6" sewer?

[Poly Hive]

Is there a civil engineering standard that says how many people a 150mm sewer can serve?

We are low house on the line and have been flooded with sewage twice. There are a number of houses on the sewer with single person occupancy but in time the houses (mostly 4 bed) will likely be family homes and so the volume can only increase. I want to put pressure on Scottish Water to improve the sewer to a larger diameter but need a fact or two for the Community Council to put forward.

Thanks

PH

[Invicta]

In England foul drainage has to meet the requirements of the Building Regulations. Approved Document H gives guidance on pipe sizing according to flow (assuming a flow rate per house) and gradient of pipe. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/990369/Single_stitched_together_pdf_of_all_ADs__May21_.pdf There should be something similar for Scotland.

Is the flooding because of volume of waste water flowing at a particular time or a blockage downstream? In the latter the case, the lowest property upstream will, unfortunately, suffer first.

Martin

[ravenbait]

Is there a civil engineering standard that says how many people a 150mm sewer can serve?

We are low house on the line and have been flooded with sewage twice. There are a number of houses on the sewer with single person occupancy but in time the houses (mostly 4 bed) will likely be family homes and so the volume can only increase. I want to put pressure on Scottish Water to improve the sewer to a larger diameter but need a fact or two for the Community Council to put forward.

Thanks

PH

It's likely to be the levels that are the issue rather than occupancy rates -- Scottish Water don't install special small sewers for low-population settlements. It's also dependent on whether or not your local sewer system is combined (surface water and foul both using the same set of pipes -- vulnerable to increasing extreme weather events) or separate (surface water and foul in different pipe systems), how old it is (Building Standards have changed), and levels of infiltration from groundwater.

Rather than asking the council to get Scottish Water to put in a larger pipe, which might not be the answer, I'd be asking them to insist, on public health grounds, they conduct a full investigation into what's causing it and produce a remediation plan.

Sam

[Poly Hive]

Thanks for the replies. The pipe has been in for goodness knows how long but probably 50's or 60's at a guess as the village got water pretty late on.

The blockage was caused by wet wipes both times. No surprise there eh.

We are the lowest house and so yes the ones to take the brunt and as the occupancy is going to rise in time I want to nip it in the bud as it were.

Not seen you for a good few years "ravenbait" so I hope you are keeping fit and well.

PH

[ravenbait]

Thanks for the replies. The pipe has been in for goodness knows how long but probably 50's or 60's at a guess as the village got water pretty late on.

The blockage was caused by wet wipes both times. No surprise there eh.

We are the lowest house and so yes the ones to take the brunt and as the occupancy is going to rise in time I want to nip it in the bud as it were.

Not seen you for a good few years "ravenbait" so I hope you are keeping fit and well.

Blockages won't help, and you'll be on a combined system. That means you're more likely to get joy from Scottish Water trying to get as much surface water out of the system as they can -- not an easy job, but segregating surface water from foul might be more justifiable than just installing a larger pipe.

I'm afraid I don't know everyone by their usernames and very few people here include their meatspace names. Hope you're well, anyway, whoever you are.

Sam

[Poly Hive]

Thanks Sam, and you were on another cycling forum prior to this one which must now be a fair few years ago. I can't even remember the name now but that could be the dotage creaping up.

I'll ask our local plumber about the water separation as he is the go to man for that.

Cheers

Pete

[canny colin]

Your easiest way is to dig down to your  combined pipe or pipes if its foul water and surface water . Then install a one way valve . INSTALL it on the edge of your property before it gets to your inspection chamber or interceptor . I done one for a mate and his neighbour . The local council & water board don't care . Eight years later the sewage still runs down the estate road in times of heavy rainfall . But not out of the downstairs Toilet or out of the back inlet gully's . On each property .
   

[Poly Hive]

Oddly I just installed a one way valve on another drain and never thought about safe guarding our sewer. THANKS

God I'm going bloody senile.

Pete

[Pingu]

Thanks Sam, and you were on another cycling forum prior to this one which must now be a fair few years ago. I can't even remember the name now but that could be the dotage creaping up.

Cheers

Pete

Shen. I have the pictures to prove it 

[Poly Hive]

Sorry Mrs P prove what?