By Bay Stephens EBS Staff Writer

BIG SKY – The Big Sky Water and Sewer District unveiled an estimated $21.7 million wastewater treatment plant upgrade on Nov. 27 that would meet the district’s growing flow and load demands and resolve failing equipment issues during a special meeting at the district office.

Arranged in two phases, the first would include upgrading the plant with a new filtration technology that would provide a higher DEQ classification of effluent, allowing effluent disposal options beyond irrigating area golf courses, according to project manager Scott Buecker of Advanced Engineering and Environmental Services, which the district hired for the upgrade.

Based on very preliminary numbers, district finance officer Terry Smith said the phase one upgrade would increase ratepayers’ annual sewer bills by approximately 45 percent once the plant came online.

The second phase of the upgrade would position the district to reach even higher levels of effluent quality and could usher in drinkable reuse options.

The district currently disposes of all its treated effluent through irrigation on local golf courses, pumping a significant amount to Spanish Peaks Mountain Resort and the Yellowstone Club. Through this system, the district operates without any direct discharge to the Gallatin River or its tributaries, which is extremely rare among water treatment facilities nationwide, Buecker said.

However, last winter set records for snowfall and visitation, and the district’s capacity to store water was maxed out last spring as they waited for the summer to begin irrigating, Water and Sewer District Board President Packy Cronin said.

“We just didn’t have anywhere to store water,” Cronin said.

Once irrigation season began, the district disposed of roughly 200 million gallons of effluent through irrigation, pumping more than half that volume up 2,000 feet in elevation through a 7.2-mile pipeline to the Yellowstone Club and Spanish Peaks, according to Grant Burroughs, the district’s wastewater superintendent. Without the clubs’ additional disposal ability, the district would not have been able to handle the volume of effluent produced last winter, Edwards said.

The treatment facility is also pressing against its capacity to treat raw sewage, reaching 90 percent of its rated daily capacity on April 23, Buecker said, adding that the plant is due for an expansion.

“Besides encroaching on its rated capacity, we’re starting to see equipment that is starting to degrade,” he said.

The phase one upgrade would approximately double the treatment capacity of the facility and would allow the district to diversify its “portfolio” of possible effluent disposal options by pursuing avenues such as snowmaking, subsurface discharge, and potentially direct discharge to the main stem of the Gallatin River.

When contention arose at the meeting over the possibility of direct deposit into the river, potentially harming the fragile ecosystem, the district clarified that they don’t intend to stop irrigating effluent in exchange for discharging into the Gallatin. Rather, the upgrade would enable the district to develop redundant means of effluent disposal that create a safety net so the district would have other disposal options if a pipeline went offline or a holding pond required maintenance. Phase one would not yet provide this redundancy, but would be the first step toward it with the higher quality of effluent.

Visit bigskywatersewer.com for more information or to watch a video of the full meeting.