Tennessee Code Title 68. Health, Safety and Environmental Protection § 68-221-510

(a) The authority shall establish the monthly payment due from the municipality to the state necessary for the municipality to fund the project.

(b) The municipality shall establish a water service fee and/or such ad valorem taxes as necessary to provide funds sufficient to pay the monthly payments established, plus the costs of operation and maintenance of the water works, including depreciation according to generally accepted accounting principles, and any other debt service expense of the system.

(c) It is the intent that the water service fee be the primary source of payment of such costs and payments.

(d) The water service fee shall be adjusted periodically by the municipality so that such fees will be sufficient to pay such monthly payments and costs, but will create a minimum excess.

(e) It is the intent that such water service fees shall only be for the purpose of providing for such monthly payments and costs.

(f) The water service fee shall be expressed as a single charge on the utility bill.