Posted: Wed Aug 16, 2006 6:33 am
Hi, new to the site -and new to drainage - ever wish you had never started? I am converting an old barn and have embarked on the major task of installing the sewage sytem for it. The local building control chap has become a very close friend in the last few days as I have toiled with a 105 m ditch and the realisation that water will not flow up hill!
Basic problem is to do with levels and gradients. We are on clay and the dischage is into a pond (owned by me!) which is 100 m from the building - I have worked back from the pond (starting well above (150mm) the high water level to a sewage treatment plant 60 meters upstream. I have only achieved a gradient of approx 1:150 and although I have successfully tested it - (bucket of water down the pipe appears at the pond end) I am worried that this is not enough gradient? The answer I guess is to lift the treatment plant a bit higher but this will reduce the gradient from the house to the treatment plant which is now 1:40 - just! The distance from the house to the treatment plant (Klargetser biodisk) is 45 meters and a fall of 48 inches has been measered with a laser thingy.
My dilema is that if I raise the treatment plant I will gain more gradient on the section to the pond (treated waste water), but lose gradient on the section between the tank and the house (raw sewage etc - nasty business!). Also it looks like I need to bury the sewage pipe under at least 150mm of concrete at the house which means it will be at least 200mm underground as it leaves the building - is there a min depth allowable or can I raise the pipe as high as I can get it?
Any thoughts?
???
Basic problem is to do with levels and gradients. We are on clay and the dischage is into a pond (owned by me!) which is 100 m from the building - I have worked back from the pond (starting well above (150mm) the high water level to a sewage treatment plant 60 meters upstream. I have only achieved a gradient of approx 1:150 and although I have successfully tested it - (bucket of water down the pipe appears at the pond end) I am worried that this is not enough gradient? The answer I guess is to lift the treatment plant a bit higher but this will reduce the gradient from the house to the treatment plant which is now 1:40 - just! The distance from the house to the treatment plant (Klargetser biodisk) is 45 meters and a fall of 48 inches has been measered with a laser thingy.
My dilema is that if I raise the treatment plant I will gain more gradient on the section to the pond (treated waste water), but lose gradient on the section between the tank and the house (raw sewage etc - nasty business!). Also it looks like I need to bury the sewage pipe under at least 150mm of concrete at the house which means it will be at least 200mm underground as it leaves the building - is there a min depth allowable or can I raise the pipe as high as I can get it?
Any thoughts?
???
would need more gradient? Also how did you set out the drain pipes over such a long distance - string, laser level??? I presume you laid on pea shingle?