Hand-Dug Well Inspection
Hand-dug wells are ground excavations and their associated structures used to access groundwater in underground aquifers. Until modern times, all artificial wells were hand-dug.
- Hand-dug wells are still the most common means of collecting water in certain parts of the developing world.
- The historical indispensability of hand-dug wells has made its way into important literary references, including the Bibleís story of Jesus meeting a woman at Jacob's well, and even a nursery rhyme called "Ding Dong Bell" about a cat in a well.
- Long ago, manual well-digging was a profession enjoyed by workers of small stature who could fit in a confined space. They used simple tools, such as picks and short shovels.
- Britainís Woodingdean Well, at a depth of 1,285 feet, is the deepest hand-dug well in the world. Generally, however, they are much shallower than their drilled counterparts.
Advantages of Hand-Dug Wells
- The familiar postcard image of a hand-dug well, together with an above-ground wall and a bucket lowered by rope into the well, adds a rustic charm to a yard. Its aesthetic appeal may even increase the property value.
- Hand-dug wells are inexpensive and low-tech compared to standard drilled wells. A bucket and rope have worked for thousands of years.
- Their large diameter is exposed to a correspondingly large area of the aquifer. Hand-dug wells are suited to obtain water from less-permeable soils, such as fine clay, sand and silt.
- They can be made deeper easily. By contrast, when the depth of a drilled well becomes insufficient due to increased demand or a lowered water table, it may cost the homeowner tens of thousands of dollars to deepen the well.
- A hand-dug well's operational and maintenance costs are low.
- Construction can incorporate community participation, as digging does not require skilled labor.
Disadvantages of Hand-Dug Wells
- They are not suited to rocky or exceptionally hard ground.
- Their construction can be dangerous due to collapsing soils, falling objects, and asphyxiation of workers inside the well.
- Their construction is labor-intensive and can take a long time.
- They are easily contaminated by surface runoff.
- Their ability to deliver water for the demands of a modern household, in terms of both quantity and flow rates, is limited.
Construction Safety Considerations
Building a hand-dug well can pose serious safety hazards, such as the following:
- collapse of the sides, which can kill a worker if he's in the well when it collapses;
- objects that fall into the well from the surface above, which can seriously injure workers in the well; and
- a lack of oxygen in the well.
- People and animals can fall into the well, where they may become trapped or drown. Prevention against this hazard is two-part:
- provide an above-ground wall around the well to prevent children and animals from falling into the well; and
- provide a child-safe, heavy, secure cover at ground level. Inspect the cover periodically for decay, corrosion, and anything that may make it weak.
No one should be allowed to enter the well without a safety harness and supervision.
- Direct the surface runoff away from the well, and test the water frequently for potability and for surface-borne water contaminants. To do this:
- make sure that the well is located upstream of potential pollution sources, such as pit latrines, gas stations, rubbish pits and burial grounds;
- prohibit surface pollution at the well site; and
- ensure that any spaces between the well's structural concrete rings are filled in with concrete.