N.Y. Comp. Codes R. & Regs. tit. 21, § 890.50 – Service metering.

(a) Owners of water supply systems serving the public (purveyors) in the basin that distribute water supplies in excess of an average of 100,000 gallons per day during any 30-day period shall install, or require to be installed, water meters incident to the provision or maintenance of service at the retail level.
1. (1) Meters shall be installed so as to record water use at all service connections.
2. (2) Water furnished for fire suppression purposes shall be exempt from metering, provided that fire suppression (sprinkler) systems are equipped with detector check or flow detection devices.
3. (3) Water removed from fire hydrants shall be exempt from metering unless otherwise required by a purveyor, or state or local government.
(b)
(c) Water use shall be recorded or measured by means of a metering device that conforms to the performance specifications of the American Water Works Association. Purveyors shall adopt and implement a program for periodic maintenance, calibration and replacement of meters to ensure meter accuracy.
(d) Water charges collected by purveyors shall be based in part on metered usage.
(e) It is recommended that, at least once a year, each purveyor:
1. (1) provide each metered residential customer with information on savings available through water conservation; and
2. (2) explain different methods of residential water conservation and their cost-effectiveness, and the availability of water conservation devices.
(f) Installation of meters at existing unmetered connections shall be completed within 10 years of the effective date of this section [April 30, 1987].
(g) To avoid duplication of effort and to insure proper enforcement of this section, the executive director is hereby authorized to enter into administrative agreements with the Delaware Department of Natural Resources and Environmental Control, New Jersey Department of Environmental Protection, New York Department of Health, Pennsylvania Department of Environmental Protection, and other state agencies where appropriate, authorizing such agencies to administer and enforce the provisions of this section to the extent practicable and to adopt such rules and regulations of procedure as may be necessary to insure the proper administration and enforcement of this section. In the absence of an administrative agreement, the commission shall serve as the administration and enforcement agency for this section.