What is the minimum diameter for pipes used in a gravel system?

The minimum diameter for pipes used in a gravel system is established at 4 inches to ensure proper flow capacity and to prevent clogging. This diameter allows for the adequate movement of wastewater while also providing sufficient space to accommodate any solids that may be present in the effluent. When pipes are too small, there is a risk of blockages which can lead to system failure and environmental contamination.

Using a 4-inch diameter pipe helps maintain an optimal hydraulic radius, which is critical for the functioning of the septic system. This size supports gravity flow effectively, reducing the likelihood of build-up within the pipes and ensuring that the effluent can be evenly distributed throughout the gravel bed. In Illinois, these standards are crucial for safeguarding public health and protecting groundwater resources from the risks associated with inadequate waste management.