Columbia Falls council hears that wastewater plant is nearing capacity as major developments await allocations

City Manager delivered a detailed briefing to the Columbia Falls City Council on the city's wastewater treatment capacity and the implications for pending development applications. Manager said the city is "nearing capacity of the wastewater system" and explained that recent engineering work has produced different estimates depending on modeling assumptions, flood-event inclusion and the post‑expansion performance of a recently completed bioreactor.

The manager told the council the 2023 HDR Engineering calculations and a later Morris & Merrill preliminary engineering report used different maximum-flow baselines: a June 2022 flood peak (about 630,000 gallons per day) was used in some models, while excluding that anomalous event reduces the modeled maximum flow to roughly 570,000 gpd. He said the bioreactor expansion raised facility capacity in models to about 710,000 gpd and that, depending on the approach, remaining population-equivalent capacity estimates range from approximately 816 people to as many as 1,894. "Today, I do not have a number…