ID#1578 made on
WEc1 - Water efficient landscaping
LEED BD+C: New Construction, LEED O+M: Existing Buildings, LEED BD+C: Core and Shell
I am the LEED administrator for a Water Treatment Plant project (currently registered on LEED On-line, v2.2) We are not pursing LEED certification for the entire treatment facility. We are only pursui...
I am the LEED administrator for a Water Treatment Plant project (currently registered on LEED On-line, v2.2) We are not pursing LEED certification for the entire treatment facility. We are only pursuing LEED Certification for the primary building on the site (Administration/Operations Center). We have established a reasonable and consistent boundary for the subject building (including Sustainable Site considerations). As a water treatment facility, the project involves accessing water rights from the adjacent river for processing, treatment, and distribution of water to the public. In order to meet the criteria for WE Credit 1.1, 1.2 - Water Efficient Landscaping - we are considering: 1. Plant species factor 2. Use of captured rainwater - when available from the proposed on site stormwater retention basin and 3. Use of raw water - directly from the river For item 3 above, I have noted previous CIR's on this subject which deny the use of river water for this credit. I have also noted in the Reference Guide that the intent is to limit or eliminate the use of natural surface or subsurface resources for irrigation purposes. Yet, in the Reference Guide, page 115, under Requirements, "Use of water treated and conveyed by a public agency specifically for non-potable uses" is noted as a consideration. Most water (potable or non-potable) conveyed by a public agency is ultimately sourced from surface or subsurface resources. Therefore, it seems that an office building project, for example, could use non-potable water conveyed by our agency and that project would be eligible to gain the LEED credit. Whereas if our agency uses the same water for itself, the credit would not be granted. This raw, un-treated water, which would normally be processed through the treatment plant, will be diverted from the processing and treatment stream (saving energy and use of chemicals) and will be used directly for irrigation for the landscaping within the proposed LEED boundary surrounding the subject building on the water treatment plant site. We would like to confirm that USGBC concurs with our interpretation that this proposed source for irrigation water from the river (non-potable, raw water) will meet the intent of WE c1.1, 1.2. We believe that in essence, this raw water is equivalent to (is actually environmentally better than) "Use of water TREATED and conveyed by a public agency specifically for non-potable uses" as indicated on page 115 of v2.2 Reference Guide).
Plant species factor and onsite captured rainwater are qualifying strategies to achieve this credit. Based on v2.1 WEc1.2 CIR rulings dated 1/20/04 and 11/5/2005, the use of surface water or water drawn from receiving waters is not an acceptable way to meet the credit intent. LEED-NC v2.2 WEc1 allows the, "Use of water treated and conveyed by a public agency specifically for non-potable uses," however, these sources are not typically "sourced from surface or subsurface resources." Common sources include effluent from treatment plants and recycled graywater harvested from within the region. If this water treatment plant supplies water to offsite customers specifically for non-potable uses AND the raw water proposed for irrigation would otherwise be processed for this non-potable system, then the intent of the credit has been met. While the avoided energy and chemical inputs for this raw water are laudable, this is not a deciding factor. Applicable Internationally.
Related Addenda (Corrections & Interpretations)