What can snow or heavy rain cause regarding OSSFs?

Heavy snow or heavy rain can lead to potential saturation and failure of the drain field in On-Site Sewage Facilities (OSSF). When excessive moisture accumulates in the soil surrounding the drain field, it can exceed the soil's absorption capacity. This saturation can prevent effluent from properly draining through the soil, leading to backup issues, surface ponding, or even a complete failure of the system to treat wastewater effectively. Such a scenario can compromise the health and safety of the environment, as untreated effluent may surface and pose risks to nearby water sources and public health.

The other options relate to the functioning of the septic system but do not accurately capture the primary concern that arises specifically in the context of heavy precipitation or snow, which emphasizes the saturation of the drain field directly affecting its operational integrity.