Conducting Dye Tracing
July 12, 2022
What is Dye Tracing
How do you determine if surface water flows into a sinkhole or a karst feature actually discharges at nearby springs or creeks? One option is to conduct a dye tracing event. Dye tracing can be conducted for numerous applications in mapping subsurface connections from sinkholes to discharge points.
Dye tracing is a method of tracking and tracing various flows using dye as a flow tracer when added to a liquid. This method may be used to analyze the flow of the liquid or the transport of objects within the liquid. It tells us about the movement of water and where the water discharges.
Where to Use Dye Tracing
Dye tracing is typically performed in karst terrains such as closed depressions, open throat sinkholes, karst windows, springs, dropouts, and caves.
Dye tracing event examples:
- Dye trace sinkholes through karst windows to springs
- Dye trace sewer manhole to determine the plume movement once it intersects a river
- Dye trace at impoundments/ponds to determine leaks or bypassing
- Dye trace studies at numerous locations to determine subsurface water boundaries for different springs or creeks
- Developing a sinkhole ordinance to reduce flooding issues
A dye trace helps evaluate an injection point (sinkhole, manhole, creek, river) and aims to find the discharge point, a connection between two or more locations, flooding-related issues, and general building aspects. Dyes used for this specific purpose are food grade and non-toxic and range in colors such as green, red, pink, yellow, and more.
An essential first step in dye tracing events is knowing the geology through a karst inventory. Therefore, you can determine what exists in the area and also identify your dye injection points. It is also important to consider if there are already present “dyes.” For example, diesel fuel and antifreeze have a color (dye) added to them and can affect the results of your dye tracing event outcomes.
S&ME Dye Tracing Project
Clark County Pre-School Dye Tracing
The Clark County School System in Winchester, KY plans to build a preschool on property owned by the school system.
Two sinkholes were present at the site. Among additional geotechnical and construction observation and testing services, our team performed a dye tracing study. Dye was injected into the sinkholes to determine if injection points were connected to the discharge locations along the stream (springs) and the potential impact the sinkholes/springs had to site grading and drainage plans.