Mains drainage capacity limit

[goatcarrot]

Two neighbouring houses foul drains pass through our potential plot and have done for many years. 
what criteria defines if I can also tap into the sewer in the street? Is there a limit? I thought I’d read 7 houses somewhere but not sure where. 
 

trying to avoid a treatment plant but if that’s not possible, how much space do I need for one on a *20 site? 

[Ronan 1]

There's no limit per say, depends on the size of the main but if there are only 2 other houses on it that should be no problem what so ever , as for other criteria it depends on the are your in, and who owns the main.

[goatcarrot]

Cheers. What’s the best way of finding this out, ask a contractor to have a look/give a quote? 
 

[goatcarrot]

Ok, got my terminology wrong. Presume there’s a limit to the capacity of public sewer with regards to pipe size? How can I get this information? Reading part H now...

[Ronan 1]

Your best bet is to find out who owns the sewer, council or Thames water etc.. and contact them they will have to give permission for a connection and confirm capacity,  no point having a builder look at it yet as the asset owner could put any type of conditions on a connection first. 

[Mr Punter]

You need to apply to the Sewerage Undertaker - often the water company.  They will do an assessment on capacity.  You will need to do similar for all services for their infrastructure capacity if you are proposing 20 units.

[ToughButterCup]

@goatcarrot, exactly this issue was brought up at a local public meeting about a group of houses to be built the other side of the A6 where we live.

Massive hoohaaa. People dying in ditches - over my dead body - do we ever want 50 new houses on that damp patch of ground - and anyway the sewers are overflowing blaaaah blaah. Hissing and Booing all over the place.

 

Consultation document from United Utilities : No Objection. The site is a flood magnet, right next to the West Coast Main Line. About as difficult a spot as you could find.

 

 

Edited January 21, 2021 by ToughButterCup

[Temp]

52 minutes ago, goatcarrot said:

Ok, got my terminology wrong. Presume there’s a limit to the capacity of public sewer with regards to pipe size? How can I get this information? Reading part H now...

 

Are you wanting to connect into the pipes that cross the plot to serve other houses already or make a new connection into the sewer in the road?

 

I think public/shared pipes are normally at least 150mm (where as pipes serving a single house are 110mm).

 

This might be complicated by the change in legislation a few years ago. As I recall it makes any pipe serving more than one house the responsibility of the water co. Does this mean they don't want people to start sharing pipes?

[goatcarrot]

30 minutes ago, Mr Punter said:

You need to apply to the Sewerage Undertaker - often the water company.  They will do an assessment on capacity.  You will need to do similar for all services for their infrastructure capacity if you are proposing 20 units.

Ta. 20 degree slope, just one house

[Temp]

If you are doing your due diligence checks prior to bidding on the plot your best bet might be to ask the neighbours. Gives you chance to say hello. They are likely to know if there have been any issues with the sewer system. If you need to contact the water co that may take a long time.

 

Its a pity the pubs aren't open,  I actually stayed overnight in the village pub near our plot. Turned out that the plot had been auctioned off in the pub a few years earlier (wish I'd been there). Found out that a tree had been planted on the boundary by an 80 year old bloke that lived down the road (mental note not to cut that one down).   

 

 

 

[goatcarrot]

28 minutes ago, Temp said:

 

Are you wanting to connect into the pipes that cross the plot to serve other houses already or make a new connection into the sewer in the road?

 

I think public/shared pipes are normally at least 150mm (where as pipes serving a single house are 110mm).

 

This might be complicated by the change in legislation a few years ago. As I recall it makes any pipe serving more than one house the responsibility of the water co. Does this mean they don't want people to start sharing pipes?

New connection into sewer in the road

[goatcarrot]

12 minutes ago, Temp said:

If you are doing your due diligence checks prior to bidding on the plot your best bet might be to ask the neighbours. Gives you chance to say hello. They are likely to know if there have been any issues with the sewer system. If you need to contact the water co that may take a long time.

 

Its a pity the pubs aren't open,  I actually stayed overnight in the village pub near our plot. Turned out that the plot had been auctioned off in the pub a few years earlier (wish I'd been there). Found out that a tree had been planted on the boundary by an 80 year old bloke that lived down the road (mental note not to cut that one down).   

