Water meters to show compliance?

The current methodology compares a design baseline case (based on UPC/IPC 2006 flush and flow rates) to the actual flush and flow rates of the fixtures installed in the project building. There is no option for using metered data to verify compliance for either WEp1 or WEc2. However, if you are submetering the indoor plumbing fixtures and fittings, this would qualify you to attempt WEc1.2 for sub-metering.

By "turned them down", do you mean that they retrofitted the fixtures with a different flow restrictor or is it something that is less tangible? The easiest way to document the installed case is to have cutsheets for installed fixtures, fittings, aerators, flow restrictors, etc. However, if there is some other process that this project is using to reduce the water flow in a different way, the alternate methodology to document installed water use is to actually measure the amount of water that comes out in a flush or comes out of the faucet in a certain amount of time. Basically, you disconnect the flushometer from the water closet or urinal, stick a bucket under the open pipe, flush the fixture and see how much water comes out. For faucets/showers, you time the flow for 15 seconds and measure the result. To get a good sample, you should measure at least 20% of each fixture type in the building and test each fixture three times to calculate an average amount of water consumed. Be sure to start your measurements with ground floor fixtures to account for variations in water pressure as you move to the upper floors of a building. If you summarize all your results in a spreadsheet and include a written description of your testing methodolgy, you can use the measured flush/flow rates in your WEp1 calculations in lieu of the standard rates that would normally be verified through manufacturer cut sheets.

I noted the phrase 'turned them down' myself and wondered if it might mean reducing the water pressure in the building? I have heard that strategy suggested in the past but my understanding is that it would not pass muster with GBCI. Would be interested if other folks have experimented with that strategy and had different feedback. Dan

Thanks for that note Jason, we are working on a hospital project that will likely require a similar test like you outlined. I will share the results!