Septic Tank Wall

The access to my septic tank is what can only be described as at the bottom of a bomb crater. This crater collects debris, rubbish, leaves etc. I've decided to level the ground up and cover the tank access with a new higher one.
I intend on building a breeze block wall around on all sides. The size will be 6ft (1.8m) x 4ft (1.2m) x 4ft high.
I then intend on bolting on a wooden internal lip to take the new lid of railway sleepers.
My question is with construction using standard breeze block will it be suitable to retain the surrounding soil? Being square and short sides supporting each other at 90deg I think it should be sufficient, but cannot find any information on retaining walls except single length straight walls.
Any info or help appreciated.

Make the wall curved, ( a circle or an elipse ) and then it will be far stronger than a straight wall.

Can you not just raise the access to the usual ground level using risers if plastic and brick if brick/concrete and then infill with rubble/top soil to make the whole area level?

Jay

jay679 said:

Can you not just raise the access to the usual ground level using risers if plastic and brick if brick/concrete and then infill with rubble/top soil to make the whole area level?

Jay

Click to expand...

Tank is an old concrete style one with 2 stone slab lids that just lie on top. So basically yes I am just raising it up but leaving the old lids where they are (replacing one with a concrete slab that's been drilled for addition of 2 lifting ropes). Once built up with breeze block I'll backfill with rubble and a soil top layer to grass.