The objectives of this study were to determine if the concentration of nitrate/nitrite in human milk is unsafe for consumption by infants under 6 months of age, and to compare the concentration of nitrate/nitrite in private well-water used as a primary source of drinking water to the concentration of nitrate/nitrite in human breast milk. Participants included 20 women who were either exclusively breast feeding or breast and bottle feeding, and 24 women who were formula feeding. Five of the 20 breast feeders indicated rural well-water as their source of drinking water, and 6 of the 24 formula feeders used private well-water supplies. Three of the eleven wells had nitrate levels greater than the Health Advisory Limit (HAL), but none of these 3 women offered their infants supplemental water or prepared formula using the high nitrate content well-water. Nine of the 20 women who reported exclusive or partial breast feeding had analysis of water, breast milk, and urine samples done. The urine nitrate levels were equal to or up to 69 times greater than the nitrate concentration in breast milk. Analyses of the breast milk indicated in all cases the nitrate concentration was markedly below the HAL.