in article , Repeating Decimal at
wrote on 9/11/03 1:06 PM:

One fumigant that I used was metam sodium, also known as vapam or sodium
methyldithiocarb. I may still have some in my garage although it was banned,
at least in California when a trainload was dumped into a river. It was
pretty good for sterilizing soil.

By coincidence, there was a PBS broadcast on KOCE (Orange County, CA)
tonight about a metam sodium spill on the then Soutern Pacific RR into the
Upper Sacromento River. It killed off everything in the river including
fish, snails, and plants. It took about a decade for the river to recover as
it was restocked from unaffected tributaries.

Bill