本文站在政府之防污立場，建構集合住宅污水防制之最適污水排放定價模式，以使得污水排放之社會福利最大。政府如何透過單位用水的定價及污染排放課稅，誘導集合住宅在用水利益最大化考量下，投資最適用水減污設備為本模式之主要內容。政府所訂定之單位用水最適污染排放課稅的性質，及其相對於環境因素之敏感度分析之討論，則為本文的主要研究結果。

This paper is attempted to set up an appropriate taxation model for sewage emission on a compound housing community. The model is believed that it is able to enforce the government’s capacity for decreasing water pollution and increasing social welfare. The researcher places the main content of this model on how, by way of charging users of water on rates based on their different amounts, the government will allure people living on compound housing community to invest pollution-prevention equipments, in consideration of their maximal benefits. The most appropriate and official way to decrease the sewage charge from per unit and the sensitive analysis from the relatively environmental factors are the main results of this paper.