What hydrogen peroxide really did to Lincoln Memorial Reflecting Pool revealed in new aerial footage

Workers are now deploying hydrogen peroxide in a bid to bring an algal bloom under control in the Lincoln Memorial Reflecting pool.

The cause of the pool turning green is an algal bloom, which has happened following the renovations of the historical landmark.

Several theories have been put forward about why the alga started to bloom in the pool, including a theory that the new 'American flag blue' color has been a factor.

Now, work has started to bring the bloom under control, with employees from the national parks service putting hydrogen peroxide into the water in an effort to bring the bloom under control.

According to the Department of the Interior (DOI), the service is also using an advanced filtration system.

This will break down contaminants and toxins in the pool with ozone-injected nanobubbles, saying that this and the hydrogen peroxide have 'no harmful side effects to marine life or to the environment'.

But what is the hydrogen peroxide actually doing?

The water has turned a vibrant shade of green (Chip Somodevilla/Getty Images)

Steve Goodale is a pool maintenance expert, and spoke to CNN about the impact of this process.

“It is definitely a legitimate process for dealing with an open-water environment like this, where you can’t use something that would be more harmful like chlorine, which you would find in a residential swimming pool," he told the outlet.

"But that wouldn’t be good for the local wildlife, so that’s not the kind of system you would use here.”

Goodale explained that the hydrogen peroxide would be 'kind of like a turbocharge button' for oxidation in the water, which would help to contain the algae.

“This is some six-and-a-half million gallons of water we’re talking about here, so that’s a lot of bottles of anything that you’d have to add,” he said.

“But the hydrogen peroxide is an oxidizer itself, in the same way that the nanobubbler system is, so the two systems are essentially the same thing, just a different approach to it.”

National Parks employees working on the reflecting pool (Ken CEDENO / AFP via Getty Images)

However, so far the impact of the treatment has not spread through the entirety of the reflecting pool, with only the edge currently clearing.

This has created a strange impression of the landmark pool, with the edges in the new dark blue, while the center is still swamped by the algal bloom.

The work reportedly cost some $14 million to complete, with Donald Trump since rejecting criticism that it is just a 'paint job' in a post on Truth Social.

“This was not a paint job,” he wrote. “This was highly sophisticated material, industrial strength, that could last for 100 years … The material is thick, strong, flexible, and has a natural, beautiful color, the dark blue of the American Flag!”