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Drought yields lake's treasures and trash

As archeologists gather Okeechobee's clues to South Florida history, water managers work to clean up toxic muck.

July 19, 2007|Carol J. Williams | Times Staff Writer

LAKEPORT, FLA. — Conservationist Marjory Stoneman Douglas once famously grumbled that Lake Okeechobee, the liquid heart of her beloved Everglades, had been poisoned by man's careless disposal of "pesticides, fertilizer, dead cats and old boots."

She didn't know about the 1920s steamship, rusty anchors, tractor tires, fishing-boat motors, settlers' stovepipes, Native American tools and jewelry, and the bones of man and beast dating back thousands of years. All were hauled from the lake bottom this summer.

Drought has caused the second-largest freshwater lake in the United States to drop to its lowest level since recording began in 1932, and the shoreline's recession has exposed trinkets, treasures and trash from throughout the ages.

Archeologists and historians are excited by the potential insight into the little-known lives of South Florida's earliest inhabitants.

But the lake's shrinkage has also left a monumental cleanup headache: a bathtub ring of toxic sludge from dumped wastewater and the objects hurled in by hurricanes and litterbugs.

For The Record
Los Angeles Times Saturday July 28, 2007 Home Edition Main News Part A Page 2 National Desk 1 inches; 36 words Type of Material: Correction
Lake Okeechobee: A July 19 Section A article about drought-related dredging said Florida's Lake Okeechobee was the second-largest freshwater lake in the United States. It is the third-largest natural freshwater lake located entirely within the U.S.

The slimy gray lining, if not a silver one, is that the drought has given water managers an opportunity to scoop out the muck and refresh the shoreline habitat for Okeechobee's flora and fauna.

In little more than two months, contractors with the South Florida Water Management District have hauled away 2 million cubic yards of sludge -- enough to fill nine football stadiums from the field to the nosebleed seats, said Tom Debold, water district supervisor on the muck-removal project.

After the muck was scraped and temporarily stored in 20-foot-high mounds set back from the shore, scientists discovered that much of it contains excessive levels of arsenic from pesticides and fertilizers used until the 1960s.

Water district and Army Corps of Engineers officials who maintain much of the lake's surrounding levee and its intricate network of canals, sluices and pumps had hoped to sell the excavated sludge to builders for landfill. But after analysis, they concluded that "it can't be used near any kind of housing facility," said Susan Gray, a biologist and deputy director of watershed management for the district.

The residential limit for arsenic in soil or fill is 2.1 milligrams per kilogram; the Okeechobee muck had as much as 9 milligrams per kilogram, Gray said. The concentration of arsenic, which cannot be treated or neutralized, is intensifying as water evaporates from the sludge and the desiccated piles compress. Removal of the muck has allowed fresh shoots of bulrush and tape grass to sprout and will improve the habitat for the bass and crappie that draw thousands of anglers to the lake each year.

Water quality isn't expected to radically improve, however. The amount of muck removed was estimated to be about 2% of what lines the bottom of the broad, shallow lake, said water district spokesman Randy Smith.

Plans to bury the contaminated muck in trenches inside the levee are pending environmental study and permits from the corps. The $11.4-million removal project was brought to an end by recent rain bursts that promise to begin refilling the lake from its historic low of 8.88 feet above sea level reached on July 1.

Work has just begun, though, for those poring over the artifacts pulled from the exposed shores.

"It's really amazing. We live on this Earth such a short time compared to the history that's in that lake," said George "Boots" Boyer, a tree farmer and environmental restoration activist from the lake's southeast cluster of towns and villages, called the Glades.

As he plied the lake's dredged channels on his airboat this spring, he spotted objects poking through the drying grasses and gray muck. He contacted historical preservation officials from the state and Palm Beach County. The officials have deployed fish and game wardens to protect the designated search sites from beachcombers and looters.

"There's spearheads and arrowheads and pendants made from conch shells. My favorite thing is an old catfishing boat," Boyer said of the 100-year-old vessel found fully intact when the water retreated.

Human remains and cultural objects have been mapped and left in place for the waters to reclaim them, whereas hundreds of artifacts such as handblown bottles, tools, hunting gear and adornments have been taken to state and county laboratories for cleaning and inspection.

"There's been a lot of things that look kind of neat, but I don't know what they are," said Jim Sheehan, who runs the Pahokee marina. "The archeologists say, 'Oh, that -- that's a sloth tooth.' "

Palm Beach County archeologist Chris Davenport has two years to examine and catalog the implements and housewares found at 19 sites along the county's lakefront stretch, which includes the towns of Pahokee, Belle Glade and South Bay.

One of the artifacts, a spearhead, could be 8,000 years old, Davenport said, and human remains appear to date back 2,000 years.

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