Nothing in this subchapter or rules adopted under it preempts or otherwise affects any ordinance, regulation or rule of a political subdivision, limits the authority of a political subdivision to adopt or enforce any ordinance, regulation, or rule that it is authorized to adopt or enforce pursuant to the Constitution of Maine and laws of this State, or limits the authority of any department or agency of this State to adopt any rule or enforce any law or rule of this State that it is authorized to adopt or enforce under the laws of this State. This subchapter does not abridge rights of action or remedies in equity, under common law, or as provided by law.   [PL 1989, c. 464, §3 (NEW).]