Stormwater Runoff Pollution Mitigation
Client: Town of Rossville
Location: Rossville, Indiana
Rossville is a combined sewer community that was struggling to mitigate combined sewer overflows. A review of the sewer system indicated that most of the known storm sewer connections had already been removed except for approximately 10 inlets along State Route 39. These storm connections were thought to contribute significant amounts of stormwater to the sewers and were suspected to be the main cause of overflows at one of the town’s overflow locations.
The Town determined that disconnection and rerouting would be the best alternative, and Donohue was selected to prepare the design needed for rerouting the flows. In addition, Donohue found that one of the Town’s main storm sewers was known to surcharge was close to the upstream end of one of the required new storm sewers. Donohue determined that the new storm sewer on the south side of Town could act as a relief sewer for the existing storm system and recommended connection to it at an elevation near the top of the existing pipe. This connection elevation would fully utilize the existing system prior to using the relief sewer where inlets were already connected.
Plans and specifications were developed for the installation of approximately 1800 feet of 12- to 30-inch storm sewer designed to collect flow from existing catch basins and inlets and also redirect the flow from the existing combined sewer system towards Campbell’s Run. By redirecting the stormwater flows, the frequency of combined sewer overflow events was reduced to be in conformance with the Indiana Department of Environmental Management requirements.