When Routine Maintenance Finds Major Problems: Charleston Water System Turns Near Disaster into Opportunity
The Charleston Water System (CWS) Hanahan Water Treatment Plant set out to perform a normally routine maintenance task—take one 5-million-gallon clearwell (an approximately 220-foot-diameter by 20-foot-deep tank) offline to replace a baffle curtain. But when the clearwell proved impossible to dewater safely due to the failure of 84-inch butterfly valves, engineers and managers were suddenly confronted with substantial risks to millions of dollars in infrastructure investment, not to mention staff and contractors. Experienced civil engineers, expert designers and fabricators, and highly specialized subcontractors were quickly assembled, and this team of infrastructure all-stars was able to engineer, design, build and install a highly innovative bespoke solution within a few weeks.
The result—from the utility’s point of view—is a fully restored clearwell with improved hydraulics, proven contingency tools for future maintenance and a repeatable owner-led model for solving nonstandard isolation issues in critical potable-water-delivery infrastructure.
