The Public Works Department maintains approximately 150 miles of sewer pipe within the three systems throughout the Village. First there is the Sanitary Sewer System that is used to carry the waste water from indoor plumbing from residences and businesses to the Metropolitan Sanitary District (MWRD) for treatment. Next is the Storm Water System that is used to transmit rainwater runoff from streets, sidewalks and buildings to local streams. Lastly there is a Combined Sewer System which by its name is a combination of both waste water and rain water which also goes to the MWRD for treatment.