yawn... yet another 15 secs of watery goodness

http://www.startribune.com/106/story/1238853.html
another story in the strib... the lake detective...
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Simple remedy cleans lake; now it's open to swimmers

Round Lake in Eden Prairie reopened this week to swimmers thanks in large part to barley straw -- an inexpensive and eco-friendly remedy for algae-clogged water.
By Sarah Lemagie and Jenna Ross, Star Tribune
Last update: June 12, 2007 – 11:29 AM

Three years ago, Round Lake had an algae problem, and Eden Prairie was considering ways to fix it.
The city liked the idea of capturing and treating all water entering the lake, said Stuart Fox, parks and natural resources manager. But city officials were less excited about the project's $1 million price tag.
Then they heard about barley straw.
Once in a pond, the straw's high level of carbon attracts microbes that eat phosphorus that would otherwise feed algae. And less algae means better, clearer water.
It's a low-tech, cheap, eco-friendly solution that's been around for thousands of years, but that a few Minnesota cities are discovering anew. And it's one big reason why this week, Eden Prairie was able to open Round Lake to swimmers for the first time in three years.
The brains behind the project is Steve McComas, an aquatic scientist whose St. Paul company, Blue Water Science, helps clients restore and manage lakes. The company has tracked the straw's success at clearing up ponds clogged with algae since 1999, and it hopes to publish its research, McComas said.
McComas' work with Round Lake focuses on the storm-water ponds that lead to it. He guesses about a dozen ponds are part of the lake's watershed. But two or three are "really key," he said, "the lake's last lines of defense."
Workers put the barley, which costs just a dollar a pound, in mesh bags they then spread around the key ponds. The barley sinks after a week or so and decomposes fully within a year. The amount of barley depends on phosphorus and algae levels, but ranges from 200 to 300 pounds of barley per acre of water.
In cities like Lakeville, residents put the barley into their own neighborhood ponds as part of an adopt-a-pond program. Eden Prairie does not recommend that homeowners try this themselves, however, said Leslie Stovring, environmental coordinator.
But soon, the process could easily be do-it-yourself, McComas said. No clear, accurate guide for putting barley into your nearby pond exists, but McComas hopes to publish a how-to soon.
For now, he offers a key tip: Don't buy bales. They're too dense. "You want the fluffy stuff," he said. McComas gets his barley from a farmer in Cambridge.
In his research, McComas is still answering some questions. He's not sure yet if barley straw might combat duckweed. And corn might work in place in barley, but that requires more study.
In Round Lake, the effort has reduced the levels of phosphorus by about 40 percent, McComas said. The cost: $30,660 for work in 2005 and 2006.
"That's huge," he said. "A lot of times it can cost more than $100,000 just to get a 10 or 15 percent reduction."
Algae makes water murky and clings to swimmers' feet -- reasons why the number of swimmers at Round Lake declined in 2002-03, Fox said.
The other reason was geese, whose feces contaminated water to levels that exceeded state limits and required more frequent beach closings.
"The closings gave people the sense that this water is unfit to swim," Fox said.
McComas considers the city's efforts to reduce the goose population part of a strategy similar to barley that focuses on "biological manipulation" rather than chemicals. This fall, the city plans to use some combination of sprinklers, dogs and grape seeds to discourage geese from congregating on the beach.
And in a way, swimmers are in that "biological manipulation" category too, he said. In three years without people, milfoil and other weeds thrived on Round Lake's beach.
"We need the swimmers back in there to clear it out," McComas said. "They, too, have a role."