(a) The governing body of a local government may enter into an energy savings performance contract in accordance with this chapter.
(b) Each energy or water conservation or usage measure must comply with current local, state, and federal construction, plumbing, and environmental codes and regulations. Notwithstanding Section 302.001, an energy savings performance contract may not include improvements or equipment that allow or cause water from any condensing, cooling, or industrial process or any system of nonpotable usage over which public water supply system officials do not have sanitary control to be returned to the potable water supply.