If you don't have a pump above ground, and you have wires going down the
well, then you have a submersible pump. Most likely the check valve is
threaded to it.
It's possible that the vertical pipe is cracked, but not probable. It would
be spraying water out the crack when the pump is running. Can you look down
the well and check that?
It's more likely that you have a crack or pin hole in a section of pipe that
is underground.

"Dennis Straussfogel" wrote in message
...
In article .com,
"Harry K" wrote:

Bob wrote:
Sounds like a bad check valve. The water is draining back down the
pipe, and
when the pump kicks on, it sucks up air first.

"Dennis Straussfogel" wrote in message
...
I have an old (30 yr?) bladderless pressure tank on a shared (4
houses)
well. It appears that over the last six months, air has been
entering
the tank somehow and ending up in the house water lines. I've been
bleeding air out of the tank about once every week to ten days and
that
corrects the problem temporarily. My question is: is there any way
(such
as a particular pump failure mode) that would allow this to be
happening, or is the only thing that could be wrong is that we are
pumping the well faster than it can recover? (There's no obvious
reason
to think the water table has dropped in the last year.)

When I lived in New Hampshire (The Granite State), there was a
process
called "hydro-fracting" which involved dropping dry ice down the
well
shock cooling the bedrock and opening up the fissures to allow
faster
well recovery. I now live in Northern British Columbia (on probably
clay
and gravel), so my second question is: if we are overpumping the
well,
what can be done about it?

Thanks a lot for any information.

Denny

Nope. If he has a jet pump or a shallow well one on top of the well
and the check valve (footvalve) was bad, he would be loosing the prime.
If it is a submersible, it pumps from under the water level and thus
can't suck air from there. The only place I can see air entering the
system at the pump location is from the snifter valve or a flapper
valve on the side of the tank. Dissolved gases in the well water??

Harry K

There's definitely nothing on the side of the pressure tank and no
obvious places (clamps, etc.) where air could be leaking in. I suppose
the drop line may be cracked, which would reinforce some suspicion that
the problem coincided with the onset of cold weather--metal contracting
and opening up the crack.

My best guess is that it's a submersible pump in a deep well (The story
is that the original owner paid CA$10,000.00 in the '70's to have it
drilled--but there's some speculation he may have inflated that figure
to rip off the people he was going to share the well with. Nice guy.) As
I said before, I wouldn't be surprised if this is a real "half-fast"
system, just surprised it's lasted this long.

Thanks again,
Denny