1. As used in this section, the following terms mean:
(1) "Large water public utility" , a public utility:
(a) That regularly provides water service to more than eight thousand customer connections, regularly provides sewer service to more than eight thousand customer connections, or regularly provides a combination of either to more than eight thousand customer connections; and
(b) That provides safe and adequate service but shall not include a sewer district established under Section 30(a), Article VI of the Missouri Constitution, sewer districts established under the provisions of chapter 204 , 249 , or 250 , public water supply districts established under the provisions of chapter 247 , or municipalities that own water or sewer systems;
(2) "Small water utility" , a public utility that regularly provides water service or sewer service to eight thousand or fewer customer connections; a water district established under the provisions of chapter 247 that regularly provides water or sewer service to eight thousand or fewer customer connections; a sewer district established under the provisions of chapter 204 , 249 , or 250 that regularly provides sewer service to eight thousand or fewer customer connections; or a water system or sewer system owned by a municipality that regularly provides water service or sewer service to eight thousand or fewer customer connections; and all other entities that regularly provide water service or sewer service to eight thousand or fewer customer connections.
2. The procedures contained in this section may be chosen by a large water public utility, and if so chosen shall be used by the public service commission to establish the ratemaking rate base of a small water utility during an acquisition, provided that the public service commission independently concludes that a certificate of convenience and necessity should be granted pursuant to section 393.170 . In making such determination, the commission may take into account rates that may result from such acquisition.
3. (1) An appraisal shall be performed by no less than two appraisers. One appraiser shall be appointed by the small water utility, one appraiser shall be appointed by the large water public utility, and the third appraiser may be appointed by the public service commission. Each of the appraisers shall be a disinterested person who is a certified general appraiser under chapter 339 .
(2) The appraisers shall:
(a) Jointly prepare a fair and independent appraisal of the fair market value of the water system and/or sewer system, along with supporting rationale. The determination of fair market value shall be in accordance with Missouri law and with the Uniform Standards of Professional Appraisal Practice; and
(b) Return only their final appraisal, in writing and at the same time, to the small water utility and large water public utility in a reasonable and timely manner. However, nothing shall prohibit the appraisers from issuing a corrected report if factual errors are identified subsequent to the issuance of the appraisal.
(3) If all three appraisers cannot agree as to the appraised value, the appraisal, when signed by two of the appraisers, constitutes a good and valid appraisal.
4. Nothing in this section shall prohibit a party from declining to proceed with an acquisition or be deemed as establishing the final purchase price of an acquisition.
5. (1) The lesser of the purchase price or the appraised value, together with the reasonable and prudent transaction, closing, and transition costs incurred by the large water public utility, shall constitute the ratemaking rate base for the small water utility as acquired by the acquiring large water public utility; provided, however, that if the small water utility is a public utility subject to chapter 386 and the small water utility completed a rate case prior to the acquisition, the public service commission may select as the ratemaking rate base for the small water utility as acquired by the acquiring large water public utility a ratemaking rate base in between:
(a) The lesser of the purchase price or the appraised value, together with the reasonable and prudent transaction, closing, and transition costs incurred by the large water public utility unless such transaction, closing, and transition costs are elsewhere recoverable in rates; and
(b) The ratemaking rate base of the small water utility as ordered by the public service commission in the small water utility's last previous rate case as adjusted by improvements and depreciation reserve since the previous rate case together with the transaction, closing, and transition costs incurred by the large water public utility unless such transaction, closing, and transition costs are elsewhere recoverable in rates. If the small water utility and large water public utility proceed with the sale, any past-due fees due to the state from the small water utility or its customers under chapter 640 or 644 shall be resolved prior to the transfer of ownership or the liability for such past-due fees becomes the responsibility of the large water public utility. Such fees shall not be included in the large water public utility's rate base.
(2) The public service commission shall issue its decision establishing the ratemaking rate base of the small water utility in its order approving the acquisition. For any acquisition with an appraised value of five million dollars or less, such decision shall be issued within six months from the submission of the application by the large public water utility to acquire the small water utility.
(3) Prior to the expiration of the six-month period, the public service commission staff or the office of public counsel may request, upon a showing of good cause, from the public service commission an extension for approval of the application for an additional thirty days.
6. Upon the date of the acquisition of a small water utility by a large water public utility, whether or not the procedures for establishing ratemaking rate base provided by this section have been utilized, the small water utility shall, for ratemaking purposes, become part of an existing service area, as defined by the public service commission, of the acquiring large water public utility that is either contiguous to the small water utility, the closest geographically to the small water utility, or best suited due to operational or other factors. This consolidation shall be approved by the public service commission in its order approving the acquisition.
7. Any new permit issued pursuant to chapters 640 and 644 , when a small water utility is acquired by a large water public utility, shall include a plan to resolve all outstanding permit compliance issues. After the transfer of ownership, the acquiring large public water utility shall continue providing service to all customers that were served by the small water utility at the time of sale.
8. This section is intended for the specific and unique purpose of determining the ratemaking rate base of small water utilities and shall be exclusively applied to large water public utilities in the acquisition of a small water utility. A large water public utility's choice to comply with the provisions of this section does not automatically ensure that the transaction is in the public interest. The public service commission shall independently determine whether the acquisition is in the public interest, regardless of whether the matter has been put to a vote of the small water utility's ratepayers. This section is not intended to apply beyond its specific purpose and shall not be construed in any manner to apply to electric corporations, natural gas corporations, or any other utility regulated by the public service commission.
9. The commission shall promulgate rules to implement the provisions of this section. Any rule or portion of a rule, as that term is defined in section 536.010 , that is created under the authority delegated in this section shall become effective only if it complies with and is subject to all of the provisions of chapter 536 and, if applicable, section 536.028 . This section and chapter 536 are nonseverable and if any of the powers vested with the general assembly pursuant to chapter 536 to review, to delay the effective date, or to disapprove and annul a rule are subsequently held unconstitutional, then the grant of rulemaking authority and any rule proposed or adopted after August 28, 2025, shall be invalid and void.