I had this problem, and I'm just posting this in case someone else finds it useful. We had a LOT of water spitting from garden hoses. It seemed only to do it when the pump cut on, so that was worrisome. Found out, however, that the culprit was our filter. It is one that had air at the top of the cylinder to oxidize iron and make it filterable. Some of that air was moving backwards and getting into the line going to outside spigots. I put a checkvalve in the line leading to the filter and problem solved. What a relief. I was afraid we were looking at a new well.

Great info. John! Thanks for posting!

You are welcome. I figure if anyone does a search for this, it might help them. I was really concerned we might be looking at a new well, but it just strikes me as pretty hard for water to get into a well pipe without that same joint leaking water when the pump cuts on. So I contacted the filter company and they suggested this. Might add that this filter is a miracle worker for iron.