SECTION 3.13 AIR QUALITY

Transcription

1 SECTION 3.13 AIR QUALITY I. INTRODUCTION Effects to air quality were identified as an analysis issue for this project. Public comment expressed a concern that air quality impacts from approximately 8,000 acres of prescribed fire were not analyzed for Lame Deer, MT, a PM10 non-attainment area located 30 s to the west of the BLLMP project area, and the Northern Cheyenne Indian Reservation, a Class 1 Airshed located approximately 15 s to the west of the project area. Prescribed fire in the BCLMP area may temporarily increase PM 2.5 levels in the nearby vicinity. Smoke from the burning activities could temporarily obscure visibility in the project area. Smoke may temporarily pose nuisance levels to people in the area. Indicator: Smoke as measured in PM 2.5 in tons of total emission, tons/day, and in downwind concentrations in. The action alternatives propose prescribed fire on approximately 8,000 acres of the 14,053 acres BCLMP area. Under Alternative A, areas proposed for burning would be burned once at the time of project implementation. Under Alternatives B and C, these sites would be burned once at the time of project implementation, with a subsequent burn approximately ten to fifteen years later. Refer to Appendix A, Maps 1, 5, and 10 for locations of proposed burning. A. SPATIAL AND TEMPORAL BOUNDS The geographic area used to analyze the effects on air quality is the Montana Airshed 10, which consists of fourteen counties (Prairie, Dawson, Wibaux, Fallon, Carter, Powder River, Big Horn, Carbon, Sweet Grass, Stillwater, Yellowstone, Treasure, Rosebud, and Custer Counties), and is bordered on the south by the Wyoming state line and east by the North Dakota and South Dakota state lines. The BCLMP area is located in the southeastern part of the airshed in northern Powder River County. Refer to Figure Montana Airshed 10 contains a largely rural population in the east with isolated urban areas around Billings in the central portion. The Montana/Idaho State Airshed Group rarely imposes burning restrictions in Airshed 10 due to the generally strong wind gradients and lack of confined valleys that restrict airflow. Section 3.13 Air Quality 3-271

2 Figure : Montana Airsheds B. REGULATORY FRAMEWORK Custer Forest Plan The goal of air resource management in the Custer Forest Plan is to meet or exceed state air quality standards and ensure protection of air quality related values. The air quality objective in the Forest Plan is to maintain air quality of National Forest System lands at or above levels required by Federal and State laws, regulations, and standards. Applicable standards include: Air quality will be protected by cooperating with Montana, North Dakota, and South Dakota Air Quality Bureaus in the Prevention of Significant Deterioration (PSD) program and State Implementation Plans (SIP). Requirements of the PSD, SIP, and State of Montana, North Dakota, and South Dakota Smoke Management Plans will be met whenever the FS has authority to do what is required. The Forest will cooperate with states, other agencies, and organizations in identifying, evaluating, proposing solutions, and monitoring air quality problems associated with activities permitted on National Forest and National Grassland surface. The objective is to maintain air quality at or above levels required by federal and state laws, regulations, and standards. Air that passes over National Forest System lands will not be degraded below allowable increments by activities under Forest Service control. State and local governments and appropriate federal agencies will also be consulted and involved in monitoring and controlling air pollution originating on nonfederal lands and affecting air quality on federal lands. Standards developed in the Cooperative Smoke Management Plan will be used for prescribed burning activities in the applicable states (USDA 2008, p. 4, 5, 26). Section 3.13 Air Quality 3-272

3 Federal Clean Air Act The framework for controlling air pollutants in the United States is mandated by the 1970 Clean Air Act ( as amended in 1977 and 1990 (42 U.S.C et seq.). The CAA was designed to protect and enhance the quality of the nation s air resources. Stringent requirements were established for areas designated as Class I areas. Designation as a Class I area allows only very small increments of new pollution above already existing air pollution levels. Class II areas are currently all other areas of the country that are not Class I. The closest Class I area to the BCLMP area is the Northern Cheyenne Indian Reservation, located approximately15 s to the west. The CAA encourages reasonable Federal, State and local government actions for pollution prevention. State Implementation Plans (SIPs) are developed by each state to implement the provisions of the CAA. The SIPs describe the State s actions to achieve and maintain the NAAQS. Conformity Determinations The general conformity provisions of the CAA (Section 176(c)) prohibit federal agencies from taking any action within a non-attainment area that causes or contributes to a new violation of the standards, increases frequency or severity of an existing violation, or delays the timely attainment of a standard as defined in the area plan. The BCLMP area is not located in a nonattainment area. The closest nonattainment areas are located at Lame Deer (30 s to the west) and Sheridan, WY (70 s to the south). National and State Ambient Air Quality Standards Congress passed the Clean Air Act in 1963, and amended it in 1972, 1977, and The purpose of the act is to protect and enhance air quality while ensuring the protection of public health and welfare. The act established National Ambient Air Quality Standards (NAAQS), which must be met by state and federal agencies, and private industry. The NAAQS have been established for carbon monoxide, nitrogen oxide, and sulfur dioxide, lead, and PM 2.5. Particulate matter is the primary pollutant of concern for prescribed burn projects. States are given primary responsibility for air quality management. Section 110 of the Clean Air Act requires States to develop State Implementation Plans (SIP) that identify how the State will attain and maintain NAAQS, which are identical to the Montana standards for PM 10 (particulate mater with less than 10 microns). The PM 2.5 standard requires concentrations of PM 2.5 not to exceed a 24-hr average of 35 -ug/m 3 (micrograms per cubic meter). This standard was changed from 65- by the EPA on 9/21/06 ( Average annual arithmetic PM 2.5 concentrations are not to exceed 15-ug/m 3. The SIP is promulgated through the Montana Clean Air Act and implementing regulations. The regulations provide specific guidance on maintenance of air quality, including restrictions on open burning (ARM ). The act created the Montana Air Quality Bureau (now the DEQ) and the regulatory authority to implement and enforce the codified regulations. Section 3.13 Air Quality 3-273

