The Village of Chelsea, Michigan, population of 4,200 residents, needed to upgrade or replace their existing iron removal plant to provide additional capacity for the growth they were experiencing and to replace old equipment and facilities. Tetra Tech MPS (TTMPS) was retained to examine the options for upgrading the treatment facility and to apply for State of Michigan Drinking Water Revolving Fund (DWRF) loan monies for the project. The first step in this process, preparation of a Project Plan, was completed in 1999. This Plan examined the options for treatment plant upgrades. The most cost-effective alternative was the construction of a low pressure, reverse osmosis (RO) membrane treatment system for softening of the groundwater supply. This option was compared with conventional lime softening and the existing treatment for iron removal. Significant public input was solicited throughout the planning and design process to determine whether the users wanted to upgrade their water treatment process from iron removal only to softening. The public response was overwhelmingly in favor of upgrading to softening treatment. Based on this response, the Village elected to proceed with the membrane softening option. The Michigan Department of Environmental Quality (MDEQ) required that a pilot study be done for all new membrane treatment plants. At the beginning of the project, there were no other membrane softening plants in the State either in operation or design. Because of the strict funding deadlines for the DWRF program, and the Village's need to get new capacity on line as soon as possible, there was not sufficient time to conduct a pilot study. Fortunately, TTMPS was simultaneously completing a pilot study for a low pressure, RO treatment system in a neighboring community with a similar quality source of groundwater. Based on the results from this pilot study, the State waived the requirement for a separate pilot study for Chelsea provided that the same equipment was used. The State did stipulate that the equipment used must have National Sanitation Foundation (NSF) certification. Design of the new treatment plant began in January, 2000 and was complete by May, 2000. Bidding of the project took place in the fall of 2000, with construction commencing in December, 2000 and completed by the summer of 2002. The plant began producing softened water in July, 2002. Includes tables, figures.