N.Y. Comp. Codes R. & Regs. tit. 21, § 461.17
(l) The conducting of studies and the establishment of quality standards, including:
(p) Approval and execution of contracts or grants with respect to existing structures for:
(ad) Acceptance, rejection, approval or denial, by the chairman or his duly authorized agent, of:
(ar) The operation or minor alteration of the following existing structures, buildings, facilities, mechanical equipment or topographical features involving negligible or no expansion of use beyond that previously existing. This category shall also include all levels of routine office and clerical activities, and the replacement of equipment with substantially identical equipment, except this exemption shall not apply to situations where the selection of substantial quantities of a source or type of material used in a project may have a significant environmental effect. It shall include, but not be limited to, the following authority categories:
(au) Minor alterations in the condition of land, water, vegetation and/or fish and wildlife resources. This exemption shall not apply, for example, to the stockpiling on such lands of quantities of salt, corrosive chemicals, poisonous substances, fertilizers, etc., in quantities which may cause damage to the environment. The degree to which alteration is minor or not dangerous shall be determined on the basis of its actual and potential effect. This exemption shall include such actions as planting and landscaping to improve the general vegetation quality and similar projects. This exemption shall not include any substantial change in the authorized use for land where such change may have a significant environmental effect. It shall include, but not be limited to, the following:
(ax) Administrative and service functions of the Power Authority, including but not limited to: