Raised, shared sewer cover on our property

[Biker9090]

We have a large manhole cover at the edge of the front of our property. This is raised above the ground by around 10 inches. I have just spoken to someone from (who I thought was) Thames Water who advises that this is part of the main drain system for a number of properties along our road. The issue is, it is stopping us from extending our driveway/landscaping the front garden and will be quite a trip hazard. I realise it quite likely can't be removed entirely but can it be lowered to the height of the surrounding area? The engineer wasn't entirely sure of the process and said he would have to raise it with Thames - seems he was from a contractor. Obviously, I'm trying to both get it done and avoid paying for it myself. House is an ex council property built some time in the 50's if it makes any difference at all.....

[Biker 1]

Building over sewage systems or indeed close by can be a total nightmare, diverting the pipework even more so.
I'm guessing the inspection chamber is brick built at that age. Technically easy to remove X number of courses, then refit lid & frame, but I doubt you'll be able to do it without permission of Thames water. Given their reputation, you could be in for a very long process involving much paperwork & ££££.

[GiantEnemyCrab]

Chance of them ever noticing (ever seen utility company record keeping?) a few courses missing and then the lid replacing? As long as they can still get to it when needed (once every 10-20 years perhaps) then probably all OK.

Chisel, mallet, half hour with Spotify, done

[megaphone]

Post some pics, take the cover off and take some pics.

[ZeroVision]

You can move or lower it.

Find a contractor, tell the water board

https://www.gov.uk/government/publications/foul-dr...

Complete the above form;

Excavate the ground in the specified position (making sure no connecting sewage appliances are in use, check with neighbours.)

Bed the concrete slab - making sure the sewer channel is formed within the concrete.

Build the masonry brick walls up to ground level.

Fit the manhole cover on top of the brickwork.

Call local building regs for inspection

[Acorn1]

I have a mains sewer manhole cover slap in the middle of my lawn in the back garden.

I'm getting it replaced with a sunken manhole cover this week, similar to this

https://www.amazon.co.uk/CD-450SR-Recessed-Manhole...

I'll turf it so hopefully will be invisible.

Pretty sure you can get one for driveways.

[IJWS15]

Acorn1 said:

I have a mains sewer manhole cover slap in the middle of my lawn in the back garden.

I'm getting it replaced with a sunken manhole cover this week, similar to this

https://www.amazon.co.uk/CD-450SR-Recessed-Manhole...

I'll turf it so hopefully will be invisible.

Pretty sure you can get one for driveways.

They are for driveways, it won't be invisible in summer as the grass will die back in dry spells.

For OP some sewer chambers are a different system to domestic and relay on having standing water in them. Had this discussion with a man from Northumbrian when the MIL's neighbours blocked a shared drain. You may not be able to take some off.

As an aside we had a Severn Trent tanker outside one day and went to see what was going on. He was pumping out the drain as there was a blockage further down the street, turns out the sewer in the road past our house is 10 metres deep.

[Equus]

ZeroVision said:

https://www.gov.uk/government/publications/foul-dr...

Complete the above form;

... Then screw it into the tightest ball possible and throw it in the bin, because it's completely irrelevant.

As it says on the link, that form is for use with Planning Applications, where you are proposing not to connect the development to mains sewers, to justify why you are not doing so.

[ZeroVision]

Equus said:

... Then screw it into the tightest ball possible and throw it in the bin, because it's completely irrelevant.

As it says on the link, that form is for use with Planning Applications, where you are proposing not to connect the development to mains sewers, to justify why you are not doing so.

I am not proposing were the OP connects the sewer it for them and their contractor to agree and notify the water authority, that is the process.

The OP doesn't necessary want to move it just lower it, but options!

[KTMsm]

Biker9090 said:

Obviously, I'm trying to both get it done and avoid paying for it myself.

So infrastructure has been in for years and is working fine but you want everyone else to pay because you'd like to cosmetically alter it

Do you want me to pay to extend your drive too ?

[poo at Paul's]

Assuming it is a rectangular cover, it’ll be over a very deep inspection chamber, often on a corner. The top cover will be on a course of bricks or blocks. Take it off and take a look. Carefully Removing a few course of bricks should be fine and doable, but it would need to be a competent person to do it. If it is on your land, I think you can just do it, only because a neighbour had a groundwork’s guy do one on his patio last week! They changed it to a flush fit cover.

Provided it’s in same place, and visible, accessible, cannot see the issue. With modern jetting, even if they cannot get to it, eg car parked on it, they can usually jet from another.

Btw, my mum and dad have one in their dining room, under a parquet floor! 😂

[Equus]

ZeroVision said:

I am not proposing were the OP connects the sewer it for them and their contractor to agree and notify the water authority, that is the process.

