Abstract: Chemical and microbiological data from four characteristically acidic streams in southern New Jersey were used to evaluate seven factors related to the proclivity of each stream to nitrify under the influence of secondary sewage effluent. pH, water temperature, and dissolved oxygen were used as indicators of a stream conditions while neutralization of alkalinity, nitrogen species trends, BOD/NOD incubations, and nitrifying bacteria densities served as actual nitrification indicators. Hay Stack Brook showed strong evidence for nitrification on the basis of all four nitrification indicators while Landing Creek was nitrifying little if at all. Hammonton Creek is apparently nitrifying, but because of uncertainty in the downstream trends of the nitrogen species, and a lower level of alkalinity neutralization, it is nitrifying less than Hay Stack Brook. Squankum Branch showed some evidence for nitrification on the basis of the BOD/NOD incubations. The acidic character of these streams does not appear to be an exclusive factor in determining whether the stream will undergo nitrification.