1.1 This guide offers a series of options but does not specify a course of action. It should not be used as the sole criterion or basis of comparison and does not replace or relieve professional judgment.

1.2 This guide covers methods that display, as mapped information, the chemical constituents of ground-water samples. Details required by the investigator to use fully the methods are found in the listed references.

1.2.1 The use fo maps to display water-quality data are a common technique to assist in the interpretation of the chemistry of water in aquifer, as the areally distributed values can be easily related to the physical locality by the investigator.

1.2.2 The distribution in an aquifer of chemical constituents from two water sources or of liquids of different densities may be difficult to illustrate explicitly on a two-dimensional map because of stratification in the third dimension. Also, the addition of a vertical cross section may be required (see 4.4).

1.3 Many graphic techniques have been developed by investigators to assist in summarizing and interpreting related data sets. This guide is the fourth document to inform the hydrologists and geochemists about traditional methods for displaying ground-water chemical data.

1.3.1 The initial guide (Guide D 5738) described the category of water-analysis diagrams that use pattern and pictorial methods as a basis for displaying each of the individual chemical components determined from the analysis of a single sample of natural ground water.

1.3.2 The second guide (Guide D 5754) described the category of water-analysis diagrams that use two-dimensional trilinear graphs to display, on a single diagram, the common chemical components from two or more analyses of natural ground water.

1.3.3 The third guide (Guide D 5877) presented methods that graphically display chemical analyses of multiple ground-water samples, discrete values, as well as those reduced to comprehensive summaries or parameters.

1.4 Notations have been incorporated within the illustrations of this guide to assist the user in understanding how the maps are constructed. These notations would not be required on a map designed for inclusion in a project document.

Note 1-Use of trade names in this guide is for identification purposes only and does not constitute endorsement by ASTM.