(a) The board is hereby authorized to fix and revise from time to time rates, fees, and other charges for the use of and for the services furnished or to be furnished by any water system, sewer system, or sewage disposal system or parts thereof owned, operated, or maintained by the board. Such rates, fees and charges shall be so fixed and revised as to provide funds sufficient at all times:
(b) Such rates, fees, and charges shall be just and equitable and may be based or computed either upon the quantity of water used or upon the number and size of water or sewer connections or upon the number and kind of plumbing fixtures in use in the premises connected with the water system or the sewer system or upon the number or average number of persons residing or working in or otherwise connected with such premises or upon the type or character of such premises or upon any other factor affecting the use of the facilities furnished or upon any combination of the foregoing factors.
(c) Any charges for sewer services, including services to manufacturing and industrial plants, obtaining all or a part of their water supply from sources other than the water system of the board may be determined by gauging or metering or in any other manner approved by the board.
(d) In cases where the character of the sewage from any manufacturing or industrial plant, building, or premises is such that it imposes an unreasonable burden upon the sewer system, an additional charge may be made therefor, or the board may, if it deems it advisable, compel such manufacturing or industrial plant, building, or premises to treat such sewage in such manner as shall be specified by the board before discharging such sewage into any sewers owned or maintained by the board.
(e) The board may combine any water system and sewer system owned and operated by it and may provide a single schedule of rates, fees, and charges for the services and facilities furnished by such combined system. It may also provide for reductions in such schedule in cases where water is furnished to premises which are not connected with the sewer system of the board.