Laboratory studies of a chemical denitrification process, namely copper catalyzed ferrous iron reduction of nitrate ion in basic media, demonstrated that denitrification of dilute (10 ppm NO3-N) nitrate solutions to a mixture of innocuous gaseous products was possible. 95 to 98% of the reduced nitrate was in the form of NH3, N2, N2O, NO2 and unreacted NO3. Optimum conditions for reaction were: initial pH near 8 (mole ratio of OH(-)/Fe(++)= 1.5); Mole ratio Fe(++)/NO3(-) =8; Concentration of catalyst 1-5 ppm Cu(++) with the reaction being carried out under anaerobic conditions; Fe(++) ion derived from the sulfate; NaOH used for pH adjustment; and Phosphate removed and carbonate content decreased. Preliminary investigation of reduction in a continuous flow system was encouraging. The by-product magnetite, was easily separated from the treated water in the absence of appreciable phosphate which inhibits its formation. Data from 280 experiments were tabulated. Cursory studies in potable water and secondary effluent indicate the presence of as yet unidentified inhibitory substances.