Presto: Convert a mine into a wetland
Creating a wetland from scratch often fails. But in Ruskin, a project is full steam ahead.
By CRAIG PITTMAN AND MATTHEW WAITE
Published December 17, 2006
RUSKIN - At the Caloosa Shell mining pits, William Casey spent 34 years overseeing the extraction of millions of pounds of ancient seashells. Dump trucks roared through the gates and hauled the shells away to be crushed and turned into road base.
At the end of September, Caloosa Shell went out of business, to be replaced by Casey's new enterprise: the Tampa Bay Mitigation Bank.
Now the mine will be converted into freshwater marshes and mangrove swamps connected via a creek with nearby Cockroach Bay.
At least, that's the plan.
The problem: Creating wetlands where they don't already exist usually fails. But state and federal regulators let Casey try because they were so eager to accommodate developers clamoring for a mitigation bank in the fast-growing Tampa Bay area.
Clark Hull, of the Southwest Florida Water Management District, which approved Casey's permit, said it's not the public, it's Casey and his partners rolling the dice.
"If it doesn't work, it's really their neck," he said. "They're taking the risk to get it done."
Except that when a mitigation bank fails, the environment can come out the loser. That's because the bank is supposed to make up for wetland destruction elsewhere.
Before anyone knows if the wetlands Casey builds really work, his bank is allowed to sell 60 percent of its credits. If its wetlands fail, so much for no net loss.
That's why "it kind of sets off bells in my mind of whether it would be appropriate" to approve a bank like that, said Ron Silver, who oversees mitigation bank regulation for the U.S. Army Corps of Engineers in Jacksonville.
But the corps issued Casey's group a permit, too. That's because, Silver said, "the corps isn't judging them on whether they're financially stable or not."
A 2001 National Academy of Sciences study found that creating wetlands rarely works. So the state's rules say that mitigation banks "should emphasize the restoration and enhancement of degraded ecosystems ... rather than alteration of landscapes to create wetlands."
Which is exactly what's going on here. The state granted Casey's bank 111.55 credits for creating 42 acres of saltwater wetlands and 90 acres of freshwater wetlands.
There's little demand for saltwater credits because most Florida development wipes out freshwater wetlands. To succeed financially, Casey's bank must do the near impossible - create freshwater wetlands.
Five years after getting its state permit, the Tampa Bay Mitigation Bank has yet to convert its mine to marsh. Casey said he hopes that will begin this winter, and he'll be ready to declare success three years later.
"I would not hesitate to say that's optimistic," said a skeptical Silver.
It's hardly an ideal spot for a new wetland, hemmed in by a road, a mobile home park and a commercial farm.
Yet one of Casey's partners, environmental consultant Beverly Birkett, said would-be customers are bombarding her with requests to buy credits, priced at $100,000 each.
"Consultants and developers are calling me: 'Is the bank ready to go yet?' There's a high demand in the region," she said.
Still, Casey is soured on the whole enterprise. Had he known what he was getting into, he says he would never have tried it.
In three decades of mining, Casey has always followed a routine with his quarries. "Traditionally what you do is you mine the shell, create a lake and then build houses around it."
This 161-acre parcel lacked sufficient shell deposits to make it worth tearing up. There would never be a big enough hole for a lake. But as Casey researched the idea of turning it into a mitigation bank, he came up with a way to make the mine work financially - maybe.
"I figured maybe we could sell enough material to pay for the earthwork" needed to create the mitigation bank. Mining the property "was the only way to make it feasible."
By calling the site a mitigation bank, Caloosa Shell avoided the state mining permit process. As far as the state is concerned, the mining isn't really mining; it's part of getting the site ready to become a mitigation bank.
On the day the mine officially changed over to a mitigation bank, a Caterpillar hydraulic excavator scooped out the soil, digging down to the water table to extract the last remaining shell deposits.
"In some places we dug as deep as 12 feet" to get the shell, Casey said. The excavator put the dirt back, sculpting the landscape to the contours required by an artificial wetland.
Nearby, Casey ran a big, noisy pump. Its purpose: drain water off the land that someday is supposed to be wet. Otherwise, he explained, the machines would get stuck in the muck.
[Last modified December 17, 2006, 01:05:53]
[an error occurred while processing this directive]