As used in ORS 454.782 to 454.800:
(1) “Commission” means the Environmental Quality Commission.
(2) “Department” means the Department of Environmental Quality.
(3) “Septage” means the domestic liquid and solid sewage pumped from septic tanks, cesspools, holding tanks, vault toilets, chemical toilets or other similar domestic sewage treatment components or systems and other sewage sludge not derived at sewage treatment plants.