This bill establishes an exemption from the Maine Revised Statutes, Title 30-A, sections 4364 to 4364-C for municipalities that are located wholly or partially on an island or peninsula and rely on a primary drinking water supply derived from a sole source aquifer. The bill provides that such a municipality is exempt from these provisions until a licensed geologist has analyzed the groundwater and septic capacity within the municipality or a particular area within the municipality and determined that it can support an increase in housing density. If the licensed geologist determines in the geologist's evaluation report that the area can support an increase in housing, the municipality is required to comply with the provisions of Title 30-A, sections 4364 to 4364-C, to the extent that the licensed geologist determines the area can support the increase. If the geologist's evaluation report indicates the area cannot support an increase in housing density, the municipality is exempt from Title 30-A, sections 4364 to 4364-C. The Department of Economic and Community Development and the Department of Environmental Protection are directed to adopt rules to implement this legislation. The Department of Environmental Protection has rule-making authority limited to establishing criteria by which municipalities may select a licensed geologist and other rules necessary to perform the geological evaluation required under this legislation.