Gilmore City had large amounts of inflow and infiltration (I/I) within their sewer system that was causing the controlled lagoons to discharge more frequently than the allotted twice per year, as well as causing backups in residential basements.The City hired I+S Group (ISG) to investigate solutions. After analysis, a sanitary sewer rehabilitation project was proposed to lower the City's flows to the lagoon and also to conserve the capacity within them.
ISG also recommended applying for a CDBG grant and assisted the City in applying for $300,000 through this program. As a result, approximately 70% of the town's collection system was lined, including sanitary sewer lining; grout sealing all services; cutting of protruding taps; replacing a portion of a broken sewer main; and rehabilitating all manholes in town. Nearly 30% of the remaining services connected to the sanitary sewer were closed to prevent further inflow because they were deemed inactive and/or cross connections.
Upon completion of the project, the area experienced 10 inches of rainfall in one month and Gilmore City reported flows at approximately half of what they experienced previously during similar events. Gilmore City continues to meet their lagoon discharge limits. The decrease in high flows also helps the City to better plan for impending IDNR required improvements to their existing lagoon, as well as saving the community money by reducing the need for expansion.