Dye Study

Public drinking water systems demonstrating surface water influence are examined using fluorescent tracer dyes. Studies involve introducing nontoxic biodegradable dyes into potential local and/or regional sources of surface water (as well as other contaminant sources) to assess connection to groundwater supplying system wells or springs.

This study plan map concisely assembles much of the spatial information needed to design such an investigation. A separate locator map accompanies this map in the report to clarify the location of the study area. The map illustrates streams, sinkholes, and septic systems (associated with homes in aerial photos) in proximity to the subject well. The map also conveys information about general groundwater flow direction (from water table heights) as well as surface topography (from U.S. Geological Survey quadrangles) that may influence the selection of contamination sources for dye tracing.

Several other data layers (that do not appear in this map) are also frequently used to aid in making design decisions. They include land use/land cover, wastewater facilities, and property ownership. Road and stream layers (with good attribute data) are important components of dye study maps because they orient the map reader to the location of subject material, facilitate the selection of potential stream dye locations, and guide field reconnaissance efforts.

The most interesting part about this map is that it took less than 20 minutes to create. Many maps illustrating variations (various scales or important layers) of the same data are often required to convey all necessary information regarding a subject well investigation (not to mention investigations of other subject wells). ArcGIS 9 greatly facilitates the production of multiple maps of this nature because labels (text and symbols) can be automatically placed, view extents can be bookmarked, layers can be automatically turned on and off at different scales, and a common layout can be used repeatedly.

This map is similar to one recently included in a dye study plan. It was modified here to exclude sensitive data. The original map layout was no longer available because other maps were generated using the same map file and saving the map after each revision. A complete readjustment of the map layout was required. The ability to rapidly create maps illustrating specific features of common data is an invaluable tool for water-related investigations. Investment of time in the initial map setup is returned repeatedly in time saved with each subsequent spatial analysis or map creation.