Smoke Management on Oregon’s Managed Forest Land

This year’s wildfire season brought with it the more smoke that many of us have ever experienced.  Virtually no part of the state escaped the thick unhealthy air from all the wildfires in late summer. Because of this, smoke management is a hot topic right now.

To increase their shared understanding of smoke management and role that prescribed fire plays in fuels reduction on actively managed forest land, the Board of Forestry (BOF) and the Environmental Quality Commission (EQC) met jointly to explore the current regulatory framework and on-the-ground practices. The meeting began in Eugene with an interactive discussion explaining the roles of the Department of Forestry (ODF) and Department of Environmental Quality (DEQ) in permitting, monitoring and enforcing smoke management regulations. As related to managed forestland, it’s a complicated and effective process that requires a high degree of communication and cooperation between land owners and ODF before, during and after the on-the-ground actions. ODF’s smoke management program has been in place since 1972, and has proven to be very successful at preventing smoke from debris burns impacting urban areas. For more information, go to http://www.oregon.gov/ODF/Fire/pages/Burn.aspx

Attendees next climbed into vans and headed to the hills outside of Crow, southwest of Eugene in the mixed O&C (Bureau of Land Management) and privately owned timberland of the Coast Range foothills.  Standing (in the rain) on the edge of a harvest unit that was being prepared for replanting, we looked at the debris piles that accumulated through the process of yarding trees to the landing and getting logs ready to be transported off the site.  Reducing the potential for wildfire (and the accompanying smoke) in the future, and setting the stage for replanting and nurturing the next generation of trees is the motivator for this stage of management. ODF explained that large amounts of debris on the forest floor, whether it results from management activities or from wildfire, makes it difficult and dangerous to fight subsequent fires and makes it difficult to plant tree seedlings effectively.

We got a great demonstration of how debris pile burning is managed.  Keeping the smoke to a minimum is a function of the dryness of the material, and the wind and weather at the time of burning. Conditions can’t be either too dry (danger of fire spreading) or too wet (too much smoke), and the wind must be helping move the smoke away from populated areas to minimize smoke intrusions.  Coordinating the windows that will work for smoke management is ODF’s responsibility, and requires a high degree of cooperation with landowners.

The covering of debris piles with polyethylene (black plastic) sheeting has been a debated topic in forest management for years.  Current law allows a 100 sq. ft (10’x10′) cover, 4 mils (.0004 inch) thick, to be burned in place on each pile.  The purpose of the sheeting is to keep rain off the pile.

In 2017, a study was conducted by the Environmental Protection Agency (EPA) and the state of Oregon to determine what effect plastic covers have on a burn pile’s emissions.  The joint effort was to explore whether the practice of using polyethylene sheets to cover biomass slash piles prior to burning caused  perceptible increases in air pollutants of concern.  The results suggested that use of the film actually decreases overall pollutant levels by keeping the biomass fuels dry, promoting more efficient combustion. Three burn piles were ignited for us, the tourists.  The results were easy to see:  the wet pile made a lot of smoke and burned slowly, the covered piles burned much more easily, hotter, and with more flame, minimizing the amount of smoke significantly.

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A look at a large debris pile burning efficiently.  Note the low amount of smoke.

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Demonstration of the difference in smoke emission.  The pile in the front is uncovered and wet.  The piles in the back were covered.  They were lit later than the front pile and burned faster.

Contributed by: Susan Morgan | AOC Policy Manager

2017-11-06T14:27:03+00:00 November 3rd, 2017|Categories: Public Lands & Natural Resources|