With EPANET, users can perform extended-period simulation of the hydraulic and water quality behavior within pressurized pipe networks, which consist of pipes, nodes (junctions), pumps, valves, storage tanks, and reservoirs. It can be used to track the flow of water in each pipe, the pressure at each node, the height of the water in each tank, a chemical concentration, the age of the water, and source tracing throughout the network during a simulation period.

EPANET's user interface provides a visual network editor that simplifies the process of building pipe network models and editing their properties and data. Various data reporting and visualization tools are used to assist in interpreting the results of a network analysis, including color-coded network maps, data tables, energy usage, reaction, calibration, time series graphs, and profile and contour plots.

(1) Hydraulic Modeling. Full-featured and accurate hydraulic modeling is a prerequisite for doing effective water quality modeling. EPANET contains a state-of-the-art hydraulic analysis engine that includes the following capabilities:

·        System operation based on both simple tank level or timer controls and on complex rule-based controls.

·        No limit on the size of the network that can be analyzed.

·        Computes friction headloss using the Hazen-Williams, Darcy-Weisbach, or Chezy-Manning formulas.

·        Includes minor head losses for bends, fittings, etc.

·        Models constant or variable speed pumps.

·        Computes pumping energy and cost 10.

·        Models various types of valves, including shutoff, check, pressure regulating, and flow control.

·        Allows storage tanks to have any shape (i.e., diameter can vary with height).

·        Considers multiple demand categories at nodes, each with its own pattern of time variation.

·        Models pressure-dependent flow issuing from emitters (sprinkler heads).

(2) Water Quality Modeling. In addition to hydraulic modeling, EPANET provides the following water quality modeling capabilities:

·        Storage tanks as being either complete mix, plug flow, or two-compartment reactors.

·        Movement of a non-reactive tracer material through the network over time.

·        Movement and fate of a reactive material as it grows or decays with time.

·        Age of water throughout a network.

·        Percent of flow from a given node reaching all other nodes over time.

·        Reactions in the bulk flow and at the pipe wall.

·        Accounts for mass transfer limitations when modeling pipe wall reactions.

·        Allows growth or decay reactions to proceed up to a limiting concentration.

·        Employs global reaction rate coefficients that can be modified on a pipe-by-pipe basis.

·        Allows wall reaction rate coefficients to be correlated to pipe roughness.

·        Allows for time-varying concentration or mass inputs at any location in the network.

       (3)Water Security and Resilience Modeling. Extensions to EPANET are available that work with the existing software to simulate the interactions between multiple chemical and biological agents and their interactions with the bulk water and pipe walls in water distribution systems.