(a) Duties and authority of the board include, to:

(1) Adopt, modify, repeal, and promulgate rules in accordance with the Uniform Administrative Procedures Act, compiled in title 4, chapter 5, and, after due notice, to enforce rules and regulations which the board deems necessary for proper administration of §§ 68-221-1007 — 68-221-1012;

(2) Investigate and determine the financial condition of water systems and wastewater facilities under its jurisdiction;

(3) Effect the adoption of user rates necessary for the self-sufficient operation of certain water systems and wastewater facilities and to negotiate the consolidation of certain water systems and wastewater facilities pursuant to §§ 68-221-1007 — 68-221-1012;

(4) Ameliorate the burden of rate increases effected under this part borne by low-income customers of water systems and wastewater facilities through the establishment and administration of a rate subsidy program to the extent state appropriations are available;

(5) Issue subpoenas requiring attendance of witnesses and production of such evidence as requested; administer oaths; and take such testimony as the board deems necessary in fulfilling its purpose. In case of the refusal of any person or entity to obey a notice of hearing or subpoena issued by the board under this part, the chancery court of Davidson County shall have jurisdiction upon application of the board to issue an order requiring such person to appear and testify or produce evidence as the case may require, and any failure to obey such order of the court may be punished by such court as contempt;

(6) In the case of public water systems, investigate, with the assistance of the department and the comptroller of the treasury, and determine the financial, technical, and managerial capacity of the systems to comply with the requirements of the federal and state acts; and to require systems to take appropriate action to correct any deficiencies in such areas, including, but not limited to, changes in ownership, management, accounting, rates, maintenance, consolidation, alternative water supply, or other procedures. The board also may approve or disapprove such corrections as a condition for the receipt of assistance under § 68-221-1206(a)(3);

(7) Establish, adopt and promulgate, in accordance with the Uniform Administrative Procedures Act, rules to define excessive water losses for public water systems; and

(8) In the case of public water systems, to investigate public water systems whose water loss as reported in the public water system's audit is excessive as established by rules promulgated by the board and to require those public water systems to take appropriate actions to reduce water loss to an acceptable level as determined by the board.

(b) The board shall be authorized to act only as to those water systems and wastewater facilities brought before it upon recommendation of the comptroller of the treasury as provided in § 68-221-1010.