Seawater flushing

Julian, I don't know for sure since this is very uncommon, but I expected seawater would be allowed for this credit.

The response to a CIR issued recently for a project in Hong Kong suggested it was possible for sea water flushing to contribute to the water use credit. This is logical as it is non-potable water. However, in a recent submission for a CI project the project team asked whether seawater from a municipal seawater supply system can be used to claim credit for WEp1 and WEc1. The response: No, per LEED Interpretation 1551, municipally provided greywater (in this case seawater) cannot be used to meet credit requirements. ID 1551 is dated 2006: Municipally reclaimed water is not applicable to WEc3 achievement (NC Version 2.0). This credit focuses on fixture efficiency and on-site water reuse. There seems to be a mismatch between the response to the CIR and ID1551, else the CIR response would have been 'negative'! The logic is that if I choose a building near public transport it is energy efficient, so I get points. Surely, if I choose a building using seawater flushing, which is potable water efficiency, I should get an advantage too?