Pipeline repairs

Crews from Weisz & Sons dig to gauge the damage to a ruptured water transmission line in 2016.

Mandan will be getting a new raw water intake facility, and the 30-inch transmission line that feeds the Sunset Reservoir from the water treatment facility will be replaced.

City commissioners entered into an agreement on Feb. 20 with AE2S, which will provide engineering services on the two "imminent" projects.

The new raw water intake will replace a 60-year-old facility. Estimated engineering costs on the project are $425,000, with the local share at 35 percent, or $147,000.

The project is eligible for State Water Commission funding. The Andeavor Refinery shares the intake facility and has  agreed to splitting the local share with Mandan, at $73,500 each, if a SWC grant is awarded. Mandan will pay for the expense with utility fund dollars.

The 30-inch transmission line's condition has been deteriorating over the past several years.

In 1994, the city experienced pipe failures. The line was investigated, during repairs, and it was determined the pipe is subject to both internal and external corrosion, said Jasper Klein, operations manager of AE2S.

During the past 16 months, the pipe experienced three  breaks, costing more than $500,000 to repair, he said.

In 2017, the city replaced about 1,000 feet of the transmission line as a proactive response to eliminating breaks, at a cost of $440,000. As the new pipeline was commissioned, a break occurred downstream of the replaced segment, in an original section of pipe.

"This pipeline is a very important piece of infrastructure providing water to northwest Mandan and serving commercial, industrial and residential customers. Without this important infrastructure component in operation, users could be subject to water shortages, low pressure and inadequate fire protection," Klein said.

Engineering through bidding on the 30-inch transmission line replacement is estimated at $405,000. The project has been submitted to the SWC, in an attempt to get state funding dollars. The local share on this project has not been determined.

"We feel we need to get going on project development, to have our best chance of success in receiving State Water Commission funds in order to construct these projects," said Justin Froseth, city planning and engineering director.

Construction on the new intake facility is tentatively scheduled to begin in July 2019, and replacement of the transmission line could begin as early as September.

Reach Cheryl McCormack at 701-250-8264 or cheryl.mccormack@bismarcktribune.com.)