Science Has a Name for What’s Plaguing the Reflecting Pool

The National Park Service (NPS) is grappling with a persistent algal bloom problem in Washington D.C.'s Reflecting Pool, which has intensified over the past year. Initial efforts to combat the bloom using copper sulfate treatments in late 2023 and early 2024 appear to have inadvertently exacerbated the issue, according to NPS spokesperson Mike Litterst. The NPS has now shifted its strategy, halting copper sulfate applications and exploring alternative methods to address the bloom. These new approaches include investigating the use of beneficial bacteria and potentially introducing specific aquatic plants that could outcompete the algae for nutrients. The NPS is also working with the U.S. Geological Survey to conduct further scientific analysis of the water quality and the specific algal species involved. This ecological challenge has impacted the aesthetic appeal of the iconic landmark and raised concerns about the health of the aquatic ecosystem within the pool. The NPS has stated that public safety is not currently at risk, but the long-term visual and environmental consequences are a primary concern. Further testing and monitoring are planned to assess the effectiveness of the new management strategies.