DYE TRACING FUNDAMENTALS Ralph O. Ewers, Ph.D. Peter J. Idstein, M.S. ewc@mis.net

DYE TRACING FUNDAMENTALS Questions Answered By Tracing Where are the groundwater basin boundaries ? Where does the water go ? How long does it take to get there ? What happens along the way ?

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 Springs 19 Stream Locations 3 Domestic Wells 6 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 Injection Sinking Stream

Dye Injection Backhoe Trench

Dye Injection Sinkhole

Dye Injection Well

Don’t pour it in like this Dye Injection via Well Don’t pour it in like this

Because when you add the necessary water…… 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 The Tremi Method Tremi Tube

Dye Injection via Well Tremi Tube Upward Flush With Potable Water

Dye Injection via Well Tremi Tube Downward Flush With Potable Water Upward 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 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 Analyses Laboratory Protocol

Washing

Drying

Weighing

Elution

Elution

Analysis

Analysis

Analysis

There’s No Truth Like TRACER Truth Quinlan, 85

End Part 3