Most water–whether from a building, a rainstorm, or exterior cleaning activities– eventually reaches surface waters (streams, creeks, rivers, ponds, lakes, or wetlands).  The City of Ann Arbor and the University of Michigan (U-M) use separate sanitary and storm water systems to handle wastewater and storm water runoff.

Sanitary sewer systems transport wastewater from drains within homes, offices, restaurants, laboratories, and shops to the wastewater treatment plant (WWTP), where it is treated before being discharged to a surface water body.  Whereas storm water drainage systems transport surface runoff from rainstorms and snowmelt directly to lakes, rivers, streams, and ponds.  Water that enters the storm water drainage system receives minimal treatment, if any, before being discharged.

Surface water quality can be impacted by products and waste discharged into the sanitary system if the WWTP is unable to remove it before discharge.  Surface water can also be impacted by products used outdoors such as fertilizers, herbicides, and pesticides.  Because of the potential impact from U-M operations, it is important for everyone to be aware of and take precautions against discharging materials that could prove harmful to the environment.

Soil Erosion, Sedimentation, and Debris

Chemicals, organic matter, and leachate from landfills

Trace Metals

Fuels, Oils, and Grease


E. Coli and Other Bacteria

Supplemental Information

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