Okla. Stat. tit. 27A, § 27A-2-6-107: Definition – Gray water

A. "Gray water" means untreated household wastewater that has

not come in contact with toilet waste and includes wastewater from

bathtubs, showers, washbasins, clothes washing machines and laundry

tubs and untreated municipal wastewater limited to wastewater

captured from municipal splash pads and water used by fire

departments for cleaning equipment and vehicles. Gray water shall

not include wastewater from kitchen sinks, kitchen dishwashers or

laundry water from the washing of material soiled with human

excreta, such as diapers.

B. The definition of gray water in subsection A of this section

shall apply only in municipalities enacting ordinances regulating

the use of gray water within the limits of their municipal

boundaries.

C. The Department of Environmental Quality shall not require a

permit for reusing captured wastewater from a splash pad for

irrigation or land application, with or without intermediary storage

units, if the splash pad is within the jurisdictional boundaries of

a municipality or county that has enacted an ordinance or resolution

regulating the management of wastewater from splash pads and the

ordinance or resolution, at a minimum, includes the same conditions

and restrictions as set forth in paragraphs 5, 8, 11, and 12 of

subsection A of Section 2-6-108 of this title. For purposes of this

subsection, the term "splash pad" shall also include facilities

known as spray pools, spray pads, and spray grounds.