NEORSD — Westerly Wastewater Treatment Center Improvements

The NEORSD Westerly Wastewater Treatment Center Improvements program included multiple upgrades designed to improve wet-weather treatment capacity, chemical handling, process reliability, and long-term performance at one of the region’s critical wastewater facilities. The program included work across several major treatment systems, requiring careful coordination within an active plant environment.

Major project components included:

• Ferric Chloride Tanks: Demolition of an existing four-story chemical handling building and construction of a new facility designed to house three ferric chloride tanks and two sodium hydroxide tanks.
• Wet Weather Facility Upgrades: Improvements to the Combined Sewer Overflow Treatment Facility, including replacement of coarse mechanical bar screens by updating the traveling rake technology, screening conveyor, slide gate hydraulic actuation system, settling tank collector drive mechanisms, and settled solids drainage piping. Flows to the facility can reach more than 1.5 billion gallons per day.
• Settling Tank Drive Replacement: Replacement of existing drive units while supporting the existing sludge cone, rake arms, suction piping, and surface skimming system during construction.
• Trickling Filter Rehabilitation: Temporary repairs to the rotary distribution system within the existing odor control dome.
• Chemically Enhanced High-Rate Treatment (CEHRT) Improvements: Renovations to existing combined sewer overflow tanks, including new chain and flight settling equipment, polymer feed injection, grit handling and pumping improvements, a new wet-weather overflow control chamber and conduit, and a new high-rate disinfection tank with chlorination and dechlorination systems. The work also included a new control building for high-rate disinfection and renovations to an existing disinfection building to support additional chemical storage, feed equipment, sludge pumps, drain pumps, and piping.