Should seller pay for Environmental Phase 2?

[Roberto Gutierrez]

Looking for some guidance here. In the process of acquiring an 8 unit apartment building. Going in with the units under market rent by $100, so there is a good opportunity for upside in this deal. There is a Pilot gas station about 120 ft (slight up gradient) from our property, and our environmental phase 1 shows there was a spill in 2011. A corrective action plan was put in place during 2013, and February of 2017 the soil contamination was said to be below the "site specific cleanup levels". In other words they have cleaned it up most of the way. Our engineers are recommending a phase 2, but the current owner doesn't want to pay for it. He is confident any contamination could be attributed to Pilot, and the tenants are also served with city water and sewer as opposed to well water.

This is a smaller deal, so i would rather not pay another $5200 on top of the $2000 already paid for the Phase 1. My thinking is that any competent investor would not carry on without getting an answer on this looming issue, even if there is a small chance of contamination.

Any input is appreciated. Would you all tell him to pay it or your out?