Dry Creek Wastewater Treatment Plant UV Conversion

City of Roseville, 
California

Dry Creek Wastewater Treatment Plant UV Conversion

Service Type: 
UV photo
The City of Roseville’s 18-mgd Dry Creek Wastewater Treatment Plant used gaseous chlorine for effluent disinfection and sulfur dioxide for dechlorination. Based on safety, cost, and toxicity concerns, Roseville retained Carollo to evaluate alternatives to its current disinfection system. A project to convert the existing system to UV disinfection resulted. Project scope included design, PLC and HMI programming, construction management, startup, and commissioning. As part of the project, extensive control system modifications are being implemented. The control system uses Modicon Quantum PLCs and a Dynac SCADA HMI. PLC cabinets are being added to support the UV generation system, as well as on-site hypochlorite generation, electrical system additions, chemical system changes, and plant flow control modifications. Carollo programmed the PLCs and SCADA HMI screens for the project. The UV PLCs were programmed by the vendor. Due to Carollo's programming approach, industry experience, and close working relationship with the design team, our experienced programming team was able to accommodate a number of design and schedule changes without additional cost to the owner. Roseville has new detailed programming standards to facilitate easier troubleshooting and more efficient maintenance overall. Carollo's programmers delivered system modifications in full compliance with these standards, giving the City a quality product that interfaces perfectly with its other systems and facilities.