Ducks will have to find a new place to tread water for the foreseeable future. The Reflecting Pool has been emptied for a deep cleaning.

A large scrubber could be seen sweeping down the length of the Reflecting Pool, scrubbing out “algae and goose poop,” according to the National Park Service. Officials said by the end of the week vacuum trucks will be on site to collect that slurry of muck and grime.

It has been almost completely drained as crews are scrubbing it out. The Department of the Interior told WTOP it is for the upcoming festivities for America’s 250th birthday, during which millions of visitors are expected to visit the nation’s capital.

Earlier this week fencing with privacy screens went up around the reflecting pool during the cleaning.

It is not exactly clear when they will wrap up cleaning and refill the pool.

In the meantime, the park service is asking visitors to not walk in the drained pool.