This paper presents information on a full-scale small system built for the village of Greenport in Suffolk County, New York, as part of the USEPA cooperative agreement. Information on design parameters for the anion exchange system, its economics (both site-specific and process related), plant performance and cost are presented. The paper follows the process describing the ion exchange process, pilot plants, design criteria, plant operation described in step by step fashion, and costs. Through pilot plant studies, the use of countercurrent regeneration to eliminate nitrate leakage was found to be comparable to the traditional downflow regeneration. Careful review of the regeneration steps allowed 25 percent of the regeneration water to be used as nitrate-free water for the next regeneration. Additionally, due to wastewater disposal difficulties, further reduction of waste volume was accomplished using a conductivity meter to distinguish waste from recharge water.