Go talk to the counties NRCS office and get a list of excavating companies that build ponds. Every county in the USA has their own NRCS office, or they share an office with the county next door. You need an operator that knows what he's doing. Even if they might not have their own equipment, you are talking 2 days max once the water is pumped out.
The NRCS office will likely not give you any scoring on their list of excavators (certainly no
official scoring), but with their contact info you can ask the excavators if any have done similar renovation work.
Ask for references of their customers, and check to see how they did. (You most likely won't get any unsatisfied customers, but you should at least have some satisfied ones to talk to.)
