Water tracing in karst areas is somewhat of a Missouri tradition. Old timers used wheat chaff or other particles to prove connections from sinking streams and caves to springs and water wells. Fluorescent tracers were first used to a limited extent in the early 1900s by geologists and cavers. The use of fluorescent tracers has increased dramatically in the last few years partly due to new and improved analytical techniques, but also because of an increased need for data generated. People who routinely use tracers today include: consultants, government agencies, developers, cavers, sewer workers and the general public. As more and more people use tracers, the potential for interference or the overlapping of traces increases as well. With hundreds of unregulated dye injections each year, false positive traces are inevitable.

The Missouri Department of Natural Resources' Missouri Geological Survey currently maintains a dye trace database, which contains information on nearly 500 dye traces that have been completed over the years. The division adds approximately 10 traces of its own each year to the database, but numerous other traces that are completed each year by people not employed by staff or other entities, are not reported as they should be. Geologists, hydrologists and other technicians and professionals need this information for environmental protection efforts. The locations of injections are particularly valuable in interpreting other dye traces in the same general area. The division already stores and dispenses this information to a limited extent, but we simply do not know where and when many dye injections are occurring.

In July 1991, Senate Bill 221 was signed into law. This bill, which was an amendment to the Water Well Driller's Act (1986), contains new requirements for persons involved in water tracing. In part, the bill reads as follows:

  • 256.621. All persons engaged in groundwater or surface water tracing, for any purpose, shall register with the division. This registration shall be renewed annually. The registrant shall report in writing all proposed injections of tracers to the division prior to actual injection. Written and graphical documentation of traces shall be provided to the division within thirty days of completion of each trace. The division shall maintain records for all injections and traces reported and will provide this information to interested parties upon request at the cost of reproduction.

If you intend to complete a water trace or have questions, please contact the Geological Survey Program at 573-368-2161 or gspeg@dnr.mo.gov.