Choteau Wastewater Collection and Treatment Plant

City of Choteau hired DOWL to complete a facility plan and grant applications for improvements to their wastewater collection and treatment systems. DOWL prepared and obtained TSEP and RRGL grants and SRF loan funds for completion of recommended Phase 1 Collection and Treatment System Improvements completed in 2010 including slip-lining of 2,800 lineal feet of sewer main, replacement of leaking sewer service connections, and construction of UV disinfection system for the existing lagoon effluent. Phase 2 improvements included a major wastewater treatment system upgrade to comply with scheduled ammonia limits and possible future nutrient standards in the surface water receiving stream. DOWL evaluated multiple treatment facility replacement options including aerated lagoons,  sequencing batch reactors, mechanical oxidation ditch,  and other variations of higher performance treatment options. The selected option included construction of an influent pump station, mechanical oxidation ditch with anaerobic and anoxic zones, two secondary clarifiers, influent headworks screen and grit removal, pump station building for return and waste activated sludge pumping, lined holding ponds for waste sludge, concrete sludge drying beds, and incorporation of the existing UV disinfection system.