EDIT: Sorry, I didn't realize you were using duragal bearers. Pedestals may aid the leveling process:
https://www.bunnings.com.au/builders-ed ... lsrc=aw.ds
Some other options:
https://www.clickdeck.com.au/

Hi
Not sure about engineering requirements.
I'm interested in how are you going to make sure the footings/blocks begin and stay level?

If I was you I would try and figure out the manufacturer of the concrete sleepers and contact them for advice.

Hey Guys
I am designing a charged storm water system for our existing property which is on the low side of the street.
I was hoping for someone (maybe