My question involves real estate located in the State of: Pennsylvania

I am looking to purchase land in Pennsylvania. The seller is only selling the surface rights and keeping the mineral rights. I understand that PA law allows the mineral rights owner to access minerals via the surface by reasonable measures. No one lists these reasonable measures and I guess they are open for interpretation?

My main question is that the land (surface only) I am looking to buy has the mineral rights currently leased (since 2008). The lease is a legal document and is for 5 years with one 5 year renewal. Obviously, I am bound by this document. Do I have legal rights as far selecting the location/disturbance on the surface if it impairs my rights. I would like to build a house in a select location and am concerned about the drilling company using this location?

Any advice would be greatly appreciated.