What is the required setback distance for a public drinking water spring from the edge of a drain field?

The required setback distance of 200 feet for a public drinking water spring from the edge of a drain field is based on the necessity to protect the water source from potential contamination. Drain fields, which are part of septic systems, can release effluent that may contain pathogens, nutrients, and other pollutants. By maintaining a distance of 200 feet, regulations aim to ensure that any contaminants in the effluent have a sufficiently long path to attenuate and be treated naturally by the soil before reaching the water spring.

This setback distance is crucial for safeguarding public health and ensuring the quality of drinking water supplies. Maintaining this considerable separation decreases the likelihood of contaminants reaching the water source, thereby providing an added layer of safety for communities relying on that water.

In contrast, shorter distances as suggested by the other options would not effectively mitigate the risk of contamination, making them inadequate for safeguarding public drinking water resources.