Redbird Fuels Treatment Project

Transcription

1 Redbird Fuels Treatment Project Air Report Prepared by: Melanie Pitrolo Air Quality Specialist for: Redbird Ranger District Daniel Boone National Forest July 1, 2011 Updated June 26, 2012

2 The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C , or call (800) (voice) or (202) (TDD). USDA is an equal opportunity provider and employer. 2

3 Redbird Fuels Treatment Project Table of Contents Introduction... 1 Attachments:... 1 Overview... 1 Indicators... 2 Affected Environment... 3 Existing Condition... 3 Ozone... 4 Fine Particulate... 5 Emissions Inventories... 6 Smoke Sensitive Areas... 8 Regional Haze and Vis ibility... 8 Desired Condition... 9 Environmental Consequences...10 Methodology...10 Spatial and Temporal Context for Effects Analysis...11 Connected Actions, Past, Present, and Foreseeable Activities Relevant to Cumulative Effects Analys is...11 Alternative 1 No Action...11 Effects...11 Alternative 2 Modified Proposed Action...12 Design Features and Mitigation Measures...12 Effects...13 Cumulative Effects...15 Conclusion...17 Monitoring Recommendations...18 References (Literature Cited)...18 Appendix A: Key Regulated Pollutants and their Significance in Smoke...19 Fine Particulates (PM 2.5 )...19 Sulfur Dioxide...19 Carbon Monoxide...20 Ozone...20 Nitrogen Dioxide...20 Lead...21 Appendix B: Process Used to Develop Fuelbeds, Fuel Consumption, Emissions Production and Smoke Dispersion Predictions for the Redbird Fuels Treatment Project...22 Appendix C: VSMOKE Modeling Results for the Air Analyses in the Redbird Fuels Treatment Project Environmental Assessment...23 VSMOKE Report for Britton Branch VSMOKE Report for Britton Branch VSMOKE Report for Cherry Tree...29 VSMOKE Report for Granny s Branch VSMOKE Report for Granny s Branch VSMOKE Report for Pooler...36 VSMOKE Report for Rockhouse VSMOKE Report for Rockhouse VSMOKE Report for Sugar...42 VSMOKE Report for Venus...44 iii

4 List of Tables Table 1. Fine particulate emissions (in tons per year) from the VISTAS 2002 inventory and projected maximum annual emissions increases from the proposed action... 8 Table 2. VSMOKE modeling results for the ten proposed burn units, based on worst-case firing and meteorological parameters...14 List of Figures Figure 1. Analysis area for the Redbird Fuels Treatment Project air quality assessment... 4 Figure 2. Ozone monitoring results as compared to the current and proposed national ambient air quality standards... 5 Figure 3. Fine particulate matter monitoring results as compared to the daily and annual national ambient air quality standards... 6 Figure 4. Countywide emissions of fine particulate matter near the Redbird Ranger District... 7 Figure 5. Fine particulate (PM 2.5 ) composition at Mammoth Cave National Park for the days described as having the best and worst visibility ( )... 9 Figure 6. Fine particulate (PM 2.5 ) composition at Great Smoky Mountains National Park for the days that have the best and worst 20 percent visibility days for 2000 through Figure 7. Daily and annual fine particulate matter concentrations as compared to emissions from prescribed fires...17 iv

5 Redbird Fuels Treatment Project Introduction Air quality differs from other resources in that it is not stationary. Air masses are constantly moving across the landscape, gathering pollution in one area and transporting it to another. Due to the local and regional transport of pollutants, an area larger than the actual treatment units must be used to describe air quality and the effects of emissions from proposed activities. The analysis area should be large enough to include communities that could be affected by emissions from this project (smoke from prescribed fires) as well as emissions from prescribed fires associated with other projects. Therefore, the scope of this analysis is broadened to include the counties within 50 kilometers (30 miles) of the project area. The air analysis will focus on emissions of air pollutants from the proposed prescribed fire activities. Existing air quality will be described using information from state-operated monitors located near the Forest. An emissions inventory will be created for the typical annual burning program and compared to the most current inventory of total emissions, compiled by the Kentucky Division of Air Quality, in order to assess potential impacts to air quality. Finally, smoke dispersion modeling will be conducted to assess potential short-term contributions to air quality, especially in smoke sensitive areas used by the Indiana bat and areas not attaining the national ambient air quality standards. The contribution of wildland fire emissions to greenhouse gases and global climate change will not be addressed in the specialist report. There are several reasons for this. The impact of greenhouse gases from most Forest Service projects is extremely small in the global climate context, and objective standards or thresholds do not exist yet with which to draw conclusions about the significance of the results of an analysis at the project level. Therefore, it is not meaningful to conduct quantitative analysis of the greenhouse gas emitted and/or sequestered as part of the proposed project and alternatives. Additionally, at the national level, the Environmental Protection Agency (U.S. Environmental Protection Agency, 2008) has concluded that when forest management activities (including fire emissions) are considered together with storage/sequestration activities (reforestation, etc.) the cumulative result is a net sequestration of carbon dioxide. This assumes that the proposed activity does not change the land use and the area remains forested, as is the case with the Redbird Fuels Treatment Project. Attachments: Appendix A: Key Regulated Pollutants and their Significance in Smoke Appendix B: Process Report on Developing Fuelbeds, Fuel Consumption, and Emissions Appendix C: VSMOKE Reports Overview The primary concerns with air quality are the effects of prescribed fire emissions on human health and visibility (both in terms of safety on roadways and regional haze affecting scenic views). Emissions from wildland fire include carbon dioxide, water, carbon monoxide, particulate matter, hydrocarbons or volatile organic compounds, and nitrogen oxides. Carbon dioxide and water generally make up over 90 percent of the total emissions. Recently, the Environmental Protection Agency (EPA) has found that greenhouse gas emissions, including carbon dioxide, from motor vehicles contribute to the threat of global climate change. This determination resulted in 1

6 Air Report greenhouse gas emissions from large stationary sources being subject to the permitting requirements under the Prevention of Significant Deterioration (PSD) program. However, at this time, EPA has not begun regulating greenhouse gases from activities such as prescribed fires, and therefore these emissions will not be addressed further in the Air Report. The U.S. Environmental Protection Agency (EPA) has been directed by Congress to set national ambient air quality standards (NAAQS) at two levels for the six criteria air pollutants. A primary NAAQS is set to protect public health, while a secondary NAAQS is set to protect public welfare (e.g., damage to animals, crops, vegetation, and buildings). Each standard is reviewed every few years, and revised (strengthened) if the most recent scientific research indicates that the current standard is not protective enough of sensitive populations. The six criteria pollutants are lead, sulfur dioxide (SO 2 ), carbon monoxide (CO), nitrogen oxides (NO x ), ozone (O 3 ) and particulate matter (PM). The lead and sulfur content of forest fuels is negligible, so these two forms of air pollution are not considered further. Carbon monoxide is the most abundant pollutant emitted from wildland fire. It is of concern to human health, because it binds to hemoglobin in place of oxygen and leads to oxygen deprivation and all of the associated symptoms, from diminished work capacity to nausea, headaches, and loss of mental acuity. (Details on the health effects of carbon monoxide can be found in Appendix A or Hardy et al. 2001). Carbon monoxide concentrations can be quite high adjacent to the burn unit, but they decrease rapidly as away from the burn unit toward cleaner air. Carbon monoxide exposure can be significant for those working the line on a prescribed fire, but due to rapid dilution, carbon monoxide is not a concern to urban and rural areas even a short distance downwind. Fortunately, most of the health effects from carbon monoxide are reversible because carbon monoxide is rapidly removed from the body once a person is in cleaner air. Nitrogen oxide emissions from wildland fires are very small, and hydrocarbon emissions are moderate. Alone they are not very important to human health, but they are precursors to the criteria pollutant, ozone. Ozone is formed in the atmosphere when nitrogen oxides and hydrocarbons combine in the presence of sunlight. Fire-related NO x and hydrocarbon emissions become more important to ozone levels only when other persistent and much larger pollution sources already present a substantial base load of precursors. To a limited degree, additional intermittent emissions may aggravate an already bad situation. Ozone will be discussed in this analysis. The most important pollutant from wildland fire emissions is fine particulate matter (PM 2.5 ) due to the amount emitted and the effects on human health and visibility (Hardy et al. 2001). The term fine particulate refers to particulate matter 2.5 microns or less in diameter. This analysis will address effects of the fine particulate emissions from prescribed fire on air quality within the analysis area. Emissions from the proposed action will be quantified and compared to emissions from all other sources in the same area to assess cumulative impacts. Appendix A provides additional information on wildland fire emissions. Indicators An annual emissions inventory will be developed for the proposed treatments and compared to emissions from all other pollution sources within the analysis area. Dispersion modeling will also be conducted to assess the potential for contributing to air standard violations and to address potential nuisance and safety/visibility issues. 2

