Ground water sources must be located at least how many feet from potential contamination sources?

• A. 50 feet.
• B. 100 feet.
• C. 300 feet.
• D. 500 feet.

Answer: (C)

Keeping wells farther from potential contamination sources reduces the chance that pollutants reach drinking water. Groundwater moves underground and can carry contaminants from nearby sources like septic systems, fuel storage, chemical handling, or livestock areas toward a well. A substantial separation distance gives time for contaminants to attenuate, dilute, or be intercepted by soils and natural barriers, lowering the risk of drinking-water contamination. The 300-foot setback is a commonly used minimum in many health guidelines because it provides a practical, protective buffer under typical soil and hydrogeologic conditions. Of course, actual requirements can vary by location and local geology, and in some situations greater distances or additional protections may be needed.