Page 136 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

116 Cha pte r T h ree

are roof, courtyard garden spaces, or planters included on the site which cover at least
5 percent of the the total site area and these special garden spaces/planters fulfill the other
requirements of the subcategory. In a similar fashion, it is not appropriate to substitute
hardscape surfaces as the design cases against landscape areas for the baseline in the
calculations. Hose bibs are not considered to be permanent irrigation facilities and can be
used during periods of drought or for establishing plantings during the first year.
Note that there are many special health codes governing the use or storage of
reuse waters. They vary by local or state jurisdiction. The designers, owners, and
managers should become familiar with any special health-related requirements for
use of reuse waters so that appropriate protective measures or treatments can be
included in the design and operations. The submittals must also include narratives
describing the various nonpotable water sources, local codes for their use, and
descriptions of any special treatment of these waters and other related features.
An interesting item to note about these credits is that the calculated baseline
total water applied for irrigation (TWAB) is based on the conventional practices
in the region where the project is built. The author assumes that this implies that
the conventional practices are those as of around 2005, when the LEED-NC 2.2
Reference Guide was adopted and there were not many facilities percentagewise built
to the LEED standards. As the “green” movement expands, the author hopes that the
new “conventional” practices will become greener and greener. The author suggests
that the designers date their calculations, so that in future years, these earlier baseline
criteria can possibly be used as the future baseline, even if LEED and other environmental
water-saving programs become the standard or conventional practice in the area. Otherwise
these credits will become harder to obtain and may be disregarded, which is not the
intention of LEED. There have recently been significant strides made to adopt standards
and develop protocols to evaluate products and processes for water efficiency. The
Irrigation Association has recently started the Smart Water Applications Technologies
(SWAT) program. Much of this ongoing work is being incorporated into the EPA’s Water
Sense program.
If there are special circumstances for these credits, a narrative must be submitted describing
these circumstances. There is no exemplary performance point available for these credits in
either version 2.2 or 2009.

3.2 WE Credit 2: Innovative Wastewater Technologies

USGBC Rating System
LEED-NC 2.2 lists the Intent, Requirements, and Potential Technologies and Strategies
for WEc2 as follows, with the LEED 2009 Intent and Requirements essentially identical:

Intent
Reduce generation of wastewater and potable water demand, while increasing the local
aquifer recharge.
Requirements
OPTION 1
Reduce potable water use for building sewage conveyance by 50% through the use of water
conserving fixtures (water closets, urinals) or non-potable water (captured rainwater,
recycled greywater, and on-site or municipally treated wastewater).