Posted 2/23/2021 07:22 (#8852470 - in reply to #8849496) Subject: RE: Running a new water line
Madison Co. Virginia
Here, I wouldn't hesitate to tee into the well pump pipe. Several wells on this farm have this arrangement, and it works fine. Hydrants have given us so little trouble, that I wouldn't bother making provisions for shutting them off. Then again, they're only buried 18-24" here, so it's a lot easier to dig them up. Teeing the well pipe won't work if you have a check valve inside the house, like was previously mentioned.
An underground disconnect is easy here with our 18" bury depth, but this probably won't work where you are. We drystack several cement flue blocks, and fabricate a plate steel lid. Stuff a couple of feed sacks under the lid as a thermal break.
A comment on the check valve thing -- One well on this farm has a check valve installed just before the pressure switch and tank. There have been a few times it's come in handy for replacing the well pump, since you can pull the pump without worrying about other valves. Another well can keep the system supplied while that pump is out.
Thinking further, the check valve makes the most sense for a system with multiple wells. For isolating a well, the only safe place to install a shutoff valve would be after the pressure tank and switch. This would take the pressure tank out of the system, and you would then be depending on a pressure tank a distance away. With a check valve, you can safely install that on the well side of the tank and switch, since there's no risk of it being closed while the system is operating.