NC 2009 WEc2: Innovative Wastewater Technologies

Hi Rudolph,

Above it states: "The calculations for wastewater use are based on the number of full-time equivalent (FTE) occupants. FTE calculations can sometimes be confusing in certain building types or occupancy types—see WEp1 for more information. "

Rudolph, FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. should be the intended number for the project building. I would keep this number grounded in the reality of the project—not a theoretical code-based number. If the FTE number is not known for the project (as in CS), there are default numbers to use, from the LEED Reference Guide.

S W, did you ever find any useful resources? Was your documentation approved?

Razan, I would review the LEED Minimum Program Requirements supplemental guidance document for some perspective on this question. There are cases (like with parking) where something can contribute to a credit without being in the LEED boundary. I would consider this a good possibility in your situation.

Use of well water is specifically mentioned as non-compliant in the Reference Guide for WEc1. Although not specifically mentioned in the same way for WEc2, I don't see that it would be any different. Do you?

Tristan, I agree. If well water is non-compliant for WEc1, I would think that it is non-compliant for Wec2.

The engineer should be able to provide an expected amount of annually captured rainwater based on rainwater data and the rainwater management plan.

I think the range is so wide because it depends a lot on your system—what kind of roofing or collection surface, how it's collected, etc. Is there someone designing your system who can provide input?

Perhaps purse option 1 under the credit and take exemplary preformance for it. Then apply for an ID credit for our waster water system?

You're going to be able to earn three points here—or four if this is an RPc1 credit in your zipcode.

You can use one or both options to earn two points through credit compliance, and then one Exemplary PerformanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. point via IDc1.

Does this answer your question?

No RP credits because this an international project. Yes I think I will just use option 1 for 2 pts plus 1 EP point. I was just asking about gettin more points because we are also doing option 2 (treating 100% of wasterwater and infiltrating on site). Perhaps I can take the 3 pts and apply for and ID for pt. for option 2? But I'm pretty sure you can only get 1 ID point per credit. I just feel like we should get more points since we are meet both options 1 & 2 100%. And really both have very measurable positive environmental effects.

Nelina, I think you'll be happy to read this news that RPc1 is available for international projects. There's your fourth point for WEc2!

We are flushing with captured rainwater AND on site septic, attempting to go for two points and an EP. However I am unable to select both option 1 and option 2 simultaneously. Is there any trick to overriding the template?

Interesting situation. This seems to be not possible according to the credit language, but I could imagine it being possible, in theory, if you're able to make a case that it's not environmentally damaging in any way, and meets the same credit intent. Do you think you have a shot at doing that?

Yes, I think it might be possible. The only downside that I see is mixing potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. with sea water. Even though it is the natural hydrology of the location, theoretically by doing that I would be reducing the potable water source, (though I´ll try anyway).

The intent of the credit is to “reduce generation of wastewater and potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. demand, while increasing the local aquifer recharge.” I think that what you are doing with wastewater is interesting and does have environmental benefit, but it may not meet the credit intent because your are not reducing potable water demand. If you are, make sure to explain this in your narrative very well and back it up with solid calculations. You may be indirectly recharging the local aquifer by discharging to the sea and could potential make this reasoning if you were able to back it up with some hydrologic cycle information specific to the site. Seems like a long shot....maybe consider an Innovation credit for which you'd need to demonstrate environmental benefits convincingly. Regardless, it's a beneficial strategy as long as quantities of treated water released to salt water is not excessive--as you point out it occurs naturally.

The flush fixture summary on WEc2 is derived from WEp1, so yes, I would make sure everything in WEp1 that's relevant is filled out.

As a general LEED Online tip, I would always make sure, when dealing with oddities, that you're not working on a Beta form—this is noted at the bottom of the page. GBCI will update with new forms that are available if you send them a feedback request.

Tristan, Thank you. That was exactly the problem, a Beta form WEp1. Aaargh

Yes, municipal treated wastewater is one of the options for this credit.

Direction on this is not included in the reference guide, so I would use a reasonable estimate and explain it. With 5 total uses, I would estimate 3 full, 2 low. You might try 4/1 but that could be viewed as gaming the credit; 3/2 is a little more cautious and reasonable.

Correction, meant to say 2 full, 3 low.

Yes, since you are using captured rainwater, which is a non-potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. source, you should agree with that question.

