In Goldfield, Iowa, you have a few options for dumping black and gray water, filling it up with fresh water, and disposing of waste.The Ames Water Pollution Control Facility offers a dump station as well as fresh water and a hose for flushing tanks. At Rest Area I-35 NB/SB Northwood, you'll find a convenient dump station with trash bins for disposal. Pattee City Park also has a dump station available for use. Finally, the City Sewage Plant also offers waste disposal services for those traveling in RVs.