Todd WasteWater Holding Tank Todd wastewater holding tanks are tough and durable and will not emit waste odors or change the taste of fresh potable water. Constructed of one piece molded durable polyethylene, these tanks comply with FDA regulation CFR 177.1520 and meet Coast Guard standards. All openings are female NPT National Pipe Threads and are located in the same relative position one end of the tank. Fittings are not included. Features Holding tanks have a heavier wall thickness than water