Water pressure and wells: what you need to know

Everyone wants good water pressure in his or her house. There’s nothing more frustrating than having your water slow to a trickle in the middle of a shower or some other activity.

Fortunately, there are a number of approaches to ensuring good water pressure for people who have private, household water wells. Even wells that yield a low rate of water can provide consistent pressure with the right system in place.

There are three basic approaches to ensuring consistent pressure in a well system — pressure tanks, variable frequency drives (VSDs) and control valves. A qualified water well contractor can help you decide which option is best for your well.

Pressure tanks

Pressure tanks are the most common method for providing consistent water pressure for household well systems. Usually located in the house or a crawl space, these tanks store 20 to 40 gallons of water or more depending on household needs.

Some tanks use pockets of compressed air in the top of the tank to create pressure. Others have internal diaphragms or bladders that inflate within the tank to create pressure.

When water is drawn from the tank — and pressure drops to a predetermined level — a pressure switch is triggered to turn on the well pump and refill the tank.

Pressure tanks are economical, reliable and come in several different designs. They can be made of steel, fiberglass and other materials.

If your well yields water at a low rate, increasing the size or number of pressure tanks can help ensure consistent pressure to meet your peak water demands.

Variable speed drives (VSD)

This system varies the speed of the pump motor to deliver the amount of water needed under pressure on demand. For instance, the motor runs faster when the dishwasher, shower and lawn sprinkler are all going at the same time. However, when little water is needed, it runs slower.

The motors of variable speed pumps can run up to two times faster than those with constant speeds. And VSD systems require only a small pressure tank of two gallons or so.

Control valves

A control valve can be installed between the pump and the pressure tank. It will automatically adjust flow from the well pump to a preset pressure. It is relatively easy to install and can be a good, economic solution to many problems.

Choosing a water pressure system

A qualified water well contractor should determine which system is best for you. A contractor can help you consider your water needs, costs and technical requirements. If you want to find a National Ground Water Association member contractor near you, go to http://www.wellowner.org and click on “Contractor Lookup.”

The National Ground Water Association recommends that private household well owners get an annual water well maintenance checkup and water test. If you have not done so, this would be a good opportunity to ask about any water pressure problems you might be experiencing. You can learn more about the importance of an annual well checkup “Well Maintenance” on http://www.wellowner.org.

Low well yield or low flow is different from low water pressure. Low well flow can be caused by the plugging of holes in the well casing through which water flows into the well. Also, the plugging of openings in the well screen can restrict the flow of water to the pump. In other cases, spaces in the surrounding ground or rock close up to impede the flow of water into the well.

Problems that contribute to low well flow can be addressed by a qualified water well contractor. To learn more about low well flow, go to “Well Maintenance/Restoring Flow” on http://www.wellowner.org.