7 Redbird Fuels Treatment Project Affected Environment Existing Condition The proposed project area lies within Clay and Leslie Counties in southeastern Kentucky. Due to the fact that air pollution is transported locally and regionally, and that air quality monitoring is not conducted on the Redbird Ranger District of the Daniel Boone National Forest, an area larger than the District must be used to describe air quality and the effects of emission from proposed activities. Therefore, the scope of this analysis is broadened to include counties within 50 kilometers (30 miles) of the burn units. The analysis area includes: Bell, Breathitt, Clay, Estill, Harlan, Jackson, Knott, Knox, Laurel, Lee, Leslie, Letcher, Owsley, Perry, Powell and Wolfe Counties in Kentucky, and Lee County in Virginia. To understand how the proposed activities might affect air quality, current pollution loading in the analysis area must be considered. State air regulators are responsible for monitoring air quality. Ambient air quality is described by comparing current pollutant concentrations, as measured by state air regulators, to the NAAQS established in the Clean Air Act. As mentioned above, NAAQS are threshold concentrations of criteria pollutants set by the EPA to protect human health and welfare. The NAAQS are set at conservative levels with the intent of protecting even the most sensitive members of the public including children, asthmatics, and people with cardiovascular disease. When measured concentrations of any of these pollutants consistently exceed the NAAQS, the area is usually designated as a non-attainment area by EPA. States are then required to develop plans to reduce pollution levels and bring the areas back into attainment of the NAAQS. The criteria pollutants of most concern on the Daniel Boone National Forest are particulate matter and ozone. Fine particulate matter is the leading cause of regional haze (also known as visibility impairment), while ozone can harm sensitive vegetation within the forest. Additionally, at elevated concentrations these two pollutants can impair the health of both employees of and visitors to the National Forests. State air regulators in Kentucky and Tennessee monitor ozone and fine particulate matter at three sites within the Analysis Area as shown in figure 1. Ozone: Middlesboro, Bell Co., KY (2 sites); Hazard, Perry County, KY. Fine particulate (PM 2.5 ): Middlesboro, Bell Co., KY. 3

8 Air Report Figure 1. Analysis area for the Redbird Fuels Treatment Project air quality assessment Ozone Ozone is a secondary pollutant formed by emissions of nitrogen oxides and volatile organic compounds in the presence of sunlight. At elevated concentrations, it causes human health concerns as well as negative impacts to vegetation. Prior to the spring of 2008, the ozone NAAQS was 0.08 ppm, but in March 2008, the standard was strengthened to ppm. In January 2010, however, EPA proposed to reconsider the revised standard by setting the primary NAAQS at a level between and ppm. Additionally, EPA has proposed a separate secondary standard based on the metric W126, a cumulative peak-weighted index of hourly ozone concentrations. The revised standards are expected to be finalized in late The ozone monitors closest to the proposed treatment areas are located in Bell and Perry Counties, and are classified as attaining the ozone standard (see figure 2). 4

9 Redbird Fuels Treatment Project NOTE: The ozone standard is exceeded at a site if the 3-year average of the fourth-highest 8-hour average ozone concentration is greater than ppm. Source: Accessed May 2, Figure 2. Ozone monitoring results as compared to the current and proposed national ambient air quality standards Neither of the ozone monitors within the analysis area exceeds the current ozone standards, as signified by the black horizontal line on the graphic. The yellow bar shows the range of the proposed primary NAAQS, and measured concentrations at both ozone sites near the Redbird Fuels Treatment Project exceed the proposed standards. Emissions from prescribed fires are unlikely to be a significant contributor to ozone. In much of the rural South, ozone formation tends to be NOx limited and prescribed fires are usually not a major NOx source when compared to others, such as vehicles. Also, the amount of NOx and VOC coming from forestry activities is small compared to other sources. And most importantly, weather and climate conditions in this area tend to preclude prescribed burning from becoming a significant contributor to ozone formation. Most ozone events occur in mid-spring through late summer when hot temperatures and high-pressure air masses may stagnate over an area, and pollution is not dispersed. Prescribed burning is not conducted under these types of weather conditions because of the smoke dispersion issues. Fine Particulate Particulate matter is a mixture of extremely small particles made up of soil, dust, organic chemicals, metals, and sulfate and nitrate acids. The size of the particles is directly linked to health effects, with smaller particles causing the worst impacts to human health. As a result, EPA has set a primary NAAQS for ultra small (less than 2.5 microns in diameter) particulate matter on both a short-term (24-hour) and annual basis. The 24-hour fine particulate matter (PM 2.5 ) NAAQS is currently set at 35 µg/m 3, while the annual PM 2.5 NAAQS is 15 µg/m 3. The secondary standard is set at the same level as the primary. 5

10 Air Report Fine particulate monitors filter air for complete, 24 hour periods on a 3 day cycle, collecting approximately 120 samples per year for analysis. The long-term NAAQS states that the annual average of the 24-hour sample values shall not exceed 15 micrograms per cubic meter (µg/m 3 ), based on a three year rolling average. Under the daily standard, the 98 th percentile of the 24-hour samples, based on a three-year rolling average, should be less than 35 µg/m 3. As with ozone, EPA is likely to propose more stringent standards for PM 2.5 sometime in mid- to late The monitor closest to the proposed treatment units is located in Bell County, Kentucky. Monitoring data from the past several years indicate that Bell County does not exceed either the 24-hour or the annual PM 2.5 standards (see figure 3). Source: Accessed May 2, Figure 3. Fine particulate matter monitoring results as compared to the daily and annual national ambient air quality standards In summary, air quality within the analysis area is currently meeting the NAAQS for ozone and fine particulate (Kentucky Division for Air Quality 2010 Monitoring Report at This means that current sources of pollution, including intermittent emissions from prescribed fire, are not causing air quality to exceed the current thresholds established to protect human health and welfare. However, EPA is currently reviewing the fine particulate matter standards and it is likely that more stringent NAAQS for PM 2.5 will be proposed in Significant increases in total fuel consumption (both fossil and vegetative) in the analysis area would increase the likelihood of exceeding a stricter fine particulate matter NAAQS. Emissions Inventories While air quality monitoring describes ambient pollution levels, emissions inventories provide information on the contribution of various pollution sources to total emissions for specific geographic areas. The regional planning organization, VISTAS (Visibility Improvement State and Tribal Association of the Southeast), spent considerable time and expense to develop the most current regional emission inventory available (MACTEC 2008). Figure 4 shows the countywide fine particulate matter emissions for those counties within 50 kilometers of the proposed burn units. 6

