The National Park Service is using hydrogen peroxide and nanobubbles to treat algae in the pool, according to WTOP, which cited a statement from the U.S. Department of the Interior. The department told WTOP that the algae was residual growth from water pumps and pipes after the system sat dormant during renovation, and said hydrogen peroxide and ozone nanobubble technology were being used to keep the water clean and clear.

The Associated Press reported that National Park Service employees and contractors deployed chemicals, ozone nanobubbles and pool-vacuum equipment to address the algae. The report also noted the scale of the pool, its Tidal Basin water source and the long-running challenge of algae at the site.

The renovation included a new blue coating on the bottom of the Reflecting Pool. Reuters reported June 18 that paint was peeling away from the bottom and into algae-tinted water less than two weeks after President Donald Trump announced the project’s completion. WTOP also reported that a 2- to 3-foot section of blue material appeared to be peeling away along the south side of the pool.

WTOP noted that it was unclear whether hydrogen peroxide, algae scrubbing or nanobubble technology had anything to do with the peeling. Reuters reported that the National Park Service and Atlantic Industrial Coatings, the Virginia-based company that carried out the renovation, did not immediately respond to requests for comment.

A USAspending.gov record lists a National Park Service contract awarded to Atlantic Industrial Coatings for “NAMA 291052 Paint Lincoln Reflecting Pool,” with a current award amount of $6,886,519.80. The Associated Press reported that contracts worth at least $14.8 million have been awarded for the broader project.

The White House published an April video titled “President Trump is Making the Reflecting Pool Beautiful Again,” but as of publication, PCI did not locate a White House release specifically addressing the algae return or the reports of coating peeling.

The update highlights the maintenance complexity of large public water features, where coatings, waterproofing, water chemistry, biological growth, temperature, water source and maintenance practices can all affect performance and public perception.

Sources Used:

• WTOP: Workers treating algae in newly renovated Reflecting Pool with hydrogen peroxide and “nanobubbles”
• WTOP: Blue paint on bottom of Reflecting Pool appears to be peeling away
• Reuters: The paint is already peeling in Trump’s renovated Washington Reflecting Pool
• Associated Press via ABC News: Trump administration uses hydrogen peroxide against algae in Reflecting Pool
• USAspending.gov: Contract award 140P2026C0028
• The White House: President Trump is Making the Reflecting Pool Beautiful Again
• National Park Service: Lincoln Memorial Reflecting Pool