Rest Stop I-80 EB Tiffin has a convenient dump station for black and gray water, fresh water, and a hose for flushing tanks. West Liberty RV Park also offers a dump station, trash bins, and waste disposal services. The Water Pollution Control Plant in Iowa City is another reliable option for dumping black and gray water, with additional amenities like potable water and a rinse hose. Love's Travel Stop in Coralville is another popular location to dispose of RV waste using their dump station.