I installed my own septic system. It's not that complex. The county health dept. gave me an instruction sheet. I had to hire a guy with a backhoe to dig a deep hole for the tank-$100. Then I rented a walk behind trencher from a lumber yard. $75. I rented a laser transit from a rental place and had it all done in a week or so. After 14 years, it still works fine.
Pearl 