By 1933, Port Hope had become the centre for radium refining in Canada and waste was stored by Eldorado at various planned sites and deposited at unplanned locations within the town. In keeping with the knowledge and practices of the day, the residual soil and surplus building materials from the plant site were offered to the public, free of charge. As a result, parks, ravines, and residential properties were backfilled with contaminated soil, and some homes and other structures were constructed with contaminated building materials.
The Low-Level Radioactive Waste in Port Hope is primarily contaminated soil and rocks, contaminated recycled building materials and contaminated sediment in the harbour.
As specified in the 2001 Legal Agreement, CNL is responsible for the cleanup and long-term management of up to 51,250 cubic metres of non-radioactive industrial waste in Port Hope. The waste is the result of past practices of a variety of industries. Soil contaminated with metals, boron, hydrocarbons, dried sewage sludge, sludge/soil with copper and polychlorinated biphenyl (PCBs) is transported to the Port Hope Long-Term Waste Management Facility and/or other licensed hazardous waste facilities for safe storage and monitoring.