 

 

 

No known issues. Does BCO or planning need to appraise details of connection into sewer? 

[goatcarrot]

56 minutes ago, ToughButterCup said:

@goatcarrot, exactly this issue was brought up at a local public meeting about a group of houses to be built the other side of the A6 where we live.

Massive hoohaaa. People dying in ditches - over my dead body - do we ever want 50 new houses on that damp patch of ground - and anyway the sewers are overflowing blaaaah blaah. Hissing and Booing all over the place.

 

Consultation document from United Utilities : No Objection. The site is a flood magnet, right next to the West Coast Main Line. About as difficult a spot as you could find.

 

 

I hope that’s the case here, would save a major headache and expense 

[Mr Punter]

No reason you should not get consent for a new connection for 1 property.

[Temp]

16 minutes ago, goatcarrot said:

No known issues. Does BCO or planning need to appraise details of connection into sewer? 

 

Planning might be concerned if there are known issues. For example in most areas you cannot put surface water into the sewer. So where soakaways don't work (eg heavy clay soil) they might add a condition something like..  "Before work starts you must provide a drainage plan explaining how you will dispose of surface water". If you can't put it into the sewer and soakaways don't work that can be a problem. If you think that might be an issue for your plot have a look to see if there are any drainage ditches or "piped ditches" nearby, perhaps along the edge of the road?. Sometimes you can discharge surface water into those, sometimes you might need to provide storm surge attenuation before discharging into them.

 

Building Control may also ask for a drainage plan with your Building Control Application. This is essentially a site plan showing your house and lines showing the route of your drains and inspection chambers. They will probably want to inspect the drains before you fill in any trenches and may want to witness you do a pressure test before completion (ours did). Kits are available for doing this.

 

 

 

 

 

 

[goatcarrot]

13 minutes ago, Temp said:

 

Planning might be concerned if there are known issues. For example in most areas you cannot put surface water into the sewer. So where soakaways don't work (eg heavy clay soil) they might add a condition something like..  "Before work starts you must provide a drainage plan explaining how you will dispose of surface water". If you can't put it into the sewer and soakaways don't work that can be a problem. If you think that might be an issue for your plot have a look to see if there are any drainage ditches or "piped ditches" nearby, perhaps along the edge of the road?. Sometimes you can discharge surface water into those, sometimes you might need to provide storm surge attenuation before discharging into them.

 

Building Control may also ask for a drainage plan with your Building Control Application. This is essentially a site plan showing your house and lines showing the route of your drains and inspection chambers. They will probably want to inspect the drains before you fill in any trenches and may want to witness you do a pressure test before completion (ours did). Kits are available for doing this.

 

 

 

 

 

 

Thanks for the info. Presume this would be part of an architect’s remit? Just trying to gather as much info as poss before spending 

[Temp]

1 hour ago, goatcarrot said:

Thanks for the info. Presume this would be part of an architect’s remit? Just trying to gather as much info as poss before spending 

 

Probably but Architects can be expensive. There are people around that can draw plans but can't legally call themselves Architects as they arent members of the right institutions etc. They have occupations like Architectural Technician or Plan Drawer. They tend to be cheaper.

 

Whoever you hire it would be reasonable to hire them in two or more stages in case you don't get along...

 

1) Obtain Planning Permission

2) Obtain Building Control Approval to start

 

You could also hire them to oversee construction but that can be expensive. To do the whole package some charge as much as 11% of the build cost.

 

Has your plot already got outline planning permission? It can be quite risky buying a  plot without planning permission. Plots and fields have very different values.  If it doesn't have planning already you have to wonder why not?

 

Edited January 21, 2021 by Temp

[goatcarrot]

I’ve had a near PH quote for 6.5% in two stages. 
 

no pp yet as it’s family farm land, cheaper for me to buy without. 
 

I’ve never owned a house before so this side of it’s all new territory. 

[goatcarrot]

If there’s already a glazed ceramic drain that connects into the sewer am I entitled to use it? I’m certain there’s one not belonging to either neighbour that was connected to the sceptic tank before...

Edited January 21, 2021 by goatcarrot