This paper details the development of a photovoltaic reverse osmosis water desalination system for a groundwater well in Bercy, Haiti. The well was constructed to provide potable drinking and agricultural water for the 300-person community. However, its water has a salinity level of 5,290 ppm, rendering it harmful for both human consumption and soil fertility. This reverse osmosis system is designed to be low-cost and operational off-grid while providing 900 gallons per day of desalinated water for the community. The system is composed of a photovoltaic power system, a submersible solar pump, and three reverse osmosis membranes. The system is designed to have a material cost significantly below that of any commercially-available system of similar scale. Furthermore, it has an average water production cost of $1.21/m3 and an average specific energy of 1.2 kWh/m3. Its performance was tested in the laboratory by connecting the desalination module to a DC power supply, demonstrating good agreement with its modeled performance. The installation of the full system with the PV module will take place on-site in the summer of 2016. Following implementation, the system will be monitored and compared against predicted performance. The first attempt is meant to serve as a verification and validation of the system as a whole. However, successful operation within the given cost target could pave the way for wider use of off-grid reverse osmosis systems at many remote locations with limited freshwater access around the world.