Tuesday, November 10, 2015

Air Time: Why we have burn bans

Chilly days can mean smoky skies

Many communities in Washington experience smoke year round: during wildfire season in summer; in springtime and fall when we're cleaning up our landscape debris, and when we light our woodstoves and fireplaces in winter. To reduce exposure to smoke, folks should consider alternatives to burning when they can. 

When the air gets too smoky, burn bans are called until the smoke clears out. During chilly days and nights, a warm fire is appealing. Unfortunately, the coldest days can be the worst days for burning wood. That's why it's important to burn hot and clean, and pay attention to burn bans. 

Why burning is an issue in winter 

When cold air is trapped below warmer air it's called a temperature inversion.

During an inversion, winds hardly blow and the air becomes stagnant. Pollution particles trapped in the air remain close to the ground where we breathe. These fine particles travel deep into our respiratory system and lodge in our lungs. This is unhealthy for everyone, and especially harmful to infants, young children, the elderly, and people with asthma, heart or lung disease.

Weather forecasts, air monitors  

Forecasters watch weather patterns and air quality monitors closely to identify areas that might result in unacceptable levels of pollution. They rely on data from air monitors placed throughout the state and weather models to help identify which communities will  experience air pollution problems during stagnant periods. 
Smoke builds up in some areas more readily than others because of terrain. Areas like Wenatchee, Leavenworth and  Colville, trap smoke in narrow valleys. Less obvious are bowl-shaped areas like Spokane where smoke can linger. Because outdoor burning and indoor wood heating contribute significantly to air pollution during inversions, residents and businesses may be required to restrict burning.
Washington issues burn bans in two stages: Stage 1 is applied when air pollution increases and is expected to reach unhealthy levels if some burning isn't curtailed; Stage 2 is applied when the air cannot accommodate any more pollution without becoming unhealthy.

Stage 1 burn bans

During a Stage 1 ban, all outdoor burning, including residential, agricultural and forest burning is prohibited. In addition, use of fireplaces, non-certified wood stoves, inserts and other devices is not allowed unless it is a home’s only adequate source of heat.  
Certified wood stoves, pellet stoves and other certified wood-burning devices are allowed.

Stage 2 burn bans

A Stage 2 ban applies to all burning, inside and out, including the use of all certified and uncertified wood stoves, inserts, fireplaces and other wood-burning devices, unless they are a home’s only adequate source of heat. 

Washington’s burn ban website and resources

Before lighting a fire, find out if your county has a burn ban in place by visiting waburnbans.net. 

For more information on indoor burning, including a list of approved wood stoves, fireplace inserts and other devices see our Air Quality pages. Also check out these tips for better burning in this blog: How you burn makes a difference in your pocket and in the air. 

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