They want to run through your property and then have the nerve to want to charge you 30k to hook up? Talk about kick in the ass.

What issues are you going to have if their pipe leaks and causes some sort of sink hole or major damage to your property? What trouble are they going to cause you if something damages the pipe and they blame it on you? What kind of mess are they going to make digging up the pipeline in the future if it needs maintenance? How's it going to affect your land value?

I'd find a lawyer that is familiar with this sort of situation and talk to them.