(1) All applications for new rates or changes in rates must be made to the commission in writing as prescribed by rule.
(2) Upon filing an application for new rates, the utility shall mail a copy of the application to the chief executive officer of the governing body of each county within the service areas included in the rate request. The governing body may petition the commission for leave to intervene in the rate change proceeding, and the commission shall grant intervenor status to any governing body that files a petition.
(3) Each utility’s rates, charges, and customer service policies must be contained in a tariff approved by and on file with the commission.
(4) A utility may only impose and collect those rates and charges approved by the commission for the particular class of service involved. A change in any rate schedule may not be made without commission approval.
(5) If any request for service of a utility shall be for a new class of service not previously approved, the utility may furnish the new class of service and fix and charge just, reasonable, and compensatory rates or charges therefor. A schedule of rates or charges so fixed shall be filed with the commission within 10 days after the service is furnished. The commission may approve such rates or charges as filed or may approve such other rates or charges for the new class of service which it finds are just, reasonable, and compensatory.
(6) An application to establish, increase, or change a rate or charge other than the monthly rates for service pursuant to s. 367.081 or service availability charges pursuant to s. 367.101 must be accompanied by a cost justification. The commission may withhold consent to the operation of any or all portions of the new rate schedules, by a vote to that effect within 60 days giving a reason or statement of good cause for withholding its consent. The commission shall render its final decision on the application within 8 months after the official date of filing. 
