Hi Flanagaj. We are in exactly the same situation. Found a house we really like, and it’s perfect except for a shared septic tank that I have had inspected and it’s failed on 2 counts, too small and near a water course.
My solicitor has advised that we should not proceed. I have met with the vendors and they have agreed to do the work, but I’m worried that it will still be a shared system.
The property is a semi detached cottage, and it’s the other attached cottage that shares the ST which is on the land of the cottage I want to buy.
I have said that we would prefer the neighbours to have their own sewage treatment plant installed, as it would undoubtedly be beneficial to the value of their property.
However, we appreciate its out of our control and up to the vendors to do a deal before we can purchase.
We’re interested in how your situation came out in the end?