The Basel Convention is a United Nations treaty that was signed in 1989 to control the transboundary movements of hazardous wastes and their disposal. The treaty helped define hazardous wastes, outlined how hazardous wastes are disposed and set guidelines such as approved facilities by city governments.
It’s been said that one event that prompted the Basel Convention was the Khian Sea waste disposal incident from 1986-2000. The Khian Sea cargo ship (which was registered in Liberia) was loaded with 14,355 tons of non-toxic ash from waste incinerations from the US. The story goes that a US company that handled the waste subcontracted a shipment to dump the ash in the Bahamas, however, the Bahamian government turned down the ash and so, for over one year the Khian Sea searched for a place to dump the ash. Many regions of the world refused to accept the ash and since the ash was even refused from the original area in the US from where it was received, in 1988 the crew dumped about 4,000 tons of the waste in Haiti as “topsoil fertilizer” and fled before they could pick up the ash as the Haitian commerce minister ordered. The Khian Sea then moved on to regions such as Morocco, Sri Lanka and Singapore where the captain testified to dumping about 10,000 tons of ash into the Atlantic and Indian Oceans.
Here is an image of the home port of the Khian Sea in Philadelphia: