Nitrate is a ground water contaminant that results from fertilizers and septic tank wastes. Many treatment methods have been investigated for nitrate removal but only ion exchange, reverse osmosis and electrodialysis are considered to be practical. Of these three methods, ion exchange is the most economical and thereby will be the method selected by most communities. The most important aspect of ion exchange treatment is the level of sulfate in the source water because ion exchange resins are more selective for sulfate removal than nitrate removal. Cost comparison of nitrate removal methods are presented and compared with other treatment techniques such as lime softening, ion exchange softening, and activated alumina treatment for fluoride removal.