USST: Safer, Quicker, Cheaper, Stronger This week, U.S. Submergent Technologies is performing sand and grit removal from a wastewater treatment plant in Orlando, FL, which requires confined space entry. The USST crew is removing material from two clarifiers at the plant. Both are 120 feet in diameter and 16 feet deep. Approximately 120 tons of sand and grit has been removed from Clarifier 1. “We performed a confined space entry, which includes constant air quality monitoring,” said Paul Del Favero. “Fall protection is being used as well while on the catwalk inside the tank.” The crew began work on Clarifier 2 this week, running the Model 949 and Model 934 simultaneously during the project. “We have been using our proprietary equipment for the cleaning of this tank,” Del Favero said. “It’s been a real team effort. USST expects to complete the cleaning of clarifier 2 this week.