You will find a lot of info on PCB disposal (legal) by googleing 'PCB Disposal'. There's an EPA/DEP site with a lot of info.
There is still a haunting of PCB contamination in the Hudson River (lower) and the Passaic River (NJ) leading into the Newark shipping terminals. It rears it head everytime dredging the channels comes up for public comments. Besides PCB's there's also remnants of Agent Orange from the Vietman era.
PCB's were outlawed in the mid to late 70's.
