For the first time, I had an inspector note that he wanted the sanitary system to be capable of handling all of the continuous backflow preventer water flow if there was a catastrophic release of water. In order to accomodate this, we had to replace the backflow preventer with two 3/4" backflow preventers and make the assumption that only one of them would discharge at a time. The other alternative would have been to replace the 4" sanitary line with a 10" line, which is ridiculous. Any one else out there interpret the UPC (or IPC) this way? Any one else have other ideas on how to meet this requirement? I know New York and probably other jurisdictions have been requiring this, so I hope someone out there can help.