Exactly.
The other thing is that once a pollutant is out, PAH and stuff, to use an analogy, the toothpaste has gone out. Getting it back is not going to be easy. This is true of exotic species too. If you have exotic species that invade by some boat dumping, it's there. You have a problem now for billions of dollars potentially.
The cheapest thing is to not pollute. The cheapest thing is to mitigate very early on. The only way you can mitigate very early on is to have the proper monitoring program in place. Otherwise, we're just going non-scientifically and blindly.