4 Regional Haze Rule (1990 CAA Amendments) - 40 CFR Part 51. Visibility impairment is a basic indicator of air pollution concentrations and was recognized as a major air quality concern in the Clean Air Act Amendments of Visibility variation occurs as a result of the scattering and absorption of light by particles and gases in the atmosphere. Without human-caused pollution effects, a natural visual range is approximately 90 to 140 s in the western United States (EPA, 1999). EPA s 1980 visibility rules (40 CFR ) were developed to protect mandatory Class I areas from human-caused impairments reasonably attributable to a single or small group of sources. In 1999, EPA promulgated the Regional Haze Rule (40 CFR ), which calls for states to establish goals for improving visibility in mandatory Class I areas and to develop long-term strategies for reducing the emissions of air pollutants that cause visibility impairment. Class 1 Airsheds include 156 National Parks, wilderness areas and designated portions of Indian Reservations. All other areas are considered a Class II Airshed. The regional haze regulations apply to all states, including those states that do not have any Class I areas. The Regional Haze regulations require states to demonstrate reasonable progress for improving visibility in each Class I area over a 60-year period (to 2064), during which visibility should be returned to natural conditions. The Regional Haze Rule also requires states to address visibility impairment in mandatory class I areas due to emissions from fire activities. The Preamble to the Rule emphasizes the implementation of smoke management programs to minimize effects of all fire activities on visibility. The Rule requires states to address visibility effects from all fire sources contributing to visibility impairment in mandatory class I areas. The Interim Air Quality Policy on Wildland and Prescribed Fires (U.S. EPA 1998) On May 15, 1998, the EPA issued the Interim Air Quality Policy on Wildland and Prescribed Fire to address impacts to public health and welfare. This policy was prepared in response to anticipated increases in fire use that were expected to occur as a result of implementing the 1995 Fire Management and Policy Review, which outlined a need to restore fire as an ecosystem process. The Interim Policy was prepared to integrate the goals of allowing fire to function in an ecological role for maintaining healthy ecosystems balanced with protecting public health and welfare by mitigating the impacts of air pollutant emissions on air quality and visibility. The policy was developed with the active involvement of stakeholders including the U.S. Department of Agriculture. The Interim Policy reconciles the competing needs to use fire and maintain clean air to protect public health. The Interim Policy is interim only because it does not yet address agricultural burning or regional haze (EPA 1998). It is not interim with regard to how States, Tribes, and Federal land managers are expected to address smoke from prescribed fires. The Interim Policy suggests that air quality and visibility impact evaluations of fire activities on Federal lands should consider several different items during planning (EPA 1998). In a project level NEPA document, it is appropriate to consider and address to the extent practical, a description of applicable regulations, plans, or policies, identification of sensitive areas Section 3.13 Air Quality 3-274

5 (receptors), and the potential for smoke intrusions in those sensitive areas. Other important disclosure items include applicable smoke management techniques, participation in a basic smoke management program, and potential for emission reductions. Typically ambient air quality, visibility monitoring, and cumulative impacts of fires on regional and sub-regional air quality are not explained to the same level of detail. Ambient air quality and visibility monitoring (for Class I areas) are typically done collaboratively with the states. Impacts to regional and sub-regional air are addressed operationally through a coordinated smoke management program. The EPA urges states to develop, implement and certify smoke management programs that meet the recommended requirements of the Interim Policy. If a certified program is in place and smoke exceeds the particulate standard, it may not be considered a violation by EPA. Airshed Monitoring The majority of the legal entities in Montana and Idaho (including the Forest Service) that create particulates as a result of burning activities have formed the Montana/Idaho State Airshed Group. Through a Memorandum of Understanding, this group has established a smoke monitoring system that provides air quality predictions restrictions to its members. In Montana, the MTDEQ issues an annual burn permit to the Forest Service. Issuance of this permit is based on participation and compliance with burning restrictions set by the Montana/Idaho Airshed Group. All prescribed burning implemented within the analysis area would comply with the State Requirements of the State Implementation Plan and the Smoke Management Plan (USFS 1987a, p. II-26). Prescribed burning is reported to the Airshed Coordinator on a daily basis. If the monitoring unit forecasts ventilation problems, prescribed burning is either restricted by elevation or curtailed until good ventilation exists. Smoke Management Smoke management is regulated through the State of Montana s Department of Environmental Quality (DEQ). The DEQ has established a protocol and monitors emission standards rates for all burns in affected airsheds. Prescribed burns are input into a smoke database approximately 24 hours before ignition occurs and on the day of ignition, the burn boss confirms if the prescribed fire has been approved. If emissions are likely to exceed the NAAQS rates, prescribed fires may not be approved, operations may cease, or implementation may be postponed. The Ashland RD has a history of excellent dispersion and very few smoke issues; over the past 10 years, the district has averaged over 4,000 acres of prescribed burning with only minor adjustments. II. AFFECTED ENVIRONMENT AIR QUALITY A. CLIMATE AND WIND DIRECTION The BCLMP area is located within a dry semi-arid climate zone characterized by hot dry summers and cold winters. Approximately 60 percent of precipitation falls within the months of April to June. Average annual precipitation ranges from approximately 14 to 18 inches (Section Section 3.13 Air Quality 3-275

