"Why on earth would they have sprinkler fitters there if it is a hole in the ground?"
As promised an answer to your question head2641:
Sprinkler fitting is an occupation consisting of the installing, testing, inspecting, and certifying of automatic fire suppression systems in all types of structures. Sprinkler systems installed by sprinkler fitters can include the UNDERGROUND supply as well as integrated overhead piping systems and standpipes.
I am not familiar with the trade per se but I am guessing they are pipe fitters with some form of additional qualification. So would they need pipe fitters when constructing a de-sal plant, I think yes is the answer.
Would they need a fire suppression system in a de-sal plant, I dont know but I would be willing to bet yes.
Hope that helps answer your question head2641, oh! I guess the facts may be OK after all
