Sinking Method

A sinking method is a specific way of sinking a well. Wells may be dug by hand, drilled with hand tools, or drilled with motorized equipment. Many methods and techniques are used. The particular choice depends on the available materials and equipment, the expected ground conditions at the well site, and your familiarity with a specific sinking technique.

Motorized drilling techniques are summarized in the section on Drilled Wells, but are not described in detail because of the high level of technical expertise necessary in the use of the equipment.

The following are general descriptions of hand-dug and hand-drilled sinking methods. For more details, see the manual sections on Hand-Duq Wells and Drilled Wells.

1. Hand-dug wells are sunk by digging a hole as deep as is necessary to reach water. Once the water bearing layer is reached, it should be penetrated as far as possible. This process is always basically the same, with only minor variations because of the particular tools and equipment available and the variety of ground conditions (see Fig. 1-3).

Advantages


FIG. 1-3. DIGGING A WELL

Disadvantages

2. Drilled wells are sunk by using a special tool, called a bit, which acts to loosen whatever soil or rock is at the bottom of the hole. It is connected to a shaft or line which extends to the ground surface and above. The part of the shaft or line extending above the ground can then be moved to operate the bit (see Fig. 1-4).


FIG. 1-4. DRILLING A WELL

Advantages

Disadvantages


Suitability of Well Construction Methods to Different Geological Conditions