What is the minimum distance from any other stream, canal, marsh, or other surface waters?

• A. 25 feet
• B. 75 feet
• C. 50 feet
• D. 100 feet

Answer: (C)

Setback from surface waters is about protecting water quality by keeping the septic system far enough away from streams, canals, marshes, and other surface waters so effluent won’t easily reach them.

Fifty feet is the minimum distance because it reduces the chance that runoff or groundwater carrying nutrients and pathogens will move from the septic drainfield into surface waters, even under ordinary rainfall and recharge conditions. The soil between the system and the water provides some attenuation, and the separation helps avoid issues during flood elevations when water levels rise.

This distance reflects a practical balance between protecting water resources and allowing sensible site placement. In some cases, local rules may require more distance due to slopes, floodplains, or particularly vulnerable water sources, so be mindful of site-specific regulations beyond the general standard.