Algae Returns to Lincoln Memorial Reflecting Pool Days After Refill

The Reflecting Pool at the Lincoln Memorial showed green algae within days of reopening after a project coated its floor with dark blue waterproofing material. The $14.2 million effort aimed to stop leaks and algal blooms ahead of the country’s 250th birthday next month.

The pool appeared clear when it was refilled last week, but hot and humid conditions brought the algae back by Sunday and Monday.

Project details The administration awarded no-bid contracts to two vendors, citing urgency tied to the anniversary. Atlantic Industrial Coatings of Virginia applied the dark blue coating and sealed joints between concrete slabs, finishing work on June 4.

Greenwater Services of Ohio was contracted to install an upgraded water-purification system whose status remains unclear. A spokesperson for the Interior Department said last week that crews were removing residual algae from supply lines that sat dormant for eight weeks during construction.

The same spokesperson stated that President Donald J. Trump is an expert builder who has fixed the Reflecting Pool for good.

Earlier efforts and ongoing issues The pool has required repeated interventions.

Under a previous administration, the United States spent $34 million on piping and filtration upgrades intended to draw water from the Tidal Basin. Both leaks and algae returned after that work. The Interior Department previously reported that the pool leaked about 16 million gallons of water annually before the latest project.

Officials have linked the leaks to gaps between expansion joints and to the piping system that circulates roughly four million gallons every three days.

Visitor reactions On Monday, National Park Service workers and staff from Pearl Purity Water Solutions, under contract since 2021, skimmed algae from the surface while tourists walked around the pool.