From Liability to Asset

Abstract

This article describes the process undertaken by the North Charleston (South Carolina) Sewer District (NCSD) to rehabilitate its aging, deteriorating interceptor sewer system. Part of the system is located in wetlands that promote the production of hydrogen sulfide gas, which can cause corrosion and deterioration in sewers. The NCSD has used various methods to upgrade its aging sewers, but this article focuses on the use of cured-in-place pipe (CIPP) to rehabilitate long sections of the interceptors. The CIPP approach consists of inserting a resin-filled fabric into an existing pipe by means of water pressure; hot water is then circulated within the liner, causing it to harden and bond to the interior of the host pipe. Topics include the bidding process, dealing with permits from railroads and other right-of-way holders, access the isolated manholes with a swamp buggy vehicle, locating temporary pipes around the sections being rehabilitated, limiting disruptions to the wetlands and ecosystems, and the rehabilitation of the pump station. The article is illustrated with full-color photographs of some of the unusual equipment and techniques utilized.