由于干旱、严格的废水排放要求、养分回收、开发新水源的成本以及防止海水入侵，全球范围内城市废水的再利用正在增加。本文讨论的是一个简单的经济模型，可以更好地理解为什么废水在某些情况下可重复使用，而在其他情况下则不可重复使用。废水的特性会影响有关再利用的决策。水的质量最终决定了它是否可以再利用。城市废水的再利用可用于多种用途，包括:农业生产；工业加工；工业冷却；地下水补给；娱乐以及城市消费。包括1个参考，数字。

Reuse of municipal wastewater is increasing worldwide due to droughts, stringent wastewater discharge requirements, nutrient recycling, costs of developing new sources, and prevention of saltwater intrusion. Discussed is a simple economic model that will enable better understanding of why wastewater is reused in certain circumstances but not in others. The characteristics of wastewater influence decisions concerning reuse. It is the quality of the water that ultimately determines whether or not it will be reused. Reuse of municipal wastewaters can be used for a variety of purposes including the following: agricultural production; industrial processing; industrial cooling; groundwater recharge; recreation; and municipal consumption. Includes 1 reference, figures.