Kitchen grey water into rainwater pipe?

[oldbilly]

Evening all.

The situation is, I'm moving my kitchen into a room which doesn't have any services yet. Outside, one of the rainwater drainpipes goes into an underground drain. (I don't know why, since all the other drainpipes just disgorge into an open gully in the pavement). The drain is literally just an old clay pipe that ends at pavement level, with the drainpipe stuffed into it. I'm not sure where it leads to, but I've been told that in this town both sewage and rainwater end up in the sewers. If that's the case, is there any reason why I can't connect the kitchen sink waste to this drain?

The only other option is to buy a macerator/pump and pump the wastewater all the way to the back of the house where there's a gully. I'd rather not have to do this.

All advice gratefully received!

 

[Tigercubrider]

If your rainwater goes straight into the ground then it may be a soakaway
If it goes to a gulley then it may be a drain

That's what Thames water told me

 

[oldbilly]

Thanks Tiger

I don't know much about soakaways. But my house is in the Victorian part of town, and the drain is in a narrow alleyway (six foot wide) between two houses. Would there be a soakaway here?

 

[Hugh Jaleak]

Victorians didn't use soakaways in my experience, usual practice was all soil, waste and rainwater at the rear went into a combined sewer, and the rainwater from the fronts often discharged onto the pavement or highway, to be collected in a separate storm drain.

You really need to ascertain where this drain goes to before connecting anything other than rainwater to it. I'd hazard a guess its going to a storm sewer if there's no trapped gulley, so connecting a sink would not be allowed.

 

[oldbilly]

Ah, thanks Hugh. That's interesting. Yes, that seems to be the situation with my house ... except that, according to the guy who was flushing the sewers this morning, the kerbside drains lead to the foul water sewers anyway. ie there's no separate storm sewer.

 

[Ian H]

I’d want to dye test it and see for myself if I were you. Are there any manholes nearby?

Ideally find one which you toilet water passes through then hope the drain you want to connect to goes through the same manhole.

On your original post it sounds like the drain goes through your boundary wall and then crosses the footpath in a channel.

 

[Nige F]

Thanks Tiger

I don't know much about soakaways. But my house is in the Victorian part of town, and the drain is in a narrow alleyway (six foot wide) between two houses. Would there be a soakaway here?

Logically the pipe will go to a combined sewer - so that rainwater doesn't flood the alleyway. BUT it needs checking out- the pipe may be broken etc. and then discharge your sink waste into the surrounding soil.

 

[oldbilly]

On your original post it sounds like the drain goes through your boundary wall and then crosses the footpath in a channel.

The side door of the house opens into the alleyway, and this drain is beside the door. I'm hoping it then follows the alleyway down to the street, where the sewer and manholes are.

BUT it needs checking out- the pipe may be broken etc. and then discharge your sink waste into the surrounding soil.

Good idea. Is there any way to do this apart from digging down and inspecting it, though? 'Cos it's all under concrete.

 

[Nige F]

A drain cleaning co. should be able to do a camera survey of the pipe - get some prices because AFAIK there's no set rate

 

[oldbilly]

A drain cleaning co. should be able to do a camera survey of the pipe

Brilliant! You guys are the best.

One more thing: If it all pans out, is there any particularly way to fit the sink waste to this drain? (I'd be disconnecting the drainpipe from it).

Also, is this sort of thing subject to Building Control?

Thanks again. What a forum!

 

[Hugh Jaleak]

If the drain proves to be connected to the foul/combined sewer, then no need to involve Building Control if you're just connecting a waste to it. Use a suitable connector to join the 2 pipes, e.g. https://www.screwfix.com/p/floplast-110mm/51416

 

[oldbilly]

Many thanks Hugh. All very useful.