In addition to any other authority granted by law, if the Department of Environmental Quality finds that ground water is contaminated with a hazardous substance originating at a land disposal site, the department may require cleanup of the hazardous substance pursuant to authority under ORS § 465.200 to 465.485. As used in this section, ‘hazardous substance’ has the meaning given that term in ORS § 465.200. [1993 c.526 § 3]