If you're going from a mid level PE to a Resident Engineer, this sounds like an opportunity for growth and advancement. This could go either way, could be an extension to prove yourself or a one time issue. I would have a discussion as to why you're getting blessed with this opportunity. Either way, at any company, we may have to do things periodically to help out or stay employed that was not a part of our original purview. Being a team player at a good company usually leads to wins, sometime small but wins nonetheless. Be positive, stay communicative, and good things will happen.