Algal Bloom Disrupts Newly Renovated Lincoln Memorial Reflecting Pool in Washington, D.C.

WASHINGTON, D.C.: A recently renovated section of the Lincoln Memorial Reflecting Pool has been affected by an algal bloom, turning its “American flag blue” base into a chartreuse-green color just days after the completion of its reported $14 million upgrade.

The restoration project, associated with U.S. President Donald Trump, had aimed to restore a vivid blue appearance to the historic pool situated between the Lincoln Memorial and the Washington Monument.

However, park service workers have struggled to control algae growth in the expansive water feature, which is larger than 10 Olympic-sized swimming pools and is fed by water from the Tidal Basin. Despite ongoing treatment efforts, the natural conditions of the water source have complicated maintenance.

The National Park Service, under the National Park Service, has deployed chemical treatments and ozone nanobubbles in an attempt to contain the bloom, though officials say the scale and environmental conditions of the pool present persistent challenges.

Algae growth has long been an issue at the site, which has experienced recurring water quality problems for more than a century. The recent intervention was reportedly part of a broader beautification initiative ahead of the country’s 250th anniversary celebrations.

Officials noted that while the pool has been refilled and the Washington Monument is once again visible in its waters, maintaining the desired aesthetic remains an ongoing challenge.