The City of Aurora completed preliminary engineering plans for installing separate storm sewers within the combined sewer system tributary to Aurora’s Downtown area. In 2010, the City submitted a Combined Sewer Overflow (CSO) Long Term Control Plan (LTCP) to the IEPA and USEPA in accordance with the City’s CSO NPDES Permit. Sewer separation is a component of the City’s LTCP as green infrastructure for the removal of inflow into the combined sewer system.

The North East Sewer Separation Project, which consists of expanding existing storm sewer networks in the combined sewer basin tributary to CSO No. 22 (Superior St.) and CSO No. 8 (East Benton), was one such project that the City identified towards reducing its CSO operation. WBK provided the City with final design and construction plans for the proposed improvements and subsequently provided construction observation for the improvements.

Infrastructure improvements included the installation of seven different storm sewer systems, the adjustment of water main to accommodate the new storm sewer, sanitary point repairs and all necessary improvements to make the existing combined sewer function as a sanitary sewer system. This project included the installation of over 10,000 linear feet of new RCP storm sewer ranging in size from 12 to 48-inch in diameter.