A large controlled fire on Sumas Prairie agricultural land Thursday afternoon caught the attention of the Abbotsford Fire Rescue Service due to the inordinate amount of smoke it produced.

"It's OK to burn agricultural waste, but without smoke," said Asst. Fire Chief Jeff Adams.

"You cannot create that much smoke. It becomes an environmental issue for air quality."

Agricultural waste may be burned without a permit if the size of the fire is 3m x 3m x 1m high.

Anything larger than that requires a burning permit.

"Our goal is to reduce hazards," said Larry Hooge, fire prevention officer. "The provincial government has concerns about smoke."

With agriculture there are legitimate reasons to burn, added Hooge, citing land clearing and hedge trimming. But farmers should check with the fire department before doing so.

According to a pamphlet put out by the Abbotsford Fire Rescue Service, no materials may be used as a fuel to start, assist or enhance burning except dry wood, paper or cardboard.

"People can burn within restrictions," said Hooge. "In the future, it may have to change. We're moving as a society towards less and less burning all the time, for air quality."

He cited the venting index or analysis of atmospheric conditions as the standard which tells how quickly the smoke can be vented away from an area.

So to be safe, he said, call before you burn.

The Ministry of Environment provides the venting index forecast and an air quality report for each region of the province. It also explains whether or not it is safe to burn, and where people need to go for burning approvals.

For more information call 1-888-2812992 or go to www.bcairquality.ca/topics/can-i-burn-clearing.html

Residents could be subject to a fine of up to $500 for burning without a permit, and if the fire department has to come out and extinguish a fire, they would bill for their services and the cost would be much higher.

As with last year, there will be a summer burning ban on from June 1 - Sept. 30 for everyone.

If you have any questions regarding burning, contact the fire prevention office at 604-853-3566.

UNDERSTANDING THE VENTING INDEX

The venting index is a term used in air pollution meteorology, also known as the ventilation index. The venting index is a numerical value related to the potential of the atmosphere to disperse airborne pollutants, such as smoke from a prescribed fire.

It is based on both the current wind speed in the mixed layer and the mixing height. The mixed layer is the surface layer of air that is turbulent and well mixed. The mixing height is the thickness (sometimes zero) of this mixed layer.

Forecast venting indexes (usually from a computer model) are available for 26 different areas of the province. Stronger wind speeds and thicker mixed layers will produce higher venting indexes. The Venting Index is on a scale of 0 to 100:

0 - 33 poor ventilation

34 - 54 fair ventilation

55 - 100 good ventilation

If the venting index is poor or fair, then smoke that results from burning will tend to build up, causing air pollution. To avoid such pollution, outdoor burning is restricted when the index is poor or fair.

JKonda-Witte@abbotsfordtimes.com