Storage Site Details
History of the Storage Site
The Pottersburg PCB Storage Site is the result of the Westinghouse cleanup and the cleanup of PCB contaminated soil and sediment found in downstream waterways (Walker Drain and Pottersburg Creek) in the City of London from 1984 to 1987. The ministry stepped in and took responsibility for the clean up because we wanted it done quickly and safely so that the environment and public health were no longer at risk.
Each year, the ministry collects and tests fish from thousands of lakes and rivers across Ontario for a variety of substances including mercury, PCBs and dioxins.
Elevated levels of PCBs were first discovered during routine testing on fish in the Thames River near Pottersburg Creek. Following this discovery, extensive studies were undertaken to track the source and extent of the PCBs.
Industrial sources in the area of Pottersburg Creek were found to be the source of the PCBs and the ministry took action to make sure the PCBs were cleaned up and securely stored.
In 1985 the government also formed a Technical Review Committee that brought together members of the public, scientific experts and government officials. This committee developed a plan to clean up and restore Pottersburg Creek and impacted areas around the Creek.
Over the next couple of years, PCBs were removed from Walkers Drain, Pottersburg Creek and neighbouring sites along the Creek.
The PCB contaminated soil and sediment that were removed were taken for storage at a closed, controlled and secure containment facility that has come to be known as the Pottersburg PCB Storage Site.
The facility is made up of four storage cells that were constructed to safely store the PCBs until they could be destroyed. The site contains a total of 35,500 cubic meters of soil (78,000 tonnes), sediment and debris contaminated with PCBs, or about 2100 truckloads. The total area of the site is roughly 11 acres.
There are several design features at the site to ensure the safety of the stored wastes including synthetic and clay liners, a leachate collection mechanism and a leak detection zone. PCB levels in the leachate collection zone and the leak detection zone are below the Ontario Drinking Water Quality Standard. However, as an extra precaution leachate is pumped through an on-site filter and is analyzed to ensure PCB removal. The treated water is then discharged to the sanitary sewer.
The ministry also monitors the storage cells and each month a qualified consultant hired by the ministry checks the numerous monitoring wells at the site.
During the clean up, no technology or approved sites existed for the safe destruction of PCBs so secure storage was the only option. Over the years, new technologies for the destruction of PCBs came to be developed, but these methods were cost prohibitive for the amount of PCBs at the Pottersburg Storage Site.
Now is the right time for the removal of the PCBs from the Storage Site. There are now safe and effective methods for permanently destroying PCBs that are affordable and cost effective.
