Yard hydrant sucks in mud

anesthes

So I have a yard hydrant out by my barn. When I turn it on, it's like a second or two before pressurized water fills the riser (so i know it's draining), however the first cup or so is muddy. I'm assuming the water table around the drain is high, and some muddy soil water is flowing back into the riser.

I would have *assumed* these things would have a 1 way valve on the drain, but I guess not.

What I've been doing is running it for a few seconds before filling my horse trough. Obviously, I don't want the muddy water in the clean trough due to the risk of ecoli contamination.

Any suggestions? It was installed according to mfg specs, with a fitting on the drain hole (barb) and hose running a number of feet into a pit of gravel for draining. However, I know the water table gets so high sometimes.

-- Joe