Hello,
I am working on a project where there will be a permanent irrigation system. This system will be fed by a combination of harvested rainwater, greywater treated on-site and municipal treated wastewater. These various recycled waters will serve 100% of the irrigation demand as soon as that is technically feasible.
However, there is concern that we may not have enough of these various recycled waters to meet all the irrigation needs on Day 1. We are considering the option of feeding the permanent irrigation system with potable water until the recycled waters are sufficient (there has been some rain, and some greywater has been harvested, and the municipal plant has come online) for a period not to exceed the 18 months allowable under Option 2, path 2.
Does anyone have experience with a comparable strategy, and do you know if this would be acceptable in a review?
Tristan Roberts
RepresentativeVermont House of Representatives
LEEDuser Expert
11474 thumbs up
September 5, 2012 - 11:03 pm
Daniel, I haven't heard this discussed before, but I imagine a lot of projects with this kind of system must face such a question. It seems to me that it falls squarely under the allowance of temporary irrigation for establishment of plants, and can be ignored, as it's not part of the design conditions of the facility.
Daniel Costantino
Urban Planner, LEED AP NDEcology & Environment, Inc.
69 thumbs up
September 12, 2012 - 11:00 am
Tristan, thanks for your reply. I tend to agree, but as it melds Path 1 and 2 of Option 2 and I have not been able to find any CIRs that conclusively address the issue, I'm hesitant to recommend this to my project designer.
Susann Geithner
PrincipalEmerald Built Environments
1297 thumbs up
September 12, 2012 - 1:32 pm
I don't know of any CIR either. However LEED NC is certifying the buildings design as it relates to use over the life span of the building. That's why you have to use a calculation of determining the irrigation demand for the average month. So it really doesn't matter what happens in the first year after completion. It's the building and its systems operation after that.
So as long as your system is design to meet the 100% non-potable water requirements per the calculation, you should be fine. I think there are very few zero-potable-water-system, which don't use potable water in the first year. If for plant establishment, while the system is still being installed, for testing, for maintenance, or if it simply hasn't rained yet since the system has been completed or the building is not yet fully occupied. So even thought there is no written ruling in that regards. I would be surprised if using potable water within the first year or 18 months is an issue for the reviewer.
Another way for getting around it, is to use a hose to fill the irrigation water tank, if needed during that time. That's not a permanent system but would address shortfalls during the start-up period. That I actually would even mention for LEED review purposes.
Besides a potable water connection is often installed just for maintenance purposes.
Miles Thorne
3QC2 thumbs up
February 2, 2015 - 6:31 pm
Did anything ever come of this? We have the same situation - purple pipe installed, waiting for the city to hook up their end.
Miles Thorne
3QC2 thumbs up
April 16, 2015 - 5:26 pm
FYI - this credit was achieved, with us providing a narrative saying that the system would be utilized once city infrastructure was installed.