Update October 20, 2016: See the updated “Water Use Reduction Additional Guidance” document for new guidance on applying seawater or municipal wastewater to v2009 Water Efficiency credits.
Original ruling October 1, 2013
Desalinated seawater that is not treated to potable drinking water standards may be applied as a non-potable water source in the following credits:
- WEc1 Water Efficient Landscaping
- WEc2 Innovative Wastewater Technologies
- WEc4 Cooling Tower Water Management (in LEED-EBOM)
- WEc4.2 Water Use Reduction – Cooling Towers (in LEED-Healthcare)
- WEc4 Process Water Use Reduction (in LEED-Schools for other (non-food service) equipment types such as cooling towers)
Refer to the guidance document Applicability of Seawater in Water Efficiency credits. Desalinated seawater may NOT be applied in WEp1/c3 Water Use Reduction. The focus of the water use reduction prerequisite and credit is fixture efficiency and on-site water reuse. Because sourcing water from the sea does not constitute a form of water reuse, desalinated seawater is not applicable to WEp1 regardless of whether the seawater is treated onsite or offsite. In order to take credit for using desalinated seawater as a non-potable water source in applicable Water Efficiency credits, the desalinated seawater must be:
1) Municipally supplied or explicitly approved by the municipality for on-site treatment systems,
2) Meet all applicable code and permitting requirements so as to not contaminate the system served with high salinity,
3) Treated to an appropriate level for non-potable uses, and
4) The on-site energy use to desalinate the seawater must be included in the EAp2/EAc1 calculations.
Note that seawater is water from a sea or ocean. Salty groundwater or brackish well water in coastal areas is not considered nonpotable seawater. Groundwater and water sourced from naturally occurring surface water bodies, such as streams, rivers, and lakes is also not applicable. Only seawater sourced directly from a sea or ocean may be applied