I note, eventually, the RO membrane gets clogged and has to be cleaned or replaced.  Since these systems are not generally designed to filter sea water I'd bet the operational time and volumes wouldn't be all that great, each time the membrane is pulled it has to be checked to ensure it's working properly, if not replacement membranes have to be stalled (and where are they going to get 'em?,)  & etc. & blah-blah.

Plus if you've got people doing that they aren't doing something else that may be more important?

And it is questionable the system is still functional.

If it is functional the Incident Commander may be keeping in reserve for some very good reason(s).  One reason to withhold an asset is to give yourself the ability to react/respond to the unexpected.  

And it's possible they still haven't faced-up to the situation and are more interested in playing Save-Your-Face fiddlefuck games than dealing with the situation.

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre