Oregon Revised Statutes Public Health and Safety § 466.645

(1) Any person liable for a spill or release or threatened spill or release under ORS 466.640 shall immediately clean up the spill or release under the direction of the Department of Environmental Quality. Any person liable for a spill or release or a threatened spill or release shall immediately initiate cleanup, whether or not the department has directed the cleanup. The department may require the responsible person to undertake such investigations, monitoring, surveys, testing and other information gathering as the department considers necessary or appropriate to:

(2) If any person liable under ORS 466.640 does not immediately commence and promptly and adequately complete the cleanup, the department may clean up, or contract for the cleanup of the spill or release or the threatened spill or release.

(3) Whenever the department is authorized to act under subsection (2) of this section, the department directly or by contract may undertake such investigations, monitoring, surveys, testing and other information gathering as it may deem appropriate to identify the existence and extent of the spill or release, the source and nature of oil or hazardous material involved and the extent of danger to the public health, safety, welfare or the environment. In addition, the department directly or by contract may undertake such planning, fiscal, economic, engineering and other studies and investigations it may deem appropriate to plan and direct cleanup actions, to recover the costs thereof and legal costs and to enforce the provisions of ORS 466.605 to 466.680.