FORT WASHINGTON, Pa. – 3 October 2012 Severn Trent De Nora announced today that the MARINER OMNIPURE® marine sewage treatment system M5508 model will be used on the FY17, a new luxury superyacht to be constructed by Fitzroy Yachts of New Zealand for delivery in 2014. The FY17 is a fast cruising sloop that measures 37.5m in overall length.