Learn before you burn

WASILLA — When one thinks of an Alaskan winter “postcard”, pictures of a small cabin nestled against a snow-covered mountain with white smoke wisping out of the chimney generally come to mind. The idea of that smoke being a health hazard probably doesn’t register.

Throughout the Mat-Su, and other areas of the state, heating a house or other dwelling with a wood stove is not at all uncommon. However, the borough stands to lose federal project funding if it doesn’t improve air quality standards. Those standards include measuring two types of airborne particulates or particulate matter (PM).

One is referred to as PM 10 and the other PM 2.5. For the layman, think of PM 10 as dust-sized particulates while PM 2.5 refers to smoke. Both are harmful but the PM 2.5 more so. They can be easily ingested and lodge in the lungs posing significant health risks. PM 10 is something between 2.5-10 micrometers in size, PM 2.5 is anything under that. A micrometer is one-millionth of a meter. The human eye generally cannot discern anything smaller than 40 micrometers.

According to the state website burnwise.alaska.gov, there is a dangerous misconception that burning wood is a clean fuel. The byproducts — smoke and other particulates, are linked to cancer, infant mortality and low birth rate, lung disease, heart attack, stroke and premature death. It can also cause physical ailments such as asthma, bronchitis and emphysema, persistent coughing, sneezing, itchy and watery eyes, and headaches. Even short-term exposure can aggravate health issues many people. Some of the byproducts of wood burning include benzene, formaldehyde, acrolein and methane.

Borough monitoring

Frankie Barker, borough environmental planner, said the state Department of Environmental Conservation (DEC) is pressing the Mat-Su to lower both PM 10 and 2.5 emissions with a main focus on the smaller end of the scale. The borough has two air-monitoring stations--one in Butte and the other in Palmer. Air pollution has long been problematic in the Butte area and lesser so throughout the Valley mainly due to topography. The colder winter months compound the issue.

Because of the Chugach Mountain Range and large open river beds such as the Matanuska River, particulates lend themselves to getting trapped in the air creating a haze throughout the heart of the Valley. Cold air is more dense than warm. That means during the winter months, the coldest air sinks to the lowest point of landmass — the heart of the Mat-Su — and is trapped by atmospheric inversion Inversion occurs when air temperature increases with height. Winter causes inversion layers, which in turn, results in smoke spreading and hanging low to the ground. Downwind area and valleys are most affected.

Barker said the Butte air monitoring station has been in place for 20 years. Both stations take daily air quality standards and report them on a website: http://dec.alaska.gov/Applications/Air/airtoolsweb/Aq/. Barker said for the past two years, the borough has been just over the mandated particulate limit. She said the state has given Mat-Su officials three years to begin improving overall air quality or face sanctions. This year marks the third.

There are about a half-dozen monitoring sites around the “Anchorage Bowl” including the two in the Mat-Su. But the problem isn’t limited to South-central Alaska. The Tanana Valley areas of Fairbanks and North Pole have battled the issue for years.

“Ideally, we don’t want to have that happen,” Barker said.

To meet this goal, Barker said, the borough has undertaken a major education campaign. She said the Mat-Su is using all forms of available media to get the word out about steps that can be taken to help alleviate the issue.

“We’ve partnered with DEC with a major media campaign to educate the public. It started in earnest in mid-October,” said Barker. “We’ve really focused on the Butte area and utilized target mailings (to residents). But one of the good things about Butte is that (residents) have natural gas lines.”

Barker said part of the educational push includes her putting on informational workshops for local groups or organizations. The target timeline is mid-October through the end of March. She said another reason to seek an alternative heating source is the fact that wood is getting harder to find.

If you must burn

State officials stress that homeowners who choose to heat with wood can do so in a way that is not only better for the environment, but will save them money — sometimes a substantial amount. Today’s wood stoves produce almost no smoke, minimal ash and require 30 percent less wood to generate the same amount of heat as older stoves.

New Environmental Protection Agency (EPA) certified stoves significantly reduce dust and airborne particulates while dropping outside pollution by as much as 70 percent. Overall, it is reported that a new stove is up to 50 percent more efficient than older counterparts. Alaska’s DEC recommends an upgrade if an existing wood stove has a solid metal door. Most stoves made prior to 1990 fall into that category.

The DEC advises before shopping for a new stove, determine the square footage of the dwelling where it will be located, consider whether it will heat a portion, a single room, or the entire structure. Also factor in how well weatherized the dwelling is. DEC suggests taking a floor plan with you when shopping for a new stove. A knowledgeable dealer will be able to make the best determination on what kind and size stove will be best-suited for the need. Even airtight homes can have particulate levels as high as 70 percent of those outdoors.

The higher the moisture the slower it break down, dry wood, less than 10 percent is too dry. If very dry, mix with wetter so the average is at 20 percent.

The kind of wood used is another important factor in the process.

“Wet wood is a waste of wood,” DEC officials state. Living trees are as much as 60 percent water. Even some trees that have been felled or dead for several years may contain up to 50 percent water. Inexpensive and easy to use moisture meters are available from reputable saw shops and stove retailers. Ideal wood has a moisture content of 20 percent.

The DEC offers the following suggestions for those cutting their own firewood. Split the log at least once, stack with plenty of airflow, store in an open shed or cover for at least six of year’s dryer months. Seasoned wood of a year is best. At a minimum, wood should be “seasoned” six months under the mentioned guidelines. The DEC notes that not all wood is the same. The heating potential of a piece of wood is dependent on density, moisture content and whether or not it is hard or softwood.

Here in Alaska, aspen, paper birch and poplar are considered hardwoods. Cedar, hemlock and spruce trees are softwoods. According to the DEC, one chunk of hardwood produces as much heat as two pieces of softwood. It states driftwood is not a good burning source as the salts soaked into the wood are highly corrosive to metal.

DEC officials say when selecting wood for the stove, look for cracks on the end of the rounds. Large cracks radiating from center generally indicate seasoned wood. Another way to determine whether wood is ready for the stove is weight and color. Dry wood weighs much less than wet and wood with a darkened grain is usually wet while a chunk that has a white or yellow color is more likely seasoned. Finally, knock two pieces of wood together. Dry wood has a hollow sound while wet wood will sound solid when struck.

Wood-burners are encouraged to maintain small fires in their stoves which aides in the wood burning completely. Adding too much wood can cut down on air supply. The DEC states it’s important to maintain a hot fire. Dampening down a stove cuts airflow to help burn completely, adding too much wood cuts down on air supply and results excess smoke.

They state that a chimney with smoke coming out indicates a stove wasting fuel. The state’s burnwise website offers much information on proper wood-burning . Those visiting can also find firewood suppliers participating in the DEC’s moisture disclosure program as well as a list of EPA approved stoves. For additional information, visit http://burnwise.alaska.gov/. Any group interested in having Barker discuss the topic can contact her at (907) 861-8439, or email frankie.barker@matsugov.us.