ABC's Of Aquifers – Ad Hoc Committee
The Special Citizen Ad Hoc Water Committee continues its systematic fact finding and analysis work begun in
September. The work is progressing in each of the four study areas: aquifer supply, chemistry and quality,
infrastructure, and analysis of alternative sources of surface water supply. In
this committee report, we provide a basic overview of the aquifer which
supplies our water. The Aquifer supply team is chaired by Dr. Jim Caffey, a
professional civil engineer living in Pantego. Others on the team are Jim St.
John and John Richards.
Pantego gets its supply from a system called the Trinity Aquifer group. It is a
very large structure stretching from the Red River on the North to the Hill
Country and beyond, and from East of Dallas to West of Parker County. If
you can envision a container tipped at an angle, the dark area in the map is
known as the Trinity Outcrop. Here the structure is near the surface and this
is where new rainfall and surface sources pour new water supply into the
aquifer. The aquifer goes deeper and deeper underground (the light shaded
area in the diagram) as you move east from Parker County toward Pantego
and beyond. By the time it gets to Pantego, our wells are generally reaching
about 600' to get to the
Paluxy, and around 1500'
to get to the "deep trinity"
area.
The Trinity group actually consists of seven layers of geology
consisting mostly of sand, clay and gravel. This structure holds
the water that seeps through the length of the formation. There is
no flowing underground stream. Our municipal wells go into two
of these layers. The Paluxy is the top layer in the Trinity Group.
The second set of wells goes into an area of the "deep trinity"
known as the Travis Peak-Hensell layers.
A "recharge" area (source of new water inflow from rain and surface lakes and streams) is on the western edge in
Parker and Wise County areas. That supply replenishes the aquifer over time. The supply in the aquifer is reduced
by pumping, and by fractures in the aquifer that allow the water to migrate to the surface as springs, and evaporate
or to escape as "seeps" through geologic faults. This subsurface water is under pressure, referred to as "artesian
pressure." It is this pressure that forces the water stored in an
aquifer to rise in a well that has been drilled into it. There are
instances where the pressure from the water in an aquifer is
sufficient to cause the water in a well to rise several hundred
feet up the well casing. Therefore, the pumps operated by
Pantego are not actually reaching down into the aquifer itself.
They are taking water from within the well casing that has been
forced up from the aquifer below by artesian pressure.
When artesian pressure drops, the level in the wells declines.
There have been recorded drops of 400-800 feet in some areas
of the Trinity over the last 50 years.
The major work of the Aquifer Team is to establish a position
on whether the aquifers on which we depend are threatened in
any way that would make it an unreliable source of supply for
the next 20 years, which is the period being examined by the committee. Even though there is a great deal of
documentation that the static level of water from the aquifer has been declining regionally, and is projected to
decline more with future demand, the committee's research has been able to determine that monitor wells provided
by the Texas Commission of Environmental Quality indicate that there has been no significant "drawdown", or
lowering of the water levels in their test wells in Crowley and Handley. That has lead to a preliminary finding by the
Aquifer study team that there is no reason at this time to conclude that Pantego would not have an adequate supply
from that source for the future.
May the Wonder and Magic
of Christmas
Fill your Heart and Hearth with
Peace, Happiness, and Joy
Throughout the Coming Year.
Merry Christmas
and Happy New Year!!
Dorothy Aderholt, Mayor
Jason Williams, Mayor Pro Tem
Duane Smith
Councilman
Melody Paradise
Councilwoman
Michael Robertson
Councilman
Cal Kost
Councilman