11 Redbird Fuels Treatment Project Data obtained from the VISTAS emissions inventory obtained using the Emission Tool available at the following website: Figure 4. Countywide emissions of fine particulate matter near the Redbird Ranger District For this analysis, prescribed fires conducted in 2010 within the analysis area were used to estimate current prescribed fire emissions shown in table 1. Emissions from all other sources were obtained from the VISTAS inventory. Since the Forest is the primary prescribed burner in the analysis area, it is easy to see the contribution of these emissions to overall fine particulate. Within the analysis area, prescribed fire emissions in 2010 accounted for 4.5 percent of all fine particulate emissions. Other sources of fine particulate emissions include fuel combustion and operations at industrial facilities, waste disposal and recycling operations, construction, and agricultural activities. Table 1 will be referred to again in the Effects Analysis section of this Report. 7

12 Air Report Table 1. Fine particulate emissions (in tons per year) from the VISTAS 2002 inventory and projected maximum annual emissions increases from the proposed action Fine Particulate Emissions in Tons per Year Geographic Area From All Sources Except Prescribed Fires From Prescribed Fires Conducted in 2010 on the Daniel Boone NF From Prescribed Fires in the Proposed Units (Estimated Range) Within Analysis Area 5, Within the Immediate Vicinity of Treatment Units (Clay and Leslie Counties) a Data obtained from the VISTAS emissions inventory obtained using the Emission Tool available at the following website: Smoke Sensitive Areas Fire managers prepare a burn plan for each prescribed fire. The burn plan includes a smoke management section. One of the primary purposes of smoke management is to minimize impacts to smoke sensitive areas. Smoke sensitive areas within the analysis area include the usual schools, hospitals, highways, etc. There are also several unique smoke sensitive areas such as caves used by Indiana Bats; the Cumberland Gap National Historical Park, and Middlesboro, KY and Hazard, KY because of the ozone and fine particulate monitors sited in those locations. These areas need to be considered when prescribed fire plans are prepared in addition to other smoke sensitive targets that have been identified by District staff. Regional Haze and Visibility Within pristine wilderness areas, visitors expect to find clean conditions and magnificent views unobscured by manmade air pollution. The EPA has developed two separate strategies in order to improve visibility as well as protect human health. The Regional Haze Rule calls for state and federal agencies to work together to improve visibility in all so-called Class I areas, which includes most national parks and many wilderness areas. Also, as discussed above, the EPA has established a NAAQS for fine particulate matter, the cause of visibility impairment. The Regional Haze Rule requires that states, in coordination with the EPA, the National Park Service, the U.S. Fish and Wildlife Service, and the U.S. Forest Service, develop and implement an air quality protection plan to reduce the pollution that causes regional haze. The goal of the program is to improve visibility at all Class I areas to natural background conditions by the year Each Class I area has its own goal for reasonable progress, with a glideslope that should be met at various time intervals. The goals for reasonable progress are measured in units of deciviews (dv). This haziness index is a linear scale that measures humanly-perceived changes in visual air quality. A one dv change represents a small but usually perceptible scenic change. The scale would be near zero for a pristine area, and will increase as visibility degrades. EPA has established the IMPROVE monitoring network in order to measure progress in meeting the goals established in the Regional Haze Rule. The two closest Class I areas to the proposed burn units are Mammoth Cave National Park to the west and Great Smoky Mountains National Park to the south. Both National Parks are Class I areas, and have their own IMPROVE monitoring sites to measure visibility-impair ing pollutants. The primary cause of regional haze in the eastern United States is sulfur dioxide emitted from coal-fired power plants. Recent work by the regional planning organization, VISTAS, shows that 8

13 Redbird Fuels Treatment Project wildland fire emissions play a very minor role in development of regional haze in the eastern United States, and especially Kentucky (Final Regional Haze State Implementation Plan for Kentucky, 2008). Wildland fire would contribute to the organics portion of the speciated fine particulate matter levels that are measured by the IMPROVE monitors. Figure 5 and figure 6 show the relative contribution of the various fine particulate matter components to the pollutant load on the best and worst visibility days at Mammoth Cave and Great Smoky Mountains National Park. Best 20 Percent Days Worst 20 Percent Days Legend From the VIEWS website: Accessed: September 18, 2008 Figure 5. Fine particulate (PM2.5) composition at Mammoth Cave National Park for the days described as having the best and worst visibility ( ) Source: Figure 6. Fine particulate (PM2.5) composition at Great Smoky Mountains National Park for the days that have the best and worst 20 percent visibility days for 2000 through 2008 Desired Condition As a Federal agency, the Forest Service must comply with all federal, state, and local laws and regulations concerning air quality. In Kentucky these include: State Implementation Plans for attaining and maintaining national ambient air quality standards (NAAQS) and visibility goals under the Regional Haze Rule, as well as Open Burning regulations. The Forest Plan recognizes and addresses this responsibility in the following goal, objective and standard: Goal 4.2: Conduct the fire management program in a manner that minimizes the impacts of smoke on air quality standards and visibility goals. 9

14 Air Report Objective 4.2.B: Best available smoke management practices will be used to minimize adverse effects of prescribed fire on public health and visibility. Standard: DB-Fire-3: Conduct all DBNF management activities (including activities that require permits) in a manner that does not result in a contribution to a violation of the National Ambient Air Quality Standards or a violation of applicable provision of the State Implementation Plan. The desired condition for air quality is continued compliance with the NAAQS within the analysis area and minimizing the intermittent impacts of smoke to sensitive areas, including the bat caves, Cumberland Gap, and the towns of Hazard and Middlesboro, KY. Environmental Consequences Methodology Two techniques are employed in this analysis to quantify the impacts of prescribed burning on air quality. Annual estimated emissions from the proposed project are compared to the emissions inventory in table 1 to get a sense for the contribution of prescribed fire to overall fine particulate emissions. Short-term impacts that might occur on the day of the burn are predicted using smoke dispersion models. Impacts were predicted using the simple screening model, VSMOKE (Lavdas, 1996). As a screening model, VSMOKE provides conservative estimates of downwind impacts from smoke; if concentrations are estimated to be significant, more refined modeling is performed. In this analysis, a more refined analysis was not necessary. The amount of pollution released into the atmosphere is directly related to how much vegetation is consumed for each prescribed fire, and consumption is based on fuel loading and fuel moisture content. Fuel consumption was estimated using site-specific fuel loading plots in conjunction with the CONSUME 3.0 model (Ottmar et al., 2005) with fuels data collected on the burn units and fuel moisture content estimates provided by Alison Coons, District Fire Management Officer. A complete description of the methods used to develop fuelbeds, fuel consumption estimates and emissions production is attached (Appendix B). This process produced a unique fuelbed for each burn unit, with consumption amounts varying from 1.4 to 11.9 tons of fuel consumed per acre. Short-term impacts can be predicted using a smoke dispersion model run in the planning mode. This means that the meteorological parameters used are estimates of expected conditions and not actual forecasts. Dispersion modeling conducted at this stage of planning is done to identify potential air quality problems, and to make recommendations for burn planning where air quality issues may arise. It is important to remember that modeling results are predictions based on assumptions. As the assumptions get closer to actual conditions, modeling results become more reliable. As noted above, the VSMOKE model was used to predict smoke impacts from the proposed burn units. VSMOKE uses the Fire Emissions Production Simulator (FEPS) model to convert total emissions (from CONSUME) into hourly emissions and heat release rates. The smoke dispersion model then estimates dispersion of the emissions for any selected hour of the day. Ground-level concentrations of fine particulate at several distances downwind from the burn unit are then produced, and a graphic depiction of fine particulate concentrations can be displayed using ArcMap. More details are available in the VSMOKE modeling reports (Appendix C). 10

