The department shall take all actions necessary to respond to a substantial threat of a discharge of oil or hazardous substances into the waters of this state or to collect, investigate, perform surveillance over, remove, contain, treat, or disperse oil or hazardous substances discharged into waters of the state. The department shall keep a record of all necessary expenses incurred in carrying out any project or activity authorized under this section, including a reasonable charge for the services performed by the state's personnel and the state's equipment and materials utilized. The authority granted hereunder shall be limited to projects and activities which are designed to protect the public interest or public property. The department may use staff, equipment, and material under its control, or contract with others, to carry out its responsibilities under this section.