N.Y. Comp. Codes R. & Regs. tit. 6, § 209.5 – Monitoring of operations.

(a) The owner or operator of any process subject to the provisions of this Part for which an application for a permit to construct is received by the commissioner after October 23, 1974, must:
1. (1) install, calibrate, maintain and operate weighing devices which can be used to determine daily the weight of aluminum and anode produced; and
2. (2) maintain a record of daily production rates of aluminum and anodes, raw material feed rates and cell or potline voltages.
(b) The owner or operator of any process subject to the provisions of this Part for which an application for a permit to construct was received by the commissioner before October 24, 1974, must:
1. (1) install, calibrate, maintain and operate weighing devices which can be used to determine the average daily weight of aluminum and anode produced during a calendar month; and
2. (2) maintain a record of average daily production rates of aluminum and anodes.
(c) Weighing devices used to comply with the requirements of this section must have an accuracy of ±5.0 percent over their operating range.
(d) Records required by this section must be retained for at least two years following the date on which the measurements were made.