A composting facility in Richmond, B.C., has had its operating permit renewed for another three and a half years, but Metro Vancouver says the permit's conditions should help cut down on wafting odours.
Ray Robb, manager of environmental regulation and enforcement at Metro Vancouver, says his department has heard numerous complaints from people who say the odours are affecting their quality of life, waking them up at night or preventing them from sleeping at all.
"We heard those people, and we were really tough in terms of establishing requirements," Robb said.
As part of those new requirements, in 2017 Harvest will be required to immediately stop accepting new food waste if Metro Vancouver inspectors detect bad smells more than five kilometres from the facility for more than four days in a two-week period.
Those requirements get tighter each year of the permit: four kilometres for three days of bad smells in 2018, and three kilometres for two days in 2019.
A phased approach
Harvest will be making fundamental changes to its operation in order to achieve those targets — mostly involving oxygen supply.
The composting process, Robb said, is essentially a competition for food between different micro-organisms.
He said the key to reducing composting odours is to get oxygen-using microorganisms to out-compete the others, because the non-oxygen-using microorganisms are the ones that produce the stinkiest byproducts.
"The trick with composting is to get enough oxygen to where the food and the micro-organsims are to avoid the production of smelly gases," he said.
In order to do that, Robb said Harvest will be piloting the use of more pipes, blowers and other controls to deliver more oxygen.
The permit also prohibits the facility from stacking its compost piles more than three metres high, down from the previous permit's six metres. This, Robb said, allows more air into the piles.
Robb said Metro Vancouver is confident the permit's conditions will resolve the odour issue for Richmond residents by the time the permit is up for renewal again in three and a half years.
"If [Harvest] are not able to achieve what they say they can achieve, that's the end of it," Robb said.