UPDATE ON A NATIONWIDE I/I REDUCTION PROJECT DATABASE

In 2002, the Water Environment Research Foundation (WERF) published the report WERF 99WWF: Peak Rainfall Dependent Infiltration/Inflow Flow Reductions–Case Studies and Protocols, a report for which this abstract's author was co-principal investigator. A major conclusion of the work was that in many cases either communities did not gather flow and rainfall data following a project in order to determine I/I removal effectiveness, or their I/I removal effectiveness calculation methods were inconsistent at best and questionable at worst. This conclusion led the research team to develop an approach for consistently reviewing and reporting on a set of case studies for which there were sufficient data. The report also called for the accumulation of project results, based on this protocol, so that at some point in the future a better depiction of I/I reduction effectiveness and cost-benefit could be developed. Since completing the report, the author has collected I/I reduction project results from a number of published case studies in order to improve upon the nationwide database that was recommended by the WERF report. The paper discusses the specific evaluation approach for considering a project and how the author used published results to compare projects in a normalized fashion. Finally, the paper provides an approach for calculating the value of I/I as a component of flow that consumes system capacity. This approach will be extremely valuable and insightful for communities that have embraced and are using asset management practices to drive decisions in their sewer utility.