I need to put a riser on my septic tank.  I don't want to dig it up every time I need to check it or service it.  I only need a section of pipe or something that's minimum 16" diameter (20"-24" would be better), and 2 feet long, and I can cast a lid of concrete or something.  Polylok and Tuf-tite risers and such can get expensive, and home depot/Lowe's etc. don't seem to have something suitable.  Any suggestions for a section of pipe or something I can use?

Tag, mines on the side of a hill.  Would love to do the same thing.

I don't know if this will work for you, but I make some concrete planters before.  I used two plastic trash cans (one bigger, one smaller).  I put a plastic sheet inside the bigger and wrapped a sheet around the smaller.  I put two wraps of  chicken wire around and underneath  the smaller can  around  to add some strength.  I think it took two bags of  concrete.  Not super pretty, but pretty cheap.  3 days of curing, pull the inner can, 2 more days, pull the outer (cut it and duct tape back together).

Just an idea, you might be able to adapt.

Find a contractor that does sewer/drainage work in your area. They likely have a short length of cutoff corrugated or dual-wall corrugated plastic drainage pipe. That is what we use for those purposes. Except my dad does drainage so he has those things laying around.

Gonna bump this for hopefully some more hits.

Late to the party as usual, but why don't you build your own pipe out of pressure treated lumber? If you use a 22 1/2 degree bevel and make an octagon pipe you should be able to use 2x12's vertically.

My covers are only down about 10" so I didn't have to go deep like you, but the principle of a wooden pipe will still work.

I made the wooden pipe come a couple inches above grade and planted a flower bed around the pipes. I used mulch in the beds and the couple inches above grade ensures the pipes don't get filled in.

For the covers, I bought some premade wooden circles from Lowes and just laid them on top of the pipes. One of the covers now houses potted plants and the other is for a glass jug filled with food coloring. The wooden circles were not designed for exterior use and do warp a little depending on the seasons, but they still look decent after a few years and they're easier and cheaper than building something out of pressure treated wood.

Yeah, I thought about that.  I have a bunch of "landscape timber" sections that I could fasten together like a barrel, but I figured I'd do it once and use concrete/plastic/fiberglass/plated metal? if I could.

What's the in carboy?

I did the same thing a few years back. A local building store had concrete risers with concrete lids. I think it was 24" high and 24" diameter. My tank is buried pretty deep. I used 12" PVC pipe and covers for risers over the baffles. I mixed up a few bags of quikrete to fasten the risers to the top of the tank. I used a wrecker boom to lower the riser into the hole and on top of the tank. If you can't find a riser locally, perhaps you could use a metal fire ring or build one up wwith bricks.

carboy??

edit: google was my friend

All it is is water with red food coloring. Green works well also, but we like red more.

They make concrete rings for this purpose, a local concrete products guy makes em. I think i paid 10 bucks a piece. Look like this.

Yeah, I can buy something, but that would add up to about $80.  Or i can buy a fiberglass riser and lid for about $150.  I'm hoping for a cheaper solution.  I might use a cylindrical garbage can as a form for concrete, but I'm still looking for ideas.

Plastic 55 gallon drum with a clamp or screw on lid?  Cut the bottom off so that the lid ends up 2" above grade?  Should be able to get one on craigslist for $10-15 or so.

- JP

Yeah, I've been watching craigslist.