15 Redbird Fuels Treatment Project Results from the VISTAS regional air quality assessment, used by state air regulators in State Implementation Plan development, are used to discuss the cumulative impacts of prescribed fire emissions. Spatial and Temporal Context for Effects Analysis Air quality impacts from prescribed burning are generally short-term and the majority of smoke from a burn unit disperses within 24 hours. If burning continues into the night, when dispersion conditions are generally poor, then smoke can accumulate near the burn unit, especially in lowlying areas, and linger until late morning. The combination of early morning smoke and high relative humidity can create poor visibility conditions. However, when the sun comes up and temperature and air movement increase, smoke dispersion and visibility improve rapidly. Sometimes residual smoke from smoldering can persist for several days, but at far lower concentrations. These types of impacts usually occur fairly close to the burn unit. There are times, under certain weather conditions, when most of the smoke from prescribed fire moves rapidly to the mixing height and then downwind only to come back to earth in the afternoon or evening, possibly putting smoke into a sensitive area some distance from the burn unit. Finally, air quality is affected when smoke from multiple burns converge and move downwind. Smoke from one fire may not cause any problems, but smoke from two or more burns combined could be a nuisance, reduce visibility on a highway, or lead to violation of a NAAQS. Connected Actions, Past, Present, and Foreseeable Activities Relevant to Cumulative Effects Analysis This EA addresses prescribed burning on one section of the Redbird Ranger District. Additional prescribed burning may be planned for others areas of the District or across the Daniel Boone National Forest. Fire managers need to coordinate activity so that smoke from multiple fires does not overwhelm the dispersion capacity of the atmosphere on any one day. The treatment units in the proposed project are just north of Cumberland Gap, which also is implementing a prescribed burning program. The Forest and Cumberland Gap will need to coordinate burning to ensure that the cumulative effects of smoke are minimized. Alternative 1 No Action Effects There would be no direct effects associated with the No Action alternative. Indirect impacts may occur with the development of unplanned wildfires within the proposed treatment areas if accumulated fuels remain. With no control over weather conditions especially transport wind speed, wind direction, mixing height, stability class at the time of ignition, or the amount of fuel that may be consumed if the fuel moisture is low; the potential for impact on human populations by unplanned wildfire smoke is high. There would be no cumulative effects associated with the No Action alternative. However, air quality and standards in the analysis area would continue to be affected by all other sources of air pollution. 11

16 Air Report Alternative 2 Modified Proposed Action The proposed action is to use prescribed fire to treat up to 5,666 acres in 10 areas across the Redbird Ranger District to reduce fuel loading, reduce fire regime condition class and promote fire-mediated upland ecosystems. Burn unit size varies from 220 to 1,077 acres, and each unit would initially be treated with a 5- to 8-year burn cycle (up to four times) until the reference conditions have been reached. Annual acres burned could range from 220 to all 5,666 acres. Design Features and Mitigation Measures 1. The District will follow smoke management guidelines found in the Forest Service Manual (FSM 5144) as well as the Region 8 Supplement in order to avoid creating a nuisance situation, and minimize visibility impacts and/or impacts to people s health when implementing the prescribed fire program. 2. Each prescribed burn plan will include a smoke management plan that identifies smoke sensitive areas such as communities, health care facilities, airports, highways, homes of persons known to have chronic respiratory illness, schools, etc. The burn plan will be designed with conditions that will maximize smoke dispersion and minimize smoke impacts in these areas. 3. Each burn plan will include a public notification plan to inform those living nearby of when burns will occur. 4. The Prescribed Fire Burn Boss will obtain site-specific weather reports called spot weather forecasts, provided by the National Weather Service, to check that parameters for good smoke dispersion are met on the day of the burn and that the forecast meets the conditions described in the burn plan. This will aid in reducing smoke impacts on sensitive areas. 5. It is recommended that the District seek assistance from the Air Specialists and that a more refined model, such as HYSPLIT is used to help make go/no-go decisions on the day before or day of the burn. 6. For some treatment units, even the most diligent planning will provide no option that can avoid all smoke sensitive targets. In these cases the project can be modified or the District will seek ways to mitigate the impacts of the smoke. 7. Despite the fact that regional air quality analyses and monitoring may show that prescribed fire emissions are not affecting the NAAQS, forecasted ozone levels should be taken into consideration prior to burning to avoid putting smoke into areas with forecasts for ozone levels above the NAAQS. This is primarily a growing season concern when prescribed burn and the ozone season coincide (April October). 8. Once the decision to burn is made and firing has begun, fire and smoke behavior will be monitored for unanticipated and unacceptable situations (smoke dispersing in the wrong direction, smoke not dispersing vertically, etc.). The staff will be prepared to cease ignition and/or begin suppression if the situation cannot be controlled or mitigated. Also, staff will patrol smoke sensitive roadways through the night if the fire is still producing significant smoke at dusk. 9. The District will maintain records of any significant smoke management problems in the review section of the project burn plan. 12

17 Redbird Fuels Treatment Project Effects Prescribed fire emissions would have a direct, short-term effect on air quality in the project area. Once the smoke has dispersed, the impact is gone. The amount of smoke and how it is dispersed depend on the size of the burn, the type of fuel and the meteorological conditions at the time of the burn. In general, smoke from prescribed burning disperses into the atmosphere and combines with other existing pollutants. The wind transports the smoke and pollutants to areas many miles away where they are added to and possibly react with other gases/pollutants present in the atmosphere. The fate of emissions from prescribed fires is twofold. Most (about 75 percent) of the emissions are "lifted" by convection into the atmosphere where they are dissipated by horizontal and downward dispersion from the fire. The balance of the emissions (about 25 percent) remains in intermittent contact with the ground. Ground level smoke does not have enough heat to rise into the atmosphere. It stays in intermittent contact with the human environment and turbulent surface winds move it erratically. Human exposure to ground level smoke can be more intense, relatively brief (hours rather than days) and limited to a smaller area than exposure from smoke aloft. Smoke aloft is already dispersed before it returns to the human environment while ground level smoke must dissipate within that environment. Ground level smoke is dissipated through dispersion and deposition of smoke particles on vegetation, soil and other objects. The direct effects of smoke include human health and safety issues (Hardy et al. 2001). Fine particulates, including those found in wildland fire smoke, affect human health through the respiratory system, although eye irritation is also common. Individuals with cardiopulmonary diseases are especially susceptible. (Details on the health effects of fine particulate can be found in Appendix A or Hardy et al ) Residents near the burn unit might have some respiratory discomfort from ground level smoke, however it is expected that most impacts would be in the form of nuisance smoke and/or smell. For example, ash fallout can soil personal property and people may complain about the odors from the smoke. These impacts can be minimized by implementing the burn under weather conditions that are good for dilution and dispersion of the smoke away from smoke sensitive targets. Fine particulates can also reduce visibility at scenic views by scattering and adsorbing light. A sufficient concentration can result in a reduction in how far a person can see a distant object, and how well a person can see the color and texture of a distant object. Surveys indicate that viewing scenery is an important reason of why people visit national forests. The visibility impairment caused by the proposed prescribed fires is likely to be short term (less than 24 hours) in duration, and reductions in visibility (distance, color and texture) are likely to decrease as a person moves away from the prescribed fire. Visibility on roads can be reduced by ground level smoke, causing a safety issue. This can be particularly bad if smoke continues into the night when emissions are likely to be trapped near the ground and slowly transported from the burned area. The smoke will follow the drainages and collect in low lying areas. In a humid atmosphere the fine particles along with the water vapor released from the fuels can be a primary contributor to the formation of fog, which can become very dense. A person operating a vehicle in the vicinity of the prescribed fire may first experience good visibility conditions and then suddenly have visibility reduced significantly (perhaps to a few feet) when they drive into the fog formed by the smoldering emissions. Conditions like this can significantly increase the likelihood of highway accidents; however, the likelihood of traffic accidents can be reduced by assisting vehicles driving through the fog or directing the traffic along a different route away from the fog. 13

