The City of Medford, Wisconsin and Donohue & Associates received an American Council of Engineering Companies (ACEC) Wisconsin 2020 Engineering Excellence Best of State Award for the Innovative Low Level Phosphorus Compliance project.

The City of Medford’s wastewater treatment plant was faced with equipment issues and a future ultra-low level (0.075 mg/l) effluent phosphorus limit that could not be met with their existing filter system. Donohue designed a simple, cost-effective system that filters the clean water returned to the environment and removes phosphorus to an ultra-low level.  The system designed uses a chemical feed system to achieve low effluent phosphorus and a disk filtration system to replace an existing sand filter system. A typical approach to phosphorus compliance, membranes, would have cost the City millions of dollars more.

The solution developed also extends existing equipment’s useful life, fits within existing buildings, and reduces power consumption. Most importantly to the City, the new system does not require additional operator attention or compromise permit compliance during maintenance.

This project provides important proof to the clean water industry that ultra-low level phosphorus limits can be met simply and cost effectively.  John Fales, City Administrator and Director of Public Works, remarked, “This project was a highly collaborative effort between the engineer (Donohue), the manufacturer (Veolia), the construction contractor (Staab Construction), and our dedicated City personnel. This was a true partnership with all parties, as the installation is one of the first in the country to achieve the consistent low-level limits that we are experiencing.  Prior to this project, our 10-year average for phosphorus was 0.64 mg/l; we are now averaging 0.04 mg/l with our new system, meeting our permit requirements years ahead of schedule.”

Engineering Excellence awards recognize quality engineering achievements. Entries are judged on the basis of excellence in design, the degree to which the client’s needs are met, as well as benefit to the public welfare and to engineering practices. Learn more at www.acecwi.org.