Williams Lake’s first air quality advisory of the year was issued Wednesday morning by the Ministry of Environment in co-operation with Interior Health and lasted about 24 hours.
“We put out an advisory when the air quality objectives exceed 25 micrograms per cubic metre of particulate matter and extends over a 24-hour period,” air quality meteorologist Ralph Adams with the ministry said Thursday before the advisory was lifted at noon. “When you have those two factors you issue an advisory.”
If the values had continued to increase, which Adams said has not happened in the last decade except during wildfires, then there would be discussions with schools and hospitals.
“If there were dire circumstances the ministry does have the authority to shut down industry,” Adams added. “If the levels were in the hundreds and it had been like that for a couple of days and medical people were saying individuals are presenting themselves with symptoms then maybe you would start to trigger that.”
In Prince George there is a bylaw that stipulates if an advisory is in place residents cannot use a wood stove and in Quesnel the pulp mill can only burn clean hog fuel, he said.
“If this happened in March when more people were burning we would probably issue an open burning ban at the same time,” Adams said. “My view is that most of the particulate matter in the air sheds in Williams Lake and Quesnel is probably coming from wood stoves.
It always seems to happen when temperatures are low and we get these periods of poor dispersion.”
This week’s advisory prompted online comments about Atlantic Power’s permit amendment request to burn up to 50 per cent shredded rail ties, some suggesting it is already happening.
On Thursday, AP’s environmental manager Terry Shannon confirmed the company has not burned rail ties at the plant since 2010.