Florida City Rehabilitates More Than 1,600 Manholes

Previous repairs had helped address deterioration in a Florida water and sewer system, but corrosion continued to progress. Over a three-year rehabilitation program, the department faced the challenge of restoring manholes weakened by decades of microbial induced corrosion (MIC). Many of the affected structures were located above a 72-inch sanitary sewer trunk line or alongside a heavily traveled roadway, adding logistical and access constraints to an already demanding project. Manhole depths ranged from approximately six feet to as much as 15 feet, with varying degrees of structural deterioration.

This case study examines why the installer selected a spray-applied geopolymer lining system rather than the epoxy and cementitious materials the district had previously used. It also explains where a secondary epoxy coating was incorporated into the rehabilitation strategy and why approximately 15 of the most severely deteriorated structures required a different treatment approach. Beyond material selection, the project account explores how installation was planned around site conditions, including the use of nighttime work to minimize traffic disruption along the busy roadway. By detailing the challenges, material choices, and installation methods across the three-year program, the case study offers insight into planning rehabilitation work for sewer infrastructure exposed to persistent corrosion. Explore the project details to see how the team approached the varying conditions and carried out the work.