Period covered by reports is irregular Vols. 1-3, 1964/65-1966/67 issued by the Ontario Water Resources Commission; v. 6, 1970/71, by the Water Quality Branch (called 1974- Water Resources Branch) of the Ontario Ministry of the Environment (called 1993- Ministry of Environment and Energy) Vols. 1-3, 1964/65-1966/67 compiled by the Water Quality Surveys Branch Vol. 13 (1975/77) varies: Water quality series Vol. 13 is a special study with title: Water quality data collected for the Pollution From Land Use Activities Reference Group (PLUARG) study, 1975, 1976, 1977 Vols. 19- issued in 6 pts.: [pt. 1] Central region; [pt. 2] Northeastern region; [pt. 3] Northwestern region; [pt. 4] Southeastern region; [pt. 5] Southwestern region; [pt. 6] West Central region Title varies: 1964/65, Water quality data 12