For the Girdwood, Alaska Sanitary Sewer Collection System Infiltration and Inflow (I&I) Project, Stephl Engineering developed a multi-year flow monitoring program to determine when and where excessive runoff was entering the sewers. The 160 inches of annual precipitation, combined with high snowmelt runoff and high groundwater, was increasing sewer flows into the treatment plant by threefold during peak storms. The project included rehabilitation of 450 manholes, CCTV inspections, sewer main repairs and sewer service repairs.