Who is responsible for an issue with a sewerage pipe that crosses the boundary?

Bongowhack

Looking for some advice on a sewerage issue if you'd be so kind . . .

We live in an older property that has combined surface and soil water drains that connect to the public sewers running under the road outside. We have an issue with a pipe that crosses the property boundary and I'm trying to figure out who should shoulder the responsibility of addressing it.

I've had our water company out to inspect the issue and they ran a camera down the drain to investigate. The attached cross-section diagram below hopefully helps illustrate but, we have an interceptor trap (red) at the edge of our yard, just before the sewerage pipes join the public sewers. The pipe beyond that (blue) has dropped from it's intended position (pink), meaning the cross-sectional area for waste to travel down has dramatically reduced and it blocks easily.

When they ran the camera, they lifted the inspection cover in our yard and went from the inside out over. The boundary line between our property and the road outside is shown in the diagram in purple and, because they hit the issue while still within our boundary, they claim it's our responsibility to resolve it.

I've since located the spot more accurately by running a rod down the interceptor trap until I hit the dropped pipe, marking the rod and then laying it out in place on the ground above - the end of the dropped pipe is 10cm from the boundary. According to the engineers who came out, these sections of clay pipe are usually 80cm in length, so up to 70cm of the issue is beyond our boundary, under the road outside.

While I get it that the issue "starts" within our boundary (at least when you come at it from the inspection cover on our side - if they'd carried out the inspection from the public side the the issue would begin outside our boundary), for a clay pipe to drop in this way, the majority of the underlying problem with earth moving below the pipe would surely happen beyond our boundary. It also seems pretty clear to me that, when the sewerage system was originally put in place, the intention was for the interceptor trap to be the last portion that 'belonged' to the property, and anything beyond that was the public sewerage system.

As it stands, the water company are claiming that it's definitely my issue to resolve and I just wanted some advice on the best argument / case to respond to them with.

Thanks in advance.

Grumpy_chap

Bongowhack said:

Looking for some advice on a sewerage issue if you'd be so kind . . .

We live in an older property that has combined surface and soil water drains that connect to the public sewers running under the road outside. We have an issue with a pipe that crosses the property boundary and I'm trying to figure out who should shoulder the responsibility of addressing it.

I've had our water company out to inspect the issue and they ran a camera down the drain to investigate. The attached cross-section diagram below hopefully helps illustrate but, we have an interceptor trap (red) at the edge of our yard, just before the sewerage pipes join the public sewers. The pipe beyond that (blue) has dropped from it's intended position (pink), meaning the cross-sectional area for waste to travel down has dramatically reduced and it blocks easily.

When they ran the camera, they lifted the inspection cover in our yard and went from the inside out over. The boundary line between our property and the road outside is shown in the diagram in purple and, because they hit the issue while still within our boundary, they claim it's our responsibility to resolve it.

I've since located the spot more accurately by running a rod down the interceptor trap until I hit the dropped pipe, marking the rod and then laying it out in place on the ground above - the end of the dropped pipe is 10cm from the boundary. According to the engineers who came out, these sections of clay pipe are usually 80cm in length, so up to 70cm of the issue is beyond our boundary, under the road outside.

While I get it that the issue "starts" within our boundary (at least when you come at it from the inspection cover on our side - if they'd carried out the inspection from the public side the the issue would begin outside our boundary), for a clay pipe to drop in this way, the majority of the underlying problem with earth moving below the pipe would surely happen beyond our boundary. It also seems pretty clear to me that, when the sewerage system was originally put in place, the intention was for the interceptor trap to be the last portion that 'belonged' to the property, and anything beyond that was the public sewerage system.

As it stands, the water company are claiming that it's definitely my issue to resolve and I just wanted some advice on the best argument / case to respond to them with.

Thanks in advance.

Is the pipe shared?
If not shared, you are responsible for the pipe up to the boundary.

