That's a hell of a mess. You can try this, but be gentle and flexible. Ideally, take a septic installer with you that works in that county and has a good relationship with them.
Ask the county if you and your wife can move back in. Tell them nobody has been living in the home for 16 months and that the system has been “resting”. Tell them that you believe the drainfield was not working because there were 7 people living in the home and the drainfield was hydraulically overloaded. Tell them the lease did not allow that many people living in the home. Tell the official that you are going to have the trees removed and fix the corrugated pipe and that if any more effluent surfaces you will call a septic installer to fix it and call the county out to look at the repair.
By the way. You should not have trees growing in your septic drainfield. Only grass. Three feet from the center of the pipe in both directions should be grass. Keep that outer edge of the six foot wide swath of grass that is the drainfield ten feet away from the dripline of any trees. In other words, mentally draw a line straight down to the ground from the nearest tree leaf on a limb. That point on the ground should be ten feet from the outer edge of your drainfield (or thirteen feet from the actual corrugated pipe).
Another FYI. Technically water surfacing on the drainfield is called “surfacing effluent”. This is septage which has been partially treated by the tank, but it is still septic—in a state of disease. The tank removes most of the large poopy particles and the leftover effluent is sent to the drainfield. The septage that goes into the tank is called inffluent and the stuff that comes out is called effulent.
222 Falling Waters Road
Cullowhee, NC 28723