PALMETTO – State environmental officials Thursday proposed to more than double the amount of treated waste water dumped daily into Tampa Bay from a toxic cleanup.
The Department of Environmental Protection has asked for an emergency order to allow 2 million gallons of treated waste water from Piney Point, a former phosphate fertilizer plant, to be dumped daily into Bishop’s Harbor for three months, a DEP official said.
The DEP has dumped about 800,000 gallons of treated waste water into the harbor daily since Dec. 26, but recent heavy rains have brought the plant to the threshold of an environmental emergency, said Phillip Coram, a DEP engineer.
The DEP aims to empty reservoirs of 1.2 billion gallons of acidic waste water left at the abandoned plant. But each inch of rainfall adds about 12 million gallons to that storage, Coram said, and more than 22 inches of rain since December have filled those reservoirs to near capacity.
Site engineers estimate the reservoirs can accommodate 8 more inches of rainfall before the acidic water overflows and spills into the Bay, Coram said. Increasing the output for three months should accommodate expected heavy rainfall.
Considering the Bay’s size, 2 million gallons daily is “a trickle,” he said. It’s less than 1 percent of the total freshwater input the Bay receives daily from rivers and stormwater runoff.
Since the DEP took over the plant in February 2001, the waste water has been trucked, pumped and transferred to other sites, but those sites are full, Coram said.
The DEP met Thursday with state and local authorities who compose the Agency on Bay Management to discuss the problem. The local authorities agreed with the DEP’s suggestion, Coram said.
Officials from the Tampa Bay Estuary Program, part of the Agency on Bay Management, could not be reached for comment late Thursday.
The increase will begin once DEP Secretary David Struhs issues an executive order, which should be soon, Coram said.
The majority of the water will be treated with a double lime chemical process that removes heavy metals and phosphorous and neutralizes the acidity, Coram said. This adds about 10 times more nitrogen per liter than reverse osmosis, a treatment that filters pollutants through a membrane, he said.
The DEP has enough reverse-osmosis units at the site to treat about 300,000 gallons a day, Coram said. The agency is negotiating with vendors to obtain more units, which could take months.
DEP engineers plan to construct additional aeration ponds in the next month to reduce the nitrogen in the chemically treated water, he said High nitrogen levels can cause algae blooms, Coram said, but winter’s lower temperatures should reduce that effect.