Scope of Work for MW6-MW21 Low Flow Tracer Test
July 2002
Goal of the Test:
Compare arrival times of dye from MW-6 area and the MW-21 area to IC Spring.
This might elucidate whether a pathway from MW-6 is truly upgradient from MW-
21 as suggested by the phreatic water levels, or is on a separate pathway to the
spring. If dye from MW-21 arrives significantly before dye from MW-6 then a
longer pathway (upgradient) from MW-6 may be inferred. If dyes arrive nearly
simultaneously, or MW-6 dye precedes MW-21 dye, then separate flow paths are
inferred.
Set up and Preparation
- Prepare 50 gram injection aliquot of fluorescein.
- Prepare 225 gram injection aliquot of Rhodamine WT.
- Prepare standards for fluorometer.
- Take daily dye background samples at IC spring.
- Take background samples of 00-587, NN-300, 00-300, 00-370, OO-
125, and NN-12.
- Take background samples of Quarry and Slaughterhouse springs.
- Set up ISCO samplers sampling for dye at IC spring.
- Stage 30 gal. of clean water at MW-6 and MW-21 for flushing.
- Stage flexible aluminum injections tubes in MW-6 and MW-21 for injection.
End of the tubes should be at the 799' elevation in each well.
Dye Injection
- Monitor weather and schedule test for 3-day dry period.
- Set up peristaltic pump at each well.
- Simultaneously inject fluorescein into MW-21 and Rhodamine WT into
MW-6.
- Flush each well synchronously with 30 gal. of clean water.
Field Sampling
- Set ISCO auto samplers to begin sampling two hours before dye injection.
- Set sample frequency to alternating two hourly samples (1 hour
coverage).
- Obtain IC spring flows and calculate estimated travel time. Samplers
should run for twice the estimated sample travel time, or until
breakthrough curves for both dyes are established.
- Sample injection wells right after flushing, once at 8 hours after injection,
and once more 20-24 hours after injection.
- Sample 00587, NN-300, 00-300, 00-370, 00-125, and NN-12 twice
daily.
- Sample Quarry and Slaughterhouse springs twice daily
Dye Analysis
- Dye samples are taken to office warehouse and refrigerated.
- Dye samples are prepared for dye analysis according to SOP and dye
analysis is performed with fluorometer.
- Dye results are plotted and decision is made whether sufficient
breakthrough data are obtained. If no dye is seen within twice the
estimated travel time, sampling will continue for two more days on every 2
hour interval.
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