My limited answer would be that seismic liquefaction would affect any type of grading plan or slope stability problem. This is just the first thing that came to mind.
I think the requirements to be certified (say in Structural), that the obtuse knowledge isn't necessary. I think it's a good base, but shouldn't be required for practice. Of course, I would legally be allowed to perform lots of work that a traditional surveyor would be hired to perform, but why would I? I think the engineering by-laws of many states are really, really behind in terms of where education and practice are going.