The possible health hazard resulting from irrigation with sewage-polluted water of vegetables normally consumed raw has long concerned public health officials. Conflicting opinions have evolved on the degree of danger caused by this practice. Commonly accepted objectives for sewage irrigation practices have not been developed, nor have there been established generally approved standards for the quality of irrigation water. In the South Platte River Basin downstream from and north of Denver to Brighton, Colorado, the largest use of water is for agriculture. In the area immediately north of Denver many varieties of 'salad vegetables' were raised. At the time of this study these vegetables were irrigated with polluted water diverted via four main supply ditches from the South Platte River just below entry of the Denver Northside sewage treatment plant effluent. Other inadequately treated municipal and industrial effluents contributed to the overall pollution in this vicinity. During 1963-64 a field sampling and laboratory analysis program was conducted on vegetables, the soils in which they were grown, and the waters with which they were irrigated. Samples of vegetables, soils, and waters were analyzed for three bacterial indices of pollution.