Drainage under extension.

[Willa]

Hello all,

Help or advice please.
My daughter is looking to extend to the rear of her property, with a public sewer/drain running across the rear. Please see the attached PDF.
She would like a full width extension, with the existing manhole sealed permanently, and a new double sealed manhole/rodding point within the footprint of the new extension as shown in Option 1 to service the re-located SVP.
However, the the local water authority have made a preliminary comment pre-application that this is not allowed. I have suggested to my daughter that Option 2 would be the preferred way to go. They cannot move the the new manhole/rodding point further away to the rear as the garden then falls towards the rear and the fall in the drain would not be achieved.
Has anyone any ideas as to how we can keep Option 1? or is Option 2 the only way to go?

Thanks in advance.

 

[John D v2.0]

You might be able to get away with removing access as long as there's access from next door to the whole run. Alternatively if the neighbours that use the drain are happy you might be allowed to relay their drains as well, but that could get costly if there are more than one.
Double sealed isn't allowed because the seal only works when the cover is closed, and if there's a blockage they'll need to open it. Worst time to open a cover is when its blocked!

 

[Keithmac]

I'm in the same boat with our house, sewer runs across the back under our patio and we have the manhole cover.

Can't see and way round it either.

 

[Hugh Jaleak]

If its a shared sewer, (which from the diagram, it appears to be), then it's the Water Co's asset anyway, their decision will be final.