What is the current thinking on purchasing a former gas station where the tanks were filled w/ cement in 1984?
If the property can provide a current Phase I inspection showing no problems, is it safe to make an offer?
Unless you have one of the National gas companies, i.e. Chevron, Shell , Exxon, etc. on the hook for any long term remediation, I would not touch it. I had a situation that proved to be a mess with concrete filled tanks that came up clean on a Phase 1 only to discover that there was contamination below. It cost $250K+ to clean up (and I have seen them cost well over $1mil. Thankfully for us, it was Chevron's expense. Be very carefull. I would walk away. Too much else available.
The new laws mandate that you dig them up and prove there is no contamination, which is very expensive with no return - if there is no contamination, you've paid for all the digging and restoration of the site, and if there is contamination you are liable to ensure remediation to the State. I agree, don't buy, today is a buyers' market and there is lots of other available stock.
Phase I is only a look at historical data and visual assessments. Like the other's if you don't have someone on the hook with a very deep pocket stay away. For sure the tanks are steel and very well may have leaked. A pahse II is a must and is or can be very expensive. Look for something else.
Also, depending on state where you live (I am in NJ), once the remediation or natural attenuation has brought the comtamination levels low enough, the state will issue a letter of no further action (NFA). Until a letter of NFA is issued it can be very hard to get financing.