Reviews problem of heat discharges into waterways, especially as related to steam electrical generating plants, and their effects upon river ecological systems. Feb. 13 hearing was held in Portland, Maine; and Feb. 14 hearing was held in Montpelier, Vt., pt.1; Continuation of hearings on water pollution problems caused by electric power plants. Apr. 19 hearing was held in Miami, Fla., pt.2; Appendix includes "Heated Effluents and Effects on Aquatic Life with Emphasis on Fishes," a bibliography by Edward C. Raney and Bruce W. Menzel, Cornell Univ. for Philadelphia Electric Co. and Ichthyological Associates, July 7, 1967 (p. 1285-1374); and "Water Temperatures and Aquatic Life," a report by Charles B. Wurtz and Charles E. Renn, for the Edison Electric Institute, June 1, 1965 (p. 1139-1243), pt.4.