Regulation of stormwater runoff is increasing throughout the United States. The Environmental Protection Agency (EPA) and state agencies are beginning to move toward effluent and/or load limits for pollutants in stormwater. Compliance costs for treating urban stormwater runoff, especially in highly-developed areas where retrofits are required, will only continue to increase.
Western Michigan University (WMU) is a permitted Municipal Separate Storm Sewer System (MS4) along Arcadia Creek and the West Fork of Portage Creek in Kalamazoo, Michigan. As such, it falls within the nonpoint source (NPS) load allocation for a phosphorus total maximum daily load (TMDL) developed for the Kalamazoo River and Lake Allegan (refer to Figures 1 and 2 for location maps). The Kalamazoo River TMDL was established in 2001 and requires a 50% reduction in total phosphorus (TP) originating from NPSs, using the 1998 load as a baseline. The original timeline outlined in the TMDL set 2009 as the target date for meeting the TP reduction goal. To date, no other MS4s (or any other NPSs) in the watershed have been able to document progress or demonstrate an ability to meet this goal.
WMU has employed a unique approach toward resolving their stormwater concerns, which include MS4 permit requirements, TMDL compliance, and flooding. The University's efforts have utilized federal/state grant funding and strategic MS4 partnerships to implement stormwater best management practices (BMPs) identified within an EPA-approved Watershed Management Plan. Efforts also included applying engineering designs to target floodplain enhancements, TMDL compliance, flood mitigation, and infrastructure protection.
During the past decade, WMU implemented 14 stormwater BMPs. The most recent stormwater BMP project leveraged state funding and was completed in November 2011. The project focused on multiple goals: reducing direct discharges of urban stormwater runoff to surface waters; naturalizing conveyances and stream corridors using native plants; repairing erosion caused by urban runoff; restoring original floodplains; reducing phosphorus and sediment loads to tributaries of the Kalamazoo River; and increasing groundwater recharge.
In 2011, a WMU TMDL Compliance Planning Project demonstrated that WMU has achieved TP load reductions sufficient to meet TMDL load allocation compliance goals. The final TMDL Compliance Plan document provided a “road map” outlining future implementation of on-campus and off-campus stormwater BMPs. This plan will also help move WMU into a position of becoming Stormwater Neutral ™. A framework for a water quality monitoring program also was included in the plan to enable successful measurement of stormwater BMP effectiveness. To complement the compliance plan, several BMP treatment recommendations for future implementation were pre-designed. These designs clearly defined costs and environmental benefits in terms of water quality and hydrology improvements to ensure that efforts are reasonable, feasible, and beneficial.