(1) Upon the receipt of an application complying with Section 58-33-120, the commission shall promptly fix a date for the commencement of a public hearing, not less than sixty nor more than ninety days after the receipt, and complete the hearing and issue an order on the merits within one hundred eighty days of receipt of the application.
(2) The testimony presented at the hearing may be presented in writing or orally, provided that the commission may make rules designed to exclude repetitive, redundant or irrelevant testimony; however, all expert testimony must be prefiled with the commission, with responsive expert testimony of non-applicants being received with enough time for the applicant to meaningfully respond, and in no case would expert testimony be filed less than twenty days before the hearing.
(3) 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 proposed change in the facility would result in any significant increase in any environmental impact of the facility or a substantial change in the location of all or a portion of the facility; provided, that the Public Service Commission shall forward a copy of the application to all parties upon the filing of an application.