本文阐述了1986年《安全饮用水法》修正案可能对小型供水系统产生的影响，重点介绍了三家使用地下水作为唯一供水来源的小型公用事业公司。其中之一，蒙大拿州的山水公司，面临着将其水源之一重新指定为地表水源的可能性——这可能是一个昂贵的前景。加利福尼亚州范登堡村的另一家公用事业公司的问题是，要达到总三卤甲烷的预期最低最高污染物水平。第三家公用事业公司，加利福尼亚州圣保拉水厂，可能不需要因新规定而进行任何更改。通过仔细研究潜在的法规遵从性问题，小型系统可以在可能需要的地方规划成本效益高的项目。包括表、图。

This article illustrates how the 1986 amendments to the Safe Drinking Water Act may affect small water systems by focusing on three small utilities that use ground water as the sole source of supply. One of these, Mountain Water Company in Montana, faces the possibility of having one of its water sources redesignated as a surface source - a potentially expensive prospect. The problem of another utility, in Vandenberg Village, Calif., involves meeting the expected lower maximum contaminant level for total trihalomethanes. The third utility, Santa Paula Water Works (Calif.), may require no changes as a result of the new regulations. By carefully studying potential compliance problems, small systems can plan for cost-effective projects where they are likely to be needed. Includes table, figure.