MODERN SEWER CONSTRUCTION: IS IT REALLY BETTER

Conventional wisdom is that newly constructed sanitary sewers will be watertight. However, flow monitoring and inspection conducted in the Louisville and Jefferson County Metropolitan Sewer District (MSD) do not support this view. In response to these findings, MSD has executed several studies and pilot projects designed to identify deficiencies in new sewer construction including post acceptance inspections of new manholes and pipe and a pilot installation of a HDPE gravity sewer system. These investigations identified three major areas where defects commonly occur: manhole chimneys, lateral connections, and pipe joints. As a result, MSD is reviewing and reformulating their approach to new sewer construction and acceptance of new capital projects and private developments. These revisions have drawn heavily on lessons learned through inflow and infiltration (I/I) rehabilitation.