Bradfield Environmental Services, Inc. has located and developed wells capable of producing one to three million
gallons of water per day for the cities of Erwin, Elizabethton, Decatur, Athens, and Loudon, Tennessee. All of
these Public Water Systems have realized significant savings in construction and treatment costs that quickly
offset the cost of developing their ground-water resources. Information about ground-water source development
and discussions of investigations have been published in Tennessee Public Works Magazine.
Published articles include a review of local geology, the number of wells required to locate suitable sources for
each utility, the results of aquifer tests, and the benefits realized from using ground water over other options
available to these Public Water Systems.
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2000 GPM for Loudon Utilities. |
Developing large-producing wells in areas underlain by rock formations requires a detailed investigation to identify
areas most likely to produce ground water. The geology of the study area is mapped at the 1:24,000 scale on topographic
maps. Areas underlain by limestone formations are more likely to produce water than are areas underlain by shale
formations. Most water movement in areas underlain by rock is along faults and bedding-plane openings between different
geologic formations.
The discharge of streams in the study area is then measured at 15 to 20 sites to identify those
reaches of streams that are gaining water from the ground water system and those reaches of streams that are losing
surface water to the ground water system. Drainage areas for each measurement site are also mapped, enabling a comparison
of different areas based on the volume of stream discharge per square mile. Productive wells are often located in areas
with losing or dry reaches of streams.
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Once specific areas likely to produce ground water are identified, a number
of test wells are drilled. The number of wells required will depend on the size of the area considered and on local
geologic and hydrologic conditions. Because of the difficulties in locating fractures in rock formations, it is critical
that enough wells are drilled to fully explore an area for ground water. Those wells that appear to produce large
volumes of water as the well is being drilled are selected for aquifer tests. Productive wells are pumped for a
minimum of 24 hours to establish the sustainable yield of the well and the amount of draw down in water levels associated
with pumping over an extended period of time.
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