Wow, diesel fuel in the water? That's harsh...
I always lean towards "Bioremediation". Let the critters (microbes, etc.) do what God intended them to do. In the end, if you've the area to do it, it's always more cost effective than hauling the soil to some hole in the ground. That's where it originally came from, and you see how it's not improved a bit since it was spilled.
In a lifetime, the average driver will honk 15,250 times. My wife figures I'm due to die any day now...
