Deep well pumps are not for every well. In fact, they are meant for really deep wells. They serve several purposes. The following purposes, and why it matters, highlight a product that may or may not be beneficial to you.
You Have a VERY Deep Well
Some wells take forever to dig because the water aquifer that you are trying to tap is so far down under soil and rock. When you can finally tap that water, a typical well pump does not have the necessary power to pull water up from those depths. With a well that deep, you need a pump with serious power, and a deep well pump has it.
The Pump Reduces The Need to Dive
With some well excavations, a diver has to enter the well to install the pump. In a deep well, that is not easy to do, nor is it recommended. A deep well pump is weighted on its bottom so that the pump can be sent all the way to the bottom of the well and land on its base without much human manipulation. At this point in the well, the pump is able to begin sending up water until the well runs dry, or until the pump needs repair (which is very rare).
You Can Get a Lot More Water From the Well
Despite the fact that you have a deep well, these kinds of pumps are designed to quickly and forcefully pump water up and out of the well. The control box will even allow you some control over how much water and how fast. There is little waiting time to get the water you need when you need it. If you also have a holding tank connected to the well pump's lines, then you have a constant source of water that is constantly refilled.
If You Have to Dig a New Well That Is Equally as Deep, You Already Have the Right Pump
Wells eventually dry out, but typically they do not dry out for years. Still, if you find that you have to dig a new well while you are still living in the same house, and that well is equally as deep, you can just transfer the old pump to the new well. Just make sure you maintain your deep well pump so that it is in very good condition and it can be transferred to a new, deep well.