Purchased my home 2 years ago and now this where do I stand

Bought a home over 2 years ago , 6 months ago my front door was knocked on at 7pm. It was the guy who rents/farms the field next door, said our septic was leaking into field, he said i needed to do this and do that, I disregarded as we had a septic "inspection" the renter of the field called health department and long story short they determined a lateral of mine is tied into a field tile in the field over a 1000 feet from property line. And now we have to get everything up to code. What can I do? I did not do this , this was done before I was born as I looked into it and at one point a previous owner owned my property/the farmland and the farmhouse across from us. I am just trying to be a home owner and hit with this. Where do i stand, what can i do? The health department is making me out to be the culprit and blaming me. Thanks LOCATION: midwes usa illinois

Author: BlueberrySwimming837