(any environmental issue)?  

We have an environmental/ hazardous waste company pick up the drum for us.

I think a lot of this depends on the age and construction of property, what amenities it has, and the environmental factors (geography / weather). 

Money well spent and applies to other asset classes. 30 days is standard but if issues come up definitely alright to extend because you don't want to just start ordering environmental or septic inspections which can be expensive without clearing the duie diligence you can at no cost.

We're bidding in Michigan where all prior liens are excused in a tax deed auction, with limited exceptions such as IRS and environmental liens.

The levels are fairly high levels but based on the environmental consultant probably did not include manufacturing just contamination from heavy use via smoking. 

With some programs, even land with environmental issues still counts.

You need to worry about environmental contamination, illegal dumping next to the gas station over the years, and leaking of gas tanks.It doesn't matter who caused the contamination the EPA will make the current owners clean It up.If it's a new build the seller should have a phase one completed on the land.

The liability with providing "clean water" and the potential environmental costs with a septic system makes the risk much higher even on a great cashflow deal.  

I would even spend a few dollars on grading the soil and maybe even get a few test done, environmental and feasibility study..But yes I wouldn't do it alone.. no way