‘50,000 bags of fertilizer:’ What could Piney Point do to Tampa Bay?

Scientists are trying to forecast what comes next. Environmentalists fear algal blooms and fish kills.
Aerial view looking toward Tampa Bay from Piney Point on Sunday in Palmetto.
Aerial view looking toward Tampa Bay from Piney Point on Sunday in Palmetto. [ LUIS SANTANA | Times ]
Published April 5, 2021|Updated April 6, 2021

The focus for emergency teams at the old Piney Point phosphate plant property is stopping a flood from surging out of an enormous, leaking reservoir of polluted water.

Success on that front could mean pumping a majority of the 480 million gallons of wastewater into Tampa Bay, posing an ecological danger to the treasured estuary that clean water advocates say may endure for weeks or months.

Releases as of early Monday had dropped the pond level by approximately 100 million gallons. “That’s like dumping 50,000 bags of fertilizer into the bay all at once,” said Ed Sherwood, director of the Tampa Bay Estuary Program.

The Estuary Program has tracked the nitrogen load, mostly from runoff, in that portion of the bay from Port Manatee to Pinellas Point and south for years. The releases to the port, if they continue until the pond is empty, could in a matter of days put in “double the amount of nutrients ... than what we would like to see in an entire year,” Sherwood said.

Related: Next update on Piney Point expected midday Monday

Like fertilizer on land, the nitrogen may encourage growth in the water, in the form of algal blooms. The Estuary Program is working with researchers at the University of South Florida to forecast where the polluted discharges from Piney Point might flow, and how quickly they will leave the bay.

“Real provisional at this point, but we’re concerned about the plume heading south to the east on the shore of Tampa Bay,” Sherwood said. If the wastewater is carried into shallow areas of the Terra Ceia Aquatic Preserve, he said, scientists fear algal blooms will follow. The model results are preliminary, and it remains uncertain how much waste will hit the bay and where currents and tides will carry it.

If the nutrients do fuel a bloom, oxygen levels in the water would drop as the algae decays, said Mark Luther, a University of South Florida oceanography professor. That could mean fish and other marine life die in large numbers around the polluted area.

Related: Five questions answered about Piney Point leak in Manatee County

“An algal bloom will take a few weeks before you see it,” Luther said. He is not working on the current modeling, he said, but he did contribute research in 2001 when previous discharges were dumped at Piney Point. The basic functions of the bay have not changed since then. Luther recalls periods when a nearby harbor was “just one big green algae muck pit, ... growing like slimy lettuce.”

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The extra nitrogen, he said, comes during the dry season when nutrient levels in the bay are already low. That’s helpful, he said, because the estuary is not already full of those materials from stormwater runoff.

But the lack of rain also means fresh river flows into the bay are low, according to Luther, so circulation — thriving on an interplay of fresh and saltwater — is “at its most sluggish.”

“That’s what flushes the bay, keeps it healthy, keeps bad stuff from accumulating,” Luther said. “Whatever is being pumped out of this pond, it’s going to take longer for that to be flushed out of the bay.”

Tides, he said, will also help to move the water.

Related: In Manatee’s Piney Point evacuation zone, it’s just another Saturday

Sherwood said the main freshwater influence near Port Manatee is the Little Manatee River, which he said is flowing into the bay at a rate of about 100 cubic feet per second. The Piney Point release, he said, is estimated to be hitting at between 30 and 50 cubic feet per second.

Fishing guides like the area around Port Manatee because it features rare undeveloped stretches of shore by the aquatic preserves, said Capt. Todd Romine, 57, of Bradenton.

The controlled discharges, he said, seem a lot like the plant property owners “flushing their toilet into Tampa Bay.”

Romine, who said he has fished the bay for more than three decades and is on the water about 250 days a year, was one of several captains who spoke Monday afternoon at an event organized by a clean water advocacy group, Suncoast Waterkeeper.

The estuary around Piney Point, he said, is a great spot to find snook, trout and redfish. A fishery closure for those species has been in effect since after 2018′s devastating Red Tide but could end soon.

“Things are moving in the right direction,” Romine said. If Red Tide arrives again, though, he worries the nutrients from Piney Point could worsen a bloom.

Capt. Carson Stipcich, 28, of Bradenton, shared that concern. He said Port Manatee is also a place to catch grouper and snapper by deep water.

“It doesn’t look good,” he said. “It’s a bad deal for everybody.”

Meanwhile, James Powell, director of the Clearwater Marine Aquarium Research Institute, is worried about manatees. If the reservoir were to collapse, he said in a statement, it might pollute the bay near the power station where they winter.

“A discharge of this magnitude could have a major impact on the seagrass beds near Piney Point they use to feed,” Powell said. “At this point we don’t know what the outcome may be, but it could cause those grasses to die off or have toxicity levels that could potentially be harmful to manatees.”

The old fertilizer plant property holds three ponds of water and stacks of radioactive phosphogypsum, waste from the industry that lingers in big heaps because regulators say it is too dangerous to reuse in most circumstances.

The state has said the water in the leaking reservoir is not radioactive. It is a mix of seawater from an old dredging project, rainwater and polluted water that is a byproduct of fertilizer manufacturing, regulators say.

Manatee County officials have said it is about as acidic as a cup of coffee. It has elevated levels of phosphorus and nitrogen, according to the Department of Environmental Protection.

Gov. Ron DeSantis on Sunday said: “The water quality issues that are flowing from this, for us, (are) less than the risk of everyone’s health and safety, particularly folks who may live in the area.”

Related: DeSantis, Manatee officials work to prevent 20-foot wall of wastewater at Piney Point

Peter Clark, founder of Tampa Bay Watch, a group that works on protecting and restoring Tampa Bay, said officials at Piney Point are in a hard position given the imminent threat.

“We understand that catastrophic release is something that has to be avoided at all cost,” he said.

Water dumped over the last week is less contaminated than previous releases from Piney Point, according to Luther, including those that were a concern 20 years ago. But it still carries nutrients from fertilizer processing and probably some metals or pollutants in the old dredge material pulled up after years of runoff settling on the bottom of the bay.

Putting the waste into Port Manatee, where the water is relatively deep for mixing, is preferable to an uncontrolled collapse that would send a surge toward shallow water at nearby Bishop Harbor, Clark said. There, he said, “the material would do significantly more damage.”

Related: Plastic liner known to be in poor shape before Piney Point leak, records show

But winds, currents and tides will still move the plumes around.

“Port Manatee is located right in between two aquatic preserves, Terra Ceia and Cockroach Bay. There are very sensitive communities to the north and south,” Clark said.

And it is frustrating, he said, to be reliving an old story. “I’m very disappointed that after 20 years we’re dealing with the Piney Point phosphate plant yet again.”

Editor’s note: This story has been updated to correct how much water drained from the pond is equivalent to 50,000 bags of fertilizer.