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Dan Vercruysse Travels to Cambodia: Part 2 of 5

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    • Dan Vercruysse Travels to Cambodia: Part 2 of 5

      Well Drilling

      One of the Trailblazer Foundation’s (TF) primary activities is drilling wells in rural communities that lack consistent access to nearby safe water sources. The process begins with TF’s three-person crew and a volunteer or two loading their well truck with supplies and driving out to the recipient village. Upon arrival, we set up the drilling rig, which consists of a three-pole frame with a mount for an auger motor. The motor is set in place and metal cutting pipes are attached to it–the frame also has a centering yolk at its base to ensure the pipes remain straight as they cut the shaft into the ground. The auger motor has an inlet valve that is connected to a nearby water source–this allows the cutting pipes to have water pushed through them to both assist in cutting the new shaft, as well as flush the shaft of any debris (soil and gravel).

      The motor is repeatedly lowered and raised via a hand cranked pulley system, with extension poles added each time, driving the cutting head deeper and deeper. Once the cutting head has reached a depth with a consistent water supply, a PVC tube with an end cap and inlet slots cut into the sides of it is lowered, section by section, into the newly cut shaft until to reaches the bottom. Gravel is then dropped into the shaft to set the PVC well column position and create a place for the ground water to collect. The remainder of the PVC column is packed in place with a sandy soil mix until the shaft is full. The water that was pumped into the motor/cutting pipes is then redirected into the PVC column, pushing water through the PVC column/well shaft to flush the entire system of gravel and sand debris. This takes a bit of time, allowing for the crew to rest (and if you’re lucky, enjoy a lunch prepared by the villagers!).

      On another day, the drilling team comes back to the new well site to construct a concrete pumping base and PVC well head/pumping assembly. The team decides on the best location for the well pump and begins to layout the concrete base. Once outlined the base receives a layer of course gravel with a site mixed concrete perimeter to start the setting of a structural clay tile border curb (think light-weight bricks). This curb wraps the perimeter of the base. Then a small splash guard wall is constructed to help manage water and make sure the well head location is not eroded over time. Additional concrete is mixed and the entire assembly receives a parget coat, with remaining concrete being used for the base slab. While this is happening another crew member cuts and assembles PVC sections that make the well head assembly. The well head supports the manually operated pump, which consists of a smaller diameter PVC pipe section (handle) that fits within the main horizontal outflow pipe–this pumping rod has a small disc attached to its end with holes drilled into it and a “custom” (recycled rubber) washer that act as the pump’s seal and gate by which the water is allowed to flow out when the pump is in operation. Once the well head/pump is installed, the concrete base assembly is painted, and numbered for long term identification. This final touch completes the well drilling process.

      Keep in mind the well alone does not provide a safe (for consumption) water source, its function is to provide a consistent, easily accessible water source for household use after filtering.

      Next up, biosand water filters, the second half of the story…

    • well assembly plan and section drawings
    • setting the yolk
    • mounting the motor
    • locating the base
    • setting the foundation
    • assembling the backsplash
    • mixing concrete
    • assembling the well head
    • finishing touches
    • complete!
    • well operation
    • About the Author

      Dan Vercruysse

      • Architect / Senior Associate
      • dan@msrdesign.com
      • 612 359 3225
      • View Bio