Not sure for an above ground but for a underground a few yrs back was 6-10per foot. How big of line, what size right a away are they asking for and will this "above ground" line be in the way of anything? I know I wouldn't like an above ground line running through my property unless I didn't use that part or the property at all.
An above ground line would (in all likelihood) be a temporary line.
A fair price would depend upon very many variables:
How long it would it be in place?
What exactly it is carrying: fresh water?, Frac Fluid?, spent Frac Fluid (with formation water)?, a combination of the forementioned?
Capacity (size) of pipe?
Indemnification for any damages from leaks or spills?
Length of pipeline?
Need for clearing of land/timber?
Effect upon agriculture on the land?
It would be difficult to assess an appropriate payment without knowing the answer to questions such as those above.
If your relative could obtain answers to the above, they could take this information (along with a draft agreement obtained from the O&G company) to an Attorney with O&G experience - for review. If your relative has a maximum amount of information in hand prior to consulting an Attorney, it will require less (expensive)Attorney time.
A recent post on this Discussion makes note of a temporary water line.
You may wish to read that post and follow the discussion on that Discussion: