Gas station near apartment complex - how close is too close?

[Nick B.]

Hello BP!

I am considering a small 16-units apartment complex but there is gas station across the street from it. I know that gas stations present potential environmental problems and Phase I report is a must. However, is there a quick rule of thumb as to how close a gas station can be to a residential building without causing any issues? Something like: if the distance is X, then don't even look at that apartment financials - run away. But if is the distance is X+Y, then it's OK to proceed further.

Location, if that matters, is Denton, TX (DFW metro).

Thanks
Nick