Fly ash from Metro Vancouver's garbage incinerator that tested high in toxic cadmium in July and August has been contained at the Cache Creek landfill.
But Metro officials say they're still trying to determine why waste-to-energy plant operator Covanta Energy was slow to inform the regional district of the test failures.
About 2,000 tonnes of the fly ash, which is particulate collected from scrubbers that keep toxic metals from going up the stack, was trucked to the Interior landfill.
Provincial regulation requires the ash pass two different tests to ensure it can be safely dumped at a landfill.
Solid waste manager Paul Henderson said there was a range of sample results, but the highest cadmium readings were more than double the provincial limit.
"It wasn't marginally over the limit, they were substantially over the limit," he said.
The main test, done at the end of each month, usually comes back with results within three weeks.
But Metro wasn't informed of both failures until Sept. 26 – about a month later than should have happened for the failed July test results and a day after Cache Creek landfill operator Wastech noticed the results were late and demanded the data.
"We're working closely with Covanta to understand what happened with regard to those communication issues," Henderson said. "They've told us to date there was human error in the communication."
Cadmium exists in minute quantities in municipal garbage, from sources such as batteries, dyes and some films and plastics, Henderson said.
Environment ministry officials will decide whether the ash that was trucked to Cache Creek can stay there or has to be taken to a special waste facility.
Subsequent tests on it there found most of the sampled material is within provincial limits.
Every truckload of fly ash produced at the Burnaby incinerator since Sept. 25 has been individually tested and found to be within limits, Henderson said.
But Metro took the added precaution of shipping it to a landfill near Hinton, Alberta until more is known.
Henderson said it didn't make sense to pile in more new ash at Cache Creek if it's decided the July and August shipments require special treatment.
He said Metro doesn't believe the local environment or the Wastech workers at Cache Creek were at risk, but added both Metro and the landfill operator want to ensure no ash is ever delivered again that exceeds limits.
It's the first time in 12 years incinerator fly ash samples failed testing.
Air emissions from the Metro incinerator have always been within operating limits and are not affected by the fly ash incident, Henderson said.
Covanta Energy said in a statement it believes the summer failures were an "aberration" and the fly ash sent to Cache Creek should not be considered hazardous waste.
The firm said it's checking its ash-conditioning process to ensure it's working properly and there are no future problems.
"We deeply regret this event and are working to resolve this lapse in communication," the statement said. "At no time was information related to this issue purposefully withheld."
Surrey Coun. Marrvin Hunt, who sits on Metro's zero waste committee, said fly ash from the initial years of the incinerator's operation went to the long-closed Coquitlam landfill until approval was gained to send it to Cache Creek.
He said fly ash typically hardens into a cement-like material that should pose no hazard at Cache Creek.
"The greatest concern is the lack of timely reporting," Hunt said.
Washington State landfill operator Rabanco – which has repeatedly tried to land Metro Vancouver as a customer – said its Roosevelt Regional Landfill has a special cell for incinerator ash and could accept Metro ash shipments by rail, eliminating the need for it to be trucked to Alberta.