The State Water Resources Control Board (State Water Board) is a Responsible Agency for the Project. The State Water Board’s Drinking Water State Revolving Fund (SRF) Program is financing the Project referred to internally as Groundwater Treatment Plant (PFAS) - Phase B. The Project includes upgrades to groundwater treatment plants at five locations: Willow Park Site, Downtown Site, Katella Avenue Site, Brookhurst Site, Santa Cruz Site. Upgrades include installation of ion-exchange groundwater treatment systems. The Project would involve installing resin vessels that are approximately 17 feet tall and 12 feet in diameter at each location. The Project would also involve installing features such as prefilters, pumps, pipes, valves, and electrical equipment. The Santa Cruz Site would receive a new backup generator, and a new control building would be constructed. New piping would be installed beneath roadways near the Project sites, including beneath Anaheim Way and Orangewood Avenue. Groundwater supply wells near each site would be rehabilitated with new liners installed to improve groundwater production capacity. Two new groundwater supply wells would be drilled at the Santa Cruz Site. Security features such as block walls, wrought iron fences, and chain-link fences would be installed at each site, along with new lighting and security cameras. Some trees and vegetation would be removed from within the footprint of the Willow Park Site to facilitate construction of the treatment equipment and new fences and walls.