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LEED 2012 – 3rd Public Comment – WE (Water Efficiency) Section

Discussion of key changes
March 1, 2012

Key changes in the the WE section of LEED-NC (part of LEED BD&C) in the third public comment draft of LEED 2012 are discussed below. Do you have comments or questions on this draft? Discuss them below with your fellow LEED professionals. Substantive comments submitted here during USGBC's third public comment period here will be submitted to USGBC and considered "official" public comments.

More information on LEED 2012 certification and the third public comment.

A renamed Outdoor Water Use Reduction prerequisite (not “Landscape Water”) has simplified requirements that do not appear to represent significant changes from the second draft. Projects can avoid irrigation entirely or reduce water use for the peak watering month 30% below a baseline established by the WaterSense Water Budget Tool.

The fundamental 20% water reduction baseline is unchanged, but the name is now Indoor Water Use Reduction. As with the second draft, only fixtures in the project scope are covered, not all fixtures in the building, and water-efficiency baselines remain the same from that draft. A new Appliance and Process Water Use Reduction prerequisite has been folded into this prerequisite, bringing minimum performance requirements for some appliances and processes. For example, residential clothes washers and dishwashers must be Energy Star and  commercial clothes washers must be CEE Tier 3A.

The Building-Level Water Metering prerequisite has been moved here from the Performance category, which did not stick in this draft. The gist remains the same: all water conveyed to the project—regardless of source—must be metered. Reporting of metering data, including submeters, to USGBC would be required for five years. Submetering requirements, like those for projects with significant irrigation, have been dropped.

The Outdoor Water Use Reduction credit remains similar to the prerequisite in its use of the WaterSense Water Budget Tool. The basic 50% and 100% reduction thresholds remain unchanged from LEED 2009 and from the first two drafts, but other requirements have been simplified since the last round. For example, not only can playgrounds and athletic fields be excluded from the credit calculations, but best management practices such as metering are no longer required for them.

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The Indoor Water Use Reduction credit builds on the prerequisite in a straightforward fashion, while also similarly folding in the Additional Appliance and Process Water Use Reduction credit that had been introduced in a previous draft. This portion of the credit creates 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.

The Sustainable Wastewater Management credit (Innovative Wastewater Technologies in LEED 2009) has been dropped from this draft. While USGBC had been developing the credit toward recognizing nutrient recovery from wastewater, it apparently decided that new water-related requirements included elsewhere raise the LEED 2012 bar enough.

One of those places is Cooling Tower Water Use, which is mostly intact from the previous draft, with some simplifications. Requirements for drift eliminators and control of blowdown with conductivity meters are eliminated, for example, while retained requirements focus on control of scale and corrosion in the system.

A Water Metering credit is retained from previous drafts and moved to the WE category from Performance. The current version is a simplification, removing a requirement for remote reporting of data while retaining requirements for submetering that have been jettisoned from the prerequisite, notably submetering for any reclaimed water, domestic hot water, and any boiler with aggregate projected annual water use of 100,000 gallons or more.

What do you think of the proposed changes? Please post your public comments below.


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April 9, 2012 - 1:57 pm

For LEED 2012 is the integrated water budget for just outdoor irrigation use or will the LEED 2012 integrated water budget include indoor and outdoor use? Is there any mention of how they will calculate this budget?

Thank you for your help!!!!

March 26, 2012 - 8:26 pm

With USGBC's comment period closing in 12 hours, LEEDuser must close this forum as of now as an officlal place to comment. Please visit USGBC directly to make an official comment in the next 12 hours. Thanks for the great discussion!

March 27, 2012 - 7:27 am

Based on the USGBC homepage, I had been telling people last night
that the comment period closes today at 9 a.m. EDT. However, I received
the following communication thiis morning from USGBC:

Despite our efforts to widely communicate the one-week extension for
third public comment, overnight we heard from a few folks who  thought
they had all of Tuesday, rather than the 9 am EST cut-off we had
communicated.  Since it won’t materially affect the schedule, we’re
extending the cut-off until 5 pm EST today, March 27, 2012.

March 21, 2012 - 1:15 pm

It will be an prerequisite to only use toilets, urinals and private lavatory faucets and shower heads, which are Water Sense labeled. The water sense label basically sets a maximum flush/flow rate and requires independent testing of that and the map test, just to name a few things.
I think it's great to finally restrict flows per fixture and have a form of verification as to function of the fixture. So the reduction doesn't scarifies the function.
However I'm working on lots of international projects and get lots of questions from international teams in regards to where they can find products that can even help meeting the current LEED requirements. If we add even stricter limits and additional certifications to that. It will be impossible for many projects to meet the minimum requirements. So to be more specific: toilets shall not exceed 1.28 gallons ( 4.8 liters). In Germany you need an exemption from the public sewer district to use toilets below 5l, which be the way usually gets denied.
Urinals: 0.5 gpf (1.9 liter)
Shower 2 gpm (7.6 liter)
Private faucets: 1.5 gpm (5.7 liter)at 60 psi, not less than 0.8 gpm (3 liter) at 20psi
In Europe they are just getting started with certifications that would cover this, but it's a long way to have just a few products to choose from that would meet the requirements for this prerequisite.

