I'm curious as to what those street cleaners spray on the road when they sweep the streets here in California. I heard that it might be a weak acid! What the heck?! But then someone said it might just be water. If suppose you drive by one or get sprayed by one in a parking lot, will the "liquid" do any damage to your paint or metal parts? Thanks.

Its water to keep the dust down

I was just thinking water to keep the dust down. See if they'll give you a urine sample, which by the way is what they might ask of you if you chase a street sweeper with a sample bottle at 3:30 am! Anyhow once you have a sample I'll send you some ph test strips so you could check it out.