Lake George groups optimistic about effort to control invasive clam

By DAYELIN ROMAN, droman@poststar.com

LAKE GEORGE — Work to suffocate invasive clams in Lake George may succeed in killing off the population by next summer, the Fund for Lake George’s executive director said.

The Asian clams were discovered by a Darrin Fresh Water doctorate student in August at the southern end of the lake.

They are considered an invasive species because they reproduce so quickly they can clog water pipes. They also compete with native organisms for algae and excrete nutrients that contribute to algae blooms, which are often associated with poor water quality.

When the clams die, they release calcium that contributes to the spread of zebra mussels, another invasive species in the lake, and their sharp shells can make a sandy beach unfriendly to bare feet.

They can also turn blue water green.

Since the August discovery, environmental groups around the lake have spent more than $45,000 to study and get rid of the clams. Several groups, including the Fund for Lake George, RPI’s Darrin Fresh Water Institute, the Lake George Park Commission, the Lake George Waterkeeper, the Lake George Association, the Adirondack Park Invasive Plant Program, the Lake Champlain Basin Program, Bateaux Below and the Adirondack Park Agency have been involved in the effort.

Technical experts from Lake Tahoe, where work to control a bustling Asian clam population is ongoing, have also been involved in efforts at Lake George and have visited the lake to study the new clams, a press release from the Darrin Fresh Water Institute states.

According to a newsletter from the Fund for Lake George, a 4-acre area of infestation has been identified in the village of Lake George that runs from the English Brook delta to the area around the Boardwalk restaurant. The clam population is estimated at more than 5,000 per square meter in heavily infested areas around docks and close to shore.

Divers have been testing different types of mats laid over the lake bottom, called benthic barrier, to see how effectively they can suffocate clams, the Fund for Lake George’s newsletter states. That study will shape efforts to kill off the entire Asian clam population after ice melts in April. Over the winter, the newsletter states, permits and materials will be secured, but the cost of the project is estimated at $250,000 for the 4-acre area.

“So far, the benthic barrier seems to be working,” Fund for Lake George Executive Director Peter Bauer said.

Owasco Lake affected by foam, Asian clams, blue-green algae

Justin Murphy The Citizen

AUBURN — Three recent reasons for concern about the water at the northern end of Owasco Lake are likely interrelated, the Cayuga County Water Quality Management Agency concluded Thursday.

In a nutshell: the lake appears to have a growing population of Asian clams, an invasive species.

The clams consume green algae, thereby allowing competing blue-green algae to grow out of control. The blue-green algae contributes to a rise in the levels of phosphorous and other organic materials, creating white foam on top of the water.

All three issues — the algae, the clams and the foam — have generated a lot of phone calls recently from concerned residents, Environmental Health director Eileen O’Connor said.

It’s not clear whether the clams or the blue-green algae came first, or how the clams originally got into Owasco Lake.

“It’s a correlation, but I don’t think you can prove a causation,” Robert Brower of the Institute for the Application of Geospatial Technology said.

Asian clams have been in Seneca Lake since 1999 and have appeared in the last few years in Lake George, the Champlain Canal and the Erie Canal near Utica, county environmental engineer Bruce Natale said.

“They’ve been around, but they’ve just started to move around to new places recently,” Natale said.

The clams prefer water that is warm, shallow and clear, without too many weeds. Deauville Island at the north end of Owasco Lake fits that description well, Natale said.

Asian clams are hermaphroditic, meaning that one organism can reproduce on its own at a rate of 400 eggs a day, Natale said. The calcium they produce attracts zebra mussels, another invasive species.

The clams could be eliminated if the water temperature in the lake gets below 38 degrees for a period of time during the winter, Owasco Lake inspector Jessica Miles said. Without the clams, the blue-green algae and foam might go away as well.

O’Connor stressed that the foam on the lake is not from soap or laundry detergent and is not dangerous.
“Rich bodies of water with a lot of organic material will tend to foam,” she said.

