Lincoln Memorial Reflecting Pool Renovation Faces Algae and Coating Failures Ahead of July 4

The Lincoln Memorial Reflecting Pool’s renovation, ordered by President Donald Trump in April to turn the water “American flag blue” for the nation’s 250th birthday celebrations, has encountered significant setbacks. Within weeks of completion, chunks of polyurea coating have peeled off and floated in the water, while an algae bloom has turned the pool green despite treatment efforts. The combined failures have drawn widespread attention and expert scrutiny.

Experts suggest the coating failure may result from multiple factors, including improper surface preparation, rushed timelines, and environmental conditions. David McFayden of KTA-Tator noted that such failures are rarely due to a single cause. Tim Auerhahn of the Aquatic Council added that factors like delayed application between layers, vehicle traffic, and bonding to a granite substrate could have contributed. The Department of the Interior, which oversees the National Park Service, did not respond to requests for comment.

The algae bloom, caused by common non-toxic green algae species Desmodesmus or Scenedesmus, has persisted despite the National Park Service dumping hydrogen peroxide into the water. Scientists explain that the pool’s enormous surface area, shallow depth, and warm summer temperatures create ideal conditions for algae growth. Additionally, city water used to refill the pool contains phosphorus, added to prevent lead leaching, which may fuel the bloom. Wildlife droppings from geese and ducks in the park provide further nutrients.

President Trump has suggested without evidence that vandalism may be responsible, while the US Park Police have arrested individuals for touching the water. The renovation cost has ballooned from an original estimate of under $2 million to nearly $16 million. Pool expert Steve Goodale, known as “Swimming Pool Steve,” said the pool is “mercilessly complicated” but that even laypeople can see something is wrong when coating floats in chunks. Experts express skepticism that the pool can be made reliably blue by the July 4 deadline.