underground water leak...airlock...or something?

Hi all

am after a bit of your knowledge/suggestions.

we are on private water and are having a few problems but i'm not sure if we've got a leak or not.

the pipe from the pump house runs down hill for about 8-12 meters then enters the house (somewhere*) and upto the loft watertank (which is prob. about 2 meters higher than the well. so theoretically when the pump stops pumping the pipe should be full of water (there’s a non-return valve on the inlet in the well)

anyway we have a tap @ the pump house and if you open the tap and put your thumb over it (once the pump stops running) you can feel a vacuum and take your thumb off you can hear/feel an intake of air – you can repeat this a number of times (if you think of the letter ‘n’, the pump is at the bottom of the right had side and the tap is half way up the left side).

Coupled with the fact that water flow to the tank is very slow i suspect a leak.... BUT if you turn off the stopcock going into the tank (at tank height) and leave the pump running you can’t see the water level drop in the well (though I’m going to try that again tonight when i get home)

I’m out of ideas – could it be an airlock in the pipe somewhere which is reducing our flow... but if so what’s the ‘sucking’ through the pipe when the pumps not on??

And finally – i’ve dug a number of holes around the garden trying to find the pipe to the house – what sort of depth should i be going too (gone around foot 1/2 )

(hope that makes sense)


Many thanks


*the house is over 100 years old and we *think* the original plumbing from the well to the house was put in in the 40s or 50s ... there was an extension in the 60s so who knows where the inlet pipe is.... I don’t but want to replace it as its lead (allegedly))

I have had a private supply like this in the past, although ours was high enough that it didn't need a pump. When our tank stopped filling I turned the water off removed the ball valve and it was blocked with bits of a frog. When I asked about this contamination of the water I was told that frogs only survive in clean water. So don't worry, that may be your problem and The usual way to lay the pipe in those days was a tractor pulling a mole under ground with the pipe attached to it, It can vary since its private but you will have a job finding it without a detector its depth can be anything from 1 foot to 2.5 feet. Good luck.

If the pipe is lead then you might be able to detect it with a good metal detector!

Or find someone who can devine water AND metal!

Tony

am sure the inlet/ball valve isn't blocked as at the moment we're filling the tank via a hose pipe connected to the in the pumphouse... though that doesn't mean there isn't blockage somewhere else in the pipe...

at the moment i'm digging a trench parallel to the pumphouse to a depth of around 70cm - we've contacted a few plumbers in the district but none of them have the means to find the pipe - the nearest one we can find is 50 miles away so lord knows how much that would cost on a call out... as for a metal detector haven't been able to find anyone i could borrow one off at the mo


anyway our well is not back up to a much more reasonable level so tonight i'm going to try filling the tank through the pipes.

the only thing i don't really understand is the sucking intake into the pipe once the pump is turned off (if the tap is open) - the pump isn't losing prime so water must be going somewhere (unless there's an air lock/?)

either way many thanks for the replies

just a quick update - have now found the pipe(s)

looking like the 'leak' is under our kitchen floor as there's nothing happening in the garden - going to do a pressure test this weekend to confirm there is a leak then it's onto the insurance firm

not necessarily an insurance job
lack off maintenance is not an insurance job
when was the pipe last repaired ??

If it's a metal pipe you can probably find it with a cat scanner and a generator. Call up some electrical contractors and they might be able to help you better, as they use these all the time to find, and prevent hitting, electrical cables.

just an update on this...

ran a pressure test (getting the kit took 2 weeks!!!) - nowhere sold them up here so ordered one off ebay.. didn't arrive.. so ended up having to order another one... yadda yadda...

failed on the pressure test - so rang the insurance firm, who sent someone out..

long story short - leak IS under the kitchen floor and the bloke who inspected it is recommending that they [the insurance firm] dig up the kitchen floor and repair as required - due to the fact that there's probably quite a large sink hole next to the foundations.

now it's a case of playing the waiting game to see what the insurance firm actually do with this information


hohum...

thanks for the update
damage caused by the leak should be covered
the leak its self probably wont be covered but they may choose to fix it to save further damage

Just a bit of closure for those people who might be intrested (personally hate threads that just..... hang....)

Someone (well 2 people) finally came out (paid via insurance) last week.

The head boss man wasn't convinced that we had a leak as he couldn't hear anything (bloody typical.... normally there was loads of noise)..... anyway after a bit of talking about the history he finally got round to digging..

long story short 2 holes were dug in the kitchen floor - 2hrs and first hole 50cm deep (dry...me getting nervous) 2nd 80cm deep - the 2nd contained the leak!!!! 22mm pipe had a rip 50% of the way round just happened (luckily or not) to be pretty much over an old field drain so no sink hole & drained pretty quickly so no damp problems Etc

absolute minimum repair (that's what insurance firms do allegedly?!?!), backfilled and gone... water tank has never filled this quick.. so must have been leaking since before we moved in 2 1/2 years ago

2 people 6hrs!... would upload a photo but it's just holes in the floor - lol

so many thanks to everyone who suggested/help - very much appreciated

So how much did the firm charge?

How much will insurance cover?

Tony

haven't a clue how much the firm charged but i was only charged the £100 excess (as per my buildings insurance) - so a bit of a result as far as i'm concerned...

though i reckon (as did the lead guy who did the actual fixing) it would've been a lot quicker and more cost effective to just T off the exisiting pipe in the garden and run a new supply into house... but the insurance firm wouldn't allow that - it's 'fix only' not 'upgrade'