Drastic measures are being taken to remove green algae that is filling the Lincoln Memorial Reflecting Pool just days after multimillion-dollar renovations were completed.

President Donald Trump promised the pool would be an "American Flag Blue," but weeks before the country celebrates its 250th birthday the U.S. Department of the Interior is working to ensure the pool returns to its normal color.

As videos shared online Tuesday indicate, that work included a toxic chemical being being poured into the pool.

But are the videos real? Here's what we know.

A video shared Tuesday morning by a CBS News reporter showed workers pouring gallons of hydrogen peroxide into the reflecting pool.

Additional videos also showed several boxes lining part of the pool as workers poured the liquid from the gallon jugs into the pool.

In a statement June 15 to USA TODAY Network, the Department of the Interior said it was deploying "nanobubbler technology" to destroy the pool's algae, saying the reflecting pool would be fixed "for good."

The department later confirmed it would be using hydrogen peroxide to treat the pool, calling it a milder treatment than chorine.

"There are no harmful side effects to marine life or to the environment," according to the statement. "The nanobubble technology has been tested and validated by the National Oceanic & Atmospheric Administration (NOAA), The Ohio State University and The University of Florida."

The hydrogen peroxide poured into the pool appeared to be Harris 12%, a concentrated formula the brand says is "safe for use around people and pets when used as directed."

The Occupational Safety and Health Administration has deemed the chemical to be hazardous. OSHA said the chemical can cause skin burns and eye damage if touched and could cause mouth and throat irritation and pain if swallowed.

"Avoid contact with skin, eyes, and clothing. Avoid breathing vapors, mists, or spray," OSHA says.

It's unclear how many gallons of the liquid were used, but some people believe it would likely take thousands of gallons to effectively shock the pool.

Most of the pool remained green at 1 p.m. Tuesday.

Contributing: Joey Garrison, USA TODAY

This article originally appeared on USA TODAY: Why was a toxic chemical poured in the Lincoln Memorial Reflecting Pool?