington since Trump’s initial deployment in August.

Trump says his actions are aimed at improving domestic security.

Democrats and rights advocates say these efforts have targeted political opponents and amount to federal overreach.