Washington, D.C.'s man-made reservoir at West Potomac Park and a focal point of the National Cherry Blossom Festival
A $14m renovation of the Lincoln Memorial Reflecting Pool has produced a dark blue lining that is peeling and the water has returned to bright green from an algae bloom. Federal crews have been treating the water with ozone nanobubbles and hydrogen peroxide and are vacuuming algae, while the administration has claimed vandalism and reported arrests without publicly releasing evidence.