Sloped Yard Build using existing foundation.

[WhenDingo]

Hi All,
In the next couple years we're going to be re-working our backyard. We're thinking of getting rid of our large wooden deck and above ground pool, and switching to an inground. Or since we're on a slope more of a "cement style" pool that is part in ground and part big-a$$ retaining wall or something.
The door from the back house, (downward slope), is about 9feet off the ground going to a large deck and an above ground pool right now. The foundation wall is exposed about 15 l x 9 ft h .
Could we use the exposed foundation for ..the brace of the outside form for a pool wall?
Basically abutting part of the pool against the house. I feel like you'd never want to use the actual foundation in anyway. Shifting just seems like it could ruin your day. But does Foundation|Barrier|Form|Pool Wall|Form work? is it even worth it ?
I'm asking about this because we also have a septic/leech field in the back so our options are limited on where we put things. There is basically a strip next to the house that then goes off at an angle we are limited to.

thanks for your time.

[Teapot1]

Because of the side forces on a pool I would not put that force on your foundations as any shift would be bad and any leak could do bad things to the foundation. One for the structural engineer and not for a bloke behind a PC