Lincoln Memorial Reflecting Pool Turns Green After Trump Orders Repaint With American Flag Blue

The Lincoln Memorial reflecting pool in Washington, D.C. turned green after it was refilled with water earlier this month following President Trump’s order to repaint the pool’s neutral grey bottom “American flag blue.”

NPR reported that algae blooms were expected in the pool’s conditions, with Steve Goodale saying, "It's called 'New Pond Syndrome.'"

ABC News

NPR also quoted Rosalina Stancheva Christova, a professor of aquatic ecology at George Mason University in Virginia, saying the algae is "growing in excessive amounts" but is not toxic or harmful.

The Interior Department told NPR over email that algae and other contaminants have "long plagued the Reflecting Pool since 1922," and pointed to the Obama-era renovation as an example.

NPR added that the Trump administration said the algae came from residual material in supply lines that had lain dormant for weeks, and that extreme temperatures that hit D.C. last week brought heat index values to 95 degrees and above.

As the algae and peeling blue material drew attention, President Donald Trump posted that law enforcement is investigating vandalism at the Lincoln Memorial Reflecting Pool and suggested “radical left lunatics” were behind some of the structure’s issues.

MS NOW reported that Trump wrote, “Just like three days ago, they destroyed the grass outside of the Pool, they’ve also done everything possible to hurt the inside surface that was just installed,” apparently referring to the stenciling of the numbers “86 47” on the lawn near the pool.

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The Washington Post reported that David Hearn, a Bethesda man, was arrested by U.S. Park Police on a misdemeanor charge of destruction of government property after he noticed a piece of the new “American flag blue” liner partially detached from the pool bottom.

Hearn told the Washington Post, “didn’t destroy or break or peel anything,” and was scheduled to appear in D.C. Superior Court on July 9.

AP reported that Hearn said authorities arrested him and held him for five hours on Friday after he reached down into the pool, and that he described himself as “I’m a curious citizen.”

The Interior Department said it was using hydrogen peroxide to kill algae and also deploying what it calls “high-tech nanobubble ozone technology” to neutralize algae and other pathogens in the pool.

NPR quoted the Interior Department’s approach, saying hydrogen peroxide is a "milder treatment than chlorine" and that there are "no harmful side effects to marine life or to the environment."

In a statement on X, the Interior Department posted that the nanobubble technology had "very effectively killed the algae," and that National Park Service crews would spend several days vacuuming up the dead algae.

ABC News reported that the pool, which cost more than $14.65 million to repaint, continued to peel as algae remained visible, and that workers were seen pumping out the algae into drains.

CNN reported that Trump claimed the algae is “75% gone” and that the condition would soon be completely remedied, while the Interior Department dismissed visible signs of algae and described the water as being “crystal clear.”