DES MOINES, Iowa (AP) -- In the dim light just after dawn, Bill Blubaugh parks his Des Moines Water Works pickup truck, grabs a dipper and a couple plastic bottles and walks down a boat ramp to the Raccoon River, where he scoops up samples from a waterway that cuts through some of the nation's most intensely farmed land.
Each day the utility analyzes what's in those samples and others from the nearby Des Moines River as it works to deliver drinking water to more than 500,000 people in Iowa's capital city and its suburbs.
"Some mornings walking down, it smells like ammonia," he said. "It's concerning. I'm down here every morning and care about the water."
Water Works for years has tried to force or cajole farmers upstream to reduce the runoff of fertilizer that leaves the rivers with sky-high nitrate levels but lawsuits and legislative lobbying have failed. Now, it's considering a drastic measure that, as a rule, large cities just don't do -- drilling wells to find clean water.
Small communities and individuals use wells, but large U.S. metro areas have always relied primarily on rivers and lakes for the large volumes of water needed. Surface sources provide about 70% of fresh water in the U.S., as a reliance on wells for big populations would otherwise quickly deplete aquifers.
However, the utility in Des Moines is planning to spend up to $30 million to drill wells to mix in pure water when the rivers have especially high nitrate levels from farm runoff, most likely in the summer.
After spending $18 million over the last two decades on a system to treat the tainted river water, it's frustrating to pay out millions more for something other cities wouldn't imagine, say utility officials.
"I look at it in disbelief," said Ted Corrigan, the CEO and general manager of Water Works.
Des Moines has become an extreme example of the conflict over clean water between agriculture and cities in farm states with minimal regulation.
Iowa is a national leader in producing corn, soybeans, eggs and pork, and all that agricultural bounty results in enormous amounts of chemical fertilizer and animal waste pouring into waterways. The state's 23 million pigs produce waste that would be the equivalent of 83 million people -- more than 25 times the state's human population, according to University of Iowa research engineer Chris Jones.
Most of that manure is spread over Iowa's 26 million acres of cropland, along with chemical fertilizers.
The natural and chemical fertilizers have helped Iowa increase its corn and soybean production by roughly 50 percent over the past 30 years, but much of it ends up in Iowa's waterways, especially in areas of north-central Iowa that drain into the Des Moines and Raccoon rivers. That's because the area's farmland is relatively flat and relies on drainage systems called tiles that don't allow excess fertilizer to filter through the soil but instead quickly pour it into streams, leading to high levels of nitrate and phosphorus.
Although there is plenty of agreement on ways to filter out chemicals, such as by leaving buffer zones and planting cover crops like rye when the ground would otherwise be bare, the state's farm lobby has opposed mandatory rules and Iowa legislators have favored a voluntary approach that so far hasn't made a dent in the problem.
Water Works and other groups have filed lawsuits demanding more rigorous action, but judges have decided to leave the issue to the Legislature.
Lately, utility officials have become concerned by increased algae blooms, caused by a combination of fertilizer runoff, high temperatures and slow-moving water. Rivers tainted by the algae can't be used as drinking water. Nitrates can cause so-called blue baby syndrome in which infants lose the ability to properly process oxygen into the bloodstream, giving their skin a bluish tint.
"The question was ... 'what's next with these challenging surface waters we're dealing with?" asked Corrigan. "Are we just going to have a rolling series of multimillion-dollar processes that make our treatment process more complex and more expensive?"
Water Works is now paying the U.S. Geological Service $770,000 to evaluate spots to drill wells just north of the city.
Brian LeMon, vice president of Minneapolis-based Barr Engineering Company, said he didn't know of another large city with such high levels of nitrate. The much larger Minneapolis/St. Paul metro area to the north has no similar problem with the water it takes from the Mississippi River, in part because of less intensive farming and animal production upriver, required buffer strips and the river's larger volume.
"Nitrate removal is not cheap," said LeMon, whose company is a consultant for Des Moines Water Works' planning process.
Mike Naig, Iowa's secretary of agriculture, acknowledges the runoff problem but supports the state's voluntary Iowa Nutrient Reduction Strategy, which uses limited state and federal funding to pay for water quality projects on farmland. Workers are now installing buffers and implementing other efforts in Polk County, where Des Moines is located, but even advocates acknowledge that making a significant difference would require filtering runoff at thousands of locations, potentially costing billions of dollars.
Dave Walton, who grows soybeans and corn in eastern Iowa, said farmers should do their part to reduce nitrates but that each farm is different and regulations wouldn't be uniformly effective. He said preventing runoff is costly and would require public-private partnerships that likely would take decades.
"If a farm operation is going to be sustainable, they have to create profit year after year," Walton said. "To ask a farmer to invest in something that doesn't add to the bottom line in a period of time when they were not making a profit anyway, it's just a moot point."
Timothy LaPara, an engineering professor at the University of Minnesota, said nearly every city faces some complication in ensuring safe drinking water, but Des Moines' problem requires an unusual solution.
"Nitrate doesn't usually get to the levels you see in the Des Moines and Raccoon rivers," he said. "Central Iowa has some of the worst water quality you'll find."