18 Air Report As mentioned previously, the conservative screening model VSMOKE was used to estimate downwind fine particulate matter concentrations. See the modeling report (Appendix C) for more details. The indirect effects of smoke are similar to the direct effects, but are experienced at greater distances from the burn. These effects are usually the result of the lifted portion of the smoke. Prescribed fires are managed to disperse and dilute smoke to avoid the negative effects of emissions, especially downwind of the burn. But mass ignition techniques (such as aerial ignition from helicopters) that have become more commonly employed in order to treat more acres over a shorter time period, can also put more particulate matter into the atmosphere over a relatively short time. In some situations this increase in particulate concentration might be enough to cause already dirty air to violate air quality standards, affect human health or reduce visibility; and this can occur some distance downwind. Dispersion modeling was conducted for all 10 of the proposed burn units in order to examine the potential for contribution to a violation of the 24-hour fine particulate NAAQS, as well as the potential for any impacts on downwind smoke sensitive targets. Using worst-case firing scenarios and the regional minimum meteorological parameters, most of the units are predicted to result in downwind fine particulate matter concentrations outside of the Forest at levels that are not of concern to the most sensitive populations. While a few of the units have the potential to transport smoke beyond the national forest at levels of that could be considered unhealthy for sensitive populations, potential impacts could be mitigated by burning with a wind direction away from the Forest boundary. Table 2 summarizes the dispersion modeling that was performed; as shown, the three burn units with the potential to cause Code Orange fine particulate matter concentrations outside of the National Forest are Cherry Tree, Pooler, and Sugar. Table 2. VSMOKE modeling results for the ten proposed burn units, based on worst-case firing and meteorological parameters Burn Unit Name Predicted Downwind Extent for Fine Particulate Matter Concentrations (in miles) Code Red (Unhealthy for All) Code Orange (Unhealthy for Sensitive Populations) Closest National Forest Boundary (in miles) Britton Branch Britton Branch Cherry Tree Granny s Branch Granny s Branch Pooler Rockhouse Rockhouse Sugar Venus Another indirect effect of prescribed burning on air quality could be a reduction in emissions resulting from wildfire. When hazardous fuels are removed through prescribed burning, wildfire occurrence and associated emissions should decrease. Emissions from wildfire generally affect human health and visibility conditions much more than prescribed fire emissions, because the 14

19 Redbird Fuels Treatment Project land manager does not have control over weather conditions affecting fire behavior and smoke dispersion. Cumulative Effects In addition to using prescribed fire in one of the 10 burn units being proposed in the Redbird Ranger District each year, the Forest may conduct controlled burns in one of the other units or in nearby areas. Depending on the timing of the burns, both the short-term (24-hour) and long-term (annual) NAAQS for fine particulate could be affected. Cumulative impacts will be discussed as they relate to the these standards. Past Actions Smoke from individual prescribed fires usually disperses quickly (in hours rather than days) and once the smoke has cleared the effect is over. Therefore, prescribed burning from the previous year does not contribute to a cumulative effect. However, when prescribed fire is used on closely located burn units over consecutive days, then it is possible to have residual smoke accumulate and effects could be increased. Communication between prescribed fire managers can mitigate this to some extent by planning burns to minimize the number of consecutive days of burning in any particular area. This gives the smoke time to disperse and concentrations of fine particulate to diminish. Present Actions Multiple prescribed fires could occur on the same day within the analysis area if burning conditions were favorable, and equipment and staffing were available. It is acknowledged that multiple burns, occurring at the same time, could cumulatively increase particulate levels. These short-term impacts are best assessed through smoke dispersion modeling to determine how plumes intersect, the resulting particulate concentrations and the likelihood of exceeding a 24-hour NAAQS. However, at this stage of planning, combinations of burn units that might be treated on the same day are not known, and therefore, modeling the cumulative impact on the 24-hour NAAQS is not an option. Communication between prescribed fire managers is essential to minimize the chances of smoke from multiple burns merging, whether they are ignited on the same or consecutive days. Two tools are currently available to model smoke dispersion from multiple units, one to two days before burning takes place (Southern High Resolution Modeling Center sponsors Bluesky at and NOAA sponsors Hysplit at Reasonably Foreseeable Actions The Forest plans to conduct multiple prescribed fire projects each year, in addition to these units. Thus, each year multiple burns will take place within the analysis area and emissions from these burns have the potential to affect the annual standard (NAAQS). The best way to assess the longterm cumulative air quality impacts from any activity is to include these emissions, along with those from all other sources, in regional air quality modeling exercises. Regional air quality modeling is conducted by air regulators to assess the effectiveness of various pollution control strategies; and specifically to demonstrate that a selected set of strategies will allow the area to meet the NAAQS. An emissions inventory of all source types is a necessary component of modeling. The results of the modeling describe the cumulative effects of pollution on air quality, and can also identify the pollution contribution from various source categories. 15

20 Air Report The VISTAS regional modeling exercise, completed in 2007, used emissions inventories developed to reflect current and future emissions from all sources in the southeastern states, including wildland fire emissions (from both wildfire and prescribed fire). Recent prescribed fire activity on all ownerships (averaged for years 2000 through 2004) was used to develop the baseline inventory. Future year inventories (2009 and 2018) incorporated anticipated increases in the use of prescribed fire on national forest system lands. These inventories also included emissions reductions anticipated between now and 2018 as a variety of Federal and state emissions control programs are implemented in order for Kentucky to demonstrate progress toward meeting the national visibility goal by The specific control programs are listed in the Executive Summary on page iv of Kentucky s Regional Haze State Implementation Plan (SIP) which was finalized in June The analyses conducted in support of the Regional Haze SIP included emissions changes occurring throughout the region, not only the state of Kentucky. The complete SIP, including comparison of current and future emissions inventories, can be viewed at the following URL: Future emissions estimates for the Daniel Boone National Forest were based on approximately 30,000-34,000 acres of prescribed fire occurring by the years 2009 and 2018, respectively. The emissions inventory also assumed PM 2.5 emissions of 2-3 tons per acre, and a maximum blackened area of 1,500-1,700 acres per burn unit. The results from VISTAS analyses indicate that prescribed fire emissions, including future increases, are not expected to cause or contribute to NAAQS violations in the analysis area. VISTAS also found that wildland fire emissions are not a significant contributor to visibility impairment at the Class I areas located in the Southern Appalachians or Mammoth Cave National Park in Kentucky (Final Regional Haze State Implementation Plan for Kentucky, 2008). As long as prescribed burning is conducted within the assumptions of the VISTAS analysis, the results can be used to demonstrate that the cumulative long-term impact of the Redbird Fuels Treatment Project, along with any other burning that is occurring on the Forest, would not cause or contribute to a NAAQS violation, or contribute significantly to visibility impairment at the closest Class I areas. Furthermore, fine particulate monitoring results from Bell County do not appear directly related to prescribed burning taking place on the Redbird Ranger District. As figure 7 shows, the highest emissions of fine particulate matter from prescribed fires over the past several years occurred in 2007, and yet fine particulate matter concentrations as measured in Bell County were lower than in the previous year. 16

