单独采样通常会提供一个系统内水质动态的不完整图像，在考虑系统设计和运行的变化时，其帮助有限。EPANET是美国EPA风险降低工程实验室开发的第三代公共领域软件，用于模拟配电系统内的水质。该程序对加压管网内的水力和水质状况进行长周期模拟。在多时间段模拟过程中，它跟踪每条管道中的水流、每个管道接头处的压力、每个水箱中的水高度以及每个接头处溶解物质的浓度。除了浓度，还可以模拟水龄和水源追踪。该软件包实际上由两个程序组成。其中一个使用输入和输出报告的数据文件执行水力和水质模拟。 第二个程序提供了一个图形用户界面，用于交互式运行模拟器，并通过地图、数据表和时间序列图查看其结果。下面列出了该程序的主要功能及其使用方法。

Sampling alone often provides an incomplete picture of water quality dynamics within a system and is of limited help when contemplating changes in system design and operation. EPANET is a third-generation public domain software developed by the US EPA's Risk Reduction Engineering Laboratory for modeling water quality within distribution systems. The program performs extended period simulation of hydraulic and water quality conditions within pressurized pipe networks. It tracks the flow of water in each pipe, the pressure at each pipe junction, the height of water in each tank, and the concentration of a dissolved substance at each junction during a multi-time period simulation. In addition to concentration, water age and source tracing can be simulated. The package actually consists of two programs. One performs the hydraulic and water quality simulations using data files for input and output reports. The second program provides a graphical user interface for interactively running the simulator and viewing its results via maps, data tables, and time series graphs. Major features of the program and how it can be used are listed.