What is the minimum distance from any Class I or II reservoir to the sanitary system?

• A. 100 feet, from normal pool elevation
• B. 50 feet, from normal pool elevation
• C. 25 feet, from normal pool elevation
• D. 150 feet, from normal pool elevation

Answer: (A)

The key idea is protecting drinking-water sources by keeping septic systems at a safe distance from surface water. For Class I or II reservoirs, a minimum buffer of 100 feet from the reservoir’s normal pool elevation to the sanitary system is required. This distance helps prevent septic effluent—containing potential pathogens and nutrients—from reaching the water supply through groundwater or surface runoff. The normal pool elevation is the typical water surface level, and the setback is measured horizontally from that level to the nearest part of the septic system. Other distances (50 feet, 25 feet, or 150 feet) don’t meet the required minimum; 100 feet is the standard minimum.