GROUND WATER IN NORTH-CENTRAL TENNESSEE

228 GROUND WATER IN NORTH-CENTRAL TENNESSEE
MUNICIPAL GBOUND-WATMR 8UPPUEES8
Lebanon. Lebanon, the county seat of Wilson County, derives its municipal
supply from three drilled wells about 75 yards east of the Tennessee Central
Eailroad station, on the west bank of Sinking Creek. These wells, which are 205,
196, and 351 feet deep, are described on pages 230-232. The chemical character of
the water is shown by analysis 333 (pp. 116-117). Water is raised from the wells by
air-lift pumps, chlorinated, and pumped into a 450,000-gallon elevated steel stand-
pipe by two horizontal centrifugal pumps with capacities of 750 and 500 gallons
a minute. These pumps are driven by directly connected electric motors. Dis­
tribution is effected by gravity, and the average domestic pressure is about 45
pounds to the square inch. The aggregate capacity of the three wells ranges from
about 200 gallons a minute during long dry periods to 750 gallons a minute during
the winter and spring. The maximum daily consumption, which is measured by
an automatic recording flow meter, is about 450,000 gallons, and the average
consumption about 326,000 gallons. Hence the present source is barely adequate
to supply the demand in the dry periods.
Foxhill, a suburb of Lebanon, derives an auxiliary water supply from a fourth
well (No. 337) about a mile northeast of the three already described. This well,
which is about 250 feet deep and 6 inches in diameter, probably also taps the
Eidley limestone. It is equipped with an electrically driven deep-well pump with
a rated capacity of 100 gallons a minute, but its actual yield and specific capacity
ar& unknown. This well is used only during periods of extreme drought or other
emergency.
Two possible sources from which additional water can be obtained by the city
of Lebanon are other wells drilled to the 185-foot water-bearing bed and surface
water from the Cumberland River, which is about 9 miles north of the city at
the nearest accessible point. The capacity of the 185-foot bed depends upon the
cross-sectional area of the belt of channeled limestone that forms it, which can
be determined only by drilling. If this bed is a small ground-water artery, the
capacity of the present wells may be as large as its transmission capacity. On the
other hand, if it comprises several or many braided channels, a considerable addi­
tional amount of water may be obtainable. If other wells are drilled, they should
be located several hundred yards from those now in use and should be tested
carefully to determine the degree to which they interfere with the present wells,
especially during the summer and autumn. If they show considerable inter­
ference the aggregate capacity of the system may not be increased appreciably.
On the other hand, an adequate supply can be diverted from the Cumberland
River at all times, although the cost of the necessary pipe line, filtration plant,
and diversion structures would be rather large, The sum of the static and fric­
tion heads against which water would have to be pumped from the river would be
greater than from wells. Moreover, the water from the river would require
filtration as well a& chlorination, whereas the ground water does not need to be
filtered. Hence, both construction and operating costs for diverting water from
the river would be much larger than for operation and maintenance of wells.
However, the capacity of the source may outweigh comparative costs in deter­
mining which source of additional water is the more practicable.
Watertown. The municipal water supply of Watertown is drawn from two
wells (No. 347) 250 and 251 feet deep, south of the Tennessee Central Railroad
near the southwest corner of the city. Reference to these wells has been made
on pages 223-225, and the chemical character of the water is shown by analysis 347
(pp. 116-117). Each well is equipped with a Chippewa double-acting deep-well
pump, with a rated capacity of 60 gallons a minute, by which water is raised jto a
200,000-gallon steel tank on a hillside at the northwest corner of the town. Each