21 Redbird Fuels Treatment Project Figure 7. Daily and annual fine particulate matter concentrations as compared to emissions from prescribed fires Given that the acres of prescribed burning throughout the Daniel Boone National Forest is increasing, total annual fine particulate emissions will increase. However, the impact of increased burning on the fine particulate NAAQS (24-hour or annual) will depend primarily on the temporal and spatial occurrence of burns, the amount of fuel consumed and the weather parameters at the time of burning. Conclusion Based on existing air quality information from within the analysis area, regional air quality modeling projections, smoke dispersion modeling, and best available science; no long-term adverse impacts to air quality standards are expected as long as recommended mitigations are incorporated into prescribed fire prescriptions (and smoke management plans) and successfully implemented. However, there may be times when smoke from the proposed prescribed fires causes short-term respiratory discomfort, is a nuisance, or reduces visibility of those near the burn units. Although burns are planned to minimize these impacts to smoke sensitive areas and nearby residents, there is the potential for the smoke plume to change direction and temporarily affect those in its path. These impacts are usually short-lived and last less than 24 hours. But impacts can occur some distance downwind depending on the weather conditions. This is particularly the case for burn units that may contain higher than normal fuel loads due to insect and storm damage, and lack of regular fire treatments. For these reasons, smoke management planning is an integral part of each prescribed burn operation. Additionally, emissions from the proposed project comply with all applicable state implementation plans (SIPs). Therefore, air emissions from the proposed project do not threaten to lead to a violation of the federal Clean Air Act, nor any state or local air quality law or regulation. 17

22 Air Report Monitoring Recommendations The District should consider monitoring smoke from some of these burn units, to see how well the model predicts dispersion. This would aid in planning future burns. References (Literature Cited) Final Regional Haze State Implementation Plan for Kentucky Hardy, Colin C.; Ottmar, Roger, D; Peterson, Janice L., Core, John E., and Seamon, Paula Smoke Management Guide for Prescribed and Wildland Fire. National Wildfire Coordination Group. 226 p. Jackson, William; Lavdas, Lee; Loberger, Dale, and Kelly, David N Help files for User Interface for VSMOKE and VSMOKE-GIS version [online]. Kentucky Division of Air Quality 2008 Monitoring Report. Lavdas, Leonidas G Program VSMOKE -- Users manual. General Technical Report SRS-006. U.S. Department of Agriculture, Forest Service, Washington, D.C. 147 p. MACTEC Documentation of the Bases G2 and best & Final 2002 base Year, 2009 and 2018 Emission Inventories for VISTAS. Prepared for VISTAS March 14, MACTEC, Inc. Ottmar, R.D.; Prichard, S. J.; Anderson, G. A Consume 3.0 [online]. Sandberg, D. V.; Anderson, G. K.; Northeim, R. A., Fire Emission Production Simulator Tutorial: Student Workbook; USDA Forest Services, [online]. U.S. Environmental Protection Agency (EPA) Inventory of Greenhouse Gas Emissions and Sinks: EPA 430 R Washington D.C. [online]. 18

23 Redbird Fuels Treatment Project Appendix A: Key Regulated Pollutants and their Significance in Smoke Fine Particulates (PM 2.5 ) Particulate is a term used to describe dispersed airborne solid and liquid particles which will remain in atmospheric suspension from a few seconds to several months. Particulates that remain suspended in the atmosphere are efficient at light scattering and therefore contribute to visibility impairment. Very small particles can travel great distances and contribute to regional haze problems. Regional haze can result from prescribed burning over multiple days and/or multiple owners utilizing the air shed over too short a period of time. Cumulative particulate load may be the result of prescribed burning only, or urban and industrial sources only, or it may be a combination of the two. The causes of regional haze are often difficult to identify. Total suspended particulates (TSP) include all suspended particulates, no matter the size. Particulate matter less than 2.5 microns in diameter (PM 2.5 ), or less than 10 microns in diameter (PM 10 ) describes particles small enough to enter the human respiratory system. Fires emit large amounts of fine particulate matter that can affect human health and impair visibility. Particulate matter, alone or in combination with other pollutants, can constitute a health hazard. Particulates enter the body mainly via the respiratory system. Particulate matter may exert a toxic effect in one or more of the following ways: 1. The particle may be intrinsically toxic because of its chemical and/or physical characteristics. 2. The particle may interfere with one or more of the mechanisms that normally clear the respiratory tract. 3. The particle may act as a carrier of an absorbed toxic substance. Medical studies have shown a solid relationship between increases in particulate concentrations and rises in the number of clinic and hospital visits for upper respiratory infections, cardiac diseases, bronchitis, asthma, pneumonia, and emphysema. Deaths of elderly persons afflicted with respiratory diseases and cardiac conditions also show an increase during periods when the concentration of particulate matter is unusually high for several days. Some recent studies have indicated that urban particulate matter may be more dangerous to human health than rural particulate. There is speculation that urban pollution sources, like auto exhaust and industrial sources may be more toxic than rural sources, such as dust or wood smoke. This theory has not yet been proven definitively. There are few studies that evaluate the toxicity of forest fire smoke. Almost all investigations of the toxicity of smoke particulate matter in human populations have been conducted with particulates associated with burning coal or fossil fuels where sulfur oxides and sulfates are the important constituents. However, these chemicals are not generated in a significant quantity by vegetation fires. Sulfur Dioxide Sulfur dioxide (SO 2 ) is emitted primarily from combustion of fuel containing sulfur; generally either coal or oil. Sulfur compounds are also emitted naturally by marine sources, soils and vegetation, volcanoes, and geothermal activity. Humans respond to sulfur dioxide exposure with an increase in airway resistance. Most individuals show a response to SO 2 at concentrations of 19

24 Air Report 5 ppm (parts per million) and above and certain sensitive individuals show slight effects at 1 to 2 ppm. Excess SO 2 in the atmosphere also effects sensitive vegetation. Sulfur dioxide can also contribute to reduction in visibility. Atmospheric haze is caused by the formation of various aerosols resulting from the photochemical reactions between SO 2, particulate matter, oxides of nitrogen, and hydrocarbons in the atmosphere. Sulfur dioxide transforms into an acid when absorbed in cloud water and raindrops and can fall as acid rain. Most forest fuels contain less than 0.2 percent sulfur so sulfur oxides could be produced only in negligible quantities during prescribed fires and wildfires. Carbon Monoxide Carbon monoxide (CO) is produced by automobile exhaust and other incomplete combustion sources. Carbon monoxide is a poisonous inhalant that deprives the body tissues of necessary oxygen. Extreme exposure (greater than 750 ppm) can cause death. Impaired time-interval discrimination can occur when humans are exposed to concentrations as low as 10 to 15 ppm for 8 hours. Carbon monoxide exposure can also result in central nervous system effects such as impairment of visual acuity, brightness discrimination, and psychomotor functions. Symptoms include headache, fatigue, and drowsiness. Large quantities of carbon monoxide are emitted from wildfire and prescribed fires. Carbon monoxide exposure from these sources can be significant for fire line workers but CO dilutes very rapidly in the atmosphere and probably is not a concern to urban and rural areas even a short distance downwind. One study measured CO concentrations as high as 200 ppm close to flames but observed that the concentration was reduced to less than 10 ppm just 100 feet from the fire. Ozone Ozone is a secondary pollutant formed from the reaction of volatile organic compounds with oxides of nitrogen in the presence of sunlight. Volatile organic compounds originate from industrial processes, solvent use, and transportation. The origin of nitrogen oxides is discussed in another section. Ozone can cause eye, nose, and throat irritation, and chest constriction in humans at concentrations above 0.10 ppm. On vegetation, ozone can cause visible injury, reduced photosynthetic capacity, increased respiration, premature leaf senescence, and reduced growth. Other effects include alteration of carbon allocation, greater susceptibility to environmental stress, changes in plant community composition, and loss of sensitive genotypes from a population. Prescribed fires and wildfires emit volatile organic compounds (VOCs) which can react with urban sources of nitrogen to form ozone. Elevated ozone levels have been measured at the top of smoke plumes. Elevated ozone in cities far downwind from wildfires has been attributed in part to wildfire emissions. Nitrogen Dioxide Oxides of nitrogen are formed in a combustion process when nitrogen in the air or in fuel combines with oxygen at elevated temperatures. Nitrogen dioxide acts as an acute irritant. Some increase in bronchitis in children has been observed at concentrations below 0.01 ppm. In combination with hydrocarbons, oxides of nitrogen react in the presence of sunlight to form 20

