PASADENA, CA Parsons was recently selected by California's Inland Empire Utilities Agency (IEUA) to provide design support services to expand and upgrade Regional Water Recycling Plant 5 (RP"‘5) in Chino, California.

The RP-5 upgrade and expansion will increase liquid treatment to 30 million gallons per day (mgd) using membrane bioreactor (MBR) and ultraviolet (UV) disinfection processes and will expand the biosolids management system to 40 mgd, including thickening, anaerobic digestion and dewatering, and potential food waste treatment. It also includes cogeneration upgrades (as part of the Renewable Energy Recovery Project) as well as ancillary support facilities that involve the replacement, relocation, and construction of new offsite facilities such as sewage lift stations, force mains, brine lines, and recycled water conveyance pipelines.

"This is the largest single project undertaken by IEUA, and it is one of the nation' s largest recycled water facilities using membrane bioreactor and ultraviolet disinfection," said Mike Johnson, Parsons Group President. "High-quality recycled water is a valuable resource for groundwater recharge and reduces the region's need for imported water."

The increased biosolids treatment capacity at RP-5 will replace Regional Water Recycling Plant 2, allowing that facility to be decommissioned as well as regulatory compliance of the facilities that will be impacted at Prado Dam. Parsons recently completed predesign of Regional Water Recycling Plant 1 (RP-1) as well as RP-5 expansion and upgrade. For RP-1, Parsons evaluated possibilities to eliminate flow equalization for odor control and developed predesign of liquid and biosolids facilities expansion to meet the regulatory requirements and to produce high-quality recycled water and biosolids for use in composting. Detailed design services for RP-5 are scheduled for completion by June 2019.