unreliable sources of water. An additional disadvantage of dug wells is that, due to their
large diameter, they are difficult to maintain in a sanitary condition. For maximum
sanitary protection, dug wells should be Iined with brick, stone, or concrete, depending
on the availabiIity of materials and the cost of labor. Cement grout should be placed to
a depth of 10 feet below the ground surface between the Iining and the undisturbed
embankment to prevent the entrance of surface water along the well Iining. A
reinforced concrete slab should enclose the top of the well. The slab should slope away
from the center to preclude surface waters (see figure 6-5) entering the well. As in all
wells, the opening for the drop pipe of the pump should have a sanitary seal to prevent
Figure 6-5. Typical dug well.
MD0160
6-7