25 Redbird Fuels Treatment Project photochemical smog or ozone. Nitrogen dioxide absorbs visible light and, at a concentration of 0.25 ppm, will cause appreciable reduction in visibility. Formation of nitrogen oxides occur at temperatures not normally found in prescribed fires. Some oxides of nitrogen may be formed at lower temperatures in the presence of free radicals, and nitrogenous compounds in forest fuels are another possible source. Generally, wildland fire is considered an insignificant contributor of these emissions. Lead The principal source of lead emissions is the combustion of gasoline containing lead alkyl additives. Since use of leaded gasoline has decreased dramatically, lead air pollution is rarely a problem anymore. Lead particles that have been deposited on vegetation over decades can become re-emitted if the vegetation is burned. This phenomenon was documented during chaparral burning which took place east of the Los Angeles basin. 21

26 Air Report Appendix B: Process Used to Develop Fuelbeds, Fuel Consumption, Emissions Production and Smoke Dispersion Predictions for the Redbird Fuels Treatment Project Step 1: Develop fuel profiles representative of fuel loading conditions in the burn units, and fuel consumption estimates, using the model CONSUME. Fuel consumption is a major factor driving emissions production. a) Fuel loading for each burn unit was determined based on inventory plot data. b) A CONSUME file was created for each burn unit with the site-specific fuel loading information, with the following worst-case fuel moisture parameters: 8 percent moisture for 10-hour fuels; 16 percent moisture for 1000-hour fuels; and 70 percent moisture for duff. c) The fuel consumption from the ten burn units is estimated by CONSUME to be between 1.4 tons per acre to 11.9 tons per acre. The highest consumption is estimated on the Sugar burn unit, and the lowest is on the Venus burn unit. Step 2: Create hourly information on the amount and physical characteristics of emissions using the Fire Emissions Production Simulator (FEPS). This information is needed as input to the smoke dispersion models, VSMOKE-GIS and CALSMOKE. a) Although each burn unit is represented by a mix of fuelbeds, there is insufficient information to identify the proportion of each. Therefore, when a burn unit is modeled, the entire unit will be considered as one fuelbed. b) CONSUME results are imported into the Fire Emissions Production Simulator (FEPS). c) The following parameters were used in the software tool. 1) 100 percent of the total acres in each burn unit were assumed to be blackened over the span of the burn. 2) 50 acres are assumed to be in the active fire phase during the first hour of the burn (10am), using hand ignition. 3) A total of 500 of the acres will be burned before noon, and the remainder will be burned by 3pm, when the active fire phase ends. 4) The following meteorology values were used: i. Surface Wind Speeds: 8 mph ii. Transport Wind Speeds: 15 mph iii. Mixing Height: 4,000 feet above ground level iv. Surface Temperature: 65 ºF Step 3: Use VSMOKE to examine downwind smoke dispersion for the each of the burn units FEPS results are automatically imported into VSMOKE Details of the VSMOKE modeling results can be found in the report in Appendix C. 22

27 Redbird Fuels Treatment Project Appendix C: VSMOKE Modeling Results for the Air Analyses in the Redbird Fuels Treatment Project Environmental Assessment The purpose of conducting VSmoke modeling in conjunction with preparation of the Environmental Assessment was to demonstrate potential smoke impacts (specifically fine particulate) at downwind smoke sensitive targets. Key points/assumptions applicable to all model runs: VSmoke-GIS is based on a simple Gaussian model that does not account for variability in terrain or meteorology over time. It disperses a given amount of pollutant in a straight line and calculates the concentration at specified distances from the burn unit. It is best used for daytime dispersion conditions. Model results are not affected by the wind direction and will be the same no matter what direction the plume is plotted in. The model produces hourly predictions of ground-level fine particulate and carbon monoxide concentrations, but this report focuses on the fine particulate results. The plume rise condition used in the modeling will result in conservative results (erring on the high side for particulate concentrations). Plume rise for this exercise assumes 75 percent of the smoke is uniformly distributed vertically to the mixing height and then disperses downwind, and 25 percent of the smoke disperses at ground level. Both CONSUME (a model to estimate fuel consumption and emissions) and FEPS (a model to distribute emissions over time and develop associated heat and buoyancy factors) were used in conjunction with VSMOKE-GIS to arrive at the results presented. The process of developing fuel beds for use in CONSUME is discussed in a separate report. EPA s Air Quality Index (AQI) is used to present the results of VSMOKE in a format that relates concentration to specific public health warnings. The AQI break points between categories reflect current PM 2.5 National Ambient Air Quality Standards and current scientific knowledge of health impacts from fine particulate. 23

28 Air Report Table C-1. Air Quality Index (AQI) values for 24-hour and 1-hour PM 2.5 average concentrations (ug/m3), and cautionary statements regarding human health PM hr Avg. Concentration (ug/m 3 ) PM hr Avg. Concentration (ug/m 3 ) * Index Values Level of Health Concern Cautionary Statements Good None ** Moderate Unusually sensitive individuals should consider limiting prolonged or heavy exertion Unhealthy for Sensitive Groups People with respiratory or heart disease, the elderly, and children should limit prolonged exertion Unhealthy People with respiratory or heart disease, the elderly and children should avoid prolonged exertion, everyone else should limit prolonged exertion Very Unhealthy People with respiratory or heart disease, the elderly and children should avoid any outdoor activity, everyone else should avoid prolonged exertion > Hazardous Everyone should avoid any outdoor exertion; people with respiratory or heart disease, the elderly and children should remain indoors. * The 1-hour PM2.5 AQI values are taken from Wildfire Smoke: A Guide for Public Health Officials, July 2008 revision. ** An AQI of 100 for PM2.5 corresponds to a PM2.5 level of 35.4 micrograms per cubic meter (24-hr avg.). 24

29 Redbird Fuels Treatment Project VSMOKE Report for Britton Branch 1 Prepared by: Melanie Pitrolo Date: 6/30/11 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1100 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 66.2 degrees Fahrenheit, and the relative humidity was 45 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has 25

30 Air Report developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may impact their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 3.92 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than 6.21 miles are predicted to be code orange or worse. At distances less than 0.39 miles from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.49 miles from the fire are predicted to be code orange or worse. National Forest property extends to approximately 9.5 miles beyond the proposed burn unit. Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 823 feet from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of 26

31 Redbird Fuels Treatment Project this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. VSMOKE Report for Britton Branch 2 Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1100 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 66.2 degrees Fahrenheit, and the relative humidity was 45 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1,000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and 27

32 Air Report usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 1.96 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than 2.47 miles are predicted to be code orange or worse. At distances less than 1037 feet from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.31 miles from the fire are predicted to be code orange or worse. National Forest property extends approximately 10.9 miles beyond the edge of the proposed burn unit. Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 28

33 Redbird Fuels Treatment Project 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 413 feet from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. VSMOKE Report for Cherry Tree Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1100 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 66.2 degrees Fahrenheit, and the relative humidity was 45 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1,000 square miles under uniform weather conditions. Typically, the 29

34 Air Report Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 3.92 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than 7.82 miles are predicted to be code orange or worse. At distances less than 0.39 miles from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.62 miles from the fire are predicted to be code orange or worse. National Forest land extends at least 4.1 miles beyond the edge of the proposed burn unit. 30

35 Redbird Fuels Treatment Project Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 1,037 feet from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. VSMOKE Report for Granny s Branch 1 Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1100 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 66.2 degrees Fahrenheit, and the relative humidity was 45 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, 31

