Bozeman, Mont., Water Reclamation Facility Improvements Project

Cost: $52,539,687
Location: Bozeman, Mont.
Year: 2014-12-15
Size: 8.5 mgd
Owner: City of Bozeman
Designers: HDR
Contractor: Williams Brothers Construction, McAlvain Construction, Morrison Maierle Inc.

In order to keep up with rapid population growth by increasing plant capacity, and to meet revised discharge limits, the city of Bozeman, Mont., embarked on an upgrade of its wastewater
treatment plant. 

The upgrade of the Bozeman Water Reclamation Facility (WRF)—the largest public works project in the city’s history—was completed in September 2014. During the four-year design and construction phase, the plant was able to operate and successfully meet its discharge permit. 

The plant’s effluent accounts for 33% of the total summer flow to the nearby East Gallatin River, which experiences low flow in the summer and has elevated background nutrient concentrations. The Montana Department of Environmental Quality was prepared to develop the total maximum daily loads for nitrogen and phosphorous, and the Bozeman WRF was likely to receive strict discharge limits because of the plant’s significant contribution to the river. Because of this, the city decided to upgrade the plant’s existing processes to meet the potential new limits while design of the other facility improvements was in progress.

HDR assisted the city with the implementation of a retrofit of the existing aeration basins to incorporate a phased nitrification/denitrification process for improved nitrogen removal. This five-stage Bardenpho biological nutrient removal process enabled the city to meet the more restrictive nitrogen discharge requirements of their new permit. The process also has the ability to provide chemical precipitation for future phosphorous removal.

“We are producing some of the best effluent quality in the state of Montana, and that’s very good for the small trout stream we discharge to and for the whole watershed,” said Herb Bartle, superintendent of the Bozeman Public Works WRF. “The overall quality of the equipment and the process itself allows us to continually produce excellent effluent.”