Waste Pipe Shocker - Advice Wanted

[PhilH]

Problem: we thought our new build was connected to a mains sewer. However, it turns out we’re connected to a disused (and backfilled) septic tank on our neighbours land. 
 

Background: we brought the property in 2020.  It’s was an old cottage with planning permission, which had been vacant for 5 years. The previous owner had passed away and the next door neighbour brought the property, reduced the plot and applied for planning permission. 
 

The build: in 2021 our contractor capped the drain and demolished the existing cottage. We then completed a new build and reconnected to the drain in September 2022. 
 

Discovery: on moving in we quickly discovered that the drain was backing up. Investigations by the builder discovered that the drainage pipe led to a backfilled septic tank on our neighbours property (land which was previously associated with my plot). 

Facts: 1) The United Utilities search records shows my property is connected. 2) Adjacent properties are connected (circa 40 years ago). 3) Neighbours thought the property was connected (however, no concrete evidence)
 

Possible scenarios:

 

1) Clerical error by United Utilities. Property was never connected. Previous owner used the septic tank. 
 

2) The property was connected. The builders lost the connection during the demolition / build and connected to the disused pipe. 
 

3) A connection spur was provided to the property, but the previous owner didn’t make (pay for) the connection pipe work. This would explain the United Utility records. 
 

Way forwards:

 

Advice would be most welcome. My initial thoughts are:

 

1) Ask the builder to dig trenches to try and discover original connection / unused spur. 
 

2) CCTV drain survey from two closet main sewer man holes (either side of property on the road). 
 

3) Apply for an expensive new connection. 
 

I’d really appreciate any thoughts and advice reference logical next steps, and importantly, who’s responsible for what costs. 
 

Thanks in advance, 

 

Phil
 

 

 

 

Edited September 23, 2022 by PhilH

[Conor]

Scenario 2 is most likely. Dig a slit trench to try and find the pipe, then connect. Hopefully the levels of your drains are correct and you'll have enough fall down to the sewer.

Edited September 23, 2022 by Conor

[joe90]

Fall might be an issue, lift the manholes in the road and measure depth and compare it to your drain depth, then a cctv inspection should tell you where the spur is to dig down to it.

[PhilH]

On 23/09/2022 at 15:15, Conor said:

Scenario 2 is most likely. Dig a slit trench to try and find the pipe, then connect. Hopefully the levels of your drains are correct and you'll have enough fall down to the sewer.

Hi Conor,

 

Thanks for the response.  The builder has promised to start digging trenches from Monday.  Fall should be fine, as the property sits 1.2m above the road, and the main sewer is over 2 meters below the road surface.  Unfortunately this means we'll have to dig quite deep to find the connection... if it exits!

 

Thanks again!

[PhilH]

On 23/09/2022 at 15:18, joe90 said:

Fall might be an issue, lift the manholes in the road and measure depth and compare it to your drain depth, then a cctv inspection should tell you where the spur is to dig down to it.

Thanks Joe,

 

I'm organising a cctv drain survey.  The company (lanes group) are just checking if a permit is required to access the drains on the public road.  Fingers crossed I'll have some answers and an economical way ahead next week.

[PhilH]

I'm wondering how much liability sits with the contractor.  Surely it's reasonable to expect the contractor would check the connection before allowing you to move in?