(a)
1. The commission shall, either upon request or upon its own motion, fix rates which are just, reasonable, compensatory, and not unfairly discriminatory. In every such proceeding, the commission shall consider the value and quality of the service and the cost of providing the service, which shall include, but not be limited to, debt interest; the requirements of the utility for working capital; maintenance, depreciation, tax, and operating expenses incurred in the operation of all property used and useful in the public service; and a fair return on the investment of the utility in property used and useful in the public service. However, the commission shall not allow the inclusion of contributions-in-aid-of-construction in the rate base of any utility during a rate proceeding, nor shall the commission impute prospective future contributions-in-aid-of-construction against the utility's investment in property used and useful in the public service; and accumulated depreciation on such contributions-in-aid-of-construction shall not be used to reduce the rate base, nor shall depreciation on such contributed assets be considered a cost of providing utility service.
2. For purposes of such proceedings, the commission shall consider utility property, including land acquired or facilities constructed or to be constructed within a reasonable time in the future, not to exceed 24 months after the end of the historic base year used to set final rates unless a longer period is approved by the commission, to be used and useful in the public service, if:
a. Such property is needed to serve current customers;
b. Such property is needed to serve customers 5 years after the end of the test year used in the commission's final order on a rate request as provided in subsection (6) at a growth rate for equivalent residential connections not to exceed 5 percent per year; or
c. Such property is needed to serve customers more than 5 full years after the end of the test year used in the commission's final order on a rate request as provided in subsection (6) only to the extent that the utility presents clear and convincing evidence to justify such consideration.
Notwithstanding the provisions of this paragraph, the commission shall approve rates for service which allow a utility to recover from customers the full amount of environmental compliance costs. Such rates may not include charges for allowances for funds prudently invested or similar charges. For purposes of this requirement, the term "environmental compliance costs" includes all reasonable expenses and fair return on any prudent investment incurred by a utility in complying with the requirements or conditions contained in any permitting, enforcement, or similar decisions of the United States Environmental Protection Agency, the Department of Environmental Protection, a water management district, or any other governmental entity with similar regulatory jurisdiction.