ThisIsWeird

Hi Bongo.
Can you confirm, please - from your rodding tests/their CCTV, does the damage/collapse clearly continue beyond the boundary? And for roughly how far beyond? Pretty comprehensively so?
I'm assuming from your description that it isn't a small localised collapse at the boundary, but a longer section of pipe that has sunk and collapsed, in which case they really seem to be trying it on with their definition of responsibility. 
Even if the damage seemingly 'begins' within your boundary (as you say, it depends on which direction they are looking from!), a ~100mm distance is often beyond what can be determined as being the 'true' boundary in many cases, without a surveyor being involved. Say you were having a boundary dispute with a neighbour or highways agency, it would take a foolhardy person to point to the ground and say with any conviction, it's there! On that basis alone, it is possibly unlikely that the WB can point to the ground and claim with any certainty, "that is soooo obvs yours".
It also seems logical that the presence of this trap would have determined the end of the homeowner's intended system (depending on when it was installed), before it then continued - with a new section of pipe as a public sewer.
And if the damaged section of pipe continues clearly beyond the boundary, it seems astonishing that they could suggest it's all your responsibility just because one wee end of it may have marginally crossed over.
This is strange stuff. From what I understand, WBs are usually very ready to sort out problems with what is 'theirs', so what is going on here?! What are they actually suggesting - that they do their bit, and you repair the 4" end?! Or, blimey, that you are responsible for it all, even the outside section?!
The Ofwat site suggests that, since 1st Oct 2011, "it is usually at the boundary". I would escalate this issue to Ofwat.
(Your sewer isn't shared at all?)

https://www.ofwat.gov.uk/households/supply-and-standards/supply-pipes/

Section62

ThisIsWeird said:

It also seems logical that the presence of this trap would have determined the end of the homeowner's system, before it then continued, with a new section of pipe, on to the public sewer.

It is usual for an interceptor trap (if there is one) to be near the boundary, but the interceptor itself doesn't represent any kind of 'legal' boundary between private and public. Historically the pipe up to the point it met the main public sewer was typically private, even if under the road.

ThisIsWeird said:

And if the damaged section of pipe continues clearly beyond the boundary, it seems astonishing that they could suggest it's all your responsibility just because one end of it may have marginally crossed over.

I think what they might be doing is saying the fault - the "displaced joint" - is located on the OP's property, therefore it is their responsibility.  Although it is possible the downstream pipe has dropped, it could also be argued that the chamber and interceptor have risen (yes, this is possible e.g. if groundwater pressure acting on the base of the chamber is enough to overcome soil friction with the chamber)

Even if the cause is the downstream pipe dropping then it doesn't necessarily mean the water company need to do anything about it.  So long as there is enough CSA for normal domestic flow then they don't need to repair the pipe to 100% perfection.  And in terms of blockages, interceptor traps are notorious for causing blockages, and it would be difficult for the OP to prove it was the displaced joint that caused the blockage, rather than the interceptor.

We'd need to know exactly what the water company have told the OP, but there is a subtle difference between the water company saying they don't think they need to do any work on their pipe, vs them saying the OP must repair the water company's pipe.

ThisIsWeird said:

The Ofwat site suggests that, since 1st Oct 2011, "it is usually at the boundary". I would escalate this issue to Ofwat.
(Your sewer isn't shared at all?)

It might be a bit too early for OFWAT as they are a regulator rather than an ombudsman.  As above, I think the water company could put up a not wholly unreasonable argument that they don't need to take any action and the issue is within the OP's boundary.

OP, I'd like to give you a suggestion that would force the water company to be more charitable, but it sounds like one of those situations where you needed to get lucky with an operative/engineer who wouldn't be so tricky.

I'd suggest whatever else, it is probably a good idea to get rid of the interceptor trap as these tend to be more of a problem than a solution. Luckily the downstream pipe is lower than the outlet of the chamber which means (although it is a little bit of a bodge) you could get your contractor to lay the pipe replacing the interceptor at a fall which suits the level of the downstream pipe.  That way you'd be able to restore 100% capacity with only minimal work.

The ideal approach would be to survey the whole length of the downstream pipe to be able to prove the water company's pipe has dropped, and then somehow prove that the joint displacement is the cause of the blockages. But that would be at your own cost, and there is still no guarantee you'll be sucessful in persuading the water company to pay for the whole repair, or even for the majority of it.

By the way, pipe lengths vary considerably and there's no reason why a pipe cannot be cut shorter than standard length.  In fact it was/is normal practice to use a much shorter 'rocker pipe' immediately adjacent to any chamber which helps prevent cracking of the pipe if there is any differential movement between the pipe run and the chamber. In other words, unless the actual pipe length is measured (e.g. by CCTV survey) it is only a guess how long the pipe is, and how much of the problem sits on either side of the boundary.

Bongowhack

from your rodding tests/their CCTV, does the damage/collapse clearly continue beyond the boundary? And for roughly how far beyond? Pretty comprehensively so?

It’s not possible to determine this from poking a rod down there and when the guys ran a camera down, they only went as far as the join between the interceptor trap and the dropped pipe - mainly because the diameter was so small due to the movement of the pipe that their equipment wouldn’t go any further.

