Engineering firms will bear the million-dollar cost of an innovative water-muck separation trial for Lake Seminole.
By MAUREEN BYRNE AHERN
Published July 6, 2003
SEMINOLE - It's taken almost a year, but the county finally has secured the necessary permits to conduct a cleanup demonstration in Lake Seminole.
Although officials aren't sure exactly when the 30-day project will begin, they hope to have it under way by fall.
"I'm pretty excited about the whole process," said David Talhouk, a county engineer overseeing the lake's restoration plan. "It's a win-win situation for everyone."
That's because Bob Hayes has offered to do the monthlong project for free, Talhouk said.
Hayes' Lakeland engineering company, Hayes-Bosworth, and two others - EIMCO Process Equipment and Bird Machine - plan to spend $1-million of their own money to show county and state officials they can remove the sludge from the 684-acre lake.
They'll set up 30 tons of equipment in the north section of Lake Seminole Park that is closed to the public. The companies plan to remove 1,000 cubic yards of sediment, only a fraction of the 850,000 cubic yards of muck that covers the bottom of the lake.
"We're trying to do everything we can to address problems we've seen in other restoration projects before we begin one on this lake," Talhouk said. "This is an opportunity for (Hayes) to show his process and for us to learn whether it will work."
"We're just trying to test the process," agreed Kelli Hammer-Levy, the county's program manager for water resources.
Other lake cleanup projects in Florida have used what Talhouk calls the "pump and dump" method - a traditional dredging process where workers pump muck from the water, let it dry in holding areas and then truck it to a disposal site.
For years, Pinellas County officials have been trying to figure out the best way to remove the sludge from Lake Seminole. But without a large area of land to dry the sediment, options are limited.
"To remove the sediment from the bottom of the lake is simple," Talhouk said. "The trick is once you get the material up on shore, how do you separate the material. To me, that's the central part of this project."
The rapid dewatering system Hayes will use is much faster than the conventional method, which pumps sediment to a holding area so it can dry. But in an urban area such as Pinellas, there isn't enough land available for large drying beds.
The technology involves injecting a polymer into the sediment and squeezing water out of the muck. The polymer combines with the sediment, making it heavier, so that it settles out of the water. The muck is then spun in a large machine.
The cleaned-up water can be put back in the lake. The dry residue would be trucked to the Toytown landfill to help build a new golf course there.
For the demonstration, the water will be piped to the county's sewer system so it can be evaluated and the sludge will be taken to the park's nursery site.
If left alone, Lake Seminole would continue to fill with sediment until it became nothing but a marsh. The Fish and Wildlife Conservation Commission says bass and bluegill, once the staples of the lake's fishing business, have declined sharply since the 1960s. Lake Seminole is now dominated by gizzard shad and tilapia - junk fish to many anglers.
During the past 50 years, stormwater carrying lawn fertilizer, motor oil, sewage and other chemicals has washed in, clogging the lake bottom with silt and damaging its ecosystem. So county engineers and environmental consultants are working to reverse that trend and make the lake a viable fishery once again.
St. Petersburg has its own muck problem with Lake Maggiore, a 385-acre lake that for decades has served as a de facto retention pond for a 2,290-acre area of homes, parks and a golf course. The city has been exploring options for cleaning up that body of water since the mid 1990s.
A private company will suck the muck from the bottom of the lake and truck it to a county landfill or other disposal site. The project will cost $13-million.
St. Petersburg's Environmental Development Commission approved the project last month, but some permits are still pending.
County officials say if the project on Lake Seminole is a success, it won't guarantee Hayes and his associates the job.
Hayes says he would give the county a final report of the demonstration project and a cost estimate for the full-scale operation, which he says would take about a year.
The dredging of Lake Seminole is only one component, albeit the most expensive, of the county's $15-million cleanup plan for the lake. County officials think it could cost up to $10-million.
