The St. Regis Mohawk Tribe, located on the Mohawk Nation at Akwesasne along the New York/Canadian border, owns and operates a community water system that currently serves a population of approximately 1500, using the St. Lawrence River as the source of supply. Treatment consists of diatomaceous earth (DE) filtration and chlorine disinfection. The existing system is undersized for current water uses and has difficulty meeting demands during periods of peak water use and poor water quality. O'Brien & Gere assisted the Tribe in design of plant upgrades/expansion and in securing $2.5 million in grant funding for the project. The project involved developing an innovative treatment strategy to meet water quality goals while maintaining simple operations and low maintenance. Four alternative treatment processes were reviewed: continued use of DE filters, slow sand filtration, conventional treatment with a high rate package plant, and contact filtration using a two-stage, continuously backwashing, deep bed sand filter. The ability to meet treated water quality for highly variable influent water turbidity and color was the primary reason for exploring alternatives to DE filters. Deep bed contact filters were selected as the optimum system to achieve the identified treatment objectives. The process offers the advantages of conventional filtration but is far simpler to operate and maintain. Includes tables, figures.