I have a mysterious ground water problem in my back yard. The ground
next to my neighbors fence is always wet. It is not surface run off
water It seeps out of the ground. It is enough to keep the grass from
growing in that area and it keeps my entire back yard wet or damp.

I am not sure of its source but the following explanation is the best
that I can do. In 1987 the previous neighbor whose back yard is
slightly uphill from mine built a in ground swimming pool. In 1987
it rained heavily and everything everywhere was wet. I didn't notice
a problem. Then 1988 came around and a new neighbor moved in.
1988 was the summer of a big drought here in Michigan. I didn't notice
any thing that year either.

The following year I suspected a problem. I asked the new neighbor if
he was draining his sump pump or his pool discharge line into his back
yard drainage field that was put in when the pool was put in. The
drainage field collects water and routs it to the curb in front of his
house. He said he was not pumping water into it. I suspected that if
the drainage field was pressurized it would back flow and seep out as
ground water causing my problem. Since he said no I patiently watched
for signs of my back yard getting wet when he back flushed his pool. I
never saw it. After watching the problem over the years I believe he
is telling the truth, although I can't be absolutely sure.

An answer was suggested by someone who runs a excavation company.
He theorized that when the pool was put in it disrupted a sedimentary
clay barrier that was retaining the high water table in my area. He
called this phenomenon sheeting. The ground water takes the easiest
path of resistance when the pressure/level rises after a period of
rain. The water now can find a path to the surface This theory seems
to match up with the volume and timing of the surface ground water in
my back yard.

Two other quick notes.:

The surface ground water sits directly on top of my electric, cable
and phone underground wiring. (it would be difficult to drain it away)

In winter when the ground is frozen the warmer surfacing ground water
keeps that area wet and in some cases covers the whole backyard with
ice as the water slowly flows down hill.

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I need help in eliminating this problem. Any suggestion, legal or
otherwise would be appreciated. Please respond to this group as
my e-mail address is fictitious.

Your neighbor probably has a leak in his pool. One other thing you could do is
call the "Miss Dig", Miss Utility" or whoever it is that comes out and flags
utility lines when you dig, to see if there is a water or sewer line there.
That is usually a free call. The number is on the back of any utility truck.

One quick thing you could do. Take a sample of the water to a pool supply
company, they can test for chlorine and stabilizer. If it has stabilizer, it is
pool water. If it is just chlorine it may be city water. They may also know
which minerals would indicate ground water. The extension service can be
helpful there too.
Worst case is it has fecal coliform which would indicate septic/sewer water.
A water test can say a lot about where water was before you got it..