1.1 This guide covers the application and subsequent documentation of a ground-water flow model to a particular site or problem. In this context, "ground-water flow model" refers to the application of a mathematical model to the solution of a site-specific ground-water flow problem.

1.2 This guide illustrates the major steps to take in developing a ground-water flow model that reproduces or simulates an aquifer system that has been studied in the field. This guide does not identify particular computer codes, software, or algorithms used in the modeling investigation.

1.3 This guide is specifically written for saturated, isothermal, ground-water flow models. The concepts are applicable to a wide range of models designed to simulate subsurface processes, such as variably saturated flow, flow in fractured media, density-dependent flow, solute transport, and multiphase transport phenomena; however, the details of these other processes are not described in this guide.

1.4 This guide is not intended to be all inclusive. Each ground-water model is unique and may require additional procedures in its development and application. All such additional analyses should be documented, however, in the model report.

1.5 This guide is one of a series of standards on ground-water model applications. Other standards have been prepared on environmental modeling, such as Practice E978.

1.6 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.