Broken Drain

[geezer466]

Anyone here with any experience of this? Please bear with me this is a bit of a saga!

In July 2008 after a heavy storm my basement drain backed up. (There is very little fall on it between the appliances and the main sewer in the centre of the street). As a consequence effluent backed up the pipe a way and blocked it. This used to happen roughly every 6 Months and always after heavy rain.
Anyway called the council as we have done on the previous occasions and they sent the wagon round to jet the drain from a small inspection access in the front of the property. Jetting the drain involves pumping water under high pressure down through a steel ball with strategically placed ports allowing it to move forward.
After about 10 minutes it became apparent the council chap couldn't get his hose back out of the hole and he reported it would have to be dug out. They cut off the hose and departed.

Local Authority then served notice for us to rectify the drain blockage. We contacted our buildings insurers and a plan was put in effect with the agreement of the EHO that a saniflow would be fitted in the basement and the waste re routed to another foul drain.
This all took place over about a 6 week period was was essentially complete around September 2008.

Fast forward to November 2010 when part of the centre of the street outside started to subside (a small hole appeared growing larger over several days). Hole was reported and council investigated. a week or two later a road crew arrived and opened the road did a couple of days work re surfaced all and departed.

February 2011 and a bill arrived on my mat this morning for a bill for £3200+ for repairing what they say was my drain. The paperwork goes into a little detail with work and time sheets for the people employed in the project and hire of the kit they have used.

The description of the work is 'Excavate in carriageway to investigate subsidence, install shoring, discovered broken pipework from number 22 with jet washing hose stuck inside repair as required'.

Couple of questions if I may of anyone with any experience in this area.

Is it possible the jetting eye under a high pressure water stream could have broken the pipe?

Is it reasonable for me to assume the Local Authority have some liability here.

Is the LA not required to serve some sort of statutory notice upon me before they conduct this work?

As I understand it the subsidence could only really have been caused by spoil being washed away down the drain through the break? As soon as this drain became blocked with the hose it became unusable and indeed redundant as soon as the saniflow was fitted.

Clearly if it is my responsibility and the council completely blameless then I will pay for the repair. My buildings insurance covered the initial problems and they met the cost (less the excess) for the fitting of the saniflow. I am yet to discover if this settlement was a full and final one meaning I have no further cover!

If you have read this far then I thank you. If you can shed some light on my problems by way of experience I would be grateful.

 

[Hugh Jaleak]

I wouldn't expect a broken household drain to cause massive subsidence, as you have said, for a void of any size to be created the soil has to be washed away somehow. It is possible the void was historic, the soil being washed into the pipe during heavy rain causing the earlier blockages, however I would have expected the subsidence to present itself earlier than it did.

Environmental Health should have served a 48 hour notice prior to commencing works. As it suggests the notice supplies 48hours notice of the Council's intention to carry out work and who is liable for the bill!

I wouldnt have thought the jetter would have broken the pipe itself, however any pre existing weakness or broken pipe wall could have been aggravated by the pressure from the jetter. A CCTV survey would have been useful to determine the condition of the pipes and reasons for repeated blockages rather than keep jetting it each time. This would have shown the condition of the pipework, and would help in making a decision as to best course of action. Jetting a collapsed pipe wont achieve much, long term the only solution is to excavate and replace damaged section.

Couple of questions though. When was the property built? Is the affected drain dedicated to your property or does any other dwelling use it at that point?

 

[geezer466]

I wouldn't expect a broken household drain to cause massive subsidence, as you have said, for a void of any size to be created the soil has to be washed away somehow. It is possible the void was historic, the soil being washed into the pipe during heavy rain causing the earlier blockages, however I would have expected the subsidence to present itself earlier than it did.

Environmental Health should have served a 48 hour notice prior to commencing works. As it suggests the notice supplies 48hours notice of the Council's intention to carry out work and who is liable for the bill!

I wouldnt have thought the jetter would have broken the pipe itself, however any pre existing weakness or broken pipe wall could have been aggravated by the pressure from the jetter. A CCTV survey would have been useful to determine the condition of the pipes and reasons for repeated blockages rather than keep jetting it each time. This would have shown the condition of the pipework, and would help in making a decision as to best course of action. Jetting a collapsed pipe wont achieve much, long term the only solution is to excavate and replace damaged section.

Couple of questions though. When was the property built? Is the affected drain dedicated to your property or does any other dwelling use it at that point?

Thanks for your reply. We cannot pinpoint the exact year the property was built although we think it was around 1870 - 1880. The drain to the front we also think is a later addition as in common with other properties in the locality the front basement area was used as the 'coal hole' and the access used to deliver the coal is still evident certainly in the house next door.
I should also point out this is a 7 bedroom/3 reception room house (not counting additional space now created in the basement). When the drain first blocked we sourced the help of the EHO in trying to source a drain map who produced a hand written (not to scale and not very accurate) drawing. This was from the 60's/70's and when we suspect the drain may have been built as a bathroom was installed in the by then converted basement.

All that said it is possible that at some time the basement was servant(s) quarters as we have discovered the remains of a bell summoning device under the floorboards in the front reception during renovations.

We did discover that the course runs right under where the coal hole was.

The same drawing seemed to suggest that the drain was indeed private with no other branches in before it met the street sewer.

After the jet got lodged and the hose detached we did try to get a CCTV inspection done but the hose was stuck down the pipe this sadly was a no go. The operator did insert the hose as far as he could but could only report the fact the hose was present and the pipe was full of water.

We are also within 300 metres of the sea and as such the area has a history of effluent backing up in the sewers. Indeed up till about 10 years ago (when improvements were made) basements around here would flood quite often when heavy rain accompanied a high tide. We thought the fact our pipe blocked was just a throwback from this.