In 2019, the Prince William County Service Authority (PWCSA) lined a new manhole where corrosion was a primary concern. Unfortunately, PWCSA selected a Warren Environmental (Warren) competitor coating and leaks began shortly after. Two other coating companies attempted to stop the active leaks and reline the manhole without success. The project photos show the existing lining peeling off in sheets with no adhesion to the concrete substrate.
In August 2020, A&W Coatings was selected to fix the failed liners. The manhole was abrasive blasted and then the crew stopped all active leaks with Warren’s 151-HG hydrophobic grout. During this phase, the bench lifted three to four inches due to groundwater pressure and released a small wave of water into the manhole. Due to a high-water table and infiltration, mitigating the leaks consumed 60% of our crew’s time. In total, A&W’s team used 50 gallons of the grout before coating the area with 250 mils of Warren’s 301-14 high performance epoxy.
The lower section included a 54-inch FRP pipe coated with 250 mils of Warren’s 301-14 from the face of the pipe to 12-inches beyond the 12-inch pipe penetration and as low as possible. The project required one mobilization and four-night shifts with two-hour shutdowns the first weekend during low-flow periods.
Our crew’s expertise, coupled with Warren’s effective grout and high-performance epoxy coating, resolved PWCSA’s corrosion and infiltration issues. All while proving to PWCSA that epoxy coating systems can be effective in the most challenging sewer conditions.