La Crosse completes $65m WWTP upgrade, achieves energy self-sufficiency and targets BOD capacity increase

La Crosse completes $65m WWTP upgrade, achieves energy self-sufficiency and targets BOD capacity increaseFollowing a five-year capital project, the Wisconsin utility is now powering its wastewater operations entirely through anaerobic digestion while seeking state approval to increase its biological oxygen demand limits to support local industrial growth.

The Board of Public Works approved a final $120,000 change order to close out the $65 million WWTP upgrade, funded by the Clean Water Fund.

The facility has generated its own electricity for 40 days using methane from anaerobic digestion, eliminating reliance on Xcel Energy.

Heat off the cogeneration system is being used to produce Class A fertilizer from biosolids and heat the plant campus.

Donohue & Associates was hired to petition the DNR to raise the plant's BOD limit from 29,759 pounds per day to roughly 40,000 pounds per day.

The Board also approved $54,500 in easements for a new 24-inch water main installation along Highway 16.

The City of La Crosse, Wisconsin, has effectively concluded a five-year, $65 million wastewater treatment plant (WWTP) upgrade, transforming the facility into an energy-independent operation capable of handling higher industrial loads. On March 30, 2026, the Board of Public Works unanimously approved a final $120,000 sanitary sewer fund allocation to close out the project, with costs to be fully reimbursed by the Clean Water Fund. A major milestone of the capital program is the implementation of a new cogeneration system. According to municipal staff, the plant has produced its own electricity for the past 40 days by burning methane gas generated through the anaerobic digestion process, eliminating its need to purchase power from Xcel Energy. Additionally, waste heat from the system is being actively used to heat the plant's digesters and campus, as well as to dry biosolids into a Class A fertilizer. Staff noted the upgraded facility is also successfully meeting new low-level phosphorus limits. With the physical upgrades complete, the utility is moving to officially expand its permitted treatment capacity to accommodate local industrial growth, including increased production from Kwik Trip and City Brewery, as well as development in contracted communities. The Board approved a contract with Donohue & Associates to conduct a mass balance and re-rate the facility's biological oxygen demand (BOD) limits. Previously, the plant was limited to a BOD loading rate of 29,759 pounds per day. Staff noted that the utility took a hit on its Compliance Maintenance Annual Report (CMAR) last year, receiving a D or F grade for exceeding this limit, despite having the hydraulic capacity to pass 35 million gallons of sewage daily. By submitting the new Donohue & Associates calculations to the Department of Natural Resources (DNR), the city aims to increase its permitted limit to approximately 40,000 pounds of BOD per day. The consulting contract will be paid from the utility's operating budget and will not impact customer rates. In separate water infrastructure business, the Board approved $54,500 in Clean Water Fund expenditures to acquire four easements necessary for the installation of a new 24-inch water main along Highway 16. The Board also approved a nighttime noise exemption for contractor Gerke Excavating to allow for equipment staging during the pipeline installation.