The problem of stream pollution is assuming more and more importance in the efforts not only to maintain but also to increase the available supply of potable water for both industrial and domestic uses. Efforts to locate, identify, and eliminate as many sources of contamination as possible are continually being made by many state and national groups. One such large scale investigation has been made by the Public Health Service in the vicinity of Kansas City. All possible sources of pollution of the Missouri, Kansas, and Blue Rivers were located and identified. This investigation was a preliminary effort to determine the feasibility of using IR equipment to detect and thereby accurately to locate sources of stream pollution.