N.Y. Comp. Codes R. & Regs. tit. 16, § 255.302
(a) At least 30 days prior to the start of construction or reconstruction of any transmission line or main designed to operate at 125 psig (862 kPa) or more, each operator shall file a letter of intent and a report of specifications identical with Form A of Appendix 7-D of this Title. The letter of intent need not include said specifications where the length of the line is less than the following:
| Class location | Length |
|---|---|
| Class 1 | 1,000 feet (304.8 meters) |
| Class 2 | 500 feet (152.4 meters) |
| Class 3 | 250 feet (76.2 meters) |
| Class 4 | 100 feet (30.5 meters) |
In order to maintain continuity of service due to emergency or exigent circumstances, shorter notice is permissible with prior approval. The letter of intent must include details of these circumstances.