36 Air Report b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 3.92 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than 6.21 miles are predicted to be code orange or worse. At distances less than 0.49 miles from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.62 miles from the fire are predicted to be code orange or worse. The boundary of the National Forest is more than 9 miles from the edge of the proposed burn unit. 32

37 Redbird Fuels Treatment Project Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 1037 feet from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. VSMOKE Report for Granny s Branch 2 Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1100 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both 33

38 Air Report emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 66.2 degrees Fahrenheit, and the relative humidity was 45 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1,000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1,000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 3.92 miles from the edge of the fire may have a 1-hour particulate matter concentration predicted to be code red or worse, while distances less than 6.21 miles are predicted to be code 34

39 Redbird Fuels Treatment Project orange or worse. At distances less than 0.39 miles from the edge of the fire the 1-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.62 miles from the fire are predicted to be code orange or worse. The boundary for the National Forest is more than 9 miles from the proposed burn unit. Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 1,037 feet from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. 35

40 Air Report VSMOKE Report for Pooler Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1400 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 72.7 degrees Fahrenheit, and the relative humidity was 34 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1,000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has 36

41 Redbird Fuels Treatment Project developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 3.92 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than 6.21 miles are predicted to be code orange or worse. At distances less than 0.39 miles from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.62 miles from the fire are predicted to be code orange or worse. This burn unit is less than 2 miles from the closest National Forest boundary. Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 823 feet from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing 37

42 Air Report interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. VSMOKE Report for Rockhouse 1 Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1100 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 66.2 degrees Fahrenheit, and the relative humidity was 45 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result 38

43 Redbird Fuels Treatment Project of smoke contributing to fog formation is about 1 in 1,000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM2.5), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 3.11 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than 4.94 miles are predicted to be code orange or worse. At distances less than 0.31 miles from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.49 miles from the fire are predicted to be code orange or worse. This proposed burn unit is located 11 miles from the closest National Forest Boundary. Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 656 feet from the edge of the fire. 39

44 Air Report The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. VSMOKE Report for Rockhouse 2 Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1100 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 66.2 degrees Fahrenheit, and the relative humidity was 45 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1,000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. 40

45 Redbird Fuels Treatment Project Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 3.11 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than 4.94 miles are predicted to be code orange or worse. At distances less than 0.31 miles from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.49 miles from the fire are predicted to be code orange or worse. The proposed burn unit is more than 9 miles from the neared National Forest boundary. Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke 41

46 Air Report is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 656 feet from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. VSMOKE Report for Sugar Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1400 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 72.7 degrees Fahrenheit, and the relative humidity was 34 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. 42

47 Redbird Fuels Treatment Project The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1,000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 7.82 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than miles are predicted to be code orange or worse. At distances less than 0.62 miles from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 0.78 miles from the fire are predicted to be code orange or worse. The nearest National Forest boundary is approximately 12 miles from the burn unit. 43

48 Air Report Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 0.25 miles from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different from the calculated stability class in VSMOKE. VSMOKE Report for Venus Prepared by: Melanie Pitrolo Date: 6/30/2011 The smoke dispersion modeling analysis (using VSMOKE and/or VSMOKE-GIS) for this project was performed for acres to be burned on 04/01/2012 at the time period of 1100 hours. This time period has daytime dispersion characteristics to disperse the pollutants from the fire. The location of the fire is at approximately degrees latitude and degrees longitude ( meters east and meters north using US Albers projection). The emission rate of PM2.5 (fine particles) this hour was grams/second, and carbon monoxide was grams/second. The heat release rate was 73.8 megawatts. Both emission rates and the heat release rates were calculated using the Fire Emission Production Simulator (FEPS) model. The estimated background concentration of fine particles and carbon monoxide of the air carried with the winds into the fire are 10 micrograms/cubic meter and 2 parts per million, respectively. The proportion of the smoke subject to plume rise was percent, which means 75 percent of the smoke is being dispersed gradually as it rises to the mixing height, and 25 percent is dispersed at ground level. The meteorological conditions used in this model run were: 1. Mixing height was 4,000 feet above ground level (AGL). 2. Transport wind speed, and surface wind speed were 15 and 8 miles per hour, respectively. 3. There were no clouds in the sky. 4. Surface temperature was 66.2 degrees Fahrenheit, and the relative humidity was 45 percent. 5. The calculated stability class from VSMOKE was moderately unstable. The VSMOKE model produces three types of outputs that estimate: a) The ability of the atmosphere to disperse smoke and the likelihood the smoke will contribute to fog formation, 44

49 Redbird Fuels Treatment Project b) Downwind concentrations of particulate matter and carbon monoxide, and c) Visibility conditions downwind of the fire. The Dispersion Index (DI) is an estimate of the ability of the atmosphere to disperse smoke to acceptably low average concentrations downwind of one or more fires. This value could represent an area of approximately 1,000 square miles under uniform weather conditions. Typically, the Dispersion Index value should be greater than 30 when igniting a large number of acres within an area. The calculated Dispersion Index value was 68, which predicts the atmosphere has a good capacity to disperse smoke. Combining the Dispersion Index and relative humidity values provide an estimate (like is used in insurance actuary tables) of the likelihood of the smoke contributing to fog formation. The Low Visibility Occurrence Risk Index (LVORI) ranges from 1 (lowest risk) to 10 (greatest risk) and usually you want the value to be less than 4. The base line risk of having low visibility as a result of smoke contributing to fog formation is about 1 in 1,000 accidents. The Low Visibility Occurrence Risk Index value for this VSMOKE analysis was 1 and this is equal to the base line. High concentrations of particulate matter, especially fine particles (PM 2.5 ), and carbon monoxide can have a negative impact on people's health. The Environmental Protection Agency has developed a color coding system called the Air Quality Index (AQI) to help people understand what concentrations of air pollution may affect their health. When the AQI value is color code orange then people who are sensitive to air pollutants, or have other health problems, may experience health effects. This means they are likely to be affected at lower levels than the general public. Sensitive groups of people include the elderly, children, and people with either lung disease or heart disease. The general public is not likely to be affected when the AQI is code orange. Everyone may begin to experience health effects when AQI values are color coded as red. People who are sensitive to air pollutants may experience more serious health effects when concentrations reach code red levels. This analysis shows the air quality at downwind distances less than 0.31 miles from the edge of the fire may have a 1-hour particulate matter concentrations predicted to be code red or worse, while distances less than 0.49 miles are predicted to be code orange or worse. At distances less than 328 feet from the edge of the fire the one-hour carbon monoxide concentrations are predicted to be code red or worse, and distances less than 328 feet from the fire are predicted to be code orange or worse. This proposed burn unit is approximately 10 miles from the closest National Forest boundary. 45

50 Air Report Smoke can also have an impact on how far and how clearly we can see on a highway or in viewing scenery. The fine particles in the smoke are known to be able to scatter and absorb light, which can reduce visibility conditions. The visibility estimates from VSMOKE are valid only when the relative humidity is less than 70 percent. Also, the visibility estimates assume the smoke is passing in front of a person who is looking through the plume of smoke. The visibility thresholds used for this modeling analysis were to maintain a contrast ratio of greater than 0.05 and a visibility distance of 0.25 miles. Visibility conditions may exceed the threshold less than 328 feet from the edge of the fire. The VSMOKE-GIS model estimates where for the pre-selected fine particulate matter concentrations (39, 89, 139, 352, and 527 micrograms per cubic meter) to be predicted downwind of the fire. If an analysis was conducted then the results (map) will be attached to the last page of this report. The VSMOKE-GIS analysis had daytime dispersion characteristics to disperse the pollutants from the fire and this is the same as the VSMOKE analysis. The downwind spacing interval was set at kilometers, and the model ceased making downwind estimates at 30 miles from the edge of the fire. The stability class used for the VSMOKE-GIS analysis was slightly unstable and this is different than the calculated stability class in VSMOKE. 46