Hazardous spill in Florida highlights environmental threat decades in the making

From National Geographic.com, April 7, 2021

When a tear in the lining of a wastewater pool at a former phosphate plant threatened to unleash a 20-foot wave of contaminated water into neighborhoods in Piney Point, Florida, officials had no choice but to pump millions of gallons of the water into Port Manatee, a cargo port along the eastern shore of Tampa Bay.

The transfer of 165 million gallons into the bay averted catastrophe. But scientists and state officials are now urgently monitoring the bay’s water quality, fearful that nutrients in the wastewater could lead to harmful algal blooms and disrupt the bay’s marine ecosystem.

The 77-acre containment pond contains a mix of seawater, nitrogen, and phosphorus. Before the tear, first reported on March 25, it held 480 million gallons of wastewater. It is unclear how much of the remaining 303 million gallons will need to be drained to allow engineers to stabilize the pond, but some scientists and environmentalists are speculating all 480 million gallons might have to go.

……. When nutrients flood into marine waters and fuel algae growth, it sets off a process called eutrophication. Large swaths of algae grow and blanket the surface, preventing light from penetrating to the seagrass below and killing that critical underwater habitat. Seagrass is an important habitat for juvenile animals and food for everything from small fish to manatees.

When all that algae and dead plant matter eventually begins to decompose, it starts producing large amounts of carbon dioxide, changing the pH balance of its environment, and eventually causing what’s known as ocean acidification.

“There are other types of algae that are toxin-producing, and those are problematic for a wide range of sea life,” says Jayne Gardiner, a marine biologist at the New College of Florida. “Anything that is dying… that’s further consuming oxygen. You get into this really bad cycle.”

Gardiner says two important environmental habitats—Terra Ceia Aquatic Reserve and Cockroach Bay—are near the site where the wastewater was discharged.

“These are habitats we’ve been looking to conserve,” she says. “And now we have this pretty terrible event right in this area.”

Gardiner says it’s too early to know if the contamination could trigger a red tide event. That will depend on what types of algae happen to be present in the area.

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