The Water Quality Management Agency is coordinating a volunteer effort to determine the extent of the clam and algae problems. No clams have been reported in other lakes in the county, and the group urged residents not to transport their boats from Owasco Lake to other lakes in order to keep the clams from spreading.

Staff writer Justin Murphy can be reached at 282-2237 or justin.murphy@lee.net. Follow him on Twitter at CitizenMurphy.

How to report problems

• To report Asian clams or foam in Owasco Lake, call Owasco Lake inspector Jessica Miles at 252-4171, extension 120.

• To report blue-green algae, call the Cayuga County Department of Environmental Health at 253-1405.

Blue-green algae can cause health problems for people and animals. People should not use algae-infested water for drinking, bathing or swimming.

Special Segment: Lake Invaders

Ron Magers

November 8, 2010 (CHICAGO) (WLS) — Researchers are sounding a warning that there is a threat to the Great Lakes that may be worse than the Asian carp.

The new threat is literally eating up the basic building blocks of life in the lakes.

“We really are seeing the collapse of one of the largest lakes, food webs, in one of the largest lakes in the world,” said Dr. Charles Kerfoot of Michigan Technological University.

Dr. Kerfoot has been surprised by what he and his team have found.

“We saw a ring of chlorophyl in southern Lake Michigan,” said Kerfoot.

That was the first surprise. Something like chlorophyl is supposed to be evenly mixed in the waters of the lake. But in the late 1990s the Michigan tech team, and numerous other researchers and agencies, used boats and mini-submarines, and sophisticated buoys and even satellite imagery, to prove that a kind of doughnut exists in southern Lake Michigan. The round swirl is a merry-go-round of phytoplankton and zooplankton, the basic building block of life in the lake. The doughnut is kicked up by winter storms and it swirls around a low spot in the lake. That was surprising enough, but there was more.

“Then came the quagga mussels. We picked them up near the end of the project in 2001,” said Dr. Kerfoot.

Think of the quagga as a cousin of the more famous zebra mussel. They probably arrived in the ballast water of foreign ships. The quagga now lives in the soft bottom of the Lake Michigan. Five years ago a one-square meter soil sample of lake bottom contained dozens of them. But more recent samples show as many as 15,000 per square meter.

Quaggas are multiplying very rapidly, and they are eating the doughnut.

“They eat all the building blocks out of that water column. They are sucking down all the particulate matter, and that includes the chlorophyl. So the primary producers are being literally sucked out of the lake down to the quagga layer,” said Dr. Kerfoot.

Starting in April of 2001 when researchers first found the quagga, they found an abundance of chlorophyl, phytoplankton and zooplankton. But by 2008, they found the doughnut had been eaten away.

Further evidence is how clear the water has become in southern Lake Michigan. Kerfoot estimates the quagga are already consuming four to seven times more of the basic food building blocks than the lake can produce. He fears the lake is losing the battle.

“There’s something wrong when you get water as clear as your bathtub water. There’s nothing living in it. What is happening is a collapse of the food chain,” said Dr. Kerfoot.

The research goes on, while Dr. Kerfoot and the Michigan tech team wonder why no one else seems to hear the alarm. He says research on how to control the Quagga is desperately needed but he doesn’t know of anyone who is doing it.

(Copyright ©2010 WLS-TV/DT. All Rights Reserved.)

Efforts made to control population of invasive clam in California

Scientists in California’s Lake Tahoe are running a pioneering marine invasive species control experiment on the Asian clam. They anticipate the results in about a month.

Certified divers and research scientists from the University of California, Davis, Tahoe Environmental Research Centre (TERC) Marion Wittmann and Brant Allen recently dove to remove two separate 100-ft by 10-ft black bottom barriers the bottom of the lake installed in July to gauge how effectively they can kill the invasive Asian clams, reports Matthew Renda for North Lake Tahoe Bonanza.

