A comprehensive study of the data collected as part of the environmental Technical Specifications program for Units 2 and 3 of the Peach Bottom Nuclear Power Plant was conducted for the Office of Regulatory Research of the U.S. Nuclear Regulatory Commission. The program included an analysis of both the hydrothermal and ecological monitoring data collected from 1967 through 1976. Specific recommendations are made for improving both the present hydrothermal and ecological monitoring programs. Hydrothermal monitoring would be improved by more complete reporting of in-plant operating parameters. In addition, the present boat surveys could be discontinued, and monitoring efforts could be directed toward expanding the present thermograph network. Ecological monitoring programs were judged to be of high quality because standardized collection techniques, consistent reporting formats, and statistical analyses were performed on all of the data and were presented in an annual report. Sampling for all trophic groups was adequate for the purposes of assessing power plant induced perturbations. Considering the extensive period of preoperational data (six years) and operational data (three years) available for analysis, consideration could be given to reducing monitoring effort after data have been collected for a period when both units are operating at full capacity. In this way, an assessment of the potential ecological impact of the Peach Bottom facility can be made under conditions of maximum plant induced perturbations.