The South County Wastewater Treatment Plant was in need of capacity expansion and systems upgrades to maintain regulatory compliance standards. Gresham Smith was part of a consultant team responsible for the expansion of this advanced wastewater treatment plant from 4.5 to 10 mgd.

This biological nutrient removal (BNR) facility, using enhanced biological phosphorous removal (EBPR) and simultaneous nitrification de-nitrification (SNDN), was converted to a new 10-mgd north train, equipped with a five-stage Bardenpho process with plug flow reactor tanks, fire bubble diffused air, turbo style high efficiency blowers, nutrient analyzers for process control and external carbon feed system.

At full capacity, the facility will meet the most stringent permits in Florida while producing three billion gallons of reuse quality effluent for the region annually.


HDR, Inc.


Hillsborough County, Florida

Project Type