South Oak Pond Water Quality Improvement Project

The South Oak Pond Water Quality Project will reduce TP and TSS loading by pumping water from the South Oak Pond to an underground filtration system prior to discharging to the impaired Minnehaha Creek and Lake Hiawatha. A new pump would be added to the existing South Oak Pond lift station outlet wet well, which would pump water to an underground vault with filtration cartridges designed to handle the pumped flows and anticipated TP/TSS loads. The filtration cartridges would be designed to remove 50 lbs/yr of TP from the system. The outlet from the underground filtration vault would be connected back into the existing pond outlet pipe and would continue to discharge downstream. Vegetation and shoreline improvements including invasive species removal and stabilization of any shoreline erosion along the pond would coincide with the water quality treatment system construction to provide additional benefits to the area. The subwatershed where South Oak Pond lies was identified in the Lake Hiawatha TMDL as a high phosphorus loading area and is almost entirely developed and dominated by residential, commercial and industrial areas. The fully developed area leaves limited opportunities available for reducing the pollutant load to Minnehaha Creek and Lake Hiawatha within this priority subwatershed. Additionally, since the outlet from the South Oak Pond discharges directly to Minnehaha Creek a project at the pond provides an opportunity to treat the maximum amount of runoff possible within the 460 acre subwatershed.