What setback distance applies to Public Water Supply Within Watershed out to 5 miles?

• A. 50 feet
• B. 400 feet
• C. 250 feet
• D. 75 feet

Answer: (C)

Setback distances exist to protect drinking water sources from pesticide exposure by keeping treated areas at a safe buffer from wells and water intakes. For a public water supply that lies within a watershed extending up to five miles, the required buffer is 250 feet. This distance helps reduce the chances that pesticide drift, runoff, or any incidental spills near fields could reach the watershed and contaminate the drinking water supply.

In practice, you would plan applications so you stay at least 250 feet away from any public water supply intake within that five-mile watershed area. If a label or local rule specifies a different situation, follow that, but for this scenario the 250-foot setback is the standard.

The smaller distances listed (50 feet, 75 feet) don’t provide enough protection for a water supply in a watershed, and while a larger buffer like 400 feet exists in other contexts, it does not match the requirement described here.