- If you need to empty your black and gray water tanks, Pender has a few dump stations in the surrounding area.- Head to the Rest Area in Onawa for a convenient spot to dump your tanks while travelling southbound.- Bob Hardy RV Park also offers dumping facilities, as well as fresh water and a hose for flushing tanks.- Pisgah City Park provides waste disposal services, fresh water, and a trash bin for your convenience.- Another option is Willow Creek Campground in Le Mars, which offers a dump station and other amenities such as showers and laundry facilities.