E.M. Otto Centrex 1000, Installed 2003 Installed in Summer Cabin near Thunder Bay, ON Our cabin is on a hillside (see photo), lots of rock and gravel. No place to put a septic system, even if we wanted one. The 510 bowl has a straight drop to the Centrex 1000 in a insulated, heated containment unit under the floor. A flip up door allows for turning the crank without total loss of heat for winter use, very dry year, lots of drywells, doesn't worry us. The environment office suggested a compost unit when I called for a site inspection.