Is there a risk of contamination with shallow well pumps?

Causes of Contamination

Shallow wells, by definition, have a relatively short depth to the water table, making them more susceptible to contamination from surface sources. Common causes of contamination include poor well casing installation, inadequate seal at the top of the well, and nearby sources of pollution such as agricultural runoff, sewage, or industrial waste. In areas with high groundwater flow rates, shallow wells can also be at risk of contamination from nearby wells or aquifers.

Contamination Sources and Mitigation

Some specific contamination sources to be aware of include: nearby septic systems (within 50-100 feet), agricultural runoff (within 10-20 feet), and nearby wells or aquifers (within 100-200 feet). To mitigate these risks, it’s essential to install a proper well casing (at least 2 inches thick and extending at least 12 inches above the ground surface), a well seal (such as a concrete or steel cap), and a suitable well screen (with a minimum of 6 inches of perforated pipe). Additionally, regular maintenance, such as inspecting the well for signs of damage or contamination, can help prevent issues.

Testing and Protection

Regular water testing is crucial for shallow well owners to detect potential contamination early on. Testing should be conducted annually, or as recommended by local health authorities. In areas prone to contamination, consider installing a treatment system such as a UV filter or activated carbon filter.