I have two 2500 gallon tanks on a hill (higher elevation than the house and well). Water is pumped from the well to the tanks and then drains back down to the house. The pump was tested and pumps ~10 gallons a minute free flow at wellhead.

I would think the way it works is when the water level decreases to a certain level, a switch is closed in the tank(s) which signals the pump down in the well to turn on and pump more water to the tanks until they are full again.

Everything seems to work OK except sometimes one of the tanks seems to be overflowing and water runs out of an outlet at the top of one of the tanks for a while. I have a photo that shows this but was unable to upload it for some reason, PM me and I will send it. There are inspection ports on the top of the tanks and both are full.

What I would expect to see is:
(1) a pipe from the well to one of the tanks
(2) a pipe from one of the tanks to the house
(3) a pipe connecting the 2 tanks together
(4) 2 or 4 wires going from the tank(s) back to the pump inside the well to tell it to turn on.

What I am seeing is: (photo shows this very clearly)
(1) an approximate 2" pipe connecting the 2 tanks together at the bottom of the tanks
(2) an approximate 5" pipe from one of the tanks going under ground.

Is the 5" pipe going to the house? or well? where are the wires? where is the other pipe?

Also, there is some sort of chlorine injection system at the well but that's another story.

Thanks very much in advance for any information on this.