ARSD 74:21:02:59. Census used to determine population served by plant or system

If the population equivalent data are not available or are not higher than the actual population, the census taken each decade or a special census taken by the United States bureau of census shall be used to determine the population served by a water treatment plant, water distribution system, wastewater treatment plant, or wastewater collection system. A system may determine an actual population count served by the system or plant.