Every water-works corporation shall on or before November 15, 1935, submit for the approval of this commission proposed amendments to its tariff schedules setting forth rules and regulations covering the construction and maintenance of service pipes, such rules and regulations, among other things, to provide:
(a) The minimum depth at which all service pipes shall be laid. The depth so fixed to be sufficient to prevent freezing.(b) The size and kind of pipe and apparatus to be installed, service pipes to be at least three- quarters inch in diameter except under unusual circumstances which shall be clearly defined.(c) All connections of service pipes with the transmission mains where the covering over the main is less than five foot shall be made on the side of the main and the service pipe shall in no case have less covering than the main.N.Y. Comp. Codes R. & Regs. Tit. 16 § 502.1