# Backflow preventer



## social port (Jun 19, 2017)

Does anyone use backflow preventers on their spickets (spigots) outside? 
I was considering using a hose end sprayer to apply an ortho product and then wondered about the possibility of contaminating the house water supply. 
Is using a backflow preventer common practice?


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## Ware (Jan 28, 2017)

I think most outside faucets (where I live anyway) are equipped with an antisiphon/vacuum breaker device to meet plumbing codes.










If for whatever reason you don't have one, they make these that you can just thread on.


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## social port (Jun 19, 2017)

Thanks Ware


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## g-man (Jun 15, 2017)

The risk are really really really low. First you have to loose water pressure. Then there has to be an inside leak so the water from the ortho and the hose could travel backwards into the house supply. Then it needs to reach a point that it could tee into another pipe. Then once the pressure returns then someone will need to drink that contaminated water. Do follow the law with the required connections, but it is not a likely failure mode.


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## Ware (Jan 28, 2017)

^^^ Agree &#128175;


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## social port (Jun 19, 2017)

Thanks Fellas. 
I had no concerns about backflow when applying baby shampoo with a hose end sprayer. Quinclorac is a different story, but my mind is worry-free now.
Nice breakdown, g-man, as usual.


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## Colonel K0rn (Jul 4, 2017)

I always used to get sprayed by the spigot when I turned it off, so I removed the  thing.


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