It should be easily detected with widely available and simple technology;

It should be present in concentrations well above background concentrations of

the same constituent in the natural system that is being studied; and

It should not modify the hydraulic conductivity or other properties of the

medium being studied.

Three classes of water tracing agents are available:

Natural labels

flora and fauna, principally micro organisms

ions in solution

environmental isotopes

Pulses

natural pulses of discharge, solutes and sediment

artificially generated pulses

Artificial labels

radiometrically detectable substances

dyes

salts

spores.

Artificial fluorescent dyes are the principal and most successful water tracers for

conduit flow aquifers at the present time. Dyes are injected intentionally into ground water

for the purpose of tracing the movement of fluids in active ground water systems. Under

ideal circumstances, dyes can be injected into a perennial sinking stream on the facility site.

If a stream is not available, tank trucks of water and dye can be injected at the following sites

in a karst terrane, listed in decreasing order of desirability:

1.

Sinkhole with a hole at its bottom.

2.

Sinkhole without a hole at its bottom; excavation may reveal a hole that can be

used.

3.

Losing stream reach with intermittent flow.

4.

Class V stormwater drainage well.

5.

Well drilled on a fracture trace or a fracture trace intersection.

November 1992

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