The northern Rockies are known as a pristine fountainhead of the American West. From out of the jagged snow-cropped peaks flow the crystal clear headwaters of three venerable river systems - the Columbia, Missouri, and Colorado - that help slake the thirst of half the American population.
But even here, where hikers can ladle out a handful of liquid refreshment along the trail and streams produce tasty trout, civilization's expanding footprint has potential consequences for water that eventually reaches the tap.
Watersheds across the country are suffering from pollution problems ranging from PCBs and gasoline runoff in cities to agricultural effluent and siltation caused by logging in the countryside, according to a new report from the San Francisco-based Trust for Public Land.
Nearly 40 percent of the nation's rivers, lakes, and coastal waters are technically cleaner than in the late 1950s. But the US Environmental Protection Agency says they are still too polluted for safe fish consumption, swimming, and drinking water. Worse, many others are in a rapid state of decline.
The Trust for Public Land has a solution: By protecting the headwaters of municipal drinking water supplies now, it says, billions of dollars can be saved by avoiding costly filtration systems, pollution-related illnesses, flood control, and ecological degradation.
"Our intention is to bring questions about watershed management to the forefront of public discussion," says Trust president Martin Rosen. If implemented, the Trust's strategy would mean much tighter restrictions on how agriculture, real estate developers and industry are allowed to approach watersheds and aquifers.
Such talk has not met with enthusiasm from traditional land users. "Groups like the Trust for Public Land never saw a regulation they didn't like or a piece of private property they didn't want to buy at taxpayer expense," says Chuck Cushman, executive director of the American Land Rights Association in Battle Ground, Wash. "I question whether the government has to own all the nice places or whether it isn't better to make partners out of local landowners, trusting them to protect sensitive areas on their own," says Mr. Cushman.
So just how widespread is the problem? In California's San Gabriel Valley, a quarter of all public wells are contaminated. And the tainted Chattahoochee runs through metro Atlanta. Not all rivers are highly polluted. But many in populated areas are.
America's reputation for producing the safest drinking water in the world is being challenged. One recent example is the 1993 outbreak of the water-born virus cyrptosporidium, which was blamed for injuring 430,000 people and killing 103 in Milwaukee.
The organism is highly resistant to chlorine treatment, and its likely origin was traced to farms and feedlots upstream. Now Milwaukee will build a $54 million treatment system to try to purify the water.
Saving money and water
One less-costly solution, environmentalists say, is for the public to protect key watershed sections and buffer them against development. The Trust has protected nearly 1 million acres of land valued at over $1 billion nationwide.
By recently spending $1.5 billion to protect land around its reservoir system, New York City has avoided spending between $6 billion and $8 billion on a purification system.
"Water supply managers increasingly are coming to realize that watershed protection may be the best and cheapest way to guarantee both the quality and quantity of drinking water," writes Richard Stapleton, the Trust report's author.
The Trust is critical of the EPA, which says an investment of $138.4 billion is needed to ensure safe drinking water in the US. But the agency hasn't mentioned watershed protection as an option. An EPA spokeswoman says the agency doesn't ignore watershed protection in favor of after-the-fact filtration.
Ronal Kerbo, the national caves specialist for the National Park Service, says watersheds' natural filtration systems - such as wetlands and karstic geological structures, which include caves - have proved their worth in delivering clean water. But they are very vulnerable.
East of Tulsa, Okla., Mr. Kerbo notes, approximately 44 percent of the country's groundwater passes through karstic systems. "Every time a resident sets down a questionable septic system, they are running the risk of allowing their human waste to reach someone else's faucet."
Safety in bottled water
One key to clean water, environmentalists say, is public awareness - which seems to be growing.
"This spring a reporter asked a class of inner-city kids how many of them drank bottled water," says Rend Wentworth, who oversees the Trust's office in Atlanta.
"Half of the hands went up. These were children from families of limited means but who drank bottled water because they knew the water coming out of the faucet came from the [Chattahoochee]."
Meanwhile, in Bozeman, concerns over water quality have brought traditional foes together to seek solutions. A looming threat is wildfire followed by rains that would wash tons of dirt into streams. Foresters and loggers are working with environmentalists to plan small-scale timber cuts to reduce fire risk while protecting wildlife and water purity.
"Anyone who is concerned about their own water supply should pay attention to how the lands in their watershed are managed," says Bob Dennee, a natural resource specialist with the Forest Service. "As citizens, we all have a stake and with that stake comes a responsibility."