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LEED 2012 – 2nd Public Comment – Water Efficiency (WE) Section

Key changes in the the Water Efficiency (WE) section of LEED-NC (part of LEED BD&C) in the second public comment draft of LEED 2012 are discussed below.
August 1, 2011

Do you have comments or questions on this draft? Discuss them below with your fellow LEED professionals. Substantive comments posted here during USGBC's second public comment period  will be submitted to USGBC and considered "official" public comments.

More information on LEED 2012 certification and the second public comment

Water Efficiency (WE)

Major Changes

The Landscape Water Use Reduction prerequisite introduced with the first draft now has a simpler compliance path, in which projects show that the landscaped area does not need irrigation. All other projects with over 1,000 ft2 of exterior vegetated space would still need to reduce water use for the peak watering month 30% below a baseline established by the WaterSense Water Budget Tool.

The 20% water reduction baseline required by Minimum Fitting and Fixture Water Use Reduction is unchanged from the LEED 2009 water use reduction prerequisite. There are some minor changes to this draft, but the most interesting is a change in scope: only fixtures within the project scope would fall under the prerequisite here, not all fixtures in the building.

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The Appliance and Process Water Use Reduction prerequisite, new in the first draft, sets minimum performance requirements for some appliances and processes. As with the fixture prerequisite, this one also contains a change limiting it to the project scope. Energy Star ice machines have been added to the requirements, and they must also use air-cooled or closed-loop cooling.

The wording of Additional Fixture and Fitting Water Use Reduction (2–4 points) is simplified, with the language now referring to the prerequisite. The big change is that the proposed point thresholds are more stringent: 35% reduction for 1 point, but 40% reduction for 2 points, and 50% for three.

Tweaks to Sustainable Wastewater Management (1–2 points; previously “Innovative Wastewater Technologies”) appear to make this credit more achievable, while also offering a higher bar. Reducing sewage conveyance by 50% through Option 1 would earn one point, but reducing it by 95% would earn two points. In Option 2, reuse of 95% of wastewater would earn two points, but implementation of wastewater reuse at any level (no lower limit is given) would earn one point. Under Option 3, one point could be earned for implementing (no threshold is given) resource recovery for key wastewater nutrients (nitrogen and phosphorous), while two points would be earned for also addressing recovery of organic carbon.

Minor Changes

Additional Landscape Water Use Reduction (1–2 points) is similar to the prerequisite (see above) in its use of the WaterSense Water Budget Tool. Fairly minor changes have been made to requirements and calculations, and the credit thresholds (50% and 100%) remain unchanged from LEED 2009. Playgrounds and athletic fields may be excluded from the credit calculations, but other best management practices such as metering must be in place for those areas.

In Cooling Tower Makeup Water  (1–2 points) there have been some wording and reorganizing that does not appear to amount to significant changes to this credit, which would be new for LEED-NC projects.

Revisions to the new Additional Appliance and Process Water Use Reduction credit (1 point) since the first LEED 2012 draft create a menu of choices. Commercial washing machines, commercial kitchen equipment, commercial laboratory and medical equipment, commercial vehicle washing systems, and municipal steam systems all fall under this credit. Earning it means establishing eligibility for a given category (being connected to a municipal steam system, for example), and then meeting specified requirements for all of the given equipment within the project scope. In most cases, that entails meeting efficiency standards; in the case of municipal steam, projects would recover and reuse steam condensate.

What do you think of the proposed changes? Post your comments or questions below.

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Comments

October 25, 2011 - 12:56 pm

I probably should have looked into this sooner, but am preparing for a presentation related to a rainwater collection and reuse system on a recent LEED Platinum project, and wanted to include something about changes coming in 2012.

Where would rainwater collection come in under 2012? It almost appears that it would not be considered at all, except maybe under the wastewater innovation, but that seems focused on reuse of true wastewater (what I wouldl call black water).

Will there still be a spot to include rainwater in the reduction calcuation for the fixture and fitting credits? I would also feel this would apply to the cooling towers, and a possible way to offset any potable water use for that application.

The landscape water use specifically mentions rainwater, and rightly excludes groundwater, streams, and rivers.

September 15, 2011 - 1:35 am

Similar to how in Location and transportation, you can achieve many points by doing a LEED ND site. You could have an Alternate Compliance path that allows you to earn many points by doing a combination of water collection and use and demand reduction for the totality of the water demand that you want us to calculate in the IP section. Seems easy to do, and would synergize all of these credits and promote water collection. Right now, you can earn 5 water points without collecting a single drop for less than 5,000 dollars. In order to earn the other 5 you might have to spend 500,000. This is a disparity that should be eliminated by synergizing all of these credits and emphasising what is a well known sustainable solution - Water collection and Reuse.

September 14, 2011 - 7:48 pm

Prerequisite: Landscape - Good move to making this a pre-requisite. Good move moving the establishment period to 2 years. Good job moving the peak watering month to being site specific. Documentation has not been changed much, which is good.
Prerequisite: MINIMUM FIXTURE AND FITTING WATER USE REDUCTION: No Comments
PREREQUISITE: APPLIANCE AND PROCESS WATER USE REDUCTION: No Comments
WE CREDIT: ADDITIONAL LANDSCAPE WATER USE REDUCTION: It seems like there should be a better way to encourage condensate, rainwater use, or grey water reuse. Simply requiring 50% or 100% does not encourage these strategies which are cost prohibitive for earning 1 point. I like how the synergy has been added to collect wastewater for reuse, but that is really expensive too. It seems like more impetus should be made to coordinate all of these water credits to prioritize water collection, reuse, and demand reduction.
WE CREDIT: ADDITIONAL FIXTURE AND FITTING WATER USE REDUCTION: I like the increase to 40% and 50%, because it will require people to commit to water re-use, not just demand reduction. But, I still think the above comment is true.
WE CREDIT: SUSTAINABLE WASTEWATER MANAGEMENT: Much improved, good reduction of requirements to make reuse more attainable. Would like to see this in a more coordinated effort with other credits. Example: Greywater reuse and Condensate use.
WE CREDIT: COOLING TOWER MAKEUP WATER: No Comment
WE CREDIT: ADDITIONAL APPLIANCE AND PROCESS WATER USE REDUCTION: Much improved. Expanded requirements and good changes.

September 5, 2011 - 2:28 pm

Could an enhanced crdt be created for the application of fixture equipment for more aeas than just the project aea??

overall acceptable approach.