New Technologies in Well Evaluation and Rehabilitation

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New Technologies in Well Evaluation and
Rehabilitation

• Connecticut Environmental Health Association
• Jim Duncan The Stephen B Church Company

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There is more than 100 times as much fresh water
in the ground as there is in all of our rivers
and lakes
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Basic ground water concepts
Water table Static water level
Overburden
Saturated overburden
Bedrock
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• In overburden, the water is in the pore spaces
• In most rock, there is more water in the
  fractures than in the pore spaces

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• Bedrock Well
• Typical homeowner well, but can be public supply
  well, too
• Casing from surface into the bedrock
• Open hole in rock below the casing

Overburden
Bedrock
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• On the DVD we will see problems with
• Casing integrity
• Seal at bottom of casing
• Unstable rock
• Sand in rock well

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Wells in the Overburden(Screened wells, gravel
wells)
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Well with 15 feet of screen in this material
pumped 1180 gpm with about 20 feet of drawdown
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Screen and development the heart of the well
After development
Before development
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Screen considerations
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• Potential problems with screened wells
• Casing integrity
• Screen integrity
• Screen plugging

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What do we do when someone says they have a well
problem?
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Specific Capacity
Yield / Drawdown in units of gpm/ ft
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Underwater camera

• Camera head tilts so we can look down the well,
  at the side, or back up the well
• Camera head rotates a full 360 degrees

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Recording TV
Camera in well
Power Winch
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Steering Wheels to determine internal diameter
of well
Hose used to clear the water
Steering Wheel
Well screen
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Rock well rehabilitation
Packers
Single packer option
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Dry Ice
Dynamite
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• This is used with a high pressure pump to
  jet-clean the sides of the well where they have
  been plugged
• Rock wells or gravel wells
• Can be used while pumping at the same time

Jetting tool
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Rehabilitation of gravel wells
Incrustation
Siltation/ fine sand
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Surge, pump, treat
Solid surge blocks can be effective in rock wells
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Pre- and post -development slug testing
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Iron Bacteria
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Yellow- Fe Dark brown Ca/Fe
Black Mn Green - sulfate
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Summary
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• Contact information
• Jim Duncan
• The Stephen B Church Company
• 49 Great Hill Road
• Oxford, CT 06478
• Office 203-888-2132
• stephenbch_at_aol.com