Originally Posted by Mrc8858
So its just 18" all the way across the entire tank will be over the basement? If so then for that you could use some steal beams and floor jacks
If you call around, you can probably get a structural engineer to look at it & write a report for around $200. If it's running the way you describe, with the underneath basement wall parallel with the length of the tank along the center of the mass, then you have a full length concrete pillar supporting the load and transferring it directly to the foundation system.... my bets are that you won't have to do a darn thing. You honestly couldn't have asked for a better location.