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Seeking a prescription for sick Lake Seminole

Off Park Boulevard, at the edge of Lake Seminole, is a concrete U that created the popular lake and now has just about killed it.

It is a dam of sorts, a water-control structure called a weir built in the 1940s when Pinellas County officials decreed that the brackish estuary off Long Bayou should be turned into a freshwater lake shaped like an hourglass. The county's radical surgery created a 684-acre retention pond with no circulation.

Lake Seminole thrived for decades as a great place to ski and fish, but after 60 years of serving as a sink for polluted storm runoff, the water has turned a sickly green and the lake is fast becoming a cattail-ringed marsh full of trash fish.

So now county and state officials are contemplating another radical surgery, a lake cleanup they expect will cost taxpayers $11-million.

The trickiest part of cleaning up the lake is getting rid of 850,000 cubic yards of muck coating the bottom, which accounts for $4-million of the cost. County officials are considering hiring a company to deal with the muck whose technology has been used successfully on a few lakes in other states, but never on a body of water this big.

"What we're doing is really cutting-edge, state-of-the-art stuff," said David Talhouk, the county engineer overseeing the cleanup. "We believe they're really onto something here."

But when an earlier version of the technology was employed in trying to clean up a lake in Polk County, it proved to be an expensive failure. Lakeland officials recently abandoned the still-unfinished project.

County officials hope to make a decision this month on trying the new technology. The only alternative, Talhouk said, is a plan that has already stirred strong public opposition: trucking the muck to Largo.

On the west side of the lake is a fish camp, Bass Fishing Heaven. Displayed along one wall in the dimly lit bait shop is a row of big bass mounted on plaques, stiffly lunging as if they were still fighting to get free of the hook. All the trophies came out of Lake Seminole _ 15 or 20 years ago.

Although bait shop owner Bill Landis, 68, says he still catches some nice bass and blue crabs, he concedes that some longtime anglers now avoid Lake Seminole "because of the quality of the lake."

Lake Seminole is no different from hundreds of other lakes around the state victimized by Florida's rapid growth, say experts.

Poor planning of development around the lake routes stormwater runoff from parking lots and driveways into the lake. Every time an afternoon rain pours down, the runoff brings pollutants along for the ride, especially fertilizer from lawns. The excess nutrients fuel huge blooms of algae, which turn the water pea-green and then settle to the bottom to decay, creating a layer of muck of varying depths throughout the lake.

For now the average depth of the water is 6 feet, according to state officials, dropping to about 8 feet in the channels. If left alone, the lake would continue to fill in with muck until it became nothing but a shallow marsh, hardly suitable for skiing, much less fishing.

Lake Seminole has the added complication of the weir, approved by the county in 1945, which created the lake along with the construction of Park Boulevard. Because of the weir, Lake Seminole is a tub with a plug no one can pull.

"The problem is we have a lake that is a stagnant water body that does not flush," Talhouk said.

As a result, bass and bluegill, once the staples of the lake's fishing business, have sharply declined since the 1960s, according to Tom Champeau of the state Fish and Wildlife Conservation Commission. Lake Seminole is now dominated by gizzard shad and tilapia _ trash fish to many anglers. The bluegills that remain are stunted, unable to attain adult size.

"It's not like it's a dead lake," Champeau said. "It's got lots of fish, just the wrong kind."

County and state officials have already launched the first step in the lake's cleanup, refurbishing existing retention ponds so they work better to filter runoff from the 3,500-acre watershed around the lake, as well as building new ponds to aid in the filtration.

They plan to set up pumps to inject alum into the runoff as it pours in after a rain. The alum will combine with the sediment, forcing it to settle out in the ponds before the water flows into the lake.

And they are already thinning the cattails and hope to replace them with more desirable plants, such as eelgrass and giant bullrush, which are better for fish and wildlife habitat. They hope to have the entire project done by 2008.

But the big question mark remains what to do about the muck. And on that point, the agencies involved in the cleanup disagree.

Champeau, of Fish and Wildlife, says he has tried for 12 years to sell county officials on the idea of a drawdown: pumping water out of the lake until it's low enough to bring in bulldozers that can scrape the muck away, then refilling the lake to its proper level.

The drawdown has been successfully employed to clean up other Florida lakes, and it's cheaper than other techniques, Champeau said. He estimated a drawdown would cost about $1.40 per cubic yard of muck, while the dredging the county has decided to use typically costs more than $5 per cubic yard.

