BARABOO - For a lake researcher, it's a sad reality of life today that polluted, murky lakes are more the norm than the exception.

So it was a pleasure to see Richard Lathrop, a state Department of Natural Resources lake scientist, in such a good mood at Devil’s Lake State Park last week. He was happy because Devil’s Lake is cleaner today than it was 10 years ago.

It’s cleaner thanks to an interesting bit of science that Lathrop came across in the late 1980s, an idea that he believed could result in a cleaner lake, free of algae and even the snails that cause swimmer’s itch at the state’s most popular park.

That idea took shape in the form of a 5,500-foot-long pipeline that was, under Lathrop’s watchful eyes, sunk to the bottom of the lake in 2002 and was being dug up last week and repositioned.

The pipe proved a simple and effective solution to a complicated problem — phosphorus, which had collected in the silt at the bottom of the lake and was the legacy of years of sewage running into the water from cottages, resorts and even a long-broken sewer main in the park. That phosphorus fed the growth of algal blooms which, in turn, served as a host for the snails that cause swimmer’s itch.

But since 2002, Lathrop’s pipe has been vacuuming phosphorus from the lake bottom. It’s a process called hypolimnetic withdrawal. Lathrop knew that it had been used successfully in other lakes with heavy loads of phosphorus. But the system had never been used in a seepage lake such as Devil’s Lake, which is fed by groundwater and has no surface water outlet.

Lathrop saw no reason, however, the pipeline wouldn’t work in Devil’s Lake. In September, phosphorus is released from the sediments at the bottom of the lake because bacteria and other organisms have used up the oxygen that keeps it in place.

At the same time the phosphorus is being released, the pipe is primed to start a siphon (in much the same way you put your finger over a straw and withdraw water). The pipe begins to withdraw the phosphorus-laden water, which flows out of the lake and into the nearby Baraboo River.

The pipe extends out to where the lake is at its deepest, about 50 feet. Lathrop himself built the intake end of the pipe in 2002, working in an adjacent picnic shelter to cap the pipe and then drill numerous holes through which water could flow.

The success of the system has surprised even Lathrop. Since its installation, the pipeline has removed about 6,000 pounds of phosphorus, according to Lathrop. That translates into about 3 million pounds of algae that didn’t grow because of the loss of the nutrients that feed its growth.

The system’s effectiveness on other lakes, Lathrop added, depends at least partly on whether sources of pollution are controlled, as they are now in Devil’s Lake. Lake Mendota, for example, might pose a problem because pollution is still entering the lake.

Joel Bornitzke, who runs Three Little Devils dive shop near Devil’s Lake State Park, said the difference has been striking. "Ten years ago, the bottom of the lake was covered by snails. And there was slimy green stuff all over the rocks. We don’t see that anymore," Bornitzke said.

For Bornitzke, the lake is the basis of his livelihood so he’s especially happy to see it becoming cleaner and clearer. In recent years, he said, he’s lost return business due to the water’s lack of clarity. He’s hoping that with the success of Lathrop’s work, those customers will return to enjoy the bottom of the lake with its rock formations and its schools of fish.

Steve Schmelzer, acting park superintendent, said an added benefit of the project has been flood control. As is true for the surrounding area, recent years have seen repeated heavy rainfalls at the park, as well as snowmelt from record snowfall, and that has taken its toll. Roads and buildings have been flooded out. And the park has even had to close. But some of that threat has been lessened by using the pipeline to remove water from the lake to create more storage.

Lathrop said that serendipitous benefit of the project will be improved upon with the work that is being done on the pipeline. Last week, workers removed a hump in the pipe to improve the flow of water (and correct for some seepage from hairline cracks in one section). Also, a valve was added that will allow park officials to use the pipe to withdraw water and create more room for storage of floodwaters.

No wonder Lathrop trudged up and down the pipeline last week, proud as a parent whose child received a good grade.

"I really felt we could clean this lake up," Lathrop said. "And that if we could sustain the project for enough years, we’d see real results. Now, we’re going to see this work continue for years to come."

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