The bottom of a leaching system must be at least what depth above groundwater?

The correct depth for the bottom of a leaching system to be above groundwater is 18 inches. This requirement is in place to ensure proper functioning of the septic system and to minimize the risk of groundwater contamination. When the leaching system is placed at this depth, it allows for adequate drainage and filtration of effluent before it reaches the groundwater table. If the leaching system is too close to the groundwater, it can lead to insufficient treatment of wastewater, as contaminants might not have enough soil to filter through, thereby posing a risk to both the environment and public health. This regulation is part of maintaining septic system standards and protecting water resources.