Drain Fields The drain field is the most important component of the septic system. When properly installed and sized, it will accommodate treated wastewater (effluent) from your septic tank for many years. Your drain field requires no maintenance; however, you may want to consider locating and uncovering the distribution box and having it cleaned if your system is older than 10 years. In addition, consider following these precautions to best care for your drainage field:  Periodic septic tank pumping will prevent sludge and scum from contaminating the drain field.  Keep the following items off of the drain field: automobiles, heavy vehicles, accumulated storm water and stockpiles of snow and soil.  Mark the boundaries of the drain field as a permanent reminder.  Avoid planting trees and deep-rooted shrubs in the vicinity of your drain field.