What ever you do, send a registered letter to both the woman you bought the property from, and the neighbor, stating your objection to the encroachment on your property. You need something in writing, with both date and time, documenting your disapproval. There is a statute in most states laws known as prescriptive easement, which basically states, after a certain number of years (arkansas is 7 some are more, some less) if you allow acess across your property without ascerting your disapproval, an easement for the egress can be legally recognized by the courts as if an easement were originally granted. In other words, if you don't descent, at some point in the future, they can claim prescriptive easement, and keep their "stuff" on your land. I know for a fact this applies to "right of way" and ingress and egress, but it might possibly also apply to utility type easements as well. Demand they move it. If they refuse, hire an attorney. It is not your burden to bear their septic tank problems, and they shouldn't even question it. If they do, then you both should be the ones to file a suit against the seller, and ask for attorney fees. <font color="black"> </font>