(A) Any waterworks company or any sewage disposal system company may submit an application to the public utilities commission for an increase or decrease in any rate or charge for, respectively, water or sewage treatment, if both of the following conditions are met:

1. (1) The water or sewage treatment is provided to the company by either of the following:

   1. (a) A municipal corporation or other local governmental unit of this state whose rates are not subject to regulation by the commission;
   2. (b) Another waterworks company, or another sewage disposal system company, that is a public utility and whose rates for the water, or the sewage treatment, have been approved by the commission pursuant to an application filed under section 4909.18 of the Revised Code.
2. (2) The change in rate or charge is based solely on a change in the cost to the company of the water or the sewage treatment. Sections 4909.18 and 4909.19 of the Revised Code do not apply to any application filed under this section. An application shall be accompanied by evidence of the new rates and charges charged the company by a provider described in division (A)(1)(a) or (b) of this section.