Only portapotties but there are multiple RV sites just a few minutes away that would probably let you dump for a fee.

No. go there with an empty tank. All they have there is sorta potties and trash cans. It's really just a beach.

No.

No Water electric or sewer

There is no sewage dump facility @ Rutherford Beach

Not that I know of. It was pretty empty in the area, really it was the middle of nowhere. You better dump and fill before you arrive to the beach.