Private wells

[DickR]

Originally Posted by Merrymeeting

.... This is the reason why most ground source heat pump systems are required to have closed loop returns.

Especially in the northeast, where groundwater is plentiful and of high quality, it is quite common to use the standing column well (SCW) design for a GSHP, a specialized form of open loop. Water from the pump located down deep in the well passes through the heat exchanger of the heat pump and is returned to the well near the top, but below water level. This design is quite safe and works well. There is no risk of well contamination, since the water being returned is the same water as already is in the well. I heat my house this way.