Editors note: This is part three in a series looking at phosphorus reduction mandates at the city of Beaver Dam’s Wastewater Treatment Plant
12/30/17 – Elected officials in Beaver Dam next year will be tasked with choosing which multi-million dollar option the city will invest in to satisfy state and federal mandates to limit the phosphorus that goes into the river from the city’s wastewater treatment plant. Beaver Dam is currently studying four options to better control phosphorus. During yesterday’s newscast, we detailed the most expensive option. At just over $24-million-dollars, the construction of a new facility adjacent to the current treatment plant would allow phosphorus to be converted into a bioplastic. As part of a partnership with Clearas Water Recovery Incorporated, it also would be the only option that potentially generates revenue. The city is studying other options, though some are not considered to be promising. Beaver Dam Director of Utilities Rob Minnema outlined those options when he was our guest recently on WBEV’s Community Comment. The city looked at two options during the three-years it was fighting the phosphorus mandates in court.
Adaptive Management would allow the utility to work with other generators of phosphorus, like developers and ag producers, as part of a credit-based system to achieve compliance. Adaptive Management could include, for example, buffer strips. Another option that was explored while the city was in litigation is Water Quality Trading, which is similar to Adaptive Management but allows a utility to reduce pollutants from other sources in the watershed to offset the phosphorus output at the plant. For that, the city looked at carp removal efforts in the lake. Minnema says neither were a viable option and were ruled out.
The facilities study exploring the options is also looking at the construction of a standalone facility next to the current wastewater treatment plant. Phosphorus would be treated with chemicals and run through a pump station and filtration system. The price tag is around $15-million dollars in addition to $400-thousand dollars in annual costs for chemicals. Minnema says there would be no benefit in terms of sustainability and revenue. The $15-million dollar chemical option would also not remove nitrogen, though the $24-million dollar option would. Minnema says that he anticipates nitrogen removal to be the next nutrient reduction mandate that state and federal officials impose.