I agree with Fumblin, they should have to show hard data, that an enviromental risk does really exist. If that was their real concern, they would do more good to study each individual (potential risk) and offer a possible solution that would either eliminate or minimize each.
In my opinion, it is more about them trying to regulate something that is none of their business. If she and her junk were there first, she should have grandfathers rights, and they should leave her alone.
Now if there is real contamination that is spreading or is at risk of being spread to adjoining properties, that would be an entirely different situation.
The governmental agency that is flexing their muscle, had better have all of their ducks in a row. Because the way I see it, unless they have studied each and every other property for the same contamination risks, they are harrasing this woman, and should be sued for doing so.
The fact that she and a few others have been singled out, points to "Property Owner Profiling" based on their "outdoor collections or accumulations" that some view as being ugly and unattractive and therefore must be causing enviromental damage.
I would bet, that there is more continuous contamination from leaky vehicles, occuring daily in many Wal Mart parking lots accross the country. The difference between the two, would of course be that any contamination on her site, would most likely soak into her soil, and probably remain there for hundreds of years. Whereas parking lot runnoff occurs at each rainfall, and washes away into storm sewers, directly and immediately places all connected waterways at potential risk.