WASHINGTON — The Lincoln Memorial reflecting pool is once again making headlines, this week for turning green.The Washington, D.C.landmark was refilled with water earlier this month after President Trump had its neutral grey bottom repainted "American flag blue." The multi-million dollar project produced subtle results in the eyes of many observers, even as Trump and Secretary of the Interior Doug Burgum — whose agency managed the renovation — touted its success.In recent days, however, the pool has taken on a verdant hue — the result of algae blooms that experts say are to be expected in these conditions."It's called 'New Pond Syndrome,'" says Steve Goodale, a Canadian swimming pool specialist known online as "Swimming Pool Steve." "It's a known thing that happens when you take a natural, clear body of water like this that sits in an open air environment and you try to start it up, very often you end up with green water almost immediately."Goodale says the process took longer — a matter of days — to unfold in this case likely due to the sheer size of the pool, which measures 2,030 feet long and has a surface area of approximately 338,000 square feet.Rosalina Stancheva Christova, a professor of aquatic ecology at George Mason University in Virginia, took water samples from the pool on Tuesday.
She confirmed the algae belongs to the genus Desmodesmus, which she said is "growing in excessive amounts" but is not toxic or harmful.Christova says this kind of common green algae is found all over the region, especially this time of year.The reflecting pool in particular provides "excellent conditions" for algae growth, she said: shallow, stagnant water, strong sunlight and no shade."It could happen every single summer," she added.
"But it seems that the disturbance of the pond during the renovations [is] accelerating this process."Christova said last month's renovations may have affected the balance of nutrients in the pool, potentially accelerating the algae...