Thank you for your answer Roberts,
using both things I will have more potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. savings, that´s logical.
If I agree with the question, why the "Points Documented" change in 0?

Without "X" and typing my kGal of "Captured rainwater" i get 2 point plus Innovative Exemplary. Strange, isn´t it?

Claudia, this is potentially a flaw in the template programming. You might advise USGBC. You might try here: http://www.gbci.org/org-nav/contact/Contact-Us/Project-Certification-Que...

I'm looking at the LEED-2009 WEc2 LEED Online form, and it asks for "annual quantities" of captured rainwater, recycled graywater1. Defined by the Uniform Plumbing Code (UPC) in its Appendix G, titled "Gray water Systems for Single-Family Dwellings," as "untreated household wastewater which has not come into contact with toilet waste. Grey water includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs. It shall not include wastewater from kitchen sinks or dishwashers." 2. The International Plumbing Code (IPC) defines graywater in its Appendix C, titled "Graywater Recycling Systems," as "wastewater discharged from lavatories, bathtubs, showers, clothes washers, and laundry sinks." Some states and local authorities allow kitchen sink wastewater to be included in graywater. Other differences with the UPC and IPC definitions can probably be found in state and local codes. Project teams should comply with the graywater definitions as established by the authority having jurisdiction in their areas., etc. So it seems to be looking for a quantity of water, not a cistern size. Which makes sense, because LEED wants to know how much potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. you're replacing—the system capacity you use to do it is of less interest.

Given that this is an international project, I strongly suggest that you submit an inquiry to your LEED reviewer. Theoretically, the LEED standards are to be applied consistently throughout the world as it's adopted in other countries. However, this may be infeasible in certain cases but only GBCI can make that determination. My bias would be to agree with you because the water is treated to tertiary standards of the local governing agencies for the intended use (landscaping) and as long as you meet the overall goal of treating 50% of wastewater on site and reuse it or let it infiltrate you meet the intent of the credit, and this reuse would also contribute to WEc1.1 and 1.2, if you use no potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. for irrigation.

Septic systems do count as on-site wastewater treatment, however, for WEc2 purposes you still need to reduce potable waste water quantities for flushing by 50% through standard methods like waterless and ultra-low flow fixtures, or by using recycled grey water, captured rainwater or municipal reclaimed water. Typically, septic systems do not provide a source of tertiary treated grey water for reuse, though you may be able to incorporate this feature in your septic system.

Where is this requirement that in addition to a septic system (leech field) you have to reduce waste water for flushing by 50%? The ref guide gives you two options, and doesn't require that you do both (as far as I can tell).

You are correct, you do not have to do both if you are using option 2, however, you do have to demonstrate that at least 50% of your total wastewater is diverted to the on-site system. This is probably self-evident in most cases, but just to be clear for the reviewers make sure to clearly state the facts. I would also add that even though it's not required to reduce flushing by 50% it's still a good idea.

In my humble opinion you are calculating transient occupancy correctly and classifying them logically as visitors for the reasons you state. However, since they are technically employees, not visitors, this may be the cause for the comment. Often providing a detailed narrative explaining your logic, calculations and approach are helpful to clarify situations that don't follow state requirements exactly. You might also try the calculation converting them to FTEs to determine impact. I suggest a conversation with your review team through the portal prior to re-submitting.

Yes, this would satisfy the credit since it is replacing use of potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems.. More importantly, you will also want to check your local plumbing code which can be more problematic.

Since RO (reverse osmosis) reject water is higher up “water quality chain” because it is considered at least as clean as potable water you might consider additional reclaimed water uses that need higher quality water.

I have a related question-- we are pursuing an innovation in design credit for process waterProcess water is used for industrial processes and building systems such as cooling towers, boilers, and chillers. It can also refer to water used in operational processes, such as dishwashing, clothes washing, and ice making. savings by collecting 8gpm of RO reject water and using 6gpm of it for cooling tower makeup. Assuming plumbing code allows, we would like to store some of the additional 2gpm into a tank to be reused to flush toilets and urinals and apply to WEcr2. We are obviously not double dipping on any of the reclaimed water (6+2=8...) but have some concern that someone might have a problem with us using the same reclaim equipment to gather water used in two different credits (ID credit, WEcr2). Does anyone have any experience with submitting something like this?

Thanks