The rates to be charged for the products or services of any public utility as fixed in, or determined in the manner provided by, any franchise or amendment or renewal thereof, shall be sufficient only to provide a reasonable return upon the fair value of the property of such utility used, useful and reasonably necessary in furnishing the product or service for the furnishing of which the franchise, amendment or renewal is, or may have been, granted; and whether it be so specified in the ordinance or not, all franchises, and all amendments and renewals thereof, shall be subject to the right of the City:
(a) To repeal the same by ordinance for misuse, non-use or failure to begin construction within the time prescribed, or otherwise to comply with the terms prescribed;
(b) To require extensions of plant, equipment and service, and to establish standards of service and quality of products, subject only to the right to a reasonable return upon the fair value of the property as in this section hereinbefore defined;
(c) To require the maintenance of plant, equipment and fixtures at the highest practicable standard of efficiency;
(d) To examine and audit the accounts and other records of the utility at any time;
(e) To terminate the franchise at any time and acquire by purchase, condemnation, or otherwise, all property of the utility within the City or elsewhere used in or useful for the operation of the utility within the City;
(f) To impose such other reasonable regulations as may be conducive to the safety, welfare and accommodation of the public.