Engineers presenting Columbia Falls’ wastewater preliminary engineering report told residents that while the treatment plant currently meets permit limits, several collection system components and the plant itself will need upgrades to handle projected growth.
"Right now the plant is about 0.68 (million gallons per day) and policy choices could set a planning limit around 0.71," said a presenting engineer identifying themselves as CR. The consultants showed projections that under the chosen 2.3% growth rate the plant’s effective capacity could be reached between roughly 2028 and 2032 without upgrades.
The sewer model identified sections of gravity main that are overcapacity (marked as red on the maps) and several lift stations that may exceed pump capacity under peak flows or with known approved projects in the pipe. The consultants warned that overcapacity in gravity mains and lift stations increases the risk of backups, pressurization damage and environmental or public‑health exposure if not addressed.
Consultants also told the meeting that none of the city’s lift stations currently has permanent backup power; instead the city relies on portable generators. Engineers reviewed electrical equipment life‑cycle concerns and varied station enclosures and security, and said permanent backup power and electrical upgrades should be evaluated to improve resilience.
On treatment‑plant operations, presenters described the plant as relatively sophisticated for a community of Columbia Falls’ size and noted it removes nutrients (nitrogen and phosphorus) to meet permit limits. They flagged aging clarifiers and UV disinfection units that will need attention and said capacity is constrained by nutrient removal configuration; average daily flow was reported at about 430,000 gpd with a maximum around 630,000 gpd, approaching the nitrogen‑limited capacity near 680,000–700,000 gpd.
Engineers described next steps including alternatives analysis for treatment and collection improvements, evaluation of lift‑station backup power, and costing for prioritized projects; the PER will feed council and planning decisions about how to manage near‑term approved developments and long‑term growth.
Residents asked about PFAS testing and were told the city has tested with no detections and that additional federal testing programs have been delayed, so no additional PFAS work is currently planned. Officials invited the public to review detailed maps and data boards after the presentation.