But with Lake Seminole, "I've never been able to sell those guys on the drawdown idea," Champeau said.

The county has repeatedly turned down the drawdown, Talhouk said, because "it takes the whole lake out of usage for a long period of time." There are too many residents living on the lake whose property might be damaged by a drawdown, he said, and the sediment is so deep that driving machinery across the lake bottom would be difficult.

Instead, county officials hired a consultant, Post Buckley Schuh & Jernigan, which came up with a plan to dredge the sludge from the lake and then pump it through a pipeline under the Seminole Bypass Canal to a landfill in Largo near a mobile home park.

So much muck would be pumped into the Largo landfill that it would fill it 6 feet high. After drying out, the muck _ which would be far smaller without water in it _ would be trucked to the Toytown landfill to help build a new golf course there.

But angry Largo residents and city officials resisted the proposal, saying they feared odors from the drying muck and heavy traffic from the trucks would result. They told county officials to find some other home for its muck.

So county officials went hunting for an alternative. The one they came up with is a technology patented by the Kansas City engineering firm Black & Veatch. The technology involves injecting a chemical additive called a polymer into the muck as it is dredged up to make it dry out faster.

The polymer combines with the sediment, making it heavier, so that it settles out of the water. The cleaned-up water can then be put back in the lake. Meanwhile, the sediment is put through a press to squeeze it down further, so that there would be far less material to be disposed of, say Black & Veatch officials.

With less material to deal with, the county can then simply truck the product straight to the old Toytown landfill, which is owned by the county.

Black & Veatch has never used its polymer process on a lake in Florida, but a similar technique was employed as an experiment by Lakeland in its attempt to clean up Lake Hollingsworth.

However, difficulties with blending the polymer mixture with the various types of sediments coming out of the lake repeatedly clogged the machinery, delaying the project and driving up the cost by nearly $3-million.

"We had a lot of technical problems," said Gene Medley, Lakeland's lakes manager.

Medley said Lakeland abandoned the polymer idea in 1999, and shut down the dredging completely this spring because of the spiraling expense and a lack of water in the lake, thanks to the statewide drought.

Officials with Black & Veatch are quick to distance their process from the one used on Lake Hollingsworth, pointing out various technical differences in the mechanics. They say that, unlike the process used in Lake Hollingsworth, they can fine-tune their polymer to work with different sediments.

However, Black & Veatch has never attempted to use its process anywhere in Florida. And while they have been successful on golf course lakes in Colorado and a handful of other locations, the company has never tried using it on a lake with more than 38,000 cubic yards of sediment to process _ far less than the amount in Lake Seminole.

Talhouk said size should not matter. "If it works, it works," he said.

However, the county's consultant is now trying to figure out how much the polymer process could cost for Lake Seminole, and what it would take to do a pilot project to test its viability. If it fails, the controversial Largo landfill may be the only option for saving Lake Seminole.

"If we find it's not suitable," Talhouk said, "then we have to go back to Plan B."

The one thing the county cannot do, he said, is go back to the way things were before the dam was built. There are too many waterfront homes there now, too many people who count on having a freshwater lake for boating and riding personal watercraft.

Tear down the dam, Talhouk said, and "what you would end up having at low tide is a salt marsh. . . . It wouldn't really be a recreational facility at that point. If you lived on it, at high tide you might have water, but there would be an odor problem I'm sure."

_ Times researcher Caryn Baird contributed to this story.

Lake Seminole facts

Lake Seminole was created by a dam of sorts, a water-control structure called a weir built in the 1940s when Pinellas County officials decreed that the brackish estuary off Long Bayou should be turned into a freshwater lake shaped like an hourglass. The county's radical surgery created a 684-acre retention pond with no circulation.

BORN: 1945

DEPTH: For now the average depth of the water is 6 feet, according to state officials, dropping to about 8 feet in the channels.

CLEANUP COST: will cost taxpayers $11-million.

FISH: Lake Seminole is now dominated by gizzard shad and tilapia _ trash fish to many anglers. The bluegills that remain are stunted, unable to attain adult size.

SIZE: 684-acre lake

A U-shaped weir near the south end of Lake Seminole near Park Boulevard keeps saltwater from entering the lake. Freshwater spills over the weir. Approved by the county in 1945, the weir turned a brackish estuary off Long Bayou into a freshwater lake shaped like an hourglass. The weir is a dam of sorts and has created a 684-acre retention pond with no circulation.

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