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Water Quality Data
STANDARD GUIDELINES FOR DESIGN
AND PROPER CONSTRUCTION
OF A WATER WELL
By Roy F. Senior, Jr.*
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PRE-CONSTRUCTION CRITERIA
The factors that should be considered for shallow and deep well
selection design are:
1. Amount of water desired
2. Pumping cost
analysis
3. Life expectancy of the well
4. Effects on land value
created by a usable ground water supply.
PRODUCING WATER FROM BELOW THE CORCORAN CLAY
Proper depth selection of a well will greatly affect producing capacity over the life of the well by as much as 1000 gpm to 1200 gpm. For instance, using an approximate value of 10 gpm water production for each one foot of producing sands below the Corcoran Clay, you can determine how many feet of producing sands should be incorporated into the final well depth, thereby constructing a well of maximum capacity, efficiency and longevity. Therefore, for every 100' of producing sands added to the well depth, they additional productivity could
be as high as 4 acre feet per day. Thus, the added footage of producing sands incorporated into the final well design may be equated as usable "water-in-the-water-bank" or "money-in-the-bank." At this point in the pre-construction decisions, consideration should be given as to how much of the potential producing sands should be incorporated into the well design, remembering that every foot of saturated sand adds value to the land.
For example, a 1200' well may initially produce a sufficient amount of water to he economically feasible. However, if there are producing sands below 1200' that can be incorporated into the well, the well would produce at a higher specific- capacity, lower pumping cost and would be able to tap more usable water. This means longer usable well life, more efficient pumping cost, and increased land value.
During the initial planning stages and continuing through the well construction, as you gain more information, is the proper time to determine well depth. If a 1200' well is completed today and at a later date a 2000' well is needed, it will be necessary to either drill a new well or go to a much greater expense to deepen the existing 1200' well.
* Note: These remarks were presented by the author at a District
workshop in 1992.
Last updated January
2001