Repurpose Building to Reduce Biosolids

When the City of Watertown, SD had concerns about the future availability of land to continue the land application of liquid biosolids, the City needed to evaluate options.

The three options included transitioning from liquid land application to mechanical dewatering of biosolids with landfill disposal, continued use of City equipment, or contractor hauling of liquid biosolids.

The study determined that land application was not a long-term option for the City of Watertown. Recommendations included adding a screw press into the wastewater treatment facility process to handle dewatering of the liquid biosolids into a dewatered cake which ultimately would be disposed of at the local landfill.

The project consisted of design and construction services to repurpose a decommissioned pretreatment building into a solids dewatering building. The building now houses a new screw press used to dewater digested liquid sludge from the two primary digesters.

The project provides the City of Watertown with a low-maintenance, long-term solution for processing and handling the liquid biosolids while also allowing for the disposal that no longer requires the City to rely on the availability of farmland.  The project also saved the City significant money by designing the new equipment and layout to allow for repurposing a decommissioned building and reusing some existing equipment.