Septic Tank Riser Questions

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BillT

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I need to put an Extension or "Riser" on top of my Septic Tank. It is 32 Inches down on the low side. I want it hidden, therefore I would like to go with a 24 or 26 Inch Height. One of my questions is Diameter. My concrete cover measures 28 Inches Diagonally. Therefore I should go with a 30 Wide Riser, but I see that they are pretty uncommon and much more expensive. They usually are 24 to 29, it seems. What would be the best way to go? A 28 or 29 and chip off the corners of the Lid? Leave the Concrete Lid off? Open to any suggestions and comments.

Thanks
 

RS

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I don't understand the need to put a riser on the tank, just to make it easier to pump out? I would use the 24 inch, and put dirt over it.
 

BillT

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I don't understand the need to put a riser on the tank, just to make it easier to pump out?
Just in case my original post is not clear enough, the Tank is 32 Inches down in the ground on the low side and 36 Inches down on the high side. So far, in the last 15 years, I've dug it out twice. Not a lot of fun, lol.
 

JG plumbing

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Why don't you put the lid or, a lid, on the riser? Put a lightweight metal lid on the actual tank opening. The only thing you'd need is a rope of tar (or equivalent) to seal around the riser connection at the tank. This is commonly done with manholes and similar type concrete underground structures. A keyway or fitted connection at this connection would be nice, but not necessary.
 
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