The cost of supplying water consists, to a very large extent, of fixed costs (capital costs and personnel costs) and only to a small extent of variable costs that depend on the amount of water consumed (mainly energy and chemicals).
供水成本大部分是固定成本（资本成本和人员成本），只有小部分可变成本取决于水资源的消费量（主要是能源和化学品）。