Cache Creek landfill fly ash assessment: “minimal risk”

Cache Creek landfill once more in compliance with its Operational Certificate

The Cache Creek Landfill is back in compliance with its Operational Certificate, two years after it was discovered that 1,800 tonnes of possibly toxic fly ash had been deposited at the site.

The landfill has accepted fly ash since 2000, but only after it has been tested to ensure that the product has been suitably treated to remove any potential contamination. Shipments of fly ash deposited at the landfill in July and August 2012 tested positive for high amounts of cadmium, and were subsequently excavated and taken to a hazardous waste facility.

A letter from the provincial Ministry of Environment dated Jue 27, 2014 confirms that the advisory letter of non-compliance issued by the Ministry will be withdrawn as requested by the Village of Cache Creek and Wastech.

An independent technical assessment of the treatment and disposal of fly ash was carried out, with public meetings in Cache Creek and Ashcroft in April of this year seeking community and First Nations input. The assessment also received written comments from the Village of Cache Creek, Wastech, and Metro Vancouver.

The cumulative evidence reviewed by the independent experts indicates that it is very unlikely that leachable cadmium in the fly ash deposited in summer 2012 exceeded the hazardous waste regulation.

The letter states that the landfill’s impervious liner and leachate collection system ensure that the fly ash is fully contained and the chemical constituents are not able to leach from the site. Moreover, the leachate collection system has never produced any leachate. As a result, “the fly ash monofill poses minimal risk to human health or the environment. As long as the integrity of the monofill is maintained, including post closure, the absence of a pathway of exposure will continue to eliminate any risk.

“Based on the extremely low probability that hazardous waste was deposited, coupled with the safety provided by the fly ash being encapsulated in the monofill with no means of exposure to the public and environment, additional investigation, sampling and analyses of the fly ash monofill is not required by MOE to further characterize the material.”

Barbara Roden