Worries about Duplex next to gas station?

[George Smith]

Im looking at property that Im having a rehabber fix and sell to me. The caveat is that its next to a gas station(See photo below). I realize that i wont be living there but it is a concern about contamination. Obviously a phase 1 and possibly a phase 2 would be ordered but im still a little weary. Im curious if anyone has a property similar to this and the issues they have come across. 

Thanks.

George