Your well may be where your water comes from, but it would be useless without the mechanical system that conveys the water to your house, stores it, and provides the pressure so it will flow.

Figure 1 represents a typical well and water system for a home. In this example, the well has a screen, so it’s a well finished in the sand and gravel aquifer. The pump is in the well, just above the screen. The pump lifts the water up a pipe called a drop pipe to the pitless unit, part of the pitless adapter. There, the discharge pipe elbows horizontally and carries the water into the house.

Once in the house, the water goes into the pressure tank, or if it’s a period of heavy water use that kicked on your pump, the water goes straight into the line to your faucets, shower, or dish washer. The pressure tank stores water and also creates the pressure in the system that allows water to flow when you open up a faucet or turn on the shower. There are many additional parts that make up your water system. Some of them you can see here, including the well cap, electrical control box, pressure switch, and a faucet on your pressure tank.

We can’t stress enough the importance of a properly sealed well cap. So many systems we come across have missing bolts, are cracked or broken from being hit by a mower, or have no screen on the vent tube. Any kind of opening creates a pathway for insects or contaminants. In extreme cases, even animals can fall in a well. A sealed, properly secured cap is a simple way to provide important protection for your well.

The pressure switch and electrical control box work together to cycle your pump on and off when the pressure goes below or above pre-set levels. For example, a typical home system might have a low pressure setting of 30 PSI and a high pressure setting of 60 PSI. Your pump turns on and adds water to the pressure tank until the pressure reaches 60 PSI, then it shuts off. As you then use water in your home, the pressure in the tank slowly goes down. When it gets to 30 PSI, the pump will turn back on until the tank is again at 60 PSI.

The faucet on your pressure tank is there to allow you to periodically flush your tank. It also provides an access point to collect water samples.

The Private Well Class is a collaboration between the Rural Community Assistance Partnership and the University of Illinois through the Illinois State Water Survey and the Illinois Water Resource Center, and funded by the United States Environmental Protection Agency. The views expressed here are solely from the class authors and not endorsed or reviewed by USEPA.