USE OF DYE TRACING TO DETERMINE THE DIRECTION OF GROUND-WATER FLOW
DYE TRACING FUNDAMENTALS
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Transcript of DYE TRACING FUNDAMENTALS
DYE TRACING FUNDAMENTALS
Ralph O. Ewers, Ph.D.Peter J. Idstein, [email protected]
DYE TRACING FUNDAMENTALS
• Where are the groundwater basin boundaries ?• Where does the water go ?• How long does it take to get there ?• What happens along the way ?
Questions Answered By Tracing
DYE TRACING FUNDAMENTALS
• Monitoring Locations and Reconnaissance• Background Determination• Dye Injection• Dye Monitoring• Dye Analyses
Fluorescent Dyes
Dye Properties
• Non-Toxic• Soluble in water – thus easy to introduce• Unmistakably detectable at extremely low
concentrations• Durable in the aquifer environment• Easily quantified• A proven record of use in karst aquifers• Inexpensive to obtain and analyze
Activated Carbon Dye Receptors
Monitoring Locations
• Springs• Streams• Cave Streams and Karst Windows • Production/Domestic Wells• Monitoring Wells
A Typical Monitoring Scheme
Reconnaissance Essentials
• Search for springs along streams surrounding the site.
• Search for springs in stream valleys across the adjacent divide from the site.
• Select stream monitoring sites to insure that hidden springs will be monitored.
• Look for streams in caves.• Assess nearby wells of all types.• Look for dye introduction points that bracket the
site.
A Typical Monitoring Scheme
24 Springs19 Stream Locations3 Domestic Wells6 Monitoring Wells
Dye Background Determination
• One week exposure for dye receptors (typical)
Dye Background Determination
• One week exposure for dye receptors (typical)• Two sampling rounds (exchanges) are usual
Dye Background Determination
• One week exposure for dye receptors (typical)• Two sampling rounds (exchanges) are usual• Analyze for all potentially useful fluorescent
dyes
Dye Background Determination
• One week exposure for dye receptors (typical)• Two sampling rounds (exchanges) are usual• Analyze for all potentially useful fluorescent
dyes
• Choose the dye to be used for tracing based upon dye background and dye properties
Dye InjectionSinking Stream
Dye InjectionBackhoe Trench
Dye InjectionSinkhole
Dye InjectionWell
Dye Injection via Well
Don’t pour it in like this
Dye Injection via Well
Because when you add the necessary water……
Dye Injection via Well
You will get this !
Dye Injection via Well
Stagnant Dye Mass
Well Injection System
Dye Injection via Well
Tremi TubeThe Tremi Method
Dye Injection via Well
Tremi Tube
Upward Flush With Potable Water
Dye Injection via Well
Tremi Tube
Upward Flush With Potable Water
Downward Flush With Potable Water
Dye Monitoring
Dye Monitoring
Dye Monitoring
• Always exchange dye receptors NEVER remove them
Dye Monitoring
• Always exchange dye receptors NEVER remove them
• Typical intervals are weekly or bi-weekly
Dye Monitoring
• Always exchange dye receptors NEVER remove them
• Typical intervals are weekly or bi-weekly• Disposable gloves are typically worn
Dye Monitoring
• Always exchange dye receptors NEVER remove them
• Typical intervals are weekly or bi-weekly• Disposable gloves are typically worn • Transport of dye receptors is by express at
ambient temperature
Dye Monitoring
• Always exchange dye receptors NEVER remove them
• Typical intervals are weekly or bi-weekly• Disposable gloves are typically worn • Transport of dye receptors is by express at
ambient temperature • Water samples are often used as to provide
additional custody assurance
Dye Analyses
• Synchronous spectrofluorophotometry is the standard analytical technique
Dye Analyses
• Synchronous spectrofluorophotometry is the standard analytical technique
• Modern instruments provide part-per-trillion sensitivity for fluorescent dyes
Dye Analyses
• Synchronous spectrofluorophotometry is the standard analytical technique
• Modern instruments provide part-per-trillion sensitivity for fluorescent dyes
• Activated carbon dye receptors provide 400 to 1000 fold increase in dye concentration relative to the concentration in the ambient water
Dye AnalysesLaboratory Protocol
Washing
Drying
Weighing
Elution
Elution
Analysis
Analysis
Analysis
There’s No Truth Like TTRRAACCEERR Truth
Quinlan, 85
End
Part 3