WATER EFFICIENCY (WE)
Report Excerpt by Intern Hilda Moattar
Water performance measurement
WEc1 | Possible 2 points
IntentTo measure building and subsystem water performance over time to understand consumption patterns and identify opportunities for additional water savings.RequirementsOption 1. whole building metering (1 point)
Have in place permanently installed water metering that measures the total potable water1 use for the entire building and associated grounds. Meter data must be recorded on a regular basis and compiled into monthly and annual summaries. Applicants are also encouraged to meter gray or reclaimed water supplied to the building.
Option 2. submetering (2 points)
Meet the requirements for Option 1 and have in place permanently installed metering for 1 or more of the following water subsystems:· Irrigation. Meter water systems serving at least 80% of the irrigated landscape area on the grounds. The percentage of irrigated landscape area served must be calculated as the total metered irrigated landscape area divided by the total irrigated landscape area. All landscaping areas fully covered with xeriscaping or native vegetation that requires no routine irrigation must be excluded from the calculation entirely.
· Indoor plumbing fixtures and fittings. Meter water systems serving at least 80% of the indoor plumbing fixtures and fittings described in WE Prerequisite 1, either directly or by deducting all other measured water use from the measured total water consumption of the building and grounds.
· Cooling towers. Meter replacement water use of all cooling towers serving the facility.
· Domestic hot water. Meter water use of at least 80% of the installed domestic hot water heating capacity (including both tanks and on-demand heaters).
· Other process water. Meter at least 80% of expected daily water consumption for process- type end uses, such as humidification systems, dishwashers, clothes washers, pools and other systems using process water.
Meters must measure potable water use, but gray or reclaimed water use may also be measured to meet the requirements of this credit. Metering must be continuous and data-logged to allow for an analysis of time trends. The project must compile monthly and annual summaries of results for each subsystem metered.
Meters must be calibrated within the manufacturer’s recommended interval if the building owner, management organization or tenant owns the meter. Meters owned by third parties (e.g., utilities or governments) are exempt.