Researchers installing Bottom barrier deployment
to control Asian clam populations in Lake Tahoe. (TERC, UC Davis)

“Going by visual inspection, there were dead clams, so the barriers did have an effect,” Wittmann said. “However, workers (at the University of Nevada, Reno) are currently processing the samples, and until we get the results, we can’t truly know if the experiment was a success.”

Wittmann and Allen used a device called PONAR to collect sediment samples from lake bottoms for lab analysis.

“A lot of the animals are too small to see with the naked eye,” Wittmann said. “Also, many of the Asian clams and other native species are buried in the sediment, so the samples may contain live animals.”

The Asian clam was first seen in Lake Tahoe in 2002, and is found in waters in 38 US states. Originally a species of freshwater, it has also gone to the brackish San Francisco Bay; scientists blame the moves on the species’ significant powers of adaptation.

The clam expels high levels of nitrogen and phosphorus which provoke algal blooms. The clams also deprive native species of key nutrients and food sources by filtering high volumes of water.

Scientific studies, moreover, predict that the clams’ production of high levels of calcium could provide a hospitable environment for the introduction of quagga and zebra mussels – highly hazardous invasive species, as they could devastate the economy and ecosystem of water bodies.

Studies show that zebra and quagga mussels could survive in Tahoe, if perhaps not reproduce; the presence of Asian clams would facilitate the plague.

Back in July, Wittmann and Allen installed two large bottom barriers on separate half-ac plots on Lake Tahoe’s bottom. The 45-mm bottom barriers are thick pond liners that can deprive organisms of dissolved oxygen which they need to survive.

Lake Tahoe Species Introduction Timeline. (Graph: TERC, UC Davis)

“The goal of this experiment is to determine whether it is feasible to control clams using impermeable bottom barriers,” declared Geoffrey Schladow, director of TERC.

He said that because complete elimination of the species from the lake is not probable, the experiment concentrates on possible population control.

The experiment is estimated to cost USD 648,000; although USD 1.4 million has been assigned for studies and scientific projects to control Asian clams.

By Natalia Real
editorial@fis.com
www.fis.com

Zebra mussels spotted in two lakes

Photo courtesy of the Connecticut DEP

Zebra mussels attached to a bottle. The state DEP commissioner calls the finding of zebra mussels in two Connecticut lakes “a disturbing discovery.” The invasive species has the potential to displace native mussels, clog power plant and industrial water intakes, and affect public drinking water distribution systems.

DEP urges boaters, fishermen to take precautions to prevent spread of invasive species

Zebra mussels, an invasive species, have been discovered in Lake Zoar and Lake Lillinonah, which are created by dams along the Housatonic River in western Connecticut, the state Department of Environmental Protection announced Friday.

This is the first report of a new infestation since zebra mussels were first discovered in Connecticut in 1998 in East and West Twin Lakes in Salisbury. Only small numbers of zebra mussels have been discovered thus far, the DEP said, and it is uncertain whether they migrated from upstream sources or arrived separately.

“This is a disturbing discovery,” said DEP Commissioner Amey Marrella. “The zebra mussels have the potential to do much damage by displacing native mussels, clogging power plant and industrial water intakes, affecting public drinking water distribution systems and disrupting aquatic ecosystems.”

She asked boaters and fishermen to redouble their efforts to take precautions against spreading zebra mussels and to contact the DEP if they see them.

The zebra mussel is a black-and-white-striped bivalve mollusk that was introduced into North American waters through the discharge of ship ballast water. Since its discovery in Lake St. Clair in Michigan and Ontario in 1988, it has spread throughout the Great Lakes, the Mississippi River system and most of New York State. Zebra mussels were first found in the Housatonic River in 2009 when they were discovered in Laurel Lake in Lee, Mass., and subsequent sampling found them in the lake’s outflow into the main body of the river.

Zebra mussels have fairly specific water chemistry requirements and are limited to waters with moderate to high calcium concentrations and pH. In Connecticut, suitable habitat for zebra mussels is mostly limited to a number of water bodies in the western part of the state.

