The drainfield is ideally located in a sunny open area for maximum evaporation. Tree and shrubs should not be planted near the drainfield as root intrusion may impair the drainfield. Grasses and ground cover provide the highest level of evapotranspiration (the cycle of plants taking moisture from the soil by their roots system and giving off to the atmosphere using the suns energy) without the complication of root systems slogging drainpipes and gravel beds. Mulched areas of flower beds do hold moisture and decrease drainfield efficiency.
Walkways, patios, parking areas, decks or other permanent structures should not be constructed over either the septic tank or the drainfield. Vehicles should not drive over the drainfield on a regular basis and heavy trucks and equipment should be kept off the drainfield.
Rainwater or other drainage water should be diverted from the drainfield area. The drainfield size is designed for the amount of water coming from the house. Adding extra water from poor drainage may cause problems.