Do standard irrigation valves have a backflow preventer? I have screw on bleeders on the spigots but nothing on the hard plumbed electric valves. I guess if a neighbor contaminates the public system there’s nothing I can do either though I have a carbon block filter at the main to at least catch sand.
@Lars, no they do not. It would be a separate unit, probably brass, off the main water supply line before it comes into the house.
It is unlikely your neighbor will contaminate the whole block. But it is highly likely he will contaminate his own home and get sick from E. Coli, animal feces or pesticides.