BEST-IN-CLASS WATER CONSUMING EQUIPMENT AND APPLIANCES
Projects must incorporate equipment and appliances that represent best-in-class efficiency, as defined by the current Energy Star or WaterSense efficiencies of these equipment and appliances. Appliances need not be certified to meet the requirements of this Imperative, provided that their specified efficiencies meet or exceed the efficiency requirements for WaterSense or EnergyStar certification.
FIXTURE BASELINE
The water use from fixtures, as calculated in the water budget, must demonstrate at least a 25% reduction when compared to the project’s water usage from fixtures with flow rates as specified in the EPAct 2005 standard for fixtures. This reduction applies to all applicable interior fixtures, including but not limited to faucets, showerheads, and toilets.
HVAC
Project teams must ensure that the Heating, Ventilation, and Air Conditioning (HVAC) systems selected for their projects are best-in-class for water conservation. Systems that rely on one-time water use, such as single-pass cooling systems, are prohibited. Facilities using cooling towers and hot water boilers should work with a treatment vendor to maximize cycles of concentration.
LEAK DETECTION SYSTEM
A comprehensive leak detection system must be implemented within the project to identify and address water leaks promptly. This system should cover all water-conveying infrastructure, including distribution pipes, fixtures, and appliances. The chosen system must detect leaks at a granularity that allows for prompt remediation to minimize water loss.
METERING
Whole building/whole project water metering is required. Sub-metering for water end uses is recommended as a best practice for monitoring water consumption and addressing inefficiencies, but is not required. Where occupant usage of water fixtures and appliances deviates significantly from the budget calculations, the use of submeters can be beneficial to adjust occupant behaviors and to calibrate the budget more accurately when warranted.
MUNICIPAL RECLAIMED WATER
Project teams may use water from a municipal reclaimed water system as a resource for non-potable water, so long as the water supplied is municipally treated domestic sewage and not non-treated or minimally treated water that is sourced from the municipality’s potable water supply. Similarly, project teams may also contribute their treated greywater or treated domestic sewage water to the system. Any supplied water must be treated to the same or acceptable standards as the water in the reclaimed water system and used beneficially. Even if it is installed off-site, any piping used to connect the project to the municipal system must meet the requirements for all other Imperatives being pursued by the project.
PERFORMANCE PERIOD
See Performance Period Clarifications in Imperative I07 – Energy and Carbon Reduction, which provides guidance applicable to both water and energy on baselines and occupancy.
WATER BUDGET AND CONSERVATION PLAN
Project teams must develop a comprehensive water budget for the project that accounts for all water end uses and incorporates the required fixture-based reductions. The budget must be detailed in a spreadsheet or equivalent tool that specifies the calculated annual usage of all potable water end uses for the project, including but not limited to fixtures, equipment, appliances, HVAC, and any process water uses. The budget must include all potable water consumed by the project. It may be customized to fit specific project needs and circumstances, but budget assumptions must be cited from industry-recognized sources.
To ensure the annual water budget is met, projects must also develop and implement a Water Conservation Plan that describes a comprehensive strategy for adhering to the water budget. This strategy must encompass all aspects of water use within the project, including occupant education, leak detection, and all other operation and maintenance practices that contribute to water conservation. Regular monitoring and recording of water usage must be part of this strategy to ensure compliance with the established water budget and to identify opportunities for further water use optimization.
The water budget is considered to have been met if water consumption during the performance period is within 3% of the budgeted amount.
Projects that supply 100% of on-site water needs (as required under I06 – Net Positive Water) through exclusively on-site resources, are considered to have met the water use reduction requirement of this Imperative.
For affordable housing projects, Handprinting is also an acceptable strategy either in combination with any of the above strategies or as the sole approach for achieving the potable water reduction goals.
