And a word of caution if you remove the drain field. It's hard to know exact postion and those lines are wrapped in a mesh material holding little stuff similar to the the packing popcorn that scatters everywhere. It was real challenge to clean up, and I still wasn't happy with the appearance of the backyard. My final solution was building an enormous deck with raised areas for plants and an outdoor kitchen. Expensive, but worth it!
Grayt idea!!!