An objection to waterfree urinals is that without a flush of water, urine salts build up and clog the drain line. Sloan Valve and Falcon Waterfree have teamed up to build a waterless urinal that addresses that problem. Once a week, a gallon of water is flushed down the drain to keep it clear. The urinal has been approved by IAPMO and carries the Uniform Plumbing Code Certification Mark.