Forty-two million homes in the United States get their fresh water from a private water well system. Many of these people are living off the grid.
But what is a private water supply, and does it always come from a well? How does it work? Let’s find out.
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What is a Private Well?
This one’s easy. A private well is a type of water supply system that is less reliant on government agencies. A hole is dug on private property to access fresh water. A pump draws the water from an underground stream or aquifer.
An aquifer is the layer of permeable rock, sand, silt, or gravel that water flows through.
Wells are dug to reach the aquifer, which in some areas may be less than 25-300 feet below grade. For example, drilled wells in Connecticut must be at least 450 feet deep. Depths of 1,100 feet are not uncommon.
Wells up to 25 feet deep are called shallow wells. When they are more than 25 feet deep, they are called deep wells.
Components of a Water Well
- Well — A hole dug in the ground to reach the water below the surface.
- Well pump — A device that brings water to the surface.
- Service pipe — The pipe that carries water between the well and a pressure tank.
- Main shut-off valve — The shut-off valve is exactly what it sounds like and is located between the well and pressure tank.
- Pressure or storage tank — The tank holds H2O and is usually located on the lower level of the house or basement. It can also be stored inside a reservoir called a vault.
- Pressure switch — A private well system must have a pressure switch that automatically starts and stops the pump at predetermined pressures. Pressures above 60 psi (pounds per square inch) can harm your supply pipe.
- Pressure gauge — The pressure gauge, which displays a readout of pressure in the tank, might be located near or on the tank itself.
If a home has a pressure tank but no water meter, it’s a good bet that it is getting its H2O supply from a well or other type of private system. This could be a pond, stream, or spring on their property.
Where Do You Place a Water Well?
Although rules regarding the location of a private water well vary from community to community, it is usually required to be at least 75 feet from a private waste disposal system (like a septic tank).
Some areas require this distance to be up to 200 feet, so check with your local municipality for codes and regulations.
It should also be located uphill of any contaminating source and a required distance from a stream or pond.
Typically, the first 50 feet of the well must be protected by an impervious casing sealed at its lower end. The top end of the well should be 12-18 feet above the ground to prevent ground water from entering.
Types of Water Pumps for Wells
The purpose of a water well pump is to draw water from the well and push it through the home’s plumbing system. It has to do this with enough force to provide adequate flow (or water pressure).
A flow rate of 5-7 gallons per minute is considered adequate in most rural parts of the country. A modern home with two or more bathrooms will be better off with a pump that provides a peak flow rate of 10 gallons per minute.
Here are the different types of pumps used in private water wells.
1. Piston Pump
This type of water well pump is used in older systems and no longer installed today. It’s a motorized version of the old hand pump. If you watch Westerns or live on an older farm, you’ve likely seen them before.
It is used on shallow wells, where the motor and piston assembly are both above the ground. When used with deep wells, the motor is above the ground and the piston assembly is in the well.
2. Jet Pump
The jet pump includes a centrifugal pump and a jet assembly. Think of the centrifugal pump as a small paddle wheel driven by a motor.
The pump recirculates pressurized water into the well, creating a suction that draws more well water into the jet assembly and pushes it up to the pump. Some of the liquid enters the home’s plumbing while the rest is diverted back to the jet assembly.
To operate properly, a jet pump used in a deep well needs to be filled with water and have about 15-20 pounds of back pressure. When the well is pumped dry, it must be re-primed and pressurized before it operates again.
3. Submersible Pump
A submersible pump includes a motor and an electrically driven centrifugal pump. Designed to operate under water, these components are located inside the well. Although sometimes used in shallow wells, you’ll find them mostly in deep wells.
How Long Do Well Pumps Last?
The life expectancy of a well pump can be as short as 7-10 years. However, many well pumps last about 20 years. Submersible well pumps last about 20 years.
If you’re taking over a property with a well already on it, check to see if the equipment has a date code on it. This could tell you how old the current system is.
In the days when pumps were noisy and pressure tanks were large, well equipment was often placed outside the house in a separate pump house or an underground well pit (an underground chamber with a hatch and floor below the frost line).
Are you interested in a private well? We recommend first finding a friend or neighbor who owns one. Ask them if you can look at their equipment and learn everything you can from their experience.
Then contact a professional plumber with excavation experience and equipment. It’s a big, complex job so you don’t want to do this yourself.
But with the right help, you too can get your H2O supply from a private water well system pumped into your home.
1-Tom-Plumber’s certified team of plumbers and drain technicians respond immediately to any emergency plumbing, drain, or water damage problem, including excavation of underground water lines and sewer main lines. Our immediate-response team is available every day and night of the year, even holidays.