PORT MANATEE -- When it comes to finding a place to put potentially millions of cubic yards of dredging material, Port Manatee officials have a choice to make: Vote it onto the island, or off the island.
And if it's off the island, it can't be anywhere near the phosphate-polluted land where the port put 1.1 million cubic yards of dredge waste between 2006 and 2011.
During a meeting with Florida Department of Environmental Protection Secretary Herschel Vinyard last week, port officials laid the groundwork for finding a new location for material dredged off the sea floor. The port must periodically dredge its shipping channels to maintain adequate depth for ships to use its facilities.
The meeting comes none too soon.
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This September, the port will undertake its first maintenance dredging project since 2009. About 400,000 yards of materials pulled from the port's 2.9-mile navigation channel, a small turning channel and a ship berth will be dumped into space remaining in a 93-acre dry-land facility on port property.
After that, there will be no more room for dredge material in the existing facility.
Port officials plan to control waste storage to avoid a repeat of a recent dredging catastrophe. In May 2011, dredge material stored inside stacks of phosphogypsum at Piney Point gushed out of its containment liner. The leak sent about 170 million gallons of phosphogypsum-tainted water into Bishop Harbor.
Phosphogypsum, a byproduct of fertilizer manufacturing, is considered mildly radioactive. Organic compounds in the substance are known to trigger algae
blooms deadly to sea life.
The site just east of port property still contains millions of gallons of contaminated water.
The breached containment facility is the site of a former fertilizer plant. In 2011, the land was part of 675 acres owned by HRK Holdings LLC. The company has since sold off portions of the land as it fights legal action and bankruptcy in the aftermath of the spill.
The material that went onto the Piney Point property came from a dredging project that deepened the water at the Port's Berth 12. The DEP approved a permit to allow dredge storage in the so-called "gypsum stacks," even though it identified major concerns about using the stacks as dredging reservoirs.
Dave Sanford, port deputy executive director, said the port can choose to clear material out of its dry-land facility to make room, add dredge material to a nearby manmade island or start building a new island.
"We have a 3- or 4-year window to excavate the existing site or start a new site," he said.
The port sells dry dredge material for use in construction and as fill material. Those sales would have to accelerate to clear enough material to make room for more dredging. Adequate room would have to be made no later than 2018. The port now sells dredge material for about 35 cents a cubic yard.
Before using dry-land storage, the port piled dredge material at the edge of its harbor area. Begun in the late 1960s, the pile eventually became an island. Cleared and revegetated through a joint effort between the port and the Audubon Society of Florida in 2003, the 60-acre Manbirtee Key Island is now a bird sanctuary.
Gulf Stream Natural Gas was a financial partner in building the island. It has a gas line running under the key, Sanford said.
Future dredge material could be added to the island in a new dike-enclosed cell or piled into a new island nearby, Sanford said. He recently met with Mote Marine Laboratory officials to explore having the organization serve as a consultant on such a project.
"The motivation would be to create additional habitat," he said.
The U.S. Army Corps of Engineers would let the contract for the dredging operation. In all, the 2009 operation cost $3.9 million, according to port spokeswoman Virginia Zimmermann.
The port needs a plan in place by this summer. Sanford said a design consultant will be hired to come up with storage options for the Port Authority Board of Commissioners to choose from.
Sanford said Vinyard assured him DEP will work closely with the port to permit a new dredge-receiving site.
"He made the offer and we're certainly going to take him up on it," Sanford said.
DEP spokesman Patrick Gillespie wouldn't confirm the offer, but did say Vinyard discussed port operations and long-term planning with port staff.
Even with a new dredge material storage area, the port will remain involved with the Piney Point property for the foreseeable future. The port has filed a $12-million claim against HRK for damages resulting from the 2011 spill.
HRK sold off 36 acres of the Piney Point land to Air Products for $6 million in 2012. In November, Utah-based Thatcher Chemical purchased 8 acres from HRK for $1.57 million. Two more land sales totaling 24.5 acres and $6.95 million have yet to close.
Matt M. Johnson, Herald business reporter, can be reached at 941-745-7027, or on Twitter @MattAtBradenton.