To sustain its long-term water needs, the City of Rio Rancho, New Mexico has undertaken a feasibility study to develop a water reuse strategy that will significantly expand the use of reclaimed water, reduce groundwater withdrawals, and provide advanced treatment for aquifer recharge. Membrane treatment processes are proving to be promising technologies for wastewater purification and reclamation. This phase of the study involved pilot testing of an Integrated Membrane System (IMS) process. The process consisted of membrane bioreactors (MBR) to provide tertiary treated water followed by reverse osmosis (RO) to provide purified water that can be injected into the groundwater. supplies. The pilot study was started in May, 2004 and completed in December, 2004. The reclaimed water pilot testing will achieve the following research needs: demonstrate that MBR effluent meets reclaimed water quality goals for commercial, landscape irrigation and industrial uses as well as surface water discharge requirements; demonstrate the proposed IMS system (MBR?RO) meets water quality goals for Safe Drinking Water Act and New Mexico Water Quality Control Commission standards for groundwater recharge; provide training to City of Rio Rancho wastewater treatment operators on modern technologies (MBR and RO); evaluate pretreatment and post treatment (including disinfection) requirements and concentrate disposal options for the IMS; and, develop cost estimates (capital and O&M) for the proposed water reuse train. Pilot testing was conducted at the City of Rio Rancho Wastewater Treatment Plant No. 2 (WWTP #2). This facility currently utilizes a conventional activated sludge process to treat approximately 3.0 MGD of municipal wastewater. The existing plant consists of influent headworks (grit removal and mechanical screening), anoxic and aeration basins, conventional clarifiers, and ultraviolet disinfection. Treatment at the pilot study consisted of prescreening, anoxic and aerobic basins, MBRs, and reverse osmosis. Screening equipment and membrane bioreactors and biological treatment basins are discussed. Includes table, figures.