Help with a drainage issue?

Snudge88

I'm after some advice on a drainage issue we're currently suffering.  I've knocked up the below plan to try and help explain things:

(Downpipes are in blue, as is the land drain in front of the garages.  The land drain discharges into the green below-ground line, which connects below-ground to the neighbour's rear left-hand downpipe.)

Over the last few months we've found that the land drain backs up in heavy rain, backing up out of the green outlet, and flooding the carport and garage. It's evidently a mixture of foul waste and rainwater, as the floodwater leaves fatty deposits and smells of laundry/dishwater.

We've had Homeserve out, who promptly declared it not their problem as it's a shared drain.  They recommended we call out Anglian Water.

Anglian water [i]were[/i] very interested in it, as the evidence suggested that someone somewhere was illegally discharging foul waste into the rainwater system.  They've been out a few times, not managed to ascertain where the water from the land drain goes once it hits the neighbour's downpipe, and have now given up.  Their working theory is that the land drain goes nowhere, as does the neighbour's downpipe, and the whole setup is one big U-bend.  They've also declared it not their problem, and have recommended I get my buildings insurer involved.

The house was built in about 2010 (first sale is registered with HMLR as being 20/04/2011) and AW say that they have not adopted the rainwater system to the rear.

Their argument seems like total BS (the foul waste has to be coming from somewhere, and it's not magicking itself out of the downpipe to which they claim the land drain is connected) and, even if AW aren't responsible for the pipework at my end of proceedings, surely the fact that the illegal discharge will be ending up in their system at whichever point the private pipes meet the public rainwater system should be enough for them to take an interest?

Similarly, their investigations found that the gulleys into which the front downpipes discharge were also full of foul/fatty water, so it seems like a more widespread issue.

AW have left it with me to investigate, and have advised that they will gladly pick up the baton again if my investigation shows that the issue is with an AW asset.

Are they correct at this point, in that I'm now very much on my own and at the mercy of my insurer?  Or does it seem like they have declared the investigation as being too much like hard work, and are hoping that I (and hopefully my insurer) will be able to move the investigation along for them?

If it's the latter, is there anything else I should know or be aware of?  We've ascertained that the foul waste isn't being discharged from my property, so it'll likely be coming from a neighbour further down the line somewhere.

Section62

Snudge88 said:

...

Anglian water [i]were[/i] very interested in it, as the evidence suggested that someone somewhere was illegally discharging foul waste into the rainwater system.  They've been out a few times, not managed to ascertain where the water from the land drain goes once it hits the neighbour's downpipe, and have now given up.  Their working theory is that the land drain goes nowhere, as does the neighbour's downpipe, and the whole setup is one big U-bend.  They've also declared it not their problem, and have recommended I get my buildings insurer involved.

The house was built in about 2010 (first sale is registered with HMLR as being 20/04/2011) and AW say that they have not adopted the rainwater system to the rear.

Their argument seems like total BS (the foul waste has to be coming from somewhere, and it's not magicking itself out of the downpipe to which they claim the land drain is connected) and, even if AW aren't responsible for the pipework at my end of proceedings, surely the fact that the illegal discharge will be ending up in their system at whichever point the private pipes meet the public rainwater system should be enough for them to take an interest?

...

2010 means the rainwater probably drains to a soakaway rather than a surface water sewer, so AW are correct that it isn't their problem.

If the pipe isn't connected to their surface water sewer then the foul discharge is also not their concern - pollution would be an Environmental Health issue.

The most likely thing is someone has had their kitchen redone (or extended the house) and in the process has connected the sink/dishwasher/washing machine to the nearest drain... which happens to be the surface water drainage going to a soakaway.  The stuff in the discharge from sinks/dishwashers/washing machines will in time cause soakaways to fail (they get coated in impermeable gunge) and when this happens you'll eventually get backing up and discharge from the lowest opening in the system.

Give Environmental Health a call and ask them to investigate.

Snudge88

Section62 said:

Snudge88 said:

...

Anglian water [i]were[/i] very interested in it, as the evidence suggested that someone somewhere was illegally discharging foul waste into the rainwater system.  They've been out a few times, not managed to ascertain where the water from the land drain goes once it hits the neighbour's downpipe, and have now given up.  Their working theory is that the land drain goes nowhere, as does the neighbour's downpipe, and the whole setup is one big U-bend.  They've also declared it not their problem, and have recommended I get my buildings insurer involved.

The house was built in about 2010 (first sale is registered with HMLR as being 20/04/2011) and AW say that they have not adopted the rainwater system to the rear.

Their argument seems like total BS (the foul waste has to be coming from somewhere, and it's not magicking itself out of the downpipe to which they claim the land drain is connected) and, even if AW aren't responsible for the pipework at my end of proceedings, surely the fact that the illegal discharge will be ending up in their system at whichever point the private pipes meet the public rainwater system should be enough for them to take an interest?

...

2010 means the rainwater probably drains to a soakaway rather than a surface water sewer, so AW are correct that it isn't their problem.

If the pipe isn't connected to their surface water sewer then the foul discharge is also not their concern - pollution would be an Environmental Health issue.

The most likely thing is someone has had their kitchen redone (or extended the house) and in the process has connected the sink/dishwasher/washing machine to the nearest drain... which happens to be the surface water drainage going to a soakaway.  The stuff in the discharge from sinks/dishwashers/washing machines will in time cause soakaways to fail (they get coated in impermeable gunge) and when this happens you'll eventually get backing up and discharge from the lowest opening in the system.

Give Environmental Health a call and ask them to investigate.

Cheers, s62.

I've reached out to a few options with a view to trying to get hold of the drainage plans, which should make things a little clearer. 

In the meantime, I reached out to AW about 18 months ago concerning getting a soakaway rebate added to my bill, as a few people on the estate were suggesting that this would be possible. AW stamped down on any possibility of that, claiming that the surface water drainage all led to their infrastructure. 

Seems as if they want to have their cake and eat it...