(1) All remedial investigations conducted under the authority of this section shall: (a) meet the substantive requirements of CERCLA; (b) follow procedures established by the National Contingency Plan to avoid inconsistent state and federal action; and (c) include recommendations for remedial action.

(a) meet the substantive requirements of CERCLA;

(b) follow procedures established by the National Contingency Plan to avoid inconsistent state and federal action; and

(c) include recommendations for remedial action.

(2) (a) After determining that a hazardous substance release is occurring from a national priority list site or proposed national priority list site, and identifying responsible parties under Section 19-6-312, the executive director shall make reasonable efforts to reach an agreement with the identified responsible parties to conduct a remedial investigation. (b) The executive director may define in the agreement the scope of the remedial investigation, the form of the report, and the time limits for completion of the investigation. (c) If any responsible party fails to perform as required under an agreement entered under the authority of this section, the executive director may take action to enforce the agreement.

(a) After determining that a hazardous substance release is occurring from a national priority list site or proposed national priority list site, and identifying responsible parties under Section 19-6-312, the executive director shall make reasonable efforts to reach an agreement with the identified responsible parties to conduct a remedial investigation.

(b) The executive director may define in the agreement the scope of the remedial investigation, the form of the report, and the time limits for completion of the investigation.

(c) If any responsible party fails to perform as required under an agreement entered under the authority of this section, the executive director may take action to enforce the agreement.

(3) (a) If the executive director is unable to reach an agreement with one or more responsible parties to perform a remedial investigation, the executive director may issue an order directing one or more responsible parties to perform the remedial investigation. (b) The executive director may define in the order the scope of the remedial investigation, the form of the report, and the time limits for completion of the remedial investigation.

(a) If the executive director is unable to reach an agreement with one or more responsible parties to perform a remedial investigation, the executive director may issue an order directing one or more responsible parties to perform the remedial investigation.

(b) The executive director may define in the order the scope of the remedial investigation, the form of the report, and the time limits for completion of the remedial investigation.

(4) (a) If the executive director is unable to obtain an agreement with one or more responsible parties to perform a remedial investigation, chooses not to order any responsible party to perform the remedial investigation, or determines that the remedial investigation performed by a responsible party does not meet the substantive requirements of CERCLA, he may direct the department to conduct or correct the remedial investigation. (b) The executive director may recover the costs incurred in conducting a remedial investigation from responsible parties according to the standards contained in Section 19-6-316.

(a) If the executive director is unable to obtain an agreement with one or more responsible parties to perform a remedial investigation, chooses not to order any responsible party to perform the remedial investigation, or determines that the remedial investigation performed by a responsible party does not meet the substantive requirements of CERCLA, he may direct the department to conduct or correct the remedial investigation.

(b) The executive director may recover the costs incurred in conducting a remedial investigation from responsible parties according to the standards contained in Section 19-6-316.