No, it didn't smell like rotten eggs, it didn't even smell bad, it was just a strong smell. I doubt it was hydrogen sulfide. Could definitely be placebo but that smell is to strong to be nothing. As Panic said it may be either the Blue green algae or heavy metals, but where the water was running looked more like moss (perhaps im confusing the two?). Heavy metals is definitely a possibility.
Hydrogen Sulfide is deadly and can 'stun' your nasal receptors, if you smell rotten eggs get out. The smell may dissappear but that maybe as a result of your sense of smell failing not a lack of hydrogen sulfide. Unless you are certain you are clear of the source, you should leave.
My Guesses: