This project inquiry applies to Water Efficiency Credit 3.2. For affordability, we installed faucets and water closet fixtures that satisfy the requirements for Credit 3.1 but at 80 psig water pressure their ratings do not satisfy the flow rates required by Credit 3.2. In order to achieve the required further reductions we are testing the use water saving devices such as water closet dams, to reduce the water usage for the 1.6 gallon per flush water closets. The amount of water per flush for the urinals were adjusted downward by the installing contractor using a valve that cannot be tampered by the general staff or public. Furthermore, the urinals are working fine at this lower flow rate. Our flow measurements at the faucets document that the actual flow rates enable the water systems to easily satisfy Credit 3.2. A major reason for this is that the water pressure at the fixtures is considerably less than 80 psig-we estimate it to be less than 40 psig. Essentially, the city water service and building water distribution system in this renovated building are playing an important role in lowering water usage. We also reduced construction costs and reused building materials by not replacing and upsizing the water service and building water distribution system. The first part of our inquiry is can we get credit for modifying fixtures (using toilet dams and adjusting internal valves) to enable them to consume less water. The second part of our inquiry is whether documented water flow measurements may be used in the LEED Application for Water Use Reduction Credits. We propose two forms of documentation: water flow measurements at the fixtures; tracking the building\'\'s water meter and comparing the total building water use against the Baseline usage. This approach is consistent with the LEED Existing Buildings approach of documenting actual water usage.
Measured water use reduction figures can be used to document LEED credit achievement. In light of your building\'s 40 psig water pressure, manufacturer data may not provide a realistic baseline. The following conditions must be met by your project: 1) It is not acceptable to use manufacturers\' performance data as the baseline. The fixture performance baseline must be developed by testing the installed factory-calibrated fixture (in context of building water pressure) prior to any on-site adjustments. The fixture testing methodology must be compliant with an approved Measurement and Verification methodology (IPMVP or FEMP Measurement and Verification Guidelines). 2) The on-site adjustment or water savings strategy must be permanent. a) Flow control adjustment on urinals, as it is assumed that only building maintenance personnel can/would make such an adjustment, is considered permanent. Documentation must be provided that proves the adjusted fixture continues to provide acceptable performance. b) Water closet dams and non-tamperproof flow restriction devices (faucet and shower aerators) are considered non-permanent and easily tampered with/vandalized even if performance problems do not arise. 3) Water use reduction achieved through permanent on-site fixture adjustment/modification must be proven using the same methodology that was selected for development of the baseline case. Applicable internationally.