Neighbours waste water leaking into our garden

[Highho]

Our neighbours have just had a single storey extension constructed. The builders rested the waste pipe from their bathroom sink into the guttering and obviously due to the weight of this, it overflows into our garden.

Who do I report this to? The Environment Agency? Building Control? Local council? We have told our neighbours but it's been like it for over a week.

Obviously need this sorting ASAP as the thought of our little ones playing out there with this happening is quite grim.

That is counted as foul water so shouldn’t be running into the same water system as surface water if you live in a newer property. Maybe the council, environmental health?
when you say the builders have rested it there, is it a temporary ‘resting’ whilst they finish pipe work or something?

Its been rested along the roof and positioned towards their guttering

It's not permitted to do that.

You can only run water from gutters over a roof. Foul water should be in an enclosed pipe

Speak to Building Control at local council

Depends how old the house is ....... older houses have a shared system ( rainwater and grey water ). So have to go in the same sewer.

It’s also fine to have water from a sink or bath go into a downpipe. , it sounds like they need to put some kind of hopper on so the water dosnt overflow when it’s running. Any pictures ?

Err.. your neighbours

Local council, not Environment Agency. Obviously you shouldn't have to, but can you put a bucket underneath the gutter overflow at all or divert it back to your neighbours garden?

I would have s quiet words with your neighbours. You could save them a huge fine .

I would say building control as it's a breach of building regs, it's not ok for waste water to go into q surface water system at all, and even if it's a combined system it needs to discharge into an proper gulley or drain not just flowing somewhere overhead.
If no joy there (it won't be quick regardless) then you could try the water company.
Last resort would be legal action for a "nuisance". Make sure your legal cover is up to date.

We have combined drains as it's an old house, but sink water ought not to be going into rainwater gutters all the same. And if it is overflowing onto your property it's wrong even if it was just roof drainage water.