What should all finished grading be designed to do?

All finished grading should be designed to direct surface water away from lateral lines. This is critical for the proper functioning of a septic system. If surface water accumulates around the lateral lines, it can lead to water saturation in the soil, which negatively impacts the system's ability to treat wastewater effectively. Proper grading helps to ensure that water drains away, maintaining the required soil conditions around these lines and preventing potential failures or backups in the septic system.

While aesthetic value and support for heavy traffic are important considerations in landscaping and site development, they do not directly address the functionality and operational integrity of a septic system. Encouraging ponding water is detrimental, as standing water can compromise the system by promoting saturation and presenting a host of issues including odor, bacterial growth, and potential system breakdown. Therefore, directing surface water away from lateral lines is essential for the health and efficiency of the septic system.