contact the people who did your septic system and ask what you can do. I can plant and dig all sorts on mine, as the lines are over 3 ft deep, so no issues. Depending on how deep your lines are and the soil type ect, you may easily be able to grow root type vegetables, or put in raised beds. We were even told that we could use a tiller over our area as long as it wasn't too deep. Avoid planting trees near that have invasive roots like willow, poplars, maples. Shrubs would probably do fine as they have a much more shallow root system than trees, but you should ask your builder first what they think. I found some tall narrow shrubs that get 9 ft tall, 2 ft wide, evergreen, GreenTower Boxwood. If your lines/drainfield is deep enough you may have no issue growing these. Also ask if your sewer line from your house to your tank is schedule 40 or if it is the cheap thin stuff. Ours here was thin stuff and we dug it all up and redid it in the heavy material. Much more difficult for roots to damage that.
