From the holding tank example, how far is the tank from the natural spring source?

• A. 10 m
• B. 7 m
• C. 5 m
• D. 35 m

Answer: (D)

The key idea here is protecting a natural water source by maintaining an adequate setback from a holding tank. Holding tanks can release liquids if there’s a leak or overflows, so placing them far enough from a spring minimizes the chance that contaminants will reach the water supply. A distance of 35 meters provides a meaningful buffer, giving soil filtration and the natural travel time of groundwater a chance to dilute and attenuate any potential contaminants before they could reach the spring. Shorter distances would compromise protection because contaminants would have less soil and time to be attenuated, increasing the risk to the spring.