Geological Survey Program

Environmental Geology Section

Water Tracing Methodology

The Division of Geology and Land Survey (DGLS) water tracing methodologies have been developed over a period of four decades, to improve the quality of data collected and the interpretation of that data. The standardized process is summarized below:

• Field work is begun to determine locations of suitable monitoring and injection points that have the potential to produce useful data.
• Activated carbon and/or cotton packets are placed in select springs and surface water monitoring points as backgrounds , to determine if fluorescent compounds are present in the water which could interfere with the tracers to be used in the study.
• Water samples may be used to either supplement or replace the carbon and cotton packets data as conditions warrant.
• These packets are normally collected and replaced on a weekly basis thereafter.
• The background packets (as well as subsequently collected packets) and water samples are analyzed at the DGLS Water Tracing Laboratory in Rolla, Missouri, using a synchronously scanning spectrofluorometer.
• The specific tracers and amounts to be used in a particular study are selected only after interpretation of background analysis.
• Tracers are injected at locations selected to yield useful data.
• As the subsequent packets and/or water samples are analyzed, the information obtained from each analysis is evaluated to determine if the injected tracers are present at each monitoring point.
• If, in the opinion of the investigator, a connection has been established between the injection point and a monitoring point not located in the same water flow downstream, the evidence is presented to the DGLS Water Tracing Committee for review.
• If the DGLS Water tracing Committee concurs with the investigator, the dye trace is approved by the committee and the pertinent information is entered into the DGLS Dyetrace Database, which is a summary of the dyetrace results.
• If the DGLS Water Tracing Committee does not concur, the trace is not approved and the investigator either collects supplemental data to resubmit or abandons the attempt.
• Whether the trace is approved or not approved , the data are archived in the DGLS dyetrace files.

If you have any questions please contact the Water Tracing Committee.