The mussel can foul boat hulls and engine cooling water systems and clog power plant, industrial and public drinking water intakes. Six hydroelectric facilities along the Housatonic could be affected, the DEP said.

To prevent transferring invasive species, the DEP said boaters should make sure they drain all water from the boat, including bilge water, compartments where fish are stored and engine cooling systems after use, inspect their boat, trailer and equipment and remove and discard any aquatic plants and animals found. At home, boats, trailers and equipment should be rinsed with tap water and fish storage compartments cleaned with bleach solution. Unused bait should be disposed of in the trash, and fish and plants should not be transported between water bodies but released into the waters they came from.

To report sightings of zebra mussels or other aquatic nuisance species, contact the DEP’s Inland Fisheries Division at (860) 424-3474. For information on zebra mussels, visit:
www.ct.gov/dep/lib/dep/fishing/anglers_guide/anguide.pdf and www.ct.gov/dep/lib/dep/boating/boating_guide/boaterguide.pdf.
– Judy Benson

Great Lakes Threats Go Beyond Asian Carp, Invasive Expert Says

Dr. Reuben Keller calls for long-term solutions to protect the Great Lakes, and the Mississippi and Illinois rivers from future aquatic invasive species.

By Steve Kellman
Circle of Blue

Community ecologist Reuben Keller has made a career out of studying aquatic invasive species in freshwater systems like the Great Lakes, and measuring their ecological and economic costs. Now a lecturer with the University of Chicago’s Environmental Studies program, Dr. Keller outlined the threat posed by invaders like Asian carp in a presentation to attendees of an Alliance for the Great Lakes webcast Wednesday.

“This is a really unique situation for invasions into the Great Lakes,” Keller said. “It’s unique in that we can see this invasion coming, and we may have the opportunity to prevent its arrival…. Asian carp gives us this opportunity to be proactive.”

But just like the more than 180 biological invaders that came before it, he warned, “we need to assume that if [Asian carp] make it to the Great Lakes, we’ll never get rid of them.”

The subject of state lawsuits, EPA and Congressional hearings, and U.S. Supreme Court motions, the plankton-gobbling Asian carp threaten the Great Lakes’ $7 billion sportfish industry with their habit of eating the bottom out of the food chain and starving fish farther up the chain. That has led several Great Lakes states to file lawsuits seeking more aggressive carp-blocking efforts. Meanwhile, U.S. legislators are debating bills that would sever the connection between the lakes and the rivers, and a White House-appointed “carp czar” is overseeing the federal control efforts.

Overall, invasive species like Asian carp, zebra mussels, fire ants and purple loosestrife cost the U.S. economy an estimated $120 billion a year, Keller said. He added that aquatic invasive species, in particular, are the largest cause of biodiversity loss in lakes around the world.

Nearly a year after environmental DNA was discovered upstream of the electrical barriers that are supposed to keep the Asian carp out of the Great Lakes, new tests continue to find evidence that the invasive species has gotten beyond the barriers, according to Keller.

“There’s been a lot of controversy about how we should interpret these results, and I’ll give you my interpretation,” he said. “Asian carp DNA is turning up so often that it is really hard to explain how that DNA is getting there without there being populations of Asian carp that are beyond the electric barrier.”

This suggests that the barriers may not be working as intended to block the fish, Keller said, but even if they do, they still won’t block invasive invertebrate or plant species from getting into the lakes from the rivers, or the other way around.

That has already happened with zebra mussels, which were first discovered in the Great Lakes in 1988 and have since entered into the Mississippi by way of the Chicago-area waterways. Zebra mussels have now spread as far west as California and cause hundreds of millions of dollars in damage in the U.S. every year by fouling the pipes that deliver fresh water to municipal drinking water facilities and power plants.

“We should expect that for many species, the Chicago Area Waterway System is still a very viable conduit,” Keller said. “There’s still a very high likelihood of future invasions, future economic and ecological impacts.”

