Lincoln Memorial Reflecting Pool Turns Green Days After $14.2 Million Renovation

The Lincoln Memorial Reflecting Pool in Washington, DC has turned green just days after a multimillion-dollar renovation of the landmark was completed.

National Park Service employees were seen at the weekend working to clear clumps of algae, which had given the pool a green hue.

The project, which cost taxpayers US$14.2 million ($20.1 million), aimed to fix leaks and turn the pool a colour US President Donald Trump called "American flag blue".

It included the addition of "advanced nanobubbler technology" that has "successfully destroyed the algae", according to a Department of the Interior (DOI) spokesperson.

A federal contract between the DOI and Green Water Solutions said the technology produced microscopic gas bubbles used to control algae.

"The algae is dead and being vacuumed up as we speak," the department said in a written statement.

"We thank President Trump for fixing the Reflecting Pool for good."

Last week, a DOI spokesperson told CNN the algae was "residual" and came from supply lines that sat dormant during the eight weeks of renovations.

Algae has been an ongoing issue in the pool since it opened in 1922.

Environmental scientists have told local media outlets it would be difficult for the algae to be controlled entirely, even if the pool was drained again.

Mr Trump said in May the pool had been "filthy" for years, and his changes would make the site "beautiful".

Patrick Hicks, a Florida resident who visited the pool on Monday, told the Associated Press he was relieved to find it green.

"I think it's an impossible task, having a pool myself," he said. "I know what it takes and what an environmental wreck it is to keep dumping those chemicals in the water to keep it blue."

The Reflecting Pool measures about 600 metres in length and 50 metres in width.

"Honestly, I don't think you can fight Mother Nature," Mr Hicks said. "Anytime you have an environment that big, it's like cleaning a lake."

Maryland resident Dana Pace, who was also at the site on Monday, said she believed the project was a waste of funds.

"Realistically, the water in this area is very high in phosphate and it is prone to algae blooms," Ms Pace said.

"In order to prevent that, you have to treat it like a swimming pool with chemicals … and that's not what this pool was designed for."

The Trump administration awarded contracts to two hand-picked businesses, including a swimming pool contractor, according to The New York Times, which bypassed a legal requirement to seek competing bids.

According to the report, the government cited urgency to get the job done by July 4, marking America's 250th birthday.

Mr Trump has since said he did not know the contractor and had not used the company before.

The Reflecting Pool got its name because its shallow depth allows the water to settle quickly and provide a clean reflection of the Washington Monument.

The site abuts the Lincoln Memorial, where Martin Luther King Jr delivered his "I Have a Dream" speech in 1963.