A new Bismarck water intake capable of yielding 34 million gallons a day is expected to be constructed in 2008, according to Keith Demke, the city's director of utility operations.

Plans are to sink a 20-foot-wide caisson 120 feet deep where 80-foot collector lateral pipes, radiating from the well, will draw water from ground water below the Missouri through a thick layer of coarse gravel.

The well and eventually a pumping station will be located west of the Sertoma Park volleyball courts on the edge of a Missouri sandbar.

The city is in the formal regulatory process of applying for permits that will allow the well and subsequent pumping station, pipeline and utility road to be built. Permit applications have been submitted to the Army Corps of Engineers. A permit application also is in the works with the North Dakota State Water Commission.

"Right now we're in the middle of the corps' public input period, which ends Dec. 26," Demke says. "We've done a lot of leg work trying to identify everything that might be a pitfall. We tried to address all concerns proactively, but you never know when something might show up. We need to be sensitive."

A couple of years ago the project was estimated at $15 million, but Demke suspects it may cost more. The project, being developed by Advanced Engineering, will be built in three phases.

The well will be built in 2008, followed by a pumping station in 2009. The final phase, set for 2010, will be running a pipe from the well to the treatment plant about two miles north along with an articulated concrete surfaced road to provide service to the pumping station. Expectations are the well will go online sometime in 2010 or 2011.

Three test wells were drilled to determine where to put the new intake, one near Pioneer Park, the area they selected and another just north of the selected location.

"The one we chose was the only one with the right geology from where we can get the water we need," Demke says.

The test well indicated it could produce 34 million gallons a day, but its true capacity won't be known until the well is in place. Sizing the transmission pump and pipeline can't be done until the capacity is determined.

Demke visited a similar project in Kansas City, Kan., where a preliminary test showed a well would produce 27 million gallons a day, but it actually produced more than 40 million gallons.

The current intake, constructed in the early 1950s, can provide just over 30 million gallons a day.

"We will keep it (existing intake) in place and use it in two ways," Demke explains. "First, once we get to a point that we're using more water than the new collector can provide, we'll use the old intake to meet peak demands. We'll also use it as a backup in case there's some reason the new intake has to be shut down. That way we don't have all our eggs in one basket, which is a problem we have now."

The pump station's operating floor will have to be built 14 to 15 feet higher than ground level at the site so it isn't within the 500-year flood plain. There will be times the pump station likely will be surrounded by water as the river rises, Demke expects, and it is being built with that in mind. The road also is subject to flooding, so everything at the pump station will be automated, other than routine maintenance.

The road, which will be built at the same time the transmission line is put in, has been as much of an issue for the city as anything else because of its environmental impact, Demke says. There will have to be some wetland mitigation for the road, which is about a half mile long and closely follows the route of the existing rock embankment along the shore.

The new intake will eliminate some of the problems facing the old intake. The treatment plant deals with a lot of sand that is sucked in by the intake, which won't be a problem with the new intake.

"One thing that will be nice is that we won't see the seasonal changes in water quality. There shouldn't be a lot of temperature fluctuation," Demke said. "And we shouldn't see near the amount or organic materials that appear during certain times of the year. When you get a big runoff, like after a rain storm, you get a lot of leaves and grass. The organic stuff and chemicals we see in the runoff lead to taste and odor problems. The water we draw will be of a much more consistent quality."

There is a cost savings, but not a huge one, Demke adds. The city may get some treatment credits from the Environmental Protection Agency through new regulations intended for systems that provide greater protection against parasitic organisms, something the new system will do.

"If we're straining the water through the soil profile, it is less likely to bring in plants and stuff which we have to deal with," Demke says.

A lot of effort has been put into designing a pump station that "won't stick out like a sore thumb," Demke says. It will be about 40 feet by 40 feet, not huge, but a good-sized structure sitting by itself.

"There's a process in place to deal with the building's appearance," Demke says. "There is an architectural review committee that met over a few months and came up with some ideas. We have to be sensitive. … We can't be putting up an ugly concrete block building. I think we've come up with some concepts people will be happy with."

Once the system is completed, Demke will start looking at upgrading the treatment plant, allowing it to handle up to 60 million gallons a day in the future.

"It's not in the plans right now, but once we get to the tail end of the five-year capital improvement plan, we'll start looking at what additional things we have to do," Demke says.

Once the permits are issued, plans are to take the project to bid in either late winter or early spring with construction of the well to be finished within the construction season.

Demke feels the biggest expense of the project won't be the materials but the expertise of the company which gets the project. It's highly specialized work and there aren't a lot of companies to choose from.

(Reach reporter Gordon Weixel at 250-8255 or gordon.weixel@bismarcktribune.com.)