It's possible that part of the nature of the "cover-up", where they are pretending it's not as bad as it is, is to reduce the amount of testing done until the contaminants are attenuated by nature. For example, imagine there were tons of these chemicals that went down the stream into the Mississippi, And people knew about that right away, and it was generally accepted, then you would have a bunch of agency tests going on and the numbers would be clear for everybody to see. But if you waited a couple weeks before testing, most of that stuff would've been washed down into the golf of Mexico and the numbers would be much smaller. Maybe the thinking is pretty simplistic (for example, maybe they would account for that time and extrapolate the real numbers from test results taken two weeks later), but it sure feels like something along these lines is going on. I think the idea that they may have created something nearly as bad as Chernobyl, perhaps too many heads will roll.