Sanitary Sewer Rehabilitation

Gilmore City, IA | Water

In partnership with Gilmore City, ISG’s water solutions professionals implemented a sanitary sewer rehabilitation project that lowered the City’s flow to their lagoon and conserved its capacity. Additionally, ISG identified funding opportunities, and provided application assistance that secured funding for the project.

Gilmore City’s sanitary sewer system inflow and infiltration (I&I) was causing backups in residential basements and needed alternative solutions to resolve the high flow to their lagoon.

A preliminary engineering report from ISG and resident observation services provided alternative analysis for recommended improvements to Gilmore City’s sanitary sewer collection system. Each option involved various levels of improvements to the system including rehabilitation of deteriorating brick manholes, lining of distinct pipe sections, sealing off cross connections with the storm sewer, and grouting of active services.

With ISG overseeing the construction administration, the project included over 10,000 lineal feet of sewer lining, the reconnection and grouting of over 150 service connections, replacement of roughly 100 lineal feet of broken sewer, and the rehabilitation of nearly all existing vertical feet of manholes. ISG reduced the large amounts of inflow and infiltration within the sewer system, which was causing the controlled lagoons to discharge more frequently than the allotted twice per year and generating backups in residential basements. Decreasing the high flows also assisted the City in planning for the Iowa Department of Natural Resources (IDNR) required improvements and saved residents’ money by reducing the cost for expansion of the treatment lagoons.

Partial funding for the project came from a Community Development Block Grant, which ISG helped identify and apply for with the City. The remainder of the funding was secured through the State Revolving Fund administered by IDNR and the Iowa Finance Authority.