The Lincoln Memorial Reflecting Pool in Washington, D.C., has turned green due to an algae bloom shortly after a major repainting project [1].
The incident creates an embarrassing visual failure for a high-profile federal landmark just as the city prepares for major summer events. The pool is a centerpiece of the National Mall and serves as a backdrop for national celebrations, and political demonstrations.
Officials recently completed a renovation of the pool that lasted six weeks [2]. The project cost $14 million [2] and involved draining the basin to repaint the bottom in a shade described as "American flag blue" [1]. However, the desired aesthetic was short-lived. Reports indicate the water turned green a little more than a week after the repainting was completed [1].
Maintenance crews are currently working to clear the bloom. To treat the water and remove the algae, crews are using hydrogen peroxide [1]. This chemical treatment is intended to restore the pool's clarity and reveal the new blue paint before the next major holiday.
According to reports from June 16, 2024, the primary goal for the cleanup crews is to have the water clear in time for July 4, 2024, celebrations [1]. The timing of the bloom is particularly problematic given the high volume of tourists who visit the National Mall during the Independence Day holiday.
While some reports suggest the water turned green just days after the project ended, other sources said it took slightly over a week for the bloom to become visible [1, 3]. The proliferation of algae often occurs after water is refilled into a basin, especially when nutrient levels or temperatures are conducive to growth [1].
“The pool was repainted 'American flag blue' as part of a $14 million renovation.”
The rapid onset of an algae bloom following a multi-million dollar investment highlights the difficulty of maintaining artificial water bodies in urban environments. The need for chemical intervention immediately after a renovation suggests that the balance of the pool's ecosystem was disrupted during the draining and refilling process, creating a public relations challenge for the National Park Service ahead of a major national holiday.
