GROUND WATER IN NORTH-CENTRAL TENNESSEE
GROUND WATER IN NORTH-CENTRAL TENNESSEE
GROUND WATER IN NORTH-CENTRAL TENNESSEE
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98 <strong>GROUND</strong> <strong>WATER</strong> <strong>IN</strong> <strong>NORTH</strong>-<strong>CENTRAL</strong> <strong>TENNESSEE</strong><br />
permanent hardness is rather high and renders the water objection<br />
able as a soap consumer and scale former. (See pp. 103-106.)<br />
Analysis 220 (pp. 114-115) is typical. Again, the static level of the<br />
ground water and the shape of its pressure-indicating surface are not<br />
known exactly. Also, the artesian head may be due in part to the<br />
presence of gas. Consequently the areas of flowing wells can not be<br />
bounded definitely, although it is known that they are limited to the<br />
bottoms of branches of Turnbull and Jones Creeks in the vicinity of<br />
White Bluff. Obviously the artesian condition is local, for the<br />
horizon of the water-bearing bed seems to be represented by imper<br />
meable material in the outcrops to the north, east, and south.<br />
(See pi. 4.) To the west, the Highland Rim plateau rises far above<br />
the static level of the ground water, and therefore flowing wells are<br />
not to be expected. Artesian conditions also exist locally in a<br />
stratum at the same stratigraphic horizon in the vicinity of a minor<br />
structural dome in northeastern Sumner County. Well 120 (pp. 204-<br />
205) is the only one in this district known to overflow at the sur<br />
face by artesian pressure. The water contains so much dissolved<br />
mineral matter and hydrogen sulphide (see analysis 120, pp. 112-<br />
113) that it is wholly unfit for all ordinary uses. The artesian head<br />
is small and is doubtless due in part to the hydrogen sulphide gas in<br />
the water.<br />
Well 328 (pi. 4 and pp. 230-231), in northeastern Wilson County,<br />
finds water confined in the Lebanon (?) limestone under so much head<br />
that it rises to the surface in the well but does not overflow.<br />
The water-bearing bed tapped by this well may be part of a zone of<br />
channeling that seems to cut across several limestone formations and<br />
yields water copiously to nonartesian wells at Lebanon, about 9<br />
miles southwest. The possible extent and water-yielding capacity of<br />
this zone are discussed on pages 222-227.<br />
Artesian conditions exist locally at several points in north-central<br />
Tennessee where small solution openings occur at shallow depth in<br />
inclined thin-bedded limestone between shaly retaining beds. The<br />
artesian head and yield at these places are usually very small. Wells<br />
131 and 198-A (pp. 204, 144) typify this condition, which does not<br />
depend upon regional structure but may occur in shaly limestone at<br />
any place where its inclination is slightly more than that of the<br />
topographic surface. Artesian conditions also exist in channeled lime<br />
stone above points at which the solution channels are obstructed by<br />
clay or other debris, as represented by wells 275 and 365 (pp. 135, 215).<br />
Under these conditions the static level of the ground water may fluc<br />
tuate according to the season, and the wells may overflow at the<br />
surface only when the water table is in its highest position.