What is the maximum allowable slope for single-family dwellings in pumped effluent drainfields?

The maximum allowable slope for single-family dwellings in pumped effluent drainfields is 2%. This standard is established to ensure proper drainage and prevent issues related to effluent movement and stability within the drainfield system. A slope that is too steep can result in uneven distribution of effluent, which may lead to flooding in some areas and insufficient treatment in others.

Maintaining a slope of 2% helps facilitate the gravity flow of the effluent through the drainfield while also allowing adequate time for treatment processes to occur in the soil. This balance is crucial for protecting groundwater and preventing environmental contamination. Slope standards are therefore put in place to optimize both the functionality and longevity of the drainfield system.

Options that suggest a slope of 1%, 3%, or 4% either fall below the minimum required for effective drainage or exceed the recommended maximum, thereby increasing the risk of system failure or environmental impact.