Mains water leak

Usually, yes.

(I think it gets complicated with flats and shared access land etc.)

I had this a few years ago. The mains pipe runs along the back of my house and supplies 4 houses.

My stop c*ck access pipe was full of water, so I thought the leak must be nearby. I dug down, around 8:30 at night to inspect.With the compacted soil around it, the leak was quite minor (no visible signs on the surface, just a constant noise from the pipes, like a tap is only just turned on).

By chance, I had dug within a foot or so of the leak. It was a big mistake to start doing it then. The hole was maybe 3 feet deep, and 3 feet round. As I got closer to the leak, it got rather wet in the hole. So much so that bucketting it out was not fast enough to stop the level rising. I quickly dug a shallow trench to take the water away from the house.

The neighbour was looking for the stop tap in the street, but had no luck.

It was getting late now, so I back filled as much as possible, and left it until the morning. Rang up Severn Trent. They would come out but at a cost of around £300. They would however do a free repair if I was in no rush. So I said I'd have the free repair. In the meantime, I'd got some advice about temporarily repairing the leak - get a piece of good quailty, thick hosepipe, slit it down the middle, and get 2 jubilee clips of the righ size. You then dig down again, find the leak, clean around it, put on the hosepipe, then tighten the jublee clips at either end. I was sceptical, but it worked immediately. I did however have to buy a submersible pump, as the water level was rising so fast, I could not have done it under water.

Severn Trent came round 3 or 4 weeks later. they couldnt find the stop tap either, so they did it with the mains pipe at pressure. They had one man with an extendable pipe cuter, and another in the hole ready to slip on a push fit stop tap. It was done remarkably quickly, with only a second or 2 of leakage. The hole in the pipe was tiny - almost as small as a pin head.

So, yes, you/he are liable for the repair. If you have a street side stop tap, it should be fairly easy to do once you have found the source of the leak. I would suggest it is likely to be at the end where it comes up to the house rather than being in the middle of the run.

Alan.

Apropos of this - our water co (and also at our previous property) offers insurance against this problem - for about £30/yr they'll cover from the stopcock up to the main cutoff in your house.

Does anyone take this insurance? Do folks think it's worth it? (Seems a lot to me).

I don't know anything about the legal position, but I am wondering about the system for finding leaks.

I would have thought some electronic system would be able to detect the whereabouts of leaks, eg by measuring the resistance along the pipe, or even by firing probes into the ground.

There have been innumerable mains leaks in Ireland, and the local authorities have been appealing to people to report if they see damp patches.

Surely the science of water supplies has reached a higher level than this?

Rarely does a leak show on the surafce unless the water has no place else to go. At the leak itself the pressure will washaway the ground and make a small void, the draining away water will then carry more ground away and enlarge the void. Quite often the first thing that happens on the surface is the ground collapsing into the void.

Normally, yes.

I'm sort of surprised that a new blue plastic pipe is leaking. But does that go all the way to te stopcock in the pavement or is the a lead/plastic joint somewhere? Lead is most likely given the ago of te property. Some water boards replace lead rising mains for free...

Somewhere the Thames Water insurance blurb says in *some* cases it *may* be possible to do a one-off leak repair for free, but that they won't restore your paving or whatever else they have to dig up. Usual vague stuff from TW, but I guess they're referring to the lead pipe replacement scheme. When my son asked their engineers working in the road about having his own stopcock, the response was that a lot of people didn't have one, and "it'll cost you £500". They installed it later that afternoon and buggered off without saying a word. Go figure

The stop tap could be anywhere or indeed there might be none at all. Your responsibility starts at the boundary of your property.

The first question I would ask is how they know that there is a leak at all. If he's not complained to them they've probably heard it while doing routine monitoring or while fixing something else. They listen by putting a rod on a pipe or tap, a leak makes a distinctive hissing sound. A very hi-tech version exists which does analysis on the random noise and can tell how far away the leak is. A leak found that way wouldn't necessarily be obvious as a flow of water anywhere visible.

New blue MPDE pipe is very unlikely to be leaking, much more likely would be fittings and terminations, so check around the inside stop tap and around any joints underground.

You don't say what type of soil this is in but that can make a huge difference to the ease of locating a leak. In heavier soils the water can't run away once it's leaked so tends to run along the outside of the pipe for some distance. That makes it hard to find the source of a leak as you dig down where water is coming out of the ground and then find you have to dig along the pipe - very frustrating. In your case this is relevant because a leak which appears to be outside of your property at first could end up actually being inside once you've traced it and vice versa. I've had exactly this happen twice in 6 months, once with a leak which at first appeared to be inside our property by turned out to be in the street and once with a very small leak in the street which got very exciting when the water company dug down to it as it turned out the clay soil was keeping the water in - quite dramatic when they released it!

Here's a drawing, courtesy of Northumbrian Water:-

The text says 'boundary of your property', but the diagram shows the street stopcock as the demarcation line.

These may not be the same.

In the picture, there is a couple of feet between the stopcock and the property boundary.

I can forsee this being a longer distance in some cases, and potentially the cause of dispute.

I think they could have been more precise in their definitions.

The old fashioned but very good method is to listen to the pipe via a brass rod. A trained ear can be surprisingly accurate at detecting the presence of a leak and skilled workmen can tell you how far away it is too.

I have a guy working for me who wrote the FFT code for a modern high-tech unit. They work in much the same way. They either inject white noise or simply listen to the noise of water escaping from the pipe under pressure. By analysing the shape and frequencies of the sound they can tell how big a leak and how far away. Take a measurement in more than one place and the accuracy can be very good. Essentially they are just doing what a skilled human brain could do.

There's usually a short length of supply pipe between the water company's stopcock and the property boundary which presumably remains their responsibility because I'm sure only an authorised contractor would be allowed allowed to dig up the public pavement. This suggests that in effect only they can replace the whole of your supply pipe. I'm sure they're not going to create a join under your boundary and, if they come a foot past it, they might as well do the whole thing

It should be covered under general insurance anyway.

Indeed. Officially sponsored scam.

I have just checked my buildings insurance and under escape of water what is NOT covered :-

"The cost of excavation to gain access to the installation, making good the area disrupted during excavation and/or repairing the installations themselves, unless the damage has been caused by freezing."

Seems the insurance companies are colluding with the water companies to extract money.

My old stopcock was about 18" inside the boundary. When the meters were fitted they were put about 18* outside. A few years later I looked under the little iron flap and found that the old stopcock was still there, with HDPE to the house and lead(!) going towards the new stopcock, so I have 2 but consider the old one to be the responsibility of the company.

Not too worried about a v. short bit of lead that's covered in scale, but it's useful if a leak does occur there as there might be a legal issue to use as a cudgel.

And I get a letter from them very often offering insurance by homeserve on the pipe for something like £2 a month. Not worth it IMO. How often do they fail?

Your household insurance will probably come with a large excess which the specific policy wont have. (It's still poor value though)

tim

I have just checked my buildings insurance and under escape of water what is NOT covered :-

"The cost of excavation to gain access to the installation, making good the area disrupted during excavation and/or repairing the installations themselves, unless the damage has been caused by freezing."

Seems the insurance companies are colluding with the water companies to extract money.

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Insurance companies collude with everybody to extract money. It's called "giving commission".

tim

If this insurance, as is the case with Scottish Water, is with a company called Homeserve, then I would leave well alone. I had this company try to resolve a damaged drain situation and they were totally incompetent and a danger to anything they touch,

Rob