Abstract
The McAlpine Creek Wastewater Management Facility (MCWWMF) is the largest wastewater treatment facility operated by Charlotte Water (CLTWater). In 2018, CLTWater began a Reliability and Process Improvements project. The project involved the rehabilitation of 16 secondary concrete clarifiers that ranged from 95 to 150 feet in diameter, with the oldest clarifiers being nearly 60 years old.
CLTWater considered an epoxy coating. However, they historically ran into issues with failures of delamination. Thus, they opted to move forward with a pilot study with four different epoxy manufacturers where they analyzed cost, schedule, performance, quality, service life, and safety. Concluding the test, CLTWater determined the single coat epoxy to provide the best value for their project.
The product selected was not the lowest cost option. Yet, the epoxy's single coat application and nonhazardous attributes provided CLTWater seven months of time savings resulting in the greatest cost savings as compared to the other products tested. The coating system achieved the high build needed in one coat to rehabilitate the concrete aggregate and allowed the clarifiers to return to service within four to six hours.
The product was also free of volatile organic compounds, solvents, styrene, and isocyanates, making the product safe for applicators, workers, and the surrounding work site. This allowed multiple trades to work concurrently while the coating was applied.
