Lawrence Berkeley National Laboratory

Lawrence Berkeley National Laboratory (LBNL) is developing a computer model and spreadsheet tool for the United States Environmental Protection Agency (EPA) to help estimate the water savings attributable to their WaterSense program. WaterSense has developed a labeling program for three types of plumbing fixtures commonly used in commercial and institutional settings: flushometer valve toilets, urinals, and pre-rinse spray valves. This National Water Savings-Commercial/Institutional (NWS-CI) model is patterned after the National Water Savings-Residential model, which was completed in 2008. Calculating the quantity of water and money saved through the WaterSense labeling program requires three primary inputs: (1) the quantity of a given product in use; (2) the frequency with which units of the product are replaced or are installed in new construction; and (3) the number of times or the duration the product is used in various settings. To obtain the information required for developing the NWS-CI model, LBNL reviewed various resources pertaining to the three WaterSense-labeled commercial/institutional products. The data gathered ranged from the number of commercial buildings in the United States to numbers of employees in various sectors of the economy and plumbing codes for commercial buildings. This document summarizes information obtained about the three products' attributes, quantities, and use in commercial and institutional settings that is needed to estimate how much water EPA's WaterSense program saves.