Chemical analyses of 2,802 water samples from 784 of approximately 1,500 community water systems in the State of New York are presented. The data were collected from November 1970 to May 1975 and were originally released in a series of four U.S. Geological Survey open-file reports during the mid-1970's. The data were obtained and compiled by the Geological Survey and have been used by the State of New York in determining community system compliance with applicable drinking-water standards. The analyses include physical properties, major and minor constituents, pesticide residues, and radiochemical data. Some bottom-material analyses are included.