N.Y. Public Service Law § 123
2. On an application for an amendment of a certificate, the commission shall hold a hearing in the same manner as a hearing is held on an application for a certificate if the change in the facility to be authorized would result in any material increase in any environmental impact of the facility or a substantial change in the location of all or a portion of such facility other than as provided in the alternates set forth in the application. * 3. Unless otherwise stipulated by the applicant:
(c) for purposes of this subdivision, the following terms shall have the following meanings: