Neighbor won’t let me sell my house due to old septic lines

Location: NC

I live in a large county. When I bought my first home in 2019, it was never disclosed that my septic lines and D-box (sp?) were located on the small (approx. 1/4 acre) empty lot of the adjacent property.

Two weeks ago, I put my house on the market. The next day, my real estate agent gets a call from the neighbor who owns the empty lot demanding I move the lines.

The neighbor purchased the property in 2021. Their family has lived in the property next to the empty lot (two properties down from me) since 2005. They all knew about the septic lines and were there when they were updated by the previous owners of my house in 2018. However, none of these people have said a word to me about it since I moved in six years ago. This all became a problem when the house went on the market.

I’d have no problem moving the lines, but the county says I have no room! They said that the only way to do it would be to essentially dig up the front AND back yard, move the septic system to the front and the well to the back. We’re talk about $30-40k in costs!

The neighbor absolutely refuses to speak to me. I had my agent and the county give them my number, but they refuse to talk. They’ve contacted my agent and the county numerous time to talk about the issue, but when redirected to talk to me, they shut it down.

I’ve offered to pay for an easement. Refused. I offered to buy the property (worth approx $7k). Refused.

I cannot find a real estate attorney that practices litigation who can give me any advice.

Apparently these lines have been in place since the 1970s.

The county is telling me I cannot sell my house before I fix this and I am in “violation”. However, the only solution they are offering is to dig up the yard and pay 1/3 of what I paid for the house.