The millions of gallons of water gushing into Tampa Bay from the abandoned Piney Point phosphate plant contains high levels of a pollutant called cadmium, as well as enough nitrogen and phosphorus to potentially cause a harmful algae bloom and a fish kill, state Department of Environmental Protection officials announced Wednesday.
So far, no one knows the source of the cadmium or what damage it might cause, "but we will continue monitoring the discharge to determine if the cadmium continues to be present and what the source may be," said DEP spokeswoman Dee Ann Miller. Their big concern now is stopping the leak.
Cadmium, a heavy metal, is used in metal plating and coating and is also found in rocks mined for phosphate fertilizer. Drinking water tainted with too much cadmium can lead to kidney problems and cancer.
The old Piney Point plant, built in 1966, sits across from Port Manatee about a mile from Bishop Harbor at the southeastern edge of the bay, near the Hillsborough-Manatee county line.
The DEP took over the plant in 2001 when the owners went bankrupt and walked away, but then had to drain millions of gallons of ammonia-laden waste from its mountainous gypsum stacks because of fears it would spill into the bay and devastate sea life for miles around. That led to a big algae bloom. More recently, as the port began dredging a shipping berth, a contractor hired to dump the spoil atop the Piney Point phosphogypsum stack notified DEP officials that something had gone wrong, apparently because the stack's liner had torn.
State officials feared the gypsum stack would collapse, dumping radioactive material and other contaminants into the bay. The DEP issued an emergency order May 28 to dump the liquid into ditches that flow into Bishop Harbor, but monitor it for harmful pollutants.
They estimate the amount atop the stack was 150 million gallons.