Friday, June 26, 2009

Coastal Plain Aquifers



Two types of Coastal Plain aquifers are in layers
The water-table and deep confined aquifers are players
Distinctly separated by beds of clay
Leakage of water between is in the play
Warding off aquifer problems are in our prayers.

Recharge to the water-table aquifer is at hand.
Precipitation goes directly into exposed sand.
Almost everywhere it is for domestic supply.
But caution exists where contaminants lie.
For humans this aquifer represents an active land.

The water-table aquifer is as busy as can be
Its recharge and discharge we can almost see.
Learning from water-table fluctuations,
We understand the aquifers’ deliberations.
Streams and confining beds fit nicely to a tee.

Confined aquifers at best have water of high pressure
With optimistic view we consider this a real treasure
But with recharge conditions so slow,
We could ultimately face limited flow
Long-term use of well water we must closely measure.

Scarcer now are the artesian, or overflowing, wells
Years ago were commonly displayed in many dells
Pumping wells cause cones of depression
As lower water levels express a recession
Understanding unwinds as the long story tells.

For thousands of years in a state of storage
The confined water has little chance of flowage
For practical purposes, the water is mined
And for future use, we are getting behind
For a long period we must carefully manage.

As confined water moves coastward and down dip
It is blocked by salty water as a wall-like strip
Upward through clays some water leaks
But not a true outlet that it really seeks
Long in residence, the water never has a big trip.