One thing many people don't check is air and water monitoring/quality records for the location or nearby. An area can seem nice, but if its downwind of a chemical plant that makes fertilizer, the air could be complete shit. It is in your best interest to have a comprehensive evaluation of air, water, and soil, even if you have already purchased the property, to ensure there isn't anything unexpected. If you find something bad, in most cases, you can still do something about it, you just need the right filtration/mitigation system.
Run the county/city/town's name through the EPA and state EPA equivalent sites for environmental incidents. Very bad things can happen in rural places with very little data except possibly in government databases. One example of this is the body of water near where my parents live in a rural area, seems like a nice little place, until you dig into the state governments database and find out it is a known body of water contaminated with PCB's with an indefinite ban on fishing and "limited" recreational use due to the levels of contamination. There are no signs, and absolutely no indication that anything is wrong with the body of water. I asked a few people that live right near the body of water about it, none of them had any idea, it was never disclosed to them when they bought the property. As far as I know, except for the state EPA, no one knows about it, since people from the area routinely fish on that body of water to eat what they catch without any idea they are eating toxic fish.
Knowledge is your friend (and if you know ahead of time, you can get the land for way less).