The Best Raised Bed Garden Over Septic Drain Field References. Adding an extra foot of dirt on top of your drainfield, may hurt your system. Planting over a septic leach field (drain field) is possible if it is done with care.
However, just adding topsoil is generally ok if it isn't more. Placing a raised garden bed on top of your septic system or leach field prevents the moisture from getting out and can damage the system. Insects/slugs rain splashes will put.
