86 DOMESTIC WATER SUPPLIES FOR THE FARM 



a bore 2 inches by reaming has been known to open pools not en- 

 countered in the original hole, and a similar result is possible in 

 water wells. 



The depth of dug wells in material in which the amount of 

 water is relatively small is also important, for increase in depth 

 increases the storage space in which the water can collect during 

 periods when the well is not in use, thereby greatly adding to its 

 total capacity. 



In many regions, owing to the removal of the forests and the 

 construction of drainage ditches, the water from rainfall and 

 snowfall runs off more rapidly than formerly and much less sinks 

 into the ground. As a result the ground-water level has been 

 lowered over large areas, and wells which once afforded good sup- 

 plies are now dry. In many places there is still plenty of water 

 in the ground, the only difference being that its level has sunk 

 below the bottom of the well. In such places the deepening of 

 the well brings complete relief. 



Protection of Dug Wells. Many open wells are exposed to 

 the same danger of pollution from surface wash as springs, and the 

 same methods of protection should be used. A water-tight curb 

 should be raised a few inches or a foot above the level of the sur- 

 rounding surface and the earth banked around it, with a slope 

 away from the well. This curb quickly deflects the water and 

 prevents it from collecting and soaking through the ground into 

 the well. 



The chief means by which wells become polluted by stock is 

 through seepage from the surface. Watering troughs are com- 

 monly placed close to wells, and usually in such places the hoofs 

 of the animals soon wear holes in which the rain water and more 

 or less of the animal excrement collect and soak into the ground, 

 finally reaching the well. To prevent this contamination the 

 watering trough should be placed as far away from the well as 

 possible, the water being conducted to it by pipes. A well in an 

 open pasture, if it is to be used at all by human beings for drink- 

 ing water, should be surrounded by a fence at least 20 feet away. 



