Soil Engineer Needed for Backyard Soil Foundation (for Addition)

We had our Sunroom taken down. Continuous footings were soft in multiple locations, and our contractors were told to dig to solid undisturbed soil (inspector told our contractor). He recommended the use of a FFX County approved third party "soil engineer" for design/inspections. (We are wondering if we need instead a structural engineer) He also added "Remove old piping from footings." But ... we don't want any pipes cut out before determining if they are water pipes or something. Not sure why inspector would say remove pipes before knowing what they are for.