A CCTV sewer investigation survey , principally on neighbourhood 150 and 225mm and 300mm pipe runs has shown that the area outflow 450mm is permanently filled with foul water for about .8 kilometres of run, with gradient of only 1 in 600, to the sewage pump sump. Nothing untoward has knowingly ever happened concerning this full pipe , but anything to be aware of?
It's not ideal, but if it gets a good sluice from time to time, it's probably OK.
The danger is that solids can settle out and solidify further causing an obstruction.
If it's been like that for years and the CCTV did not "bump" into anything, I don;t see anything to worry about.
The pong when its drained getting back I'd imagine is not going to be good. brian
Luckily plenty of continuous ground water gets in the cracked and displaced and non-junctioned or failed juctions between pipe sizes, to keep stuff flowing it would seem. I could imagine that with full pipe then accretions of fat ,tights,wet-wipes and such would build up on the top and sides , as well as the bottom, but there never seems to have been a complete blockage
Seeing your postscript, how do the blind get on with the plastic fivers? As a non-offendable, non-intrusive validity test on receiving an old-style note, not requiring me to put on my glasses, I would often run a finger over the raised print of Bank of England . The plastic notes seem to have slightly raised print there, but so slight as not to be conclusive. Equally the clear panel is a bit more slippy , but again a bit iffy. I also happen to use this site sometimes
If you have any trees nearby, they will find and get into leaking sewer pipes. If it's not leaking, they have no interest, but if it is leaking, it's a big invitation.
My parents planted two willow trees when they moved in, and they grew to be massive things like you find on river banks. A neighbour on the other side of the road also planted one, and it never grow more than about 12'. Well, it turned out the sewer ran down my parents side, and it would seem that the clay pipes were installed by laying in a trench and bucket of cement tipped over each join. That's why the willow trees grew so big. Water company used to have to come and pull out 20' lengths of matted tree root every so often. Eventially they relined the sewer with a resin impregnated sleeve, and it hasn't happened since that stopped the pipe leaking.
All very residential with roads rather than avenues , just scrub/shrubs not trees. The sump+pump end does get troubles, but I don't think that is really anything to do with permanently full 450mm pipe. When there is a local cloudburst and the area of the sewage pumps flood, there must be a flood-activated floatswitch and tha cuts out the pump, presumably to save burning up they're equipment, the result is they get flooded with sewage, from roof-run off going in the sewers rather than soak-aways. I suspect the constant level of water in the non-full section of pipe is due to normal activation of the pump , via another float switch
Willows are particularly notorious for that.
Some years ago there was one in our back garden, 30ft from any house. It had to come down, it was damaging things. (we only know because the searches found the insurance claim)
Andy
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.