Nothing in this chapter prevents municipal, state or federal authorities from adopting and administering more stringent requirements regarding performance standards or permitted uses within use districts established by the commission or within districts overlapping the districts established pursuant to this chapter. Where there is a conflict between a provision adopted under this chapter and any other municipal, state or federal requirement applicable to the same land or water areas within the corridor, the more restrictive provision takes precedence. All performance standards, rules and regulations proposed for hearing by the commission must be submitted to the Commissioner of Environmental Protection, the Department of Agriculture, Conservation and Forestry, the Greater Portland Council of Governments and the Southern Maine Regional Planning Commission at least 7 days prior to the hearing for review and comment. The commission may not adopt any rule establishing air or water quality standards within the corridor in conflict with the rules of the Department of Environmental Protection without the prior approval of the Board of Environmental Protection. [PL 2011, c. 655, Pt. JJ, §37 (AMD); PL 2011, c. 655, Pt. JJ, §41 (AFF); PL 2011, c. 657, Pt. W, §5 (REV).]