Response costs means all costs of removal or remedial action incurred and to be incurred by the United States at a facility pursuant to section 104 of CERCLA, 42 U.S.C. 9604, including, but not limited to, all costs of investigation and information gathering, planning and implementing a response action, administration, enforcement, litigation, interest and indirect costs.
40 CFR § 304.12
Terms not defined in this section have the meaning given by section 101 of CERCLA, 42 U.S.C. 9601, or the National Oil and Hazardous Substances Pollution Contingency Plan, 40 CFR part 300. All time deadlines in this part are specified in calendar days and shall be computed in the manner described in Rule 6 of the Federal Rules of Civil Procedure.