Section 16. Nothing in this act is intended to prohibit the following activities, uses or facilities: In all ocean sanctuaries except the Cape Cod Ocean Sanctuary the planning, construction, reconstruction, operation and maintenance of industrial liquid coolant discharge and intake systems and all other activities, uses and facilities associated with the generation, transmission, and distribution of electrical power, provided that all certificates, licenses, permits and approvals required by law are obtained therefor, and provided, further, that such activities, uses and facilities shall not be undertaken or located except in compliance with any applicable general or special statutes, rules, regulations or orders lawfully promulgated; the operation and maintenance of existing municipal, commercial or industrial facilities and discharges where such discharges or facilities have been approved and licensed by appropriate federal and state agencies; the laying of cables approved by the department of public utilities or the department of telecommunications and cable; channel and shore protection projects, navigation aids, projects authorized under chapter ninety-one, deemed to be of public necessity and convenience, contingent upon obtaining the required approval wherever applicable by the United States Army Corps of Engineers, the division of water pollution control, the department of environmental protection, or the office; other improvements not specifically prohibited by said sections 12B to 16K, inclusive and section 18 which are approved by appropriate federal and state agencies and which are consistent with said sections 12B to 16K, inclusive and section 18, including the maintenance and repair of existing structures or uses, but not any change or extension of such structures or uses unless otherwise permitted by said sections 12B to 16K, inclusive and section 18; the harvesting and propagation of fish and shellfish in all forms, so long as the office and the office of fish and game are satisfied that such activities are carried on in accordance with sound conservation practices; temporary educational and scientific activities jointly permitted by appropriate state agencies; and the extraction of sand and gravel from the seabed and subsoil of a sanctuary for the purposes of shore protection or beach restoration, provided, however, that such shore protection or beach restoration is approved by the department of environmental protection.

Notwithstanding any general or special law to the contrary, municipal wastewater treatment facilities may discharge into the ocean sanctuary if the discharge is approved under section 16G and approved and licensed by the appropriate federal and state agencies. In the North Shore Ocean Sanctuary, discharges shall be permitted from municipal waste treatment facilities if construction is commenced prior to January first, nineteen hundred and seventy-eight or if a city or town has been awarded a federal or state grant for construction of a wastewater treatment facility prior to January first, nineteen hundred and seventy-eight, if the waste has been treated by the best practical means, if such a discharge is in accordance with plans developed under the provisions of clause (10) of section twenty-seven of chapter twenty-one, and such plans are subject to the approval of the division of water pollution control after a public hearing conducted by said division.