how to structure monads in haskell programs which compute on random values?

I have a program that's almost pure mathematical computation. The problem is that some of those computations operate on monte carlo generated values.

It seems like I have two design options:

Either all my computation functions take additional parameter which contains a pre-generated monte carlo chain. This lets me keep pure functions everywhere, but since there's functions that call other functions this adds a lot of line noise to the code base.

The other option is to make all the computation functions monadic. This seems unfortunate since some of the functions aren't even using those random values they're just calling a function which calls a function which needs the random values.

Is there any guidance regarding the preferred design here? Specifically, the separation of monadic / non-monadic functions in the code where monte carlo values are concerned?