By Bay Stephens EBS LOCAL EDITOR
BIG SKY – At their July 16 meeting, the Big Sky Water and Sewer District board chose the final layout for the wastewater treatment plant upgrade. The undertaking will require excavation and landscaping to lower and conceal the planned headworks building that will be nearest Big Sky Community Park, diminishing the risk of it becoming an eyesore to park goers.
“This is a critical path vote you just did,” said Ron Edwards, BSWSD general manager during the meeting. “We can get after design.”
With final layout approved, Advance Environmental and Engineering Solutions, the engineering firm hired to carry out the treatment plant upgrade, can move forward with designing many other aspects of the new treatment plant that have been held up.
“Until you decide how to arrange the site, you can’t do any tank or building or process design because it affects the geometry of your facilities,” said AE2S Senior Project Manager Scott Buecker, the lead engineer on the upgrade.
After a site walkthrough in preceding weeks with Buecker, the board agreed on a layout for the plant that capitalizes on the gradient provided by the slope beneath the plant, using gravity rather than expensive and complicated pumping schemes to move waste material through the plant and treatment process.
The layout also best takes advantage of the property on which the plant resides, using the parkland that the Big Sky Community Organization traded to the district late last year in return for sewer capacity for the incoming community center. It also reserves the east side, or down-gradient side, of the parcel for future expansion, according to Buecker.
A headworks building, which begins the treatment process in any wastewater treatment facility, will be the structure nearest the community park, and will remove large course solids and finer particles so they don’t damage pumps and mixers later in the treatment process. The two-story headworks building, and other structures on the west side of the plant, will be sunk 10 feet below grade and the displaced dirt will be used to build a landscaped berm between the plant and community park to maintain a low profile.
“We feel like we can keep it hidden as much as it’s currently hidden,” Buecker said.
The upgrade is 30 percent designed, according to Buecker; the next step is to finalize the preliminary engineering report to submit to Montana DEQ. He said he’s shooting to have 50 percent design completion for the upgrade by mid-October.
Upon voting, board member Peter Manka added, “I just want to qualify my vote with the fact that we’re going to be aesthetically sensitive down the road … to try to maintain support for this project and be good neighbors.”
In other news:
- The board entered into a contract with Evoqua Water Technologies to provide the equipment for the membrane bioreactor filtration (MBR) technology that will be used in the upgraded plant.
- The board approved the drilling of an exploratory well on district property near their water tower above Cascade Ridge near Beehive Basin, and is seeking access to Boyne property to drill another exploratory well. This is part of the district’s ongoing search for more water in the Mountain Village area and to streamline the water supply system, which was not designed for its current usage and relies heavily on few wells to supply water to many developments at the base of Lone Mountain.
- The district approved its indirect potable reuse study, which will clarify whether the meadow aquifer will support a process called indirect potable reuse, a process that involves injecting highly treated effluent into the ground to recharge the aquifer from which the district draws its drinking water. The process is common in municipalities in southwestern states, and is attractive in Big Sky because of the impaired status of the North and South Fork of the Gallatin River, which are legally protected from direct effluent discharge. Indirect potable reuse would also conserve Big Sky’s scarce water supply.
- As part of an ongoing rate structure assessment process, Ryan Graf and Miranda Kleven of AE2S briefed the board on several alternative rate structures that could be applied to better align the amount users pay with the cost of the district’s services.
- The board directed Edwards to reach out to the utility that conducts water and wastewater services for Firelight Meadows to learn more about the possibilities of annexing the property into district boundaries.