What impact do heavy rains have on an OSSF?

Heavy rains can significantly affect an On-Site Sewage Facility (OSSF) by leading to saturation of the drain field. When there is an excessive amount of rainfall, the soil in the drain field can become saturated, which impairs the soil's ability to absorb the effluent. This saturation can cause the system to back up and might lead to failures, such as surface ponding of effluent or untreated sewage being released into the environment.

The physical limitations of the soil and the OSSF design mean that there is a maximum capacity for water absorption. When the soil becomes waterlogged, it can't effectively filter and treat the effluent, which can compromise system performance, pose public health risks, and potentially violate environmental regulations. Thus, understanding the impact of heavy rains is critical for proper maintenance and management of OSSFs.