Laboratory Sinks

Lab sinks are typically excluded as process water. 

The logic for things like lab sinks is that they often need to deliver a certain volume of water (like filling equipment) or have unusual usage rates/types. So it's less that they're a process in the same way a cooling tower is, and more that they need to meet a specific function. Similar to why mop sinks, tub fillers, and drinking fountains are excluded - the rate doesn't matter because they're going to deliver a bucket, tub, or water bottle worth of water volume. Or a sink in an art classroom that needs to wash paintbrushes, it will have odd usage rates and needs a high enough flow to do its job.

I guess it is confusing that LEED calls these kinds of fixtures "process" the same way it calls equipment and appliances! But either way you exclude fixtures of this type because they serve a specific "process" need rather than one of the standard fixture functions. 

Right, just leave them out entirely and add a note in the form stating that lab sinks are excluded. 

Emily is spot on, as always.

I just finished a lab project and all the 'lab sinks' were excluded from the Indoor Water Use Reduction calcs; GBCI approved with no comments. 

Similarly, I was involved with a spa where each massage room had a dedicated hand washing sink. GBCI's advice was to include or exclude at my discretion. We excluded them.

Finally, there was a factory project with hand washing sinks. It was mandatory for every employee to wash their hands before entering the factory space and after leaving the factory space. GBCI allowed me to exclude these fixtures as well.