Of all the places to swim in northern Vermont, it seemed like a questionable one: The waters of Lake Champlain lapped the beach in lazy, sluggish brown-flecked licks. A few hundred yards to the north, somebody was pumping something out of the Pine Street Canal Superfund Site, not far from the wastewater plant. To the south was Blanchard Beach, closed permanently because of fecal pollution.

Yet there they waded, oblivious --a man, woman and child. Pedaling by on the Burlington Bike Path, I thought about directing the family to North Beach, or over to Oakledge, where the water seemed a bit less disgusting. But I kept my mouth shut and, instead, conducted a bit of due diligence on the doo in the lake.

As it turned out, there was probably nothing wrong with the lake at this small strip of unclaimed beach just north of the Lakeside neighborhood. Steve Roy at Burlington Public Works explained that it likely was just water being pumped from the canal. Still, says Sharon Mallory, public health environmental specialist with the Vermont Department of Health, "It's probably best for people to swim at designated areas that are being tested."

Vermont has no statewide regulations on testing swimming waters, which means it's up to communities to do their own monitoring, and to the public to decide where they want to dip. In Burlington, the Department of Parks and Recreation collects water samples at its beaches -- North, Leddy and Oakledge -- twice a week, and hands them over to the Department of Public Works to test for Escherichia coli, a bacteria that comes from poop -- dogs', farm animals' and peoples'. When E. coli is in the water, other nasty microorganisms might be lurking there, too; these can cause troubles, from cramps and diarrhea to giardiasis and crypotosporidiosis, none of which are exactly compatible with a day at the beach.

Luckily for our intestines, the state of Vermont does have standardized, acceptable limits of E. coli contamination: no more than 77 organisms per 100 milliliters of water. If there are too many of the little guys in a sample, beach officials post signs in the sand, as well as advisories online. With the exception of an 83 at Leddy Beach South on July 8, and an ongoing advisory for inner Malletts Bay in Colchester, bacteria counts have been low at most Burlington-area beaches this summer.

"The only time we ever have problems with water quality here is if we have a prolonged period of dry weather followed by a very hard rain event," says Wayne Gross, director of Burling-ton Parks and Rec. "The waste, pretty much from animals, that is built up in the watershed over the period of time, if that all washed down into these drainages that feed the beach areas, usually for a day or two after an event like that you'll get higher readings."

Gross also points out that the lake's a lot cleaner than it used to be. When Mark Spitz was scooping up medals in Munich, inspiring thousands of would-be swimmers, Lake Champlain might not have been the choice for doing laps. But chances are that this summer, after watching Michael Phelps and Natalie Coughlin go for swimming gold in Athens, more folks will go jump in the lake for a workout.

Thanks to water's anti-gravitational properties, swimming is one of the most injury-free sports -- second, perhaps, only to table tennis. It's safe for just about anyone, provided they learn the proper techniques. That said, water-based exercise is about much more than splashing around to the Mamma Mia soundtrack.

"Swimming has great cardiovascular and muscular endurance benefits and helps increase flexibility and is great for the abdominal muscles and the back," says Charlotte Brynn, head swim coach at the Swimming Hole, a community pool in Stowe. "A lot of people think swimming's about the arms and the legs, but so much of it comes from the core. And by changing the strokes around, you're cross-training your body in the water; the breaststroke works the upper back, or trapezius, while the butterfly's body motion is really good for the abdominal and gluteal muscles."

Swimming works almost all the major muscle groups, improves posture and lowers resting heart rates. Because water is 12 times more resistant than air, simple movements become complex body-boosters while swimming. Even if you're just treading water, you're working your rear end, your hamstrings and your hip abductors and adductors. "Anytime you're in deep water and not touching the bottom," says Brynn, "your trunk muscles kick in to keep you upright."

This is good news for anyone who's ever spent time in a swimming hole, nearly 100 of which are named throughout the mountains and valleys of Vermont. Many more are kept secret by the locals. Among the northern favorites are the mossy, shady, deep Bingham Falls, near Stowe; the clear, cave-pocked Bristol Falls; and Bolton's Potholes, a terraced, cliff-jumping playground carved from ancient glaciers.

"You guys have great rock in Vermont," says California-based swimming-hole sleuth Pancho Doll, author of the Day Trips With a Splash guidebook series. "And it's rock that makes a great swimming hole, because you've got to have containers."

Laid off by The Los Angeles Times, Doll began searching for natural pools in the Sierras, and got hooked. "It's the spirit of discovery," he says. "Each swimming hole sneaks up on you; it's a surprise, and no one is the same."

And though Doll has scoured the country for ideal oases with clean water and few crowds, a few Green Mountain marvels, such as the sunny, flume-filled Falls of Lana in Salisbury, easily come to mind. "Falls of Lana is enough of a hike uphill that it's kind of got a bozo filter on it," he says. "If it's more than 250 calories to get there, that cuts down on the beer-cooler brigade."

Another bozo filter is the Vermont River Conservancy, which works to protect some of the state's best swimming holes. Through property acquisitions, the group has ensured that Reading's Twenty-Foot Hole, Lower Clarendon Gorge and Ludlow's Buttermilk Falls remain hot-weather destinations for members of the public lucky enough to know where they are.

"There's a long history of Vermonters swimming in swimming holes, but these places require a gentle treatment," says Meyers, who waxes poetic on the spiritual and physical benefits of cooling off in a hidden swimming hole. We learn about the interconnectedness of nature, and the importance of wild places, he explains. "It's so different to swim in this clean, natural setting, with the water rushing over the rocks. You're in a timeless environment, and there's nothing like it."

To learn more about Burlington beaches and testing results, visit www.enjoyburlington.com. For more info on the VRC, visit http://www.vermontriverconservancy.org, and for a copy of

Day Trips With a Splash: Northeastern Swimming Holes, visit www.running-water.com.