Mitigation by annexation
Possible solution for Firelight Meadows and water and sewer district
A convergence of needs of the Big Sky County Water and Sewer District (BSCWSD) and the 216 unit condominium and chalet development Firelight Meadows could equal a win for water quality in the Big Sky area.
More assessment is needed, but the parties are talking.
As the design of the Water Resources Recovery Facility (WRRF) nears 90% complete with bidding for construction to begin this fall, the other piece of the puzzle the BSCWSD needs to face: expanding disposal of treated water. Currently, all disposal takes place with irrigation of golf courses and landscaping, which require large storage reservoirs for holding the treated water when it cannot be used – primarily during winter months. The district, Spanish Peaks and Yellowstone Club have reservoirs, but capacity is finite.
“If all goes as planned the district will start up the upgraded and expanded plant in 2022, but if rapid growth continues additional storage or snowmaking or groundwater discharge will be needed fairly soon to enable additional connections,” Scott Buecker with AE2S engineering said after the recent BSCWSD meeting.
Snowmaking would be a great discharge strategy – and is being discussed – but is completely reliant upon other parties to make it happen, he explained.
“The biggest concern after you start up the treatment plant is the potential need for additional storage, snowmaking, or groundwater discharge for additional SFEs (single family equivalents – a measurement of the amount of water or wastewater treatment demand a typical home will place on the infrastructure),” he said.
BSCWSD general manager Ron Edwards said treated water disposal is going smoothly this summer.
“We’re still working off the 160 million gallons of irrigation disposal at the Yellowstone Club,” Edwards said, and explained that there is about 100 million gallons of addition treated water disposable made available by Spanish Peaks and the Yellowstone Club.
He explained during the meeting that the district’s contracted engineer, Ray Armstrong with DOWL Engineering, found that the district has 7,088 SFEs of treatment capacity – which will be addressed with the WRRF expansion “but immediately after that his letters indicate you will have a storage capacity bottleneck, currently at 7,284 SFEs, unless you obtain additional storage at Yellowstone Club or develop other ‘storage-independent’ disposal.”
In other words, just as the district finds wiggle-room with treatment, it could find itself bottlenecked with disposal.
According to Buecker, groundwater discharge is favorable to other methods of disposal, partly because it does not require storage and partly because the permitting framework is already in place with the Montana Department of Environmental Quality (MT DEQ). It just so happens that Firelight Meadows has a natural drainfield on the land, which could prove incredibly beneficial as a 365 days a year disposal option that the district has never before had, Edwards said.
“All indicators look favorable,” he said. “What does that look like for Firelight Meadows to annex and connect? What does that cost? We haven’t gotten that far.”
Buecker noted –bottomline – whatever method the district decides to use to address disposal needs, those wheels need to be quickly set into motion.
Mark Cunnane, owner of Western Groundwater Services LLC just completed the Firelight Meadows Groundwater study commissioned by the district, basically a cost-benefit analysis for the potential annexation of Firelight Meadows into the district.
There has been discussion of possible annexation on both sides for some time.
Buecker noted that Firelight Meadows is equipped with a level 2 wastewater treatment system that at times is not meeting level 2 treatment standards established by MT DEQ – with effluent nitrogen levels higher than allowed. This put the development on the radar of the MT DEQ.
“Taking a known drainfield area, disposing of better treated water in that area, the science or math of that is because you have much lower concentrations of phosphorus or nitrogen you will be able to dispose of more water,” he said. Annexation and higher levels of treatment for the Firelight Meadows would equal lower levels of nutrient loading – a technical term for nutrient pollution that can cause algae blooms in waterways – even with a substantial increase in treated water disposal from the district.
Cunnane’s study produced interesting results from limited data. The majority of the nitrogen from the Firelight Meadows effluent is not making it through the subsurface mixing zone to the monitoring wells.
Buecker explained that either some nitrogen treatment is occuring subsurface or that there is a higher-concentration nitrogen plume that is not being captured with the current monitoring wells.
This is why Cunnane recommends the drilling of four additional monitoring wells – and testing for the next year – in order to understand what is taking place underground so the district can make an informed decision. That additional testing with the additional drilled wells comes with about a $133,000 price tag.
BSCWSD president Tom Reeves questioned the logic of spending anymore money on studies without any kind of agreement with Firelight Meadows.
“This money could be spent without any reward,” he said.
Cunnane, Buecker, and district staff are setting to work to get preliminary estimates of annexation costs in front of the Firelight Meadows HOA at its Aug. 11 meeting “to make sure they are going to still be interested and the district is not wasting money exploring option for annexation that could ultimately be rejected,” Buecker said.
If, at the conclusion of the study, the conditions are found favorable for the district, then an estimated $2-3 million investment for infrastructure will be needed to create “wastewater collection, water service, and getting the reuse water to the discharge beds or injection wells.”
The district could see a 15% expansion in discharge capacity if it is able to fully utilize the drain fields at Firelight Meadows. Whether the district will see that full potential is unknown and complicated by state regulations and whatever is going on below the surface.