If my current projects in Europe would have to use LEED 2012, they would not be able to unless they import products form the US, which don't have the required testing labels to used in buildings, which want to ever get a property insurance. So de facto I would not be able to meet WE P1.

March 20, 2012 - 7:09 pm

This credit is worth 2 points. According to the draft, you get 2 points for having two or more subsystems submetered, however if you only have one subsystem submetered, you get 0 points. This credit should be worth either 1 or 2 points, depending on if you have 1 or 2 or more subsystems submetered. Many office buildings do not have cooling towers, and many do not have landscaping (including most large office buildings in metropolitan areas). Therefore, having at least 1 subsystem seems feasible, but it seems unfair to penalize buildings that are incapable of achieving at least 2.

March 20, 2012 - 7:07 pm

The draft states that the fixture and fitting replacement and retrofit policy must specify that “all newly installed toilets, urinals, lavatory faucets and showerheads must be WaterSense labeled for label-eligible product types.” Most of the properties that we have worked with are multi-tenant facilities, many with tenants occupying multiple floors. Mandating what fixtures must be installed in tenant spaces is going to be a major challenge for most properties. This being a prerequisite could pose many challenges and issues in the future. Also, if these fixtures are deemed either economically infeasible, or infeasible due to the piping at the building, they should not be forced to use fixtures that are incapable of maintaining proper pressure.

March 21, 2012 - 3:12 pm

Absolutely, this is a major concern in existing buildings and new buildings. The plumbing system is to be seen as a whole. The fixtures change the pipe should change also otherwise it will start causing problems. If you reduce the flow to much, you have water standing in the pipe for to long, which can be lead to bacterial growth.

March 21, 2012 - 2:56 pm

Chris, I've heard the same issue with piping in existing buildings. Sometimes you can only go so low before the building and municipal infrastructure creates limits unless you replace all of the piping.

I wonder if other folks have specific examples of this they could share?

March 9, 2012 - 5:34 pm

It appears in this third draft of v2012 that rainwater reuse, greywater reuse and on-site water reclamation have been almost completely cut-out of v2012. Is this true? What is the reason for this?

March 2, 2012 - 1:00 pm

It appears that the metering faucet calculation providing a Gallons per Cycle option for flow rate has been removed from LEED 2012 Water efficiency prerequisite and Indoor water use calculation.

Is it assumed that faucet flow rate restriction is the only method to save flowing water, not restricting the meter time?

We understand the recent research, (see link) but is this conclusive enough to limit water efficiency to flow and not not consider duration?


March 20, 2012 - 4:46 pm

I think metered and automatic faucets should be treated equally with a reduced cycled compared to manual. It's a pretty simple reason. If I open the faucet and close it, that's time the faucet runs and I'm not washing my hands, were as if i hold my hands underneath the faucet I start washing hands the very first millisecond. You can also make a similar argument as for taking a shower. Turn of the shower while you are applying the soap. same can be done with an automatic faucet.
So yes definitely add some back in. I suggest to give a fixed discount for any automatic faucets if metered or just automatic. So instead of 30 sec for the manual do 20 sec for all automatic.

March 9, 2012 - 5:30 pm

In the LEED v2009 Requirements table of baseline flow rates / flush rates, it lists 0.25gpc as a faucet baseline.

A 0.5GPM faucet with a 10-sec timer = 0.083gpc which is ~67% water savings for all commercial faucet flow. This has a HUGE impact on overall water savings calculations.

If this option is removed from the LEED system (they have removed the 0.25gpc baseline from the Requirements section) - it will have a significant impact on projects. It will vary depending on the type of project - but for the typical office it will result in an overall drop of water-savings of about 10% (which is 2 tiers of LEED points).

Along those lines - a funny thing about this "metering" approach is that if you have a 0.5GPM faucet that automatically turns off when you take your hands away - there is no way to quantify any water savings in the LEED template. I was hoping they would address this in v2012 - however it is not addressed in the current third draft.

March 2, 2012 - 4:27 pm

I may be wrong, but in LEED 2009 NC I believe that in the Flow Fixture Data Table, the "metering" drop-downs for type with gallons per cycle unit do exactly that -- recongnize a savings based on not only flow but duration and flow.

If you utilize a .5gpm flow faucet vs. the .5 gpm baseline, then there is no contribution to savings. But if you use a .5gpm faucet at 12 second cycle, the gpc is .10 vs. a .25gpc baseline. Big difference.

If this has changed recently, I am not aware.


March 2, 2012 - 1:33 pm

Jeremy, there are other experts around here who know more on the topic than me, but I don't think this represents a change from LEED 2009, in which limiting duration is not accepted for WE. Just FYI.