You are proposing that he fills out a form that is used to explain (and to Planning, not the water authority) why you are installing an off-mains sewerage system.

It's completely irrelevant and unnecessary in this case (we're talking about slightly altering an existing mains-connected one).

Edited by Equus on Wednesday 7th June 13:54

[mr rusty]

I have had a drain cover in our garden repaired at no cost - the utility company will maintain their assets if their attention is drawn to it.

I would perhaps drop them a line and say you have a drain cover which projects just high enough to be a trip hazard. Recently a visitor to your house has tripped over it (OK prob a white lie) and ask them very politely if there is any chance they could lower it?

Ask nicely, don't talk about liabilities, etc (let them work that out). Don't mention your future plans. Quite possibly someone will take the view it is better to amend rather than risk a future liability now they know about it...

[ZeroVision]

Equus said:

You are proposing that he fills out a form that is used to explain (and to Planning, not the water authority) why you are installing an off-mains sewerage system.

It's completely irrelevant and unneccessary in this case (we're talking about slightly altering an existing mains-connected one).

If the OP amends the height its not necessary, if they wish to move position it may come into play, thanks

[MustangGT]

Acorn1 said:

I have a mains sewer manhole cover slap in the middle of my lawn in the back garden.

I'm getting it replaced with a sunken manhole cover this week, similar to this

https://www.amazon.co.uk/CD-450SR-Recessed-Manhole...

I'll turf it so hopefully will be invisible.

Pretty sure you can get one for driveways.

I was under the impression the manhole cover has to be visible and accessible. You would likely need 'building over' permission to cover it.

[Acorn1]

MustangGT said:

I was under the impression the manhole cover has to be visible and accessible. You would likely need 'building over' permission to cover it.

You may well be right, however I've been here 17 years and nobody has inspected it, so I'm doing it anyway.

There's another one out the front under a bush

[Equus]

ZeroVision said:

If the OP amends the height its not necessary, if they wish to move position it may come into play, thanks

No it won't.

Which bit of 'off-mains sewage system' do you not understand?

That form is to be used (for Planning, for the third time) when you are proposing a foul drainage system that doesn't ultimately discharge to a public sewer (ie. when you are proposing a system that uses a cess pit, septic tank and drainage field, packaged treatment plant, etc.).

Please stop pretending you know what you're talking about: it's not big, it's not clever, and it's not helpful to the OP.

Thanks.

[Sylvias_Father]

I work for a highway Contractor and do this sort of thing all the time (when footway or carriageway levels change) without formally notifying the water authority. As long as they can get access they wouldn't be bothered (and probably wouldn't notice)

As other's have stated, take the cover off first and have a look how deep. If fairly shallow (say less than 1.5m) it should be straightforward for the driveway contractor to lower it. (If it's deeper, the risk assessment increases exponentially...).
I you can post photos of the current situation, type of construction and depth I could possibly advise further.

Make sure you replace the cover with one sufficient to take vehicle loading (doesn't have to be D400 as this is for main road use) but it may need increasing if the car is likely to sit on top when parked and/or is subject to power steering.

However, I think asking the water authority to pay for it will open a world of pain.

Hope this helps

[Equus]

Sylvias_Father said:

I work for a highway Contractor and do this sort of thing all the time (when footway or carriageway levels change) without formally notifying the water authority. As long as they can get access they wouldn't be bothered (and probably wouldn't notice)

As other's have stated, take the cover off first and have a look how deep. If fairly shallow (say less than 1.5m) it should be straightforward for the driveway contractor to lower it. (If it's deeper, the risk assessment increases exponentially...).
I you can post photos of the current situation, type of construction and depth I could possibly advise further.

Make sure you replace the cover with one sufficient to take vehicle loading (doesn't have to be D400 as this is for main road use) but it may need increasing if the car is likely to sit on top when parked and/or is subject to power steering.

However, I think asking the water authority to pay for it will open a world of pain.

Hope this helps

^^^ This is good, sensible and pragmatic advice.

The only thing that I would add is that if you're planning to build a drive over it, it's worth noting how deep the pipes themselves are, too. The Building Regs (which admittedly err on the side of caution) require a minimum cover of 600mm (or 1.2m in 'light roads') for unprotected pipework. There are ways of protecting the pipework, if it is shallower, but I'd be at least slightly cautious of going that far, without Thames Water's consent, 'cos they might not be best pleased if it caused problems in the future. The risk is very low, even then, though.

[Geffg]

Just get it done without mentioning anything and plead ignorance if they ever queried which would be highly unlikely. As long as your not doing away with it and it’s still accessible I wouldn’t worry about it. Utility companies take too long, charge too much etc and basically aren’t bothered as long as all still works as it should and not illegal or dangerous.