What slope is considered excessive for a single-level sewage system?

For a single-level sewage system, a slope of 15-30% is considered excessive because such steep slopes can significantly impact the proper functioning of the system. Excessive slopes can cause issues with the flow of sewage, leading to rapid drainage that may prevent the system from treating waste effectively. It can also result in erosion of the soil, reduce the lifespan of the components, and potentially lead to system failure. Proper slope management ensures adequate retention time for waste treatment processes, allowing for effective filtration and breakdown of sewage before it reaches groundwater or surrounding soil. Therefore, maintaining a slope within the acceptable range is crucial for the functionality and sustainability of an onsite sewage facility.