5.1 Data are gathered at groundwater sites for many purposes. Each purpose requires a different combination of data elements. However, it is mandatory that every groundwater site include a minimum set of data elements to uniquely identify that site by precisely locating with coordinates and political regimes, absolutely identifying the owner and data source, and clearly defining the basic site characteristics. This information is described in Practice D5254.

5.2 As a part of a groundwater project, each site requires additional data elements, beyond the minimum set, to assist in the interpretation of the local and areal hydrology. As an example, for a hydrologic reconnaissance study of a groundwater basin, each well or spring site requires basic information concerning construction, water level, yield, geology, and water chemistry. Additional information is needed if the project is a waste facility investigation, usually to satisfy local, state, and federal environmental regulations.

1.1 This guide covers the selection of data elements for the documentation of groundwater sites. The data elements are described in four ASTM standards outlining information that may be collected at groundwater sites. Examples of specific investigations are given with the logic of why to select individual and combinations of data elements to meet the requirements of the studies.

1.2 Systematic and consistent data collection are necessary for the investigation of the availability and the protection or restoration of groundwater resources. The level of detail, precision and bias, and the type of data that need to be collected depend on the objective of the study, the expected complexity of the system, and the resources available for the investigation. This guide presents ideas on what information should be collected for specific st......