Lincoln Memorial Reflecting Pool Turns Green From Algae Ahead of America 250

WASHINGTON, D.C. — The Lincoln Memorial Reflecting Pool in the nation’s capital has turned green once again due to a sudden algae bloom, raising concerns just weeks before the highly anticipated America 250 festivities. Despite a recent $14 million renovation completed on June 3, 2026, the historic landmark is facing familiar water quality issues as the National Park Service works to restore its crisp blue appearance.

National Park Service spokespersons explained that the rapid shift from blue to green is the result of an algae bloom, a long-standing issue for the historic site. The problem is largely driven by environmental factors; the reflecting pool is a very shallow body of water, and during warm, humid weather, sunlight penetrates directly to the bottom. This creates an ideal environment for plants and bacteria to thrive, resulting in a bloom that has returned despite the newly installed liner.

To combat the issue, National Park Service spokespersons confirmed that the agency has deployed nanobubble technology, which treats the water with ozone to kill contaminants and algae. Additionally, the water has been treated with peroxide. Officials express strong confidence that these active treatments will successfully clear the water in the short term.

The current situation follows a major six-week, $14 million renovation of the pool completed just weeks ago. Historically, the National Park Service had considered a much more extensive and expensive renovation to address the aging granite and grouting, as the pool has dealt with leaks since its inception. However, administration officials note that President Trump personally directed the less expensive liner treatment. The president had previously stated that the algae-covered pool looked “disgusting” and wanted the issues resolved quickly. While the new liner successfully addresses the structural leaks, experts note it was primarily designed for water retention rather than algae prevention, which requires dedicated water treatment.

The timing of the algae bloom is particularly sensitive as the country prepares for the 250th anniversary of its founding on July 4th. The National Mall is a major hub for tourists, drawing millions of visitors annually to see the Lincoln Memorial and the surrounding cherry trees. With the America 250 celebrations underway, spokespersons anticipate a massive surge in daily visitors, expecting the area to be a hotbed of tourism for the next six months.

Both the administration and the National Park Service consider clearing the water a top priority. While they are utilizing every available remedy to shock the pool and combat the bloom, officials acknowledge that the situation is a humbling reminder of the challenges posed by Mother Nature when maintaining such a massive, shallow outdoor water feature.