University of Minnesota, Twin Cities
OP-23: Stormwater Management

The University of Minnesota Twin Cities (UMTC) combines its regulatory, academic and operational expertise to foster and implement best management practices. UMTC is a small Municipal Separate Storm Sewer System ("MS4") and, as such, holds a National Pollution Discharge Elimination System (NPDES) permit, requiring Storm Water Pollution Prevention Program meeting these minimal control measures:
1. Public education and outreach
2. Public participation
3. Illicit discharge detection and elimination
4. Construction site stormwater runoff control
5. Post-construction stormwater management in new development and redevelopment
6. Pollution prevention/good housekeeping

The University's Stormwater U program is the primary extension program in Minnesota for training in stormwater management (see http://www.extension.umn.edu/Stormwater/stormwaterU.html). The University's Stormwater Management policy (http://policy.umn.edu/Policies/Operations/Safety/ENVIRONMENT_PROC04.html) is implemented through the advisory, Stormwater Linkage Committee, made up of faculty and operational staff with stormwater expertise. The policy and its enforcement address illicit discharges, construction site management, aggressive post-construction management standards, and ongoing campus operations improvements. Initiatives include (1) diverting stormwater from 25% of the St Paul campus to an infiltration basin, adding then expanding a treatment forebay and infiltration area upstream of a wetland, with resulting 80% reduction in pollutants leaving campus to the Mississippi River; (2) designing and building the new stadium/medical research sector of campus with bioswales, retention ponds, permeable pavers, and infiltration/water reuse technology reducing pollutants by over 70%.

The campus has numerous, limited green roofs over underground buildings and parking ramps on: the Humphrey Institute, Coffman Union, East River Road Garage, Yudof Hall, Lily Plaza, Williamson Hall, Civil Engineering, Nolte Garage, Diehl/Wangensteen, St Paul Student Center (theater & out front), Borlaug Hall, and Classroom Office Building Plaza.

There are permeable pavement on part of the new stadium site and permeable pavers in the parking lot for Como Student Housing.

There is a rate control pond in support of the new stadium stormwater system, additional retention ponds for the large Parking Lot 33 north of the hockey arena, an infiltration pond in the Sheep Pasture, and a treatment forebay for the Sarita Wetland.

All our vegetative swales uses rip-rap to slow the runoff flow to prevent erosion and to facilitate infiltration, treatment, and evapotranspiration. Rip-rap is also used to stabilize the banks of the Mississippi River from stormwater runoff.

There are extensive rain gardens along Gortner Avenue in St Paul and a series of bioswales throughout the stadium/biomedical district in Minneapolis. There are bioswales and rain gardens to manage runoff from three other parking lots.

As part of the stadium district stormwater system, we installed (1) two hydrodynamic separators (grit chambers) for water quality; and (2) proprietary Rehbein EPIC system to store and reuse water for irrigation. We also installed a hydrodynamic separator as part of the preparation for the light rail line through campus.