A vicious killer is lurking in the waters of the Lincoln Memorial Reflecting Pool on the National Mall in D.C., and so far it’s slaughtered around 80 ducks, prompting the National Park Service to announce they would completely drain the famous D.C. feature on Sunday. A parasite that grows on snails has been infecting ducklings and killing them, prompting the NPS to decide to drain the pool on Sunday, give it a thorough cleaning, and refill it a little more than a week later.

Authorities discovered the dead ducklings starting May 20 and 21. Scientists performed a necropsy ont he ducks, and found that the cause of death were parasites found in snails that live in the pool. Because chemical treatments won’t be enough to reduce the parasite population, authorities decided draining the pool was the only way.

Humans can get the parasite too, although the symptoms are mild, including a rash known as “swimmer’s itch.” It’s also unlikely anyone would get it, because it requires sustained contact with the affected water, and the Reflecting Pool isn’t exactly a swimming hole.

“It will take approximately two days for the Lincoln Memorial Reflecting Pool to fully drain, and crews will begin cleaning the pool bottom on Tuesday, June 13 utilizing skid steers, pumper and water trucks, and a sprayer,” the NPS said in a statement. “The cleaning should be complete and refilling will begin on Friday, June 16. After the cleaning and treatment are complete, the National Park Service will continue to monitor the water quality of the pool.”