(a) The commission is hereby given power to investigate all rates, methods and practices of public utilities subject to the provisions of this chapter; to require them to conform to the laws of this state and to all rules, regulations and orders of the commission not contrary to law; and to require copies of all reports, rates, classifications, schedules and timetables in effect and used by the public utility or other person to be filed with the commission, and all other information desired by the commission relating to the investigation and requirements, including inventories of all property in such form and detail as the commission may prescribe. The commission may compel obedience to its lawful orders by mandamus or injunction or other proper proceedings in the name of the state in any circuit court having jurisdiction of the parties or of the subject matter, or the Supreme Court of Appeals directly, and the proceedings shall have priority over all pending cases. The commission may change any intrastate rate, charge or toll which is unjust or unreasonable or any interstate charge with respect to matters of a purely local nature which have not been regulated by or pursuant to an act of Congress and may prescribe a rate, charge or toll that is just and reasonable, and change or prohibit any practice, device or method of service in order to prevent undue discrimination or favoritism between persons and between localities and between commodities for a like and contemporaneous service. But in no case shall the rate, toll or charge be more than the service is reasonably worth, considering the cost of the service. Every order entered by the commission shall continue in force until the expiration of the time, if any, named by the commission in the order, or until revoked or modified by the commission, unless the order is suspended, modified or revoked by order or decree of a court of competent jurisdiction: Provided, That in the case of utilities used by emergency shelter providers, the commission shall prescribe such rates, charges or tolls that are the lowest available. "Emergency shelter provider" means any nonprofit entity which provides temporary emergency housing and services to the homeless or to victims of domestic violence or other abuse.
(b) Notwithstanding any other provision of this code to the contrary, rates are not discriminatory if, when considering the debt costs associated with a future water or sewer project which would not benefit existing customers, the commission establishes rates which ensure that the future customers to be served by the new project are solely responsible for the debt costs associated with the project.
(c) Notwithstanding any other provision of this code to the contrary, the jurisdiction of the commission over water and/or sewer utilities that are political subdivisions of the state providing a separate or combined services and having at least four thousand five hundred customers and annual combined gross revenues of $3 million or more shall be limited to those powers enumerated in subsection (b), section one of this article.