What is the difference between a separate sanitary sewer system and a combined sewer system?
A separate sanitary sewer system is designed to carry only wastewater to the treatment plant. Stormwater is carried in a separate system, and is not transported to the treatment plant. In a combined sewer system, both wastewater and stormwater are carried in the same set of pipes. Of the 83 communities in the ALCOSAN service area, 26 have been identified as having primarily a combined sewer system within their municipal boundaries. The remaining 57 communities have separate sanitary sewage collection systems.
