Me. Rev. Stat. tit. 35-A, § 6414

The rates of a standard district must be established in accordance with chapter 61. The rates must be sufficient to provide revenue to the standard district to carry out the purposes of its incorporation, without the need for any financial assistance from any municipality, other than the normal payment of water charges for services rendered and any loan or loans provided to the district for initial funds as set forth in section 6412. All customers of a standard district shall pay to the treasurer or other designated officer of the district the rates established by the district.