This is one of the reasons why the Alliance for the Great Lakes supports the permanent hydrological separation of the Great Lakes from the Mississippi River Basin, said Joel Brammeier, the organization’s president.

“Asian carp are only the latest and certainly the most graphic example,” Brammeier said. “But as Dr. Keller mentioned, we’ve already donated zebra mussels and round goby to the Mississippi River Basin, something that I don’t think the other half of the continental United States is too happy about. We can certainly count today half a dozen other invaders in either direction that could move through this system.”

He added, “No technology solution has been demonstrated to be able to provide the kind of certainty against invasion that we think the Great Lakes deserve.”

Brammeier noted that the past year has seen several promising developments in the fight to block Asian carp. In June, the Great Lakes Commission, and the Great Lakes and St. Lawrence Cities Initiative kicked off a $2 million study of hydrological separation that is expected to take 18 months to complete. The U.S. Army Corps of Engineers, which oversees the Chicago-area shipping locks that other states are suing to close, is also considering separation as a long-term option.

A bill introduced in Congress in June — the Permanent Prevention of Asian Carp Act — would require the Secretary of the Army to study the feasibility of hydrological separation. Brammeier said the Alliance for the Great Lakes would continue to push for its passage.

With the midterm elections bringing many new faces to Congress and new governors to Great Lakes states like Michigan and Ohio, the Alliance will also need to work on educating the incoming politicians on issues like invasive species, he said.

Read more about Asian carp on Circle of Blue.

State may have found Mussel evidence in Flathead Lake

by Dennis Bragg – KPAX (Missoula)

They’re still running tests, but biologists are worried they may have found evidence of exotic mussels making an appearance in the waters of Flathead Lake.

Montana Fish, Wildlife and Parks says microscopic larvae have shown up in four of 17 plankton samples that were taken from a sample collected in July near Woods Bay on the north end of the lake.

Eileen Ryce, FWP’s aquatic invasive species coordinator, says samples were sent to three out-of-state laboratories for testing last week.

Test results from independent labs in the Midwest suggest that tiny organisms within the sample have characteristics consistent with zebra and quagga mussels. Results from a lab in Oregon, however, suggest the sample shows no sign of mussel contamination.

“These larvae are notoriously difficult to identify at this stage of development,” Ryce explained. “With this sample the question mark is the size of the larvae, which are significantly smaller than what we’d expect. But we’ll err on the side of caution.”

Ryce said FWP will send a team of divers to several locations on the north end of Flathead Lake to search for adult mussels, which could be as tiny as sesame seeds.

The sample that contained the suspicious, microscopic larvae was among 11 collected from Flathead Lake by volunteers from the Whitefish Lake Institute in July and delivered to FWP in late September. The remaining suspected samples will be submitted for additional DNA testing.

FWP has also alerted downstream agencies in Idaho, Washington and Oregon since the organisms could be carried into the extensive Columbia River system via the Flathead River.

Zebra mussels were first discovered in the Great Lakes in the 1980s and appeared in Lake Mead in 2007, causing all Western States to begin screening for their spread. In Montana testing has focused on Flathead, Fort Peck Lake and Canyon Ferry because those waterways see the highest amount of non-resident boating traffic.

Lake Champlain has Healthy Whitefish Population

JEFF MEYERS
Press-Republican

PLATTSBURGH — An ongoing study looking into whitefish in Lake Champlain has found a thriving population hidden deep in its murky depths.

The whitefish is a popular sport and commercial fish in the Great Lakes, where it has faced some major problems of late, but it has become a widely ignored bottom feeder in Lake Champlain.

“The whitefish population in Lake Champlain is doing fine,” said Dr. Ellen Marsden, a University of Vermont professor and scientist who is spearheading the whitefish study.

“Everything seems to be going well for them: Their fertility looks good, they’re eating well, they have good growth and low mortality.”

CHANGE IN DIET

Whitefish are a long-lived species, surviving a quarter century or more. The Lake Champlain research project has shown strong consistency in age groups with no discernible gaps that might suggest a die-off problem during any given year over the past few decades.

