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rock_doctor
 
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Default Lake level drop due to well drawing too much water


"Tom" wrote in message
om...
Is anyone here aware of a situation where the level of an inland lake
has dropped due to the installation of a high capacity municipal well?

I am trying to find information that will put us at ease here about a
well that is likely to draw water from the same source that supplies
nearby lakes.

Thanks!
Tom


This can happen if the lake is a gaining lake (gains water from the
aquifer). If this is the case then the lake intersects the water table.
Draw down the water table and the lake level drops. I would ask around to
those who have wells near the lake and find how far down the water table is
in their wells. If the water level in their wells are with in a few feet of
the lake level then it is a gaining lake and you could possibly see an
effect. If the water level in their wells are dramatically lower then the
bottom of the lake then they should not be connected. The thing to do would
be to demand a copy of the geologists report for the well/aquifer. The
information you are looking for: where are the recharge areas for the
aquifer, the conductivity of the aquifer, how large the aquifer is in total
area (I.e. it is not a confined or a parched aquifer) and what is the
composition of the aquifer (i.e. sandstone, shale or limestone....). I
would suspect they have done an impact assessment of the well on the aquifer
and subsequently on the lakes and local streams in the watershed. If the
total conductivity of the aquifer is too low they would not be able to drill
the well. You also want to know what effect the well will have on the water
flow direction of the aquifer when the well is pumping at full capacity (not
designed capacity but with the pump at full bore). Once you ask for all
these things (and they get over the panic that you asked for it) you will
know enough to determine the impact. You may also contact your local
geology department (college or university) or request assistance from your
local department of environmental protection (DEP, DER or what ever they are
called in your area). Technically you are a tax payer and they are a
government agency so they have to look into the problem if you have a
reasonable concern. If you can supply all of the above information they
will take you seriously. All of the information will be enough for your
local DEP to determine if there will be a problem. Just get to know the
geologist that works for the water department and have a nice talk to him.
If you are not confrontational, approach him strictly for the education he
can supply and he should not have any problem talking to you. If he will
not meet with you then request a copy of his report. If they won't give it
to you then I would bring up your concerns at the local township meet. Use
google and do a little searching and read about aquifers, lakes,
conductivity ect. You may also ask for a copy of the ground water flow
model plot. It will consist of something that looks like a navigation chart
with the depths indicating depth of the water table and arrows showing the
direction of water flow in that area. With a little time you can figure out
how to read it. But above all and the first step is to talk to their
geologist and express your concern and ask him how he knows the lake will
not be impacted. Ask him to teach you a little hydrogeology. He should be
happy to do so...

good luck,
mark