Me. Rev. Stat. tit. 38, § 1209

Any sanitary district formed under this chapter shall be authorized to impose charges, in addition to any other assessments now lawfully imposed by general law, for the use of sewers, sewer systems and treatment works, and the trustees may adopt such rules and regulations as may be necessary or convenient to carry out the purposes of such district. All incidental powers, rights and privileges necessary to the accomplishment of the purposes of the district are granted to the district and its trustees, including the right of its trustees to determine when and where sewerage and treatment facilities and disposal units are needed and when and where the same shall be constructed.