Mandan's increasing need for water can be met over the next 25 years, but it will mean an increase in infrastructure and on billing statements.

The city commission accepted a draft master plan for the water treatment plant at Tuesday's meeting following a presentation by Advanced Engineering's Brett Jochim. The engineer said that the plan was the culmination of two years of effort in facility planning for the water treatment plant.

Currently the water plant can treat 12 million gallons of water a day during two eight-hour operational shifts. Projections show the need for the capability to produce 18 million gallons by 2030. Two options would be to increase the treatment plant's infrastructure to treat more water or consider a third eight-hour operational shift, meaning an increase in staffing.

Meanwhile, the city is investigating building a new intake from the Missouri River since its present intake is limited and has a problem with silt build up following large precipitation events. Three areas are being looked at for a horizontal collector well which would take water from under the river, the sediments comprising the river bottom providing filtration. Such a well could save as much as $9 million over a conventional intake over the next 25 years because of the natural filtration it affords.

Jochim said one of the three areas, and perhaps the best suited for the operation, is located on the east side of the river on property under state jurisdiction. The water would be brought to Mandan via a conduit drilled under the river. The other two spots are farther south of Mandan. Jochim said that any other locations tend to prove cost prohibitive because of their distance from the treatment plant and the expense of piping.

Aging infrastructure, limited capacity, and increasing government regulations are all issues that need to be addressed in the years to come, according to the plan.

"Don't get me wrong, it's not all doom and gloom," Jochim said. "On the good side we've got very nice finished water storage. And we're in compliance with water regulations as of today.

The plan gives the commission some idea of what to expect in costs and a timeline for improvements. The water treatment plan will be increased by either 10,000 square feet or 15,000, depending on what intake the city is saddled with.

Currently residents are charged a $2 base rate for water service plus the additional charge for water used. The plan calls for the base rate to be increased to $5 next year and then a $1 increase will be made every five years until 2030. For water used, rates will see an increase of 3 percent a year.

The average Mandan water bill, based on using 7,500 gallons a month, is just over $20, according to Jochim. Using the scenario proposed by the draft master plan, the average water bill will be just over $50 a month. It was noted that among communities similar in size to Mandan, it has among the least expensive water rates. The proposed cost in 2030 is less than what many North Dakotans are now paying.

Commissioner Tim Helbling suggested that instead of increasing the treatment plant's capacity, Mandan buy what additional water it needs from Bismarck.

"It doesn't make sense to be throwing millions into a plant that gets its water from the same source; it's a duplication of service," Helbling said. "Or perhaps we should look at staffing the plant 24 hours a day."

City engineer Tom Little went on record as recommending adoption of the master plan. Commissioner Sandra Tibke made the motion to accept the plan as presented, which was unanimously approved.

"There's a lot that needs to be done and the timelines are there. There are ways it can be done," Jochim said.