N.Y. Comp. Codes R. & Regs. tit. 21, § 5202.3 – Variances.

(a) The board shall have authority to grant variances from the strict provisions of this Part, upon application therefor and upon a showing of:
1. (1) unnecessary hardship; and
2. (2) that an alternative measure or method to be adopted will meet the objectives of the standards.
(b) In granting such variance, the board shall provide that such variance shall be for a stated period of time.