BISMARCK, N.D. - A plan to draw water from beneath the Missouri River for a thirsty Burleigh County would be among the first along the longest U.S. river and one of only a handful such projects in the nation.
Called angle wells, the system would use the Big Muddy's sand and rock riverbed to help filter the water to near "bottled-water quality," said Doug Neibauer, executive director of the Bismarck-based South Central Regional Water District.
It would provide an additional 3.5 million gallons of water daily to some 3,500 residents of northern Burleigh County, from north of Interstate 94 to Wilton, said Joe Bichler, a project manager with the Bartlett & West engineering firm of Bismarck.
"Rural water is a fast-growing need in northern Burleigh County," said Neibauer. "Most of the well water there is quite unsatisfactory."
Angle wells use a new technology to provide "good water and good yields at the lowest construction costs," Neibauer said. "It has achieved all goals."
Construction of the $17 million project began this summer, with the first phase to be completed in mid-2007. The entire project is slated for completion in 2009, Bichler said.
Residents approved a $10 million bond issue last year to help pay for the project, Neibauer said. State and federal funds are being added, he said.
Two of the six planned intake pipes have been placed at the site, about 10 miles north of Bismarck. A third is slated to be in place this month.
The wells are placed at angles ranging from 14 degrees to 23 degrees from the river's edge, with pipes extending underground to about 100 feet offshore and up to 38 feet beneath the Missouri's riverbed.
Slotted screens with ceramic filters in the 16-inch double-wall pipes allow groundwater and river water to be sucked from beneath the riverbed. The water goes through additional treatment before tying into pipelines.
The system is unaffected by ice, silt or low water, Bichler and Neibauer said.
"There are an awful lot of benefits to it," said Jame Todd, an engineer with the federal Bureau of Reclamation in Bismarck. He said the agency is studying the technology, hoping that it could provide a reliable water supply for the Standing Rock Sioux tribe.
Silt clogged the intake pipe at Fort Yates on Thanksgiving weekend in 2003, leaving hundreds without water. A temporary intake system was built at a cost of nearly $3 million.
Todd said soil samples have been taken at Fort Yates, "but so far, we haven't found soil conditions like they are in Bismarck."
For the system to work, the riverbed must have loose rock and gravel, not clays that are found in some of the river's stretches that have been flooded by dams, Bichler said.
"It's viable solution to a challenging problem _ if you have the right soils," he said.
Martha Silks, a Perry, Kan.-based hydro-geologist who worked on the Burleigh County project, said only a few such systems exist in the United States.
An angle well project planned for the Lewis and Clark Rural Water System will pipe Missouri River water from Vermillion, S.D. to customers in South Dakota, Iowa and Minnesota.
Executive Director Troy Larson said that system differs from the North Dakota project in that it would tap into an aquifer adjacent to the Missouri River, at least at first.
Angle wells were placed along the Hudson River, near Albany, N.Y., to provide municipal water.
"They were completed in 2003 and were the first in the United States, as best as we can tell," said Gary Smith, who works for White-Pierce, a Topsham, Maine-based civil and environmental engineering firm.
He said a similar system is being developed in Orange County, Calif. Those wells would go beneath the Pacific Ocean's floor to draw water for a desalination plant.
South Central Regional Water District has about 30 years remaining on a 40-year contract with the city of Bismarck to purchase water.
Neibauer said his group would continue to buy water from Bismarck as well as use the angle wells.
Keith Demke, Bismarck's utility operations director, said northern Burleigh County uses an average of about 800,000 gallons of water daily.
"That's less than 10 percent of our entire system," Demke said.
Bismarck plans on using a more-common horizontal collector well to pull water from an aquifer under the Missouri instead of taking it directly from the river, he said. The aquifer is fed by the river and not groundwater, he said.
The city's current water-intake plant has the capacity of about 30 million gallons a day, enough to cover a football field with 70 feet of water, Demke said.
He said the city has opted for a more traditional design, and he doubts the angle wells could provide the volume of water needed in Bismarck.
"We think there are some advantages to what we're doing over what they're doing," he said.