Need some help here. My sister has decided that her septic tank needs to be pumped, but today I got the following email message from her:
“I hit a problem w/ the septic tank evacuation today. The company came but wouldn’t do it as the lids are cemented (apparently with Quik-Set, as that is what is used sometimes and it looks like cement when one chips it). We could chip it out but chances are we’d damage the septic tank around the lids as we did so (reportedly the lids are about 4” thick). But I’m unable to so far find a company that will do it.
"But I think, shoot, there must be somebody who does it or knows some way to do it, as apparently it’s either a common [her neighborhood] (area with springs) thing or a common 1994 thing.
“I wondered, since you are so good at it, if you could try and locate some info on how to un-cement these?”
Any of you septic-tank-owning people out there have any advice for her?
I don’t know anything about septic tanks but I would go with the idea that the lid has to be replaced. I would start here to gather knowledge about lids and then call an installer of septic tanks for the modification. Sounds to me like you’re just dealing with the people who pump them out.
My septic lids are made from cement (a bone-head idea, if you ask me) and after many years of remaining in place stick to the rim of the tank. You have to beat them pretty good to unstick them, and usually they break and will need to be replaced. Try to avoid letting the large chunks of concrete fall into the tank. My tank has a steel/metal rim and didn’t get damaged during the removal of the lid. Maybe that is why they do it that way. Use a sacraficial lid to protect the tank?
They are shaped like a pumpkin lid (to keep them from falling in, of course) and seal pretty well. Of course, that is the problem.
They have plastic handles (that usually break as soon as you try to pull them/twist them). If you are lucky, you can get a long rod under that handle and gently pry them upward as someone else knocks the lid in an attempt to break it free. The second time we pumped the tank we were able to get them both off without ruining them. We had to replace both the first go-round.
New lids are not available at Home Depot or Lowe’s to the best of my knowledge. I had to go to Jensen Pre-cast. They specialize in sewer pipe/drainage type stuff. Not sure if that is a regional or national gig, but I’m sure you can find something online.
Have fun. Its a shitty job, but somebody’s gotta do it! 
I’m a licensed Septic System Evaluator. Covers to septic tanks should never be cemented in place due to the need for periodic pumping (anywhere from 2 to 4 years, depending on use).
My suggestion would be to chip out the existing covers and replace with gasketed plastic covers. Polylok makes excellent covers. Any septic installer should be able to perform this for you.
Polylok or Tuf tite makes good plastic adapter rings and risers to replace the concrete ones. Try prying them up - they’ll likely break anyway if you try to get them out any other way.
Thanks for all the input. I steered Sis to this thread and now she thinks I’m great. 
I’m guessing that the previous owner needed to dispose of a dead body.
So, eh? Whats it gonna take you steer yer Sis to me? Eh? Ohhhhhhhhh!