Marsden turned her attention to Lake Champlain whitefish as a natural progression from research she has assisted with in the Great Lakes.

“In recent years, there have been some dramatic changes in whitefish populations (throughout the Great Lakes), primarily because of a change in their food source,” she said.

A major portion of the whitefish’s diet in the Great Lakes has historically focused on a shrimp-like burrowing creature called diporeia that has also seen a dramatic decline in numbers over the last decade.

Although a cause for the drop in diporeia is not certain, scientists believe the Great Lake’s increase in zebra mussels has had a dramatic impact on the crustaceans.

“Subsequently, the whitefish got into trouble because they didn’t have their favorite food, and they started to eat zebra mussels, which are not a good source of food,” Marsden noted.

“In Lake Champlain, we don’t have abundant numbers of diporeia, so the whitefish’s old food source has not been damaged. That’s how my interest in this lake’s whitefish population got tweaked.”

The only study on whitefish in Lake Champlain took place 80 years ago when the species was important commercially. Though it has been largely forgotten, Marsden felt compelled to see if zebra mussels were playing a role in the health of Lake Champlain whitefish as well.

“Basically, what we found is that they are not eating zebra mussels,” she said. “Even though the (lake) bottom is lined with zebra mussels, they are for the most part ignoring them.”

PRIZED ELSEWHERE

The whitefish diet here varies. They eat mostly fish eggs — including their own species — during the spring and switch to a crustacean commonly called the opossum shrimp in the summer. They feed mostly on snails during the rest of the year but continue to avoid zebra mussels.

“From a biological standpoint, this raises an interesting question,” Marsden said. “What is the motivation for eating something — in despair because a favorite food is gone or eating it simply because it’s there—”

As commercial fishing on Lake Champlain declined in the early 1900s, the interest in whitefish both commercially and as a sports fish also disappeared.

“Today, anglers don’t even seem to know what they are,” Marsden said. “It’s not a fish that you would accidentally catch if you’re looking for something else.”

In other areas, the whitefish is still a prized sports fish, she added. In Maine, for instance, whitefish tournaments are held throughout the season. They also remain a popular seafood choice in the Midwest and even in New York City, she added.

Marsden believes the Lake Champlain whitefish population could easily handle an active interest from sports anglers and suggests that actively seeking them out could pose a new challenge for anglers.

The adult whitefish grows between 17 and 22 inches in length and can weigh from 2 to 4 pounds. The record catch weighing in at 41 pounds was taken from Lake Superior in 1918.

E-mail Jeff Meyers at: jmeyers@pressrepublican.com

Zebra Mussel Could Invade Candlewood Lake

By: Nancy Eve Cohen

The zebra mussel, an invasive species, was discovered in Lakes Zoar and Lillinonah about a month ago. But some people are concerned it could also end up in Candlewood Lake. The Candlewood Lake Authority is holding a panel discussion tonight on the zebra mussel at Western Connecticut State University. WNPR’s Nancy Cohen reports.

The zebra mussel is considered a kind of poster child for invasive species because it can be so destructive. The mussel, which comes from Russia, reproduces rapidly, choking out native mussel species and changing the way ecosystems function. They adhere, en masse, to any hard surface and can clog industrial pipes. The razor sharp shells can be dangerous for swimmers.

The zebra mussel was first found In Connecticut in East and West Twin Lakes in Salisbury in 1998. Just last year it was discovered in Laurel Lake in Lee, Massachusetts, not far from Connecticut. And in a stream from that lake that feeds the Housatonic River and in the river itself. Now it’s also in Lakes Zoar and Lillinonah. Ethan Nedeau is an ecological consultant for First Light, which has hydro electric facilities on the river. Nadeau says part of Candlewood Lake contains calcium at levels that the mussel needs to thrive.

“It does seem pretty likely that overtime zebra mussels will reach Candlewood Lake and conditions are certainly favorable in the northeast arm of the lake.”

