Fuss & O’Neill designed an ultraviolet (UV) light disinfection system to treat stormwater runoff that discharges to public and private beaches via a man-made moat, historically causing beach closures. This is the largest UV system in the U.S. designed to solely treat stormwater.

The system is designed to disinfect stormwater under a peak flow of 96 cubic feet per second (43,000 gallons per minute) to less than 104 Enterococci colonies/100 ml; the beach closure standard. The project design consisted of a fully automated SCADA control system to divert runoff from the moat through the disinfection system, using a diversion gate and axial flow pump station. Flowrate and transmittance will be measured and used to vary UV lamp intensity thereby conserving energy. Disinfected runoff will discharge back to the man-made moat downstream of the division gate. The project was funded by RIDEM SRF and Federal ARRA grant money.