(a) Except as otherwise provided in subsections (c) and (d) of this Code section, the owner or operator of a building containing residential units may install equipment or use an economic allocation methodology to determine the quantity of water that is provided to the tenants and used in the common areas of such a building; and the owner of such a building may charge tenants separately for water and waste-water service based on usage as determined through the use of such equipment or allocation methodology.

(b) Except as otherwise provided in subsections (c) and (d) of this Code section, the owner or operator of a building containing residential units may charge tenants separately for water and waste-water service, provided that the total amount of the charges to the tenants of such a building shall not exceed the total charges paid by the owner or operator for water and waste-water service for such building plus a reasonable fee for establishing, servicing, and billing for water and waste-water service and provided, further, that the terms of the charges are disclosed to the tenants prior to any contractual agreement.

(c) All new multiunit residential buildings permitted on or after July 1, 2012, shall be constructed in a manner which will permit the measurement by a county, municipal, or other public water system or by the owner or operator of water use by each unit. This subsection shall not apply to any building constructed or permitted prior to July 1, 2012, which is thereafter: (1) renovated; or (2) following a casualty or condemnation, renovated or rebuilt.

(d) All new multiunit retail and light industrial buildings permitted or with a pending permit application on or after July 1, 2012, shall be constructed in a manner which will permit the measurement by the owner or operator of water use by each unit. This subsection shall not apply to any building constructed or permitted prior to July 1, 2012, which is thereafter: (1) renovated; or (2) following a casualty or condemnation, renovated or rebuilt. This subsection is not intended to apply to newly constructed multiunit office buildings or office components of mixed use developments. Multiunit office buildings and the office component of mixed use developments may seek reimbursement from office tenants for water and waste-water use through an economic allocation which approximates the water use of each tenant based on square footage. The retail component of a mixed use development shall be constructed in a manner which will permit the measurement by the owner or operator of water use by each retail unit.

(e)

(1) A county, municipal, or other public water system, if applicable, or the owner or operator of a building which is subject to subsection (c) or (d) of this Code section shall seek reimbursement for water and waste-water usage by the units through an economic allocation methodology which is based on the measured quantity of water used by each unit.

(2) The owner or operator of such a building which includes common areas for the benefit of the units may also seek reimbursement for common area water and waste-water use through an economic allocation which approximates the portion of the common area water and waste-water services allocable to each unit.

(3) The total amount of charges to the units under paragraphs (1) and (2) of this subsection shall not exceed the total charges paid by the owner or operator for water and waste-water service for the building, plus a reasonable fee for establishing, servicing, and billing water and waste-water consumption.

(4) The director shall be empowered to issue a temporary waiver of this subsection upon a showing by an owner or operator of a building subject to this subsection that compliance with this subsection has temporarily become impracticable due to circumstances beyond the control of the owner or operator. Such waiver shall be limited in duration to the period during which such circumstances remain in effect and beyond the control of the owner or operator to change.

(5) The owner or operator who seeks reimbursement for water and waste-water usage as required by this chapter shall be relieved of liability for actions or inactions that occur as a result of billing or meter-reading errors by an unaffiliated third-party billing or meter-reading company.

(f) A county, municipal, or other public water system shall be prohibited from charging any fee or levy for the installation or use of privately owned meters or other devices which measure or assist in the measurement of water use under subsection (c) of this Code section; provided, however, that a county, municipal, or other public water system shall be permitted to charge a fee or levy for the installation or use of publicly owned meters or other devices which measure or assist in the measurement of water use.

(g) Subsections (c), (d), and (e) of this Code section shall not apply to any construction of a building the permit for which was granted prior to July 1, 2012.