The attached photo is of a 500 gallon drainage tank which is at the low spot of my property. It fills with groundwater and then gets pumped as the water level rises. I have one large Zoeller pump (on the left in the photos) that does all the work. My goal is to have a second, smaller backup pump at a slightly higher level in the tank (the one on the right) which will have its own float switch that activates if the main pump ever fails. The black ABS pipe in the photo was my idea on how to hook up the two pumps and feed into the same 100' buried pipe that leaves the tank. The configuration of piping in the photo isn't working as I had hoped. What currently happens when the main pump is running is to have part of its water come right back down into the black ABS pipe and go right back into the tank through the bottom of the backup pump. I was surprised that the main pump didn't force all its water straight up and out of the tank. What would I need to change with the arrangement of pipe fittings to make sure each pump would have all its water exit the tank and not feed back into the other pump's piping? Ideally, I would like to have two complete lines but its 100' of buried piping once it leaves the tank so I need to figure out how to configure the pipes in the tank to work with one or the other pump and not feed back. Thanks for any ideas.

Good Evening, We're in the process of building a barn which will have water and electric run out to it from the house. The location on the house where we were going to tap into for both is right where the water and electric enter the house from the street and well. We live in NH so freezing is a concern. The water line will be buried 4ft+ in the ground. The conduit from the barn for the electric is going come out of the ground right at the house and enter through the sill plate. Originally, to get water hooked up, I was going to have a new hole cored through the foundation 4ft+ down and tap into the water system just after the expansion tank. However, I may have an easier way that will keep from having a new hole poked in my foundation: Can I Tee into the water line outside the house instead? This would be between the well and the house. If so, I can do this job myself. Has anyone done this/ know whether or not it should be done? It seems that the expansion tank doesn't care which direction it's providing pressure/ flow and I can't think of another reason not to do this. I don't see a need to isolate the barn from the house so not having an exposed isolation valve isn't a concern. Thoughts? Thanks in advance!