Challenges of Implementing a Successful Service Area Wide PPI/IR Program

In 2010, the Milwaukee Metropolitan Sewerage District (MMSD) started to take action to address private property inflow and infiltration(I/I) within the service area. Legal determination concluded MMSD may “perform or fund work on private property that reduces I/I, thereby reducing operating costs, capital program expenditures, and reducing the risk of overflows and basement backups.” (MMSD, 2013A)The private property inflow and infiltration reduction (PPI/IR) program was implemented throughout the service area in coordination with the local municipalities to address I/I sources within the private property sanitary sewer systems. Each municipality identifies points of failure within their system boundaries and implements PPI/IR projects that meet MMSD policy guideline and are overseen and funded by MMSD. Projects have included investigative work, cured-in-place-pipe (CIPP) lateral lining, grouting, sump pump installation, and downspout disconnection. As part of MMSD’s oversight efforts, MMSD procured several contracts for municipalities to use for design, televising, and public relations services. These contracts are available to the municipalities but the municipalities are not required to use them. MMSD also reviews and provides feedback on all PPI/IR projects that request MMSD reimbursement. During construction, MMSD provides staff to assist with construction inspection and to make recommendations when issues arise. The keys to success include communication between all participants, being open to innovative approaches, understanding failures and sharing successes. Organization of volumes of technical and monitoring data are necessary to appreciate the program performance and to guide the decision making for effective I/I reduction on private property.