Peter Aarrestad of the Connecticut Department of Environmental Protection says the state is working hard to educate fishermen and others to clean all the water out of their boats before going from one lake to another to prevent the spread of the mussel

“Even removing aquatic plants from a boat trailer because the very small mussels can adhere to plants. That’s actually a fairly common way the mussels are transported from one water body to another.”

About 800 live zebra mussels were found in Lake Zoar and about 30 in Lake Lillinonah. It’s not known yet how they got there.

For WNPR, I’m Nancy Cohen.

Tide building on cleaner water

The sense of alarm in Prior Lake over dirty water is likely to spread as more “impaired waters” get clean-up orders.

By DAVID PETERSON, Star Tribune

Watching the filming of a documentary on the Minnesota River that aims to draw attention to its mucky waters, Tim Lies was struck by something.

“They were filming the Belle Plaine river-fishing contest,” said the mayor of that city. “And these were not tree huggers; they were catfish-fishin’, tobacco-spittin’ guys. And yet everyone in the group was extremely conscious of the environmental factors affecting the river. And it struck me, ‘Gosh, this is a metamorphosis that is the result of 20 years of work to raise awareness.'”

Environmental activists and government officials agree that they’ve never seen as much interest, as much knowledge, as much money pouring into the issue of water quality in the south metro area.

And yet they are also bracing for struggles, because a wave of new studies showing just how polluted most bodies of water around us really are is going to lead to a wave of “implementation,” pushing farmers, lakeshore owners and others responsible for the damage to change their ways.

The televised forum for candidates for Prior Lake City Council last month found fierce disagreement on some issues, but none on the need to make water-quality improvements a top priority.

That was probably the result of two well-publicized hits on the city this year: The news that its crown jewel was infested with zebra mussels, followed not long afterwards by the release of a Minnesota Pollution Control Agency (MPCA) report on the serious impairments in the connected waters in Spring and Upper Prior Lakes.

Beyond that, state officials say, similar studies are coming up on other lower-priority, smaller bodies of water.

And there’s an irony in Prior Lake becoming a poster child for water quality, they add: The city has been a pioneer in addressing the problem.

“I’m impressed with the work they’re doing,” said Chris Zadak of the MPCA. “They have been a real standout, for instance, in the area of salt and chloride.”

In 2008, the city started attacking chloride levels in Blind Lake with a “liquid brine only” program that reduces street salt use to one-seventh the quantity that was common a decade ago. Since then, according to a city memo released a few days ago, chloride in the lake is markedly down — leading to an expansion of the same program to other areas.

The process that has led to heightened concern in Prior Lake — a listing as “impaired” under the federal Clean Water Act, followed by a detailed study of what’s causing the problem, then a plan of attack — takes many years. It’s underway on many bodies of water other than in Prior Lake.

Scott County commissioners have expressed impatience that so much money seems to go into consultants and studies versus action aimed at solving things. But environmentalists say it’s vital to figure out what the major causes and solutions are rather than rush in and waste money on moves that don’t end up changing anything.

“I’ve seen some that are really well done,” said Kris Sigford, water quality specialist for the Minnesota Center for Environmental Advocacy, “so you can target the dollars in ways that make a difference — and some poorly done, vague ones that don’t provide a road map at all.”

One small sign of the change required:

The Prior Lake-Spring Lake watershed district reports that on some farms south of Prior Lake whose erosion ends up in those lakes, soil loss is running 12 times as high as the county allows: 60 tons per acre per year, when the permissible loss is five.

Reducing that, officials add, not only will make streams and lakes less muddy, it will also cut down on the pollutants such as phosphorus and nitrogen clinging to all that dirt and holding the potential to make the water on the beaches of posh lake homes so toxic that dogs can die from lapping at the shore.

The consequences for people are key to public support for solutions, said County Commissioner Tom Wolf.

“Prior Lake, Spring Lake — people are on those lakes,” he said. “Their homes are on those lakes. They didn’t move to the lake to have it be green.”