Livingston wastewater team describes months‑long recovery after plant equipment failure; effluent quality improves

City wastewater staff told the Livingston City Commission they have restored full operations and improved effluent quality after a mechanical failure last fall forced a prolonged recovery and intensive repairs.

Why it matters: The city's water reclamation facility discharges treated effluent to the Yellowstone River and operates under a permit; staff said the plant remained in compliance during the incident and the recovery work avoided violations while protecting downstream users.

Trey Sidwell, the city's wastewater superintendent, recounted an Oct. 19 equipment failure that left the plant operating on one biological treatment basin. Staff discovered a broken decanter arm and a damaged mixer arm that had come loose from the wall; the damaged mixer had over time buckled a mount. "We need to start draining it that day," Sidwell said of the damaged basin. The team elected to "waste out" settled solids through the working basin's solids handling process rather than truck them away, and they sequenced repairs to avoid losing the plant's biological treatment capacity.

Sidwell credited outside partners for assistance during the work: AE2S engineering staff provided on‑site help; **** Anderson Construction completed mixer repairs; John Hess assisted with procurement; and Scenic City (Bozeman) transferred 44,000 gallons of waste activated sludge (WAS) to seed the basin and reestablish biomass. Sidwell said the plant team replaced damaged aeration piping and roughly 2,570 aeration pods — components with a typical 7–10 year lifespan — and installed a new mixer mount rated at 240% of the expected force.

Staff described operational challenges and vendor delays. The first aeration pipe shipment arrived with incorrect dimensions; the supplier accepted responsibility and provided replacement pipe. Sidwell also described supply‑chain and tariff issues that affected timing and cost of parts. He said the failure coincided with earlier extreme flows during a 2022 flood event that exposed systems to grit and debris; that event had already prompted the plant to operate manually at high flow and adopt operational lessons that improved resilience.

Performance data and workforce: Sidwell told commissioners the plant's effluent measurements have improved since repairs. He cited an increase in UBT (a measure of water clarity) from a typical range in the mid‑40s to upper‑50s/60 and said ammonia levels were now "almost undetectable." Sidwell described the operating team as four primary employees managing a facility built for automated operation and thanked other city staff who assisted during recovery. He also urged residents to avoid flushing wipes and other hygiene products, saying the plant recorded roughly $17,000 of equipment damage from items that "should not be in the pipes." "There is no such thing" as a sanitary‑sewer‑safe 'flushable' wipe, he said.

Commissioners thanked the team and asked operational and timeline questions about the next basin maintenance. Sidwell said the second basin will be taken offline for similar maintenance (new mixers and heads) later in the summer when flows are lower, and that staff have parts staged and scheduling in place for a more‑organized repair.

What happens next: City staff will continue planned maintenance and schedule work on the second basin in July/August to install replacement components; staff said capital projects addressing inflow/infiltration will reduce peak flows and the grit burden on the plant. The commission received the report; no formal action was required.

Community context: The presentation emphasized the plant's public‑health mission and downstream consequences; staff noted that downstream communities and water systems rely on the Yellowstone's water quality.