The Trump administration spent nearly $15 million to rid the Lincoln Memorial Reflecting Pool of algae. They were not successful.Within days of the pool’s refilling, the green algae hasn’t just returned but is having a “field day” thanks to high phosphate levels in the water, according to an algae researcher at the Smithsonian who spoke with CNN Tuesday.CNN sampled and tested some of the pool’s water with the help of a swimming pool store. They found that the water contained phosphate levels “far higher than what is recommended to keep algae at bay,” based on estimates for a pool that holds 6.5 million gallons of water.The Department of the Interior has so far blamed the algae’s resurgence, in part, on residual algae that had accumulated in the pool’s pipes—which it apparently neglected to clean as part of the multimillion-dollar restoration.Washington’s hot and humid weather has also contributed to the bloom, as the Trump administration filled the Reflecting Pool with fresh water and, consequently, more oxygen. By the weekend, the green, plantlike form had coated the bottom of the pool in several areas and floated to the surface.Now park workers are throwing darts at the wall trying to clean up the monument in time for America’s semiquincentennial. On Tuesday, hi-vis park workers were spotted dumping gallons of hydrogen peroxide into the Reflecting Pool. A close-up of their equipment revealed that they were using a 12 percent concentrate, a level that can cause problems if inhaled and burns if the chemical touches the skin, according to the Centers for Disease Control and Prevention. Hydrogen peroxide is generally considered less environmentally destructive as its compounds readily break down in water, but the high concentration could nonetheless pose a risk to some of the pool’s frequent visitors, such as ducks or other birds.Photojournalists also snapped shots of buckets of Induclor around the memorial, a chlorine compound used to control bacteria, algae, slime, and fungi in water, reported The Washington Post.Fixing the Reflecting Pool is a headache that’s plagued pretty much every administration since its construction in 1923, because what makes the Reflecting Pool beautiful is exactly what makes it so difficult to maintain. The pool’s expansive length is possible due to the use of multiple large concrete slabs at its bottom. But those slabs are also prone to serious, structural leaks, which requires the White House to replace roughly 16 million gallons of water each year. And the pool’s shallow depth—which creates its mirror-like appearance—also detracts from the pool’s health by creating a breeding ground for algal blooms that turn the water green.