Five Parts of Sanitary Water Well Construction

In Pennsylvania, the construction and maintenance of private water wells aren’t regulated by any state agency. While some local mandates exist, it is primarily up to the private well owner to maintain their well to ensure a safe drinking water supply.

Anything that ends up on the ground’s surface—animal waste, sediment, fertilizer, chemicals—has the potential to be washed into wells with surface runoff after rain events. To help lessen the possibility that drinking water isn’t contaminated by surface water runoff, there are several well features to consider.

1. Well casing extending 12 inches above the ground surface. Making sure the casing is extended helps keep surface water from entering the well. If your well is lower than the ground or buried in a pit, a well driller may be able to help with extending the casing above the surface.
2. Ground sloping away from the wellhead. If the ground around your wellhead is sloped gently away from your wellhead and casing, this will also help surface water to be directed away from your well and reduce the possibility of contamination.
3. Well casing to bedrock. This is a well construction feature that needs to be in place when the well is drilled. Having the well casing extend to bedrock also helps to create a barrier between surface water runoff and your water supply. Casing can also be professionally inspected with down-well cameras to check for leaks or damage.
4. Grout seal. When a well is drilled, a grout seal—usually made of bentonite clay material—can be put in place around the casing. The grout material expands and creates a tight seal against the casing to further reduce the influence of surface water runoff. Grout is usually not used on private wells in Pennsylvania unless it is required by local ordinances or requested by the homeowner.
5. Sanitary well cap. Newly constructed wells are not automatically installed with sanitary caps and must be requested by the well owner. This is a feature that can be installed on an existing well. Most wells have a standard well cap that leaves an air gap between the well casing and the cap. This air gap allows for insects, vermin, and surface water to potentially enter a well. A sanitary well cap has a rubber gasket to allow for a tight seal with the well casing and also a screen that allows for necessary airflow. A well owner can purchase a sanitary cap from a well driller or from hardware stores or online sources. It can be installed by a well driller or by a well owner with some electrical skills.

Less than 20% of wells in Pennsylvania have all five of these features, but even having a few in place can help reduce surface water impacts on private water supplies. For more detailed information on this topic, visit: Sanitary Water Well Construction.