Check Your Well Cap

March 7-13 is National Ground Water Awareness Week, which is a good time for homeowners to check their well cap to make sure it is protecting the water supply from contamination, says Roxanne Johnson, North Dakota State University Extension Service water quality associate.

The National Ground Water Association, which sponsors the awareness week, has proclaimed Tuesday, March 9, as National Inspect Your Well Cap Day to spur private well owners to make this simple but important inspection.

“If snow prevents you from inspecting your well cap, do so at the first opportunity,” Johnson says. “A damaged or unsecured well cap can allow the entry of bacteria or other contaminants into the well. It is one of the easiest things to check, and a well owner can do it.”

The well cap is the cover on top of the well casing, which sticks out of the ground. The cap is the first line of protection against nonpoint-source pollution, which constitutes the majority of ground water contamination. Nonpoint-source pollution includes runoff of pesticides and herbicides, soil erosion and elements from the street.

Well caps also keep insects and bacteria-carrying rodents out of the well. Most caps usually are aluminum or thermoplastic and include a vented screen that allows the pressure inside and outside of the well casing to be equalized when water is pumped from the well. However, the cap’s main function is to keep contaminants out of the water supply.

Johnson suggests homeowners check the well cap periodically. Make sure that it is sealed tightly, and look for cracks and evidence of tampering. If your well cap has a lock, make sure no one has tampered with it.

If well owners do spot a damaged or unsecured well cap, they always should use a qualified water well systems contractor who knows applicable well construction codes to fix or replace it. If the well cap is damaged or unsecured, the water well contractor also may need to test the water and disinfect the well.

“Also, practice safe water habits,” Johnson says. “Do not landscape around the well cap. If you landscape your yard, make sure there is not a low area near the well where rainwater could collect. Rainwater can carry pollutants that can seep into a well. And when working with oil and gasoline or mixing herbicides or pesticides, do so over concrete so spills can’t seep into the ground.”

She adds that having your well tested is the surest way to determine that the water is safe. Even if your well cap fits tightly and your water tastes fine, the water well system should be given a checkup every year.

To learn more, visit NDSU’s water quality Web site, http://www.ndsu.edu/waterquality, or the National Ground Water Association’s Web site, http://www.wellowner.org.

NDSU Agriculture Communication