Topline

Workers were once again spotted trying to clean up the algae bloom that turned the Lincoln Memorial Reflecting Pool a sickly shade of green despite President Donald Trump’s recent $14.2 million renovations—this time resorting to dumping containers of 12% hydrogen peroxide into the pool.

The Department of the Interior told multiple outlets hydrogen peroxide was a “milder treatment than chlorine and is used in spas and specialty pools like natural swimming pools,” and it would have no adverse effect to wildlife that use the Reflecting Pool.

It remains unclear how effective the treatment will prove in the long run—aerial photos of the Reflecting Pool taken later Tuesday show signs the algae was dissipating from the sides of the pool, but remained clumped together in the center.

Department of the Interior spokesperson Katie Martin told Forbes on Monday the Trump administration was using “nanobubbler technology” that has already “successfully destroyed the algae bloom that has plagued every pool reopening since 1922.”

The department previously blamed the resurgent algae on “residual” algae from supply lines, which bring water to the pool from the Tidal Basin, a nearby inlet of the Potomac River.