Bigfork sewer main to be replaced next spring

Bigfork’s aging sewer system will undergo a major overhaul next spring. Through a combination of grant funding, low-interest state loans and local dollars, the Bigfork Water and Sewer District will replace the damaged main line and relocate the bulk of the system away from the shoreline of Bigfork Bay. The existing line runs along the Bay, from Bridge Street to a lift station on Grand Drive where it’s then pumped to higher ground.

The location is problematic for multiple reasons, but primarily for its proximity to the Swan River and Bigfork Bay. If the line were to plug up, sewage could overflow directly into the waterways.

“The Bay Sewer is a project that’s been kind of a looming environmental concern for the district for many years,” said Jeff Cicon, a civil engineer with Morrison-Maierle. “They’ve taken precautions to make sure nothing happens, but it’s expensive and it’s difficult and there’s still a possibility of issues.”

The main sewer line is wrought with dips in what is supposed to be a straight pipeline. These bellies collect debris, like grease and other solids, which can build up over time and can cause the line to clog. Many of the local restaurants don’t have grease traps, which would help prevent the substance from reaching the sewer, or have traps that don’t function properly.

“This main also gets a tremendous amount of grease — much, much higher than normal from all the restaurants,” Cicon said. “The grease will be liquid when it goes down the drain … when it cools, it will solidify. It will solidify in mains, it will solidify in manholes. Eventually, if you get enough of it, it will plug.”

To avoid disaster, the Bigfork Water and Sewer District flushes the system with high-pressured water twice a year, but this maintenance is costly and with continued development in the downtown corridor, access to the sewer line for this and other repairs has become increasingly difficult. When the system was first constructed in the 1960s, according to Cicon, a two-track road followed the shoreline, allowing crews to easily access the sewer main by vehicle. Over the years, as homes and other buildings came in, the district has had to obtain easements to complete necessary maintenance. Since the road is no longer there, crews also have to access the line by foot.

To identify the best solution to the problem, the district hired engineering firm Morrison-Maierle in 2018, to complete a preliminary engineering report, which examined possible options and their associated costs. To reduce the threat of pollution to area buildings and bodies of water, the firm came up with a plan that would relocate the main from the shoreline up to Obsborn Avenue, where it’s farther from natural resources and easier to access. The replacement of the bay sewer main is a $2.8 million project, Cicon said, that was made possible by $1.175 million in grant funding.

The main line will be removed from the shoreline and replaced with new pipes on Osborn Avenue. Sewage from buildings west of Electric Avenue will be pumped up to Osborn, rather that gravity fed along the shoreline down to the Grand Avenue lift station.

“The reason for doing that was to get the infrastructure away from the bay and up on top of the hill where it can be maintained,” Cicon said. “It’s about the only solution to the problem.”

During construction, there will be disruption downtown, he noted. However, to keep interruptions to a minimum, crews will directionally drill as much as possible, which is akin to doing surgery laparoscopically instead of opening a patient up.

“They have a big drill that drills underground from the surface. You have to dig a pit at each end, but you can drill from point A to point B, but not disturb anything on the surface,” Cicon said.

The new system will be constructed in two phases, the first in the spring of 2020 and the second in the fall of that same year, to avoid disrupting the downtown corridor during the busy summer months. This schedule is provided that easements are obtained from landowners in a timely fashion.

Cicon hopes the district will be able to abandon the existing shoreline easements in exchange for new ones, ideally in locations selected by the landowners.

To share more information about the project and interact directly with affected landowners, the district is hosting their first public meeting about the project at 6 p.m. on Wednesday, Dec. 4 at the district office located at 108 Harbor Heights Blvd. in Bigfork.

“That’s why we want to have this meeting and get the word out,” Cicon explained. “If there’s a place where they’d rather have it, if we can accommodate anything, we will.” ¦