AKM Consulting Engineers prepared the design for upgrade and expansion of the City of San Juan Capistrano’s Groundwater Recovery Plant (GWRP). The project expanded the Reverse Osmosis (RO) plant from 5 to 6.8 mgd. Project included modifications to process for removal of iron and manganese, replacing the sand filters, relocation of two cartridge filters and adding one new cartridge filter, adding a Greensand filter to the system, increasing pumping capacity of the RO feed water pumps and making recommendations for changing the RO elements. The project also included adding a 23,400 gallon reaction vessel, relocating chemical injection locations, adding flow meters to the Greensand filters influent and effluent lines, replacing two wastewater pumps, backwash pump suction modifications to backwash filters with product water versus potable water, civil site work (asphalt paving and new fencing), and California Department of Public Health permit amendment application. Water quality testing was conducted for arsenic blending (bypass water supply), and effluent discharge to local sewer. Discharge testing included pH, TSS, TDS, COD, flow monitoring.