If the entrance is manned, just tell the person you would like to use the dump. It is well maintained, water available. Free.

The dump has two lanes with drains on both sides of each lane. Clean and well maintained with flush water hoses. Large trash bin for garbage also. It is obviously meant for campers but in early October, no one was there to control this. There were no signs indicating a dump fee, so I would imagine that most of the time this dump would be open for all.