The Lincoln Memorial Reflecting Pool in Washington D.C. has been plagued by an algal bloom, turning its newly renovated ‘American flag blue’ bottom a chartreuse color. The pool, which is larger than 10 Olympic-sized pools, has been a challenge to maintain due to its size and the source of its water, the often-fetid Tidal Basin.

Cleaning Efforts

Teams of National Park Service employees and contractors have been deployed to clean the pool, using chemicals and ozone nanobubbles to keep the algae in check. The park service is also using hydrogen peroxide, a milder treatment than chlorine, to clean the pool. ‘There are no harmful side effects to marine life or to the environment,’ the park service said in a statement.

A contractor was seen wading into the pool to place an ozone nanobubble tube, while tourists and locals milled about on a sunny morning. The cleaning efforts are part of a larger renovation project, which included a new coat of paint on the bottom of the pool. However, the new paint has added an additional twist to ensuring the cleanliness of the pool, as it elevates the temperature and allows the algae to grow better.

Challenges Ahead

Cochise Wanzer II, president of the Pool Service Company in Arlington, Virginia, said that maintaining the pool as an algae-free space would be a challenge. ‘You’re basically taking natural, untreated river water, pumping it in and expecting it to do something different from what it would do out in the open,’ Wanzer said. He suggested that the pool may need to be drained, hosed down, and started from the beginning with fresh water and treatment.

Original reporting: KTBS 3 (Shreveport) — read the source article.