NPS, Interior Deploy Hydrogen Peroxide and Ozone as 95-Degree Heat Turns Lincoln Pool Green
Updated
Updated · Los Angeles Times · Jun 19
NPS, Interior Deploy Hydrogen Peroxide and Ozone as 95-Degree Heat Turns Lincoln Pool Green
3 articles · Updated · Los Angeles Times · Jun 19
Summary
National Park Service crews poured hydrogen peroxide into the Lincoln Memorial Reflecting Pool, while the Interior Department added nanobubble ozone technology to kill algae cells after the newly renovated basin turned bright green.
95-degree heat, still water and nutrient-rich inflow from the Potomac created ideal bloom conditions, and experts say the pool’s darker new blue surface may also be trapping more warmth.
Interior had initially described the algae as residual material from supply lines, but the report says the treatments mainly address symptoms rather than the conditions driving rapid regrowth.
Longer-term fixes would need to tackle the pool’s depth, color and nitrogen- and phosphorus-heavy inflow; a 2025 nanobubble pilot on the Tijuana River cut odors and bacteria before flooding ended it early.