The commissioner shall monitor implementation of closure and remediation plans. In addition to any other remedy available by law, if the commissioner determines, after opportunity for public hearing, that any party responsible for the implementation of a plan has failed substantially to meet the established time schedule or has failed to execute the provisions of the plan, the commissioner may: [1989, c. 890, Pt. B, §240 (AMD); 1989, c. 890, Pt. A, §40 (AFF).]