Geology 210

Aquifer Characterization


California State University, Sacramento


Week 6



- High K slug test solution (Butler and Garnett, 2000)



Upon completion of this unit students should be able to:

  • Evaluate oscillatory slug tests using a spreadsheet solution (Kansas Geological Survey- Butler and Garnett, 2000)


Reading for week 6:

High K slug test method (Butler and Garnett, 2000)



Quick guide to Butler solution:

Butler spreadsheet guide



Tuesday evening (Aug. 28):

  • Use the spreadsheet developed by Butler and Garnett to analyze an under-damped slug test.

  • Start by accessing the paper on-line

  • Click on live links in the Butler and Garnett paper to download the spreadsheet solution

  • Process your data from MW-3A or MW-1a, and input information to the spreadsheet, solve for K

MW-3A pneumatic test

MW-1A 4 ft slug


Weekend activities (Sept. 1 - 2):

  • Conduct a 24 hour drawdown and recovery test at the CSUS wellfield.  We will start the test Saturday morning, and end the test 24 hours later (Sunday morning). 

Results from 24 hour aquifer test


Assignment for week 6:

For Saturday (Sept. 1)

- Plot the results of the step test.  Did we exceed the capacity of the aquifer to produce water?


- Use the data from our distance drawdown test to estimate well efficiency (see week 4 results).  Look at actual drawdown in the pumped well.  Use nearby wells (MW-1A, MW-3A) to project an ideal drawdown to the pumped well.

- Analyze the pneumatic slug test data that we collected on Saturday, August 11.  Use an under-damped solution to account for the elastic response (oscillation) that we saw in the test.  Your solution can be graphical (see the iterative method by Van der Kamp in Fetter, 4th ed.) or you can use a computer solution (Butler's Kansas Geological Survey solution)


Format of the report:  Answer this question in 5 pages or less (cover letter to the client and figures are extra, and may go beyond 5 pages).  Please double space your report, with normal margins and standard font (times or arial).  Refer to all figures in the text.  Citations are optional.  Use appropriate technical writing style, and include the following sections in your report:

Cover page (letter to the client):  Provide a cover letter and company logo that introduces your report to the client.


Introduction and purpose: State the purpose of the study: Use an overdamped solution to estimate K from the slug tests we conducted on Saturday, Aug. 11.


Hydrogeologic setting: Geologic, hydrologic, land use, construction, hazards, etc. as appropriate.  Which wells did you use?


Methods: Field methods: step test, 3 hour drawdown test and slug tests were all used!  Describe your method of solution (either Van der camp or Butler) for the slug test.


Results: Summarize results. 


Conclusions and recommendations 

  • Based on your analysis of oscillatory slug tests at the CSUS wellfield, what is your estimate of hydraulic conductivity (K) in the deeper water-bearing interval?

  • How efficient is the extraction well?

  • What is the specific capacity of the system?

Due: Saturday, Sept. 1