(1) The department may determine that a change or addition to an application submitted by the applicant pursuant to ARM 17.20.805 or 17.20.806 requires an amendment to the original application and additional filing fees as provided by 75-20-213 , MCA, if the change or addition would be likely to involve the following:
(a) increased or significantly different environmental impacts than would have been likely based on the information contained in the original application;
(b) significant changes in the basis of the need for a linear facility; or
(c) significant changes in the economics of alternatives to the proposed facility as required by ARM 17.20.1301, 17.20.1302, 17.20.1304, 17.20.1305, and 17.20.1311.
(2) The department may determine that a new application and a filing fee are required if the extensive nature of a change or the timing of the notification of a change or addition to the original application would not allow the department, or the other agencies listed in 75-20-216 , MCA, to discharge their duties and responsibilities under the Act and these rules under the statutory time requirements and filing fee or under contractual terms pursuant to 75-20-215 , MCA. If a new application and a filing fee are required, processing of the original application shall be terminated. If the total filing fee was paid at the time of filing, unexpended portions of the fee shall be returned to the applicant or credited to the new fee at the applicant's request if a new application is to be filed. For an application being processed under a contract pursuant to 75-20-215 , MCA, the applicant shall be billed for the department's expenses up to the date of termination. Any studies completed or partially completed at the time of termination that are relevant to an amended or new application shall not be duplicated.
(3) The department shall inform the applicant in writing, within 30 days of receipt of information provided under ARM 17.20.805 or 17.20.806, of a determination that a change or addition to an original application requires an amendment or a new application.
(4) The applicant shall give notice upon filing an amendment or a new application as set forth in 75-20-211 , MCA.
(5) An amendment to an application shall explain any change or addition in a degree of detail comparable to that required for an original application.