Okla. Admin. Code § 252:645-1-2
In addition to the definitions contained in the Environmental Quality Code (27A O.S. § 2-1-101 et seq.), the following words and terms, when used in this Chapter, shall have the following meaning, unless the context clearly indicates otherwise:
"DEQ" means the Department of Environmental Quality.
"Septage" means either liquid or solid material removed from a septic tank, aerobic treatment system, holding tank, portable toilet, Type III marine sanitation device, or similar treatment works that receives only sewage.
"Sensitive Watersheds" means sensitive waters and watersheds as listed in the OKR 10 Construction Stormwater General Permit.
"Sewage" means wastewater that originates as human waste from certain activities including using toilet facilities, washing, bathing, preparing foods and washing laundry. Sewage, as used in this Chapter, does not include industrial solids or wastewater, waste from restaurant grease traps, or waste from car wash mud traps.
Okla. Admin. Code § 252:645-1-2