groundwater recharge scheme exists in the area, providing a much-needed freshwater barrier to intruding seawater. Part of the injected water consists of recycled water, starting as of 1976 with Water Factory 21, which used RO and high lime to clean the water (production capacity of 19,000 m3 per day). This plant was de-commissioned in 2004 and has since made place for a new project with a higher capacity (265,000 m3 per day with an ultimate capacity of 492,000 m3 per day), under the name of Groundwater Replenishment System. This newer scheme uses the newer technological combination of RO, MF, and ultraviolet light with hydrogen peroxide. Plans are also underway to further increase the capacity of the system, which already provides up to 20% of the water used by the country. In the US, San Diego, California is the leading state implementing IPR. MF, RO and UV/H2O2 are employed prior to groundwater replenishment with the treated effluents (CDPH, 2013). In San Diego, the effort to increase the share of recycled water was rekindled with an extensive study in 2006. MF provides substantial removal of the dissolved effluent organic matter (dEfOM), while dEfOM reduction down to 0.5 mg/L (in terms of TOC) is achieved through RO application. The chemical oxidation treatment (UV/H2O2) following the membrane steps, results in the mitigation of N-nitrosodimethylamine (NDMA), as well as in the improvement of the effluent quality with respect to its organic content. The City of El Paso's (Texas, USA) water sources include groundwater aquifers and surface water from the Rio Grande. In order to increase groundwater levels, the El Paso Water Utilities injects advanced treated reclaimed water into the aquifer. The advanced treatment facilities use two-stage powdered activated carbon (PAC), addition of lime, two-stage recarbonation, sand filtration, ozonation, granular activated carbon (GAC), and chlorination for purifying the water. The Hueco Bolson Recharge Project, which initially began in 1985, currently recharges 1,700 acre-feet per year of reclaimed water at 10 injection wells and 800 acre-feet per year at an infiltration basin for groundwater recharge. In Colorado, USA, the Colorado River Municipal Water District implemented a project to capture treated municipal effluent from the City of Big Spring, and provide additional advanced treatment prior to blending into their raw surface water delivery system (2012). Advanced treatment of the municipal effluent consisted of MF, RO, and ultraviolet oxidation, producing very high quality water, which is blended with surface