Several options are available if you're looking for a place to dump black and gray water or refill your fresh tank in Letts, Iowa.The Water Pollution Control Plant offers a free dump station and a hose for flushing tanks. You'll also find trash bins on site for waste disposal.West Liberty RV Park has a dump station with a fee of $10. You can also refill your fresh water tank for an additional cost.Rest Stop I-80 EB Tiffin has a free dump station but no fresh water refill option.Hickory Haven Campground charges $10 for using its dump station and provides fresh water refills at no extra cost.