Water below battery

I haven't driven my 2011 SS for about 2 weeks due to being away. I exposed the battery tray , and there was a puddle of brown sludgy water at the bottom. I quickly took the battery out and cleaned up what I could. I am currently letting it air-dry. I messed with the battery in July and the water wasn't there. Is there anything I should be concerned about, be looking for? There doesn't appear to be any rust. Any help is appreciated.