A. 
The purpose of the Four Corners Sewer District Usage Fee Regulation is to provide a means for the Town of Groton, acting through the Sewer Commission, to raise sufficient revenues to pay the expenses associated with the administration, operation, construction, maintenance, and repair of the Four Corners Sewer System, including collecting sewers, interceptor sewers, pumping stations, force mains and system appurtenances to serve the Four Corners Sewer System in the Town of Groton; the cost of land and easements, the cost of initial and additional capacity in the Town of Ayer's facilities when it becomes necessary, the Town of Ayer connection charge and for the treatment and disposal of its wastewater at the Town of Ayer's wastewater treatment plant.
B. 
The Sewer Commission shall establish just and equitable annual usage fees based upon water usage for the use of the Four Corners Sewer System. The Commission shall review and adjust the fees on an annual basis; however, the Sewer Commission shall have the right to calculate and bill owners on a per-wastewater basis. In doing so, the Sewer Commission will measure the volume of wastewater flowing from connected property to the public sewer, convert it to "water" units (as hereafter defined), and bill by the same method as if billed on a water usage basis. When the usage fee is to be billed upon a wastewater usage basis, the Commission may use estimates of the volume of wastewater flowing from the connected property during the billing period. The estimate shall be based upon periodic measurements of the flow for a duration which, in the judgment of the Groton Sewer Commission, are sufficient to provide a reasonably accurate estimate of the actual flow for a billing period.
C. 
Usage fees for the use of the Four Corners Sewer shall be paid by every owner of improved property connected to the public sewer.