In the camera footage, it appeared that the pipe itself was intact but the whole thing had sunk. As it’s a rigid clay pipe, the end wouldn’t bend independently to the rest of the length so the sinking does continue beyond the boundary. How far it continues depends on the length of the pipe and that’s not something I can determine from the evidence I have. The guy told me that the sections of pipe are 800mm in length (hence I proposed that 700mm of the affected pipe will be beyond my boundary) but other replies above reckon the pipe could’ve been cut to any length so that’s not something to be relied upon.

I'm assuming from your description that it isn't a small localised collapse at the boundary, but a longer section of pipe that has sunk and collapsed

As above, it’s not clear how far beyond the boundary the ‘damage’ extends as the team who came out only went at it from within my property and stopped when they got to the dropped pipe. If they’d come at it from the other direction then they’d have been able to see where the ‘damage’ extends to and also how long that length of pipe is.

What are they actually suggesting - that they do their bit, and you repair the 4" end?! Or, blimey, that you are responsible for it all, even the outside section?!

They admit there’s an issue but that because it starts on my property that it’s my issue to resolve. When I pushed them on the the fact that only the very end is on my property, they said that I should repair the section that is on my land and then, if they need to do any further work to resolve the issue beyond my boundary, they will come to address that at a later date.

Your sewer isn't shared at all?

I don’t believe so, no. There are various other pipes coming into the inspection pit before the interceptor trap but I believe they’re disused drains from historical outside toilets.

So long as there is enough CSA for normal domestic flow then they don't need to repair the pipe to 100% perfection. And in terms of blockages, interceptor traps are notorious for causing blockages, and it would be difficult for the OP to prove it was the displaced joint that caused the blockage, rather than the interceptor.

There isn’t really enough CSA for normal domestic flow as the joint between the trap and the subsequent pipe has really reduced it. The trap itself is actually fine, it’s that sudden drop in CSA with a ‘sharp’ edge that’s leading to the blockages. The trap blocks sue to the pipe beyond it catching waste – rodding over the top of the u-bend in the trap to where the pipe joins is what frees the blockage.

there is a subtle difference between the water company saying they don't think they need to do any work on their pipe, vs them saying the OP must repair the water company's pipe.

They agree that there is an issue that needs to be resolved but claim it’s on me to do so. My argument is that the majority of the issue is actually on ‘their’ part and that it’s not even possible for me to correct the problem with the small section of pipe that’s on my property without digging way out into the road and therefore fixing the whole thing. This also throws up various issues over permissions – firstly to dig up the public highway for access to the pipe and also to carry out work on the pipe that is mostly the WB’s property.

ThisIsWeird

Work out 100% that your sewer isn't shared.
How much work would it be to dig up and expose your part? Hopefully you'll then at least know.

Section62

Bongowhack said:

....and that it’s not even possible for me to correct the problem with the small section of pipe that’s on my property without digging way out into the road and therefore fixing the whole thing.

As I mentioned above, because the downstream pipe has 'dropped' relative to your chamber, you've got the option of relaying between the chamber and the last joint on the water company's pipe to restore 100% CSA.  Not elegant, but a pragmatic solution if the water company really aren't interested in doing anything.

Bongowhack said:

This also throws up various issues over permissions – firstly to dig up the public highway for access to the pipe and also to carry out work on the pipe that is mostly the WB’s property.

Unless the pipe is very shallow it should be possible to dig down from a hole wholly within your boundary to gain access to the full length of the first pipe under the highway ('undercutting').  It is a fairly common technique that experienced operatives would use - but does have some risks so shouldn't be attempted by a novice.  Because no 'opening' is being made in the highway there shouldn't be an issue in terms of streetworks permissions.

But you do also have a potential solution which does minimal work to the water company's pipe, and shouldn't involve any work under the highway (see above).

Bongowhack

Work out 100% that your sewer isn't shared.

Yeah, when I next get a chance I'm going to lift the inspection cover and ask the neighbours to flush their toilet just in case. I did carefully lower my phone down the inspection shaft to take a some still images and video footage of those other pipes and they look like they're filled with soil etc from when they were 'decommissioned'.

you've got the option of relaying between the chamber and the last joint on the water company's pipe to restore 100% CSA

I understand your idea but I'd be concerned about the fact that the pipe has already dropped and, without either remedying that and returning it to its original position or otherwise somehow shoring up it's current position, there wouldn't be much to stop it dropping further in the future.