Algae Overruns Renovated Lincoln Memorial Reflecting Pool: Causes and Historical Context

This week, the Lincoln Memorial reflecting pool in Washington, D.C., turned green with algae right after a multi-million-dollar renovation. President Donald Trump had ordered the renovation, highlighting its new “American Flag Blue” color.

Recent Developments

The reflecting pool, stretching from the Lincoln Memorial to the World War II Memorial close to the White House, had been refilled just days prior. Images now show algae spreading rapidly across the surface. This raises questions about whether the redesign might have created conditions conducive to algae blooms.

Algae has been a persistent issue since the pool first opened over a century ago. Recently, Trump focused efforts on permanent solutions for the pool’s problems.

Combating Algae Growth

On Tuesday, National Park Service teams and contractors introduced chemicals and ozone nanobubbles into the water, attempting to curb the algae. Hydrogen peroxide, often used in water treatments to oxidize and decompose organic material, was part of these efforts.

Historical Significance of the Reflecting Pool

The Lincoln Memorial reflecting pool has been a significant site for many historical events and everyday activities in the nation’s capital.

1963: March on Washington

The pool served as the backdrop for the March on Washington for Jobs and Freedom, highlighted by Reverend Martin Luther King Jr.’s “I Have a Dream” speech.

1968: Poor People’s Campaign

Five years later, Martin Luther King Jr. continued advocating for economic rights, leading to the Poor People’s Campaign rallies by the pool.

1989: Mobilize for Women’s Lives Rally

The National Organization for Women organized a significant nationwide abortion-rights demonstration around the pool in November 1989, drawing 350,000 participants.

1993: Call for Reunion

Quincy Jones organized a grand event for President Bill Clinton’s inauguration, featuring performances by stars such as Michael Jackson and Aretha Franklin.

New Year’s 2000: Millennium Celebrations

Fireworks were launched from the pool and the Washington Monument at midnight on January 1, 2000, to welcome the new millennium.

2009: President Barack Obama’s Inauguration

The pool was a central part of celebrations for Obama’s inauguration, featuring musical acts and historical readings.

2010: Algae Visibility

In August 2010, photographs showed the pool with a green tint on a cloudy day.

2012: Major Refurbishment and Algae Return

During Obama’s presidency in 2012, the pool underwent a $30 million refurbishment. Algae reappeared soon after it was refilled.

2020: March for Justice

The National Action Network, led by Al Sharpton, organized a march demanding criminal justice reform on the anniversary of the March on Washington.

2021: 20 Years Since 9/11

The pool appeared gray-green once more on September 11, 2021, marking 20 years since the terrorist attacks on Washington D.C. and New York City.

Capacity and Renovations

The pool holds approximately 6.5 million gallons of water. It is around 18 inches deep at the edges, reaching 30 inches at the center. A 2012 refurbishment added a new water circulation and filtration system, drawing water from the nearby Tidal Basin. Trump criticized this refurbishment, citing quality concerns.

Trump’s Renovation Efforts

Trump’s ordered renovations aimed to revamp the pool with a dark blue coating to enhance appearance and fix leaks. The pool was drained for extensive repairs, and crews resurfaced the interior with a coating to achieve the “American flag blue” effect before refilling. The compressed timeline from draining to refilling left a short period for water systems to stabilize, increasing vulnerability to rapid changes in water quality.