No one knows.

The question, though, has prompted an unprecedented effort to protect the lake with pollution limits.

Policymakers have joined with scientists and environmentalists to develop the first-ever water-quality standards for Utah's extraordinary, ancient lake that is a haven for millions of birds, for brine shrimp, brine flies, boaters, hunters, bird-watchers and whole industries.

Nathan Darnall, a U.S. Fish and Wildlife Service biologist, says there is a moral obligation, as well as a legal one under the federal Clean Water Act, to safeguard the lake's future.

"If we were to just blindly discharge [pollutants] into the lake," he said, "we might wake up someday and find it's really dead out there."

Though maybe "extreme," the scenario is also entirely possible, he added. "It is important for us to know what our actions are doing."

The effort to set pollution limits for the Great Salt Lake grew out of separate plans to clean up contaminated water.

Byproducts from decades of Bingham Canyon mining were seeping into southwestern Salt Lake Valley's groundwater and spreading. In the mid-1990s the U.S. Environmental Protection Agency joined forces with Kennecott Utah Copper, the Jordan Valley Water Conservancy District and the state Department of Environmental Quality to address the problem.

Their solution: Build two plants that use "reverse osmosis" to filter out the pollutants. In addition, the $60 million investment would transform much of the polluted water into drinking-quality water, enough for about 6,500 households.

But the solution created a new problem - what to do with the briny wastewater from the plants that contains too much sulfate and selenium.

Selenium caused the most concern. A mineral essential for human health in trace amounts, at higher levels it can be deadly to wildlife.

Environmentalists, who had been clamoring for years to get water-quality standards for the Great Salt Lake, noted that high selenium elsewhere has devastated wildlife, causing deformities and death to fish and waterfowl.

It would be logical for selenium to build up in the Great Salt Lake, since it is a "terminal" water body, said Maunsel Pearce, chairman of the Great Salt Lake Alliance. "Everything stays there, except the water, which can evaporate."

So, pollutants from treatment plant wastewater would wind up adding to whatever dumps into the lake from rivers, runoff and other sources, such as Kennecott. Some say the selenium gets buried in lake sediments. Others worry about a buildup.

The solution might seem simple enough - apply to the Great Salt Lake the clean-water standards already used for Utah's other lakes and streams. But the usual standards - fishable, swimmable, drinkable or otherwise usable - don't apply to the Great Salt Lake.

With water 10 times as salty as the ocean, it is in a class of its own and falls through the regulatory cracks.

State water-quality officials also wondered if they should allow any more "discharge permits" for the Great Salt Lake.

"Our concern is protecting the health of the lake into the future," Pearce said.

Dianne Nielson, director of the Utah Department of Environmental Quality, organized the Great Salt Lake Water Quality Steering Committee last year to tackle the tough scientific and public-policy chore of setting a selenium standard for the lake.

"Everybody looks first at the water they consume," Nielson said. But the Great Salt Lake "is an integral part of our ecosystem, just as our other water bodies are in the West."

After a half-dozen meetings, the panel has made "pretty substantial" progress, said Richard Bay, assistant general manager and chief engineer for the Jordan Valley Water District.

His district, which serves about 80,000 customers, has arranged to piggyback on the Kennecott discharge permit, if necessary. But getting permission to discharge the wastewater from its reverse-osmosis plant would mean more water to help meet the needs of the half-million extra people expected in the valley in the next few decades.

"Jordan Valley is going to be scrambling to develop any water it can," he said.

The demand for more water in growing desert-state communities is not lost on the 18-member steering committee. Made up of people from industry, government, academe and environmental groups, its goal is to develop a selenium standard for the Great Salt Lake by the end of next year.

Even with most of its $804,000 budget yet to be spent, the panel will be pressed to answer the selenium question in time to address Jordan Valley's likely request for a discharge permit.

One reason is that it's too late for humans to know how they have affected the Great Salt Lake ecosystem. More than a century of building roads, homes, dams and other alterations to the environment has made it impossible to know how the lake functioned before people altered the natural selenium input.

Another reason meeting the deadline will be difficult is the lake's uniqueness. For instance, members of the science team struggled to find water-testing methods that did not exaggerate or undercount the selenium concentrations in the lake water. It took about a year to determine what measuring tools work best.

The steering committee also began this month to set research priorities. Among other tasks, they plan to:

l Take a comprehensive bird census that includes a look at the marshes and eggs.

l Double-check the selenium samples collected so far by Kennecott and the U.S. Geological Survey, making sure to use the newly approved testing methods.

l Request proposals from scientists to gather biological samples that can be tested for selenium.

l Size up the selenium "life cycle," including measuring where it comes from and how it moves in the ecosystem.

Some hope that, if the selenium study is successful, it will clear the way for other water-quality standards for the Great Salt Lake. For instance, many would like to see limits on the amount of toxic mercury, which has been found in higher concentrations in the Great Salt Lake than anywhere else in the United States.

"There isn't enough funding to answer all the questions that need to be answered, and there probably isn't enough to do all the research" already planned, Pearce said.

"It's complicated," he added.

fahys@sltrib.com

Water cleanups

* The Jordan Valley Water Conservancy District plans a $40 million treatment plant to help clean up contaminated groundwater.

* Kennecott Utah Copper has built a $20 million treatment plant to remove the contamination from historical mining operations at Bingham Canyon. Together, the plants are expected to produce about 8,235 acre-feet of drinking water, enough to serve nearly 10,000 households a year.