When farm and acreage owners need more water, it is not uncommon for them to get more by installing a larger pump. While this is often done in an effort to save money, overpumping a well can be a very costly mistake.
“Overpumping is one of the leading causes of premature well failure,” said provincial water specialist Dan Benson. “Unfortunately, we run into this situation all too often.”
Overpumping can lead to premature well failure, but can also cause other issues. One is more sand and silt in the water, which reduces water quality and plugs up pump and plumbing fixtures. Overpumping can also lower the water in the well to the point where more air is drawn, and this promotes the growth of aerobic bacteria which can biofoul a well.
In the worst-case scenario, you can create a low-pressure zone around the well, which can cause a cone of depression around it and cause permanent damage to the aquifer.
When a well is drilled, a pump test is required that will provide information to the driller for determining a sustainable pumping rate. The driller will also recommend an optimal depth for pump placement.
The online Alberta Water Well Information Database contains records of individual water well drilling reports and chemical analysis reports and can be used as a resource when you’re not sure where your original drilling report is. (It can be found online — search for ‘well water database.’)
“It’s important to understand how to read the drilling report,” said Benson. “Sometimes people will mistake the rate of pumping during the pump test for the recommended pump rate and that can be a problem.”
It is up to the licensed well driller and the well owner to ensure that the pump is sized correctly so it cannot pull water faster than the rate at which the aquifer is capable of transmitting water. It is also a good idea to regularly monitor your well to identify any changes in both the static and pumping water levels.
If you have a low-producing well, you can restrict the flow by installing a cistern or storage tank, along with a flow control valve, to prevent overpumping during times of peak consumption.