The Eastern Municipal Water District (EMWD) currently uses reverse osmosis (RO) at it’s Menifee and Perris I Desalter to produce drinking water from otherwise unusable brackish groundwater. A third RO facility is currently under construction (Perris II). The three RO systems are co-located to form the Desalination Complex and are projected to produce up to 13.4 million gallons per day (MGD) of drinking water and up to 4.0 MGD of concentrate once Perris II is online. EMWD’s Desalination Complex reduces reliance on imported water supplies and assists with salinity management in the area to allow for the expansion of water recycling and the protection of local groundwater. However, as an inland utility with finite local water supply, EMWD incurs substantial costs associated with water imports and brine disposal. In an effort to minimize brine discharge and maximize local water production, EMWD conducted lengthy pilot testing of Desalitech’s Closed-Circuit Reverse Osmosis (CCRO) technology.The high-level objective of pilot testing was to determine if a CCRO could successfully recover concentrate produced by the Menifee Desalter beyond conventional RO recovery limits at a life-cycle cost that would be favorable to EMWD. Achieving high recovery was a known challenge from the start, as the groundwater in Perris and Menifee has higher total dissolved solids, total hardness, alkalinity, and silica levels than alternative water types that have had successful CCRO pilot operation at recoveries between 92 and 95 percent (e.g. in advanced wastewater treatment). After fifteen months of fine tuning physical and process levers, pilot results showed that a CCRO could be integrated at the Desalination Complex to increase raw water recovery to 90 percent at a significantly favorable 30-year life-cycle cost.
This presentation is available to AMTA Members only.
- Daniel ten Bosch
- Black & Veatch
- AMTA/AWWA Membrane Master Class Webinar II - Part 1, Online
- AMTA/AWWA Membrane Master Class Webinar Series II
- CCRO, Brine Minimization, Brine Concentrator