A quick scan of the Toxline database came up with about 600 refs.
Dieldrin is classed as a nasty carcinogen, is a cholrinated organic
compound, and can get into the aquatic food chain or water supplies
fairly easily. One disturbing study found Dieldrin contamination in
50% of the well water sources in Eastern NC. I think you may want
to send this one out for hazardous waste disposal. More info if you
need it.
Jeff in NC