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Tampa's Sulphur Springs too far gone, experts say

TAMPA

Twelve years ago, when a panel of experts published a report on everything wrong with Florida's springs, one meager ray of light came from Sulphur Springs in Tampa.

In the late 1800s, Sulphur Springs became a popular spot for settlers looking to cool off with a swim and to socialize with a picnic on its sandy shore. Homes and stores grew up around it. When Tampa built a streetcar line, the springs were its northernmost terminus.

In modern times, though, what made the spring off Interstate 275 near the Tampa Greyhound Track important was its steady flow of water even during droughts. That gush from underground would flow into the Hillsborough River, the main source of Tampa's drinking water.

Since the 1960s, every time the river's flow dipped too low, the city would pump water directly from Sulphur Springs to its reservoir two miles away. The city continued using the water even though the spring suffered from such high bacterial counts that the swimming area was closed in 1986, replaced by a pool unconnected to the spring.

The pollution increased even as the flow declined by 44 percent, a drop due in part to increased pumping of water from the surrounding aquifer.

Sulphur Springs appeared to be "a prime example of the serious degradation that can occur in the absence of planning and protection," the 2000 state springs report said.

But that could all change, the report pointed out. The city and the Southwest Florida Water Management District — commonly known as Swiftmud — had hired two hydrogeologists to study how the spring might be restored, improving both its flow and its cleanliness.

Sulphur Springs' main problem, they found, was that it was connected underground to a more than a dozen nearby sinkholes that funneled water into it from the surface.

The biggest one became clogged in the 1950s. A car dealer had built a lot next to it, and during a major storm a Dumpster slid into the sinkhole and blocked it off completely, said John Dumeyer, who did the Swiftmud study with Peter Schreuder.

Other sinkholes were clogged by garbage that had been tossed in over the years. Schreuder said they found "refrigerators, car parts, tires and battery casings." Plastic bags tossed in the holes caught on twigs and tree limbs that fell in naturally, "and it forms a dam," he said.

"It's a terrible shame," Schreuder said. Those weren't the only things blocking it, either.

"Many have been deliberately filled with soil and concrete debris to facilitate construction of homes and businesses," Schreuder and Dumeyer wrote in their study.

And at least two of the remaining sinkholes had been converted to stormwater ponds by the city. Pollution collected in those ponds — fertilizer, gasoline and a host of other contaminants — flowed straight into the aquifer feeding the spring.

Cave divers hired by the city in the mid-1990s to explore the spring saw the consequences of the pollution pouring in.

"You could see the slick on the surface from the petroleum product in the water," cave diver Jeff Peterson recalled. "I know people who would dive in and said they would get sick from E. coli (bacteria).''

Peterson said he didn't suffer any health effects, but the pollution took its toll on his wardrobe: "The elastic on our waistbands would break up after two or three dives."

Later, the divers made an even more disturbing discovery. While diving the freshwater spring, they found saltwater vents had opened up in the spring's tunnels. Thanks to increased pumping from the aquifer, the pressure pushing fresh water out of the spring had dropped and allowed chloride — salt — to intrude.

Ultimately, after checking scores of monitor wells and consulting with the divers, Dumeyer and Schreuder concluded that Sulphur Springs was too far gone to be restored.

In their 2004 report, Dumeyer and Schreuder wrote that the underground tunnels that once ran between the sinkholes and the spring were too clogged. The connection between the main sinkhole and Sulphur Springs was "not feasible to reconnect," they wrote.

"There's no way to put a Roto-Rooter into those underground channels," Dumeyer explained.

The engineers also warned that Tampa's continued dumping of stormwater in those sinkholes "will further endanger the connection" because debris and pollution were affecting the stability of the walls.

The continued blockage of those sinkholes cut the flow of water in the spring by 10 million gallons per day, the report noted, so that "the salinity of Sulphur Springs increased proportionally with the decline of freshwater recharge" from the clogged sinks.

They decided that the only way to get the missing water from the sinkholes over to the river or reservoir would be to spend millions building a pipe above the ground to bypass the spring entirely, Dumeyer said.

The failure of the spring restoration plan, and the report on everything wrong with it, did not discourage city officials from continuing to tap the spring for water. During droughts in 2000 and in 2004 the city pumped water from the spring to its reservoir. In 2009, the city spent three months pumping 3.2 million gallons a day out of the spring.

They have to keep an eye on the salt so it doesn't make the reservoir too salty, explained Brad Baird, director of Tampa's water department. But they're not concerned about all the pollution, which he said is easily handled by the city's water treatment process.

Go down by the spring run and walk along the footbridge over the channel that runs to the river, he said. "It's a nice setting," he said. "And if you look at the spring run, you'll see it's clear water."

Sulphur Springs is to be “a prime example of the serious degradation that can occur in the absence of planning and protection,” a 2000 state report said about the springs’ pollution and reduced flow.

Sulphur Springs is to be “a prime example of the serious degradation that can occur in the absence of planning and protection,” a 2000 state report said about the springs’ pollution and reduced flow.

Tampa's Sulphur Springs too far gone, experts say 11/23/12 [Last modified: Friday, November 23, 2012 7:20pm]

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