Separate Sanitary and Storm Sewer System

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During the 1960s, developers and municipalities began to realize that the idea of collecting and conveying sanitary and storm water in the same pipe was problematic. During this time, the Village’s first separate sanitary sewer systems were installed. Separate sanitary sewer systems collect and convey sanitary waste in one pipe and storm water in a completely separate, unconnected, pipe. The separate sanitary sewers discharge to the MWRDGC interceptor system which, in turn, conveys the wastes to a treatment plant. The storm sewers discharge directly to area creeks.  

The oldest separate sanitary sewer systems were different than those constructed today. Most notably, the first separate sanitary sewer systems featured primarily gravity connections (no sump pumps, ejector pumps, or overhead plumbing) and several sources of rain water inflow. Footing tiles and area drains were directly connected to the house service line allowing rain water to enter the separate sanitary sewer system. Later design iterations included a combination sump pump that collected storm water from footing tiles and yard drains or exterior stairwell drains along with sanitary wastes generated in the basement level of the home and pumped it into the separate sanitary sewer. It is likely that these clear water sources were permitted because of an affinity for the idea that some clear water in the sewer helped to flush and control odors.

 Today, sanitary sewer design features a complete separation of sanitary and storm flows. Ejector pumps collect sanitary wastes and pump them up to a sanitary sewer service line that exits the home at an elevation just below the basement rafters. In most cases, these elevated or "overhead" sewer services virtually eliminate the potential for sewer backup through floor drains or basement sanitary facilities; sewage will back-up through street manholes before backing up inside a home. Sump pumps perform a similar function for clear water collected by footing tiles and area drains. However, sump pumps discharge outside the home at grade rather than discharging to the sanitary sewer.

Generally, the outlying, or newer, areas of the Village are served by separate storm and sanitary sewers. Today, approximately 66 percent of the Village is served by separate sanitary and separate storm sewers. All new developments utilize separate sanitary and storm sewer systems. Homes in these areas typically do not experience floor drain backups unless the floor drain or sump pump is directly connected to the sanitary sewer system or if there is a high amount of stormwater infiltration into the sanitary sewer system. Sewer backups are rarely experienced in these areas where overhead plumbing is utilized.