6 3.4 Water Resources, p ). A trace of precipitation falls during the winter months to a high of 2.6 inches in the month of June. Wind data collected from the Fort Howes weather station ( ) shows winds throughout the year ranging between 2 and 17 s per hour with an average 7 s per hour. The most predominate wind direction is from the southwest. During frontal passages however, winds can be from the east. B. AIR QUALITY/POLLUTION The BCLMP area lies within Powder River County in Airshed 10, which is considered to be in attainment by the Montana DEQ. The nearest non-attainment areas for PM 10 are Lame Deer (30 s to the west) and Sheridan, Wyoming (70 s to the south). The nearest Class I Airshed is the Northern Cheyenne Indian Reservation, located approximately 15 s to the west. The rest of the Airshed is Class II. Air quality within Power River County is excellent with very limited local emission sources and consistent wind dispersion. Existing sources of emissions in the greater area include occasional construction equipment, vehicles, road dust, residential wood burning, wood fires, and smoke from logging slash disposal. Emissions are very limited with no local visible sources of impairment. Wind dispersion throughout the entire area is robust, with no visible inversions or localized concentrations of emissions. The major source of emissions in the vicinity of the project are the towns of Ashland and Colstrip with vehicle exhaust, wood burning smoke, and road dust although both communities are in compliance with National Ambient Air Quality Standards (NAAQS). Colstrip also has a coal-fired power plant that produces emissions. Ashland and Colstrip emissions visibly do not impact the project area and are strongly dispersed by predominant south and southwest wind direction with generally good wind gradients. Other types of emissions in the area include vehicle and agriculture equipment exhaust, road dust, wood smoke from residential, smoke from pile burning, broadcast burning, and wildfires. Wildfires in Eastern Montana within the last 20 years have had a high frequency with several large fires in the last ten years. These fires produce considerable smoke though it is generally short duration (one to three days) and winds dissipate it quickly. Regional wildfire smoke has accumulated within the area during periods of extensive wildfire activity in 1988, 1994, 2000, 2003, 2006 and The prime source of wildfire emissions is from central and southern Idaho, Northern Wyoming and SW Montana. Background particulate levels of 5-10 µg/m 3 per 24-hour average are typical for remote, non-developed areas. During wildfire events, particulate levels may exceed NAAQS for PM 10 and PM 2.5, reaching levels of hundreds of µg/m 3 per day during intense wildfires - like the year 2000 wildfires in Montana and Idaho (Story et al 2005). Generally the project area does not develop temperature inversions, which trap smoke and reduce smoke dispersal. Dispersion of emissions within the project area is very high due to the broken terrain and high wind activity. Section 3.13 Air Quality 3-276

7 III. EFFECTS COMMON TO ALL ACTION ALTERNATIVES A. DIRECT & INDIRECT EFFECTS ON AIR QUALITY Sources of smoke emissions from the project area include the following: Table : Sources of Smoke Emissions Fire Treatment Alternative A Acres Underburn assoc. with Commercial Treatments Pile Burning assoc. with Commercial Treatments (Landing Piles) Underburn assoc. with noncommercial treatments Pile Burning assoc. with Noncommercial Treatments (Hand Piles) Broadcast burning alone (no mechanical or hand thinning) Alternative B Acres Alternative C Acres ,594 3,594 3,506 Total 9,630* 9,587* 7,693* * Acres were calculated from Tables 2.2, 2.3, 2.4, and 2.5 in Chapter 2. The total sum appears higher than the burning acreage in Chapter 2 because the landing piles (row 2) overlap with unit acreage for commercial underburning (row 1). Action alternatives would add smoke to an immediate area, but because approval is given on a burn day by burn day basis, ambient air quality standards governed by the Montana DEQ would not likely be exceeded. For additional information on ambient air quality standards, refer to Montana s Air Quality website at: Potential air quality effects of the BCLMP were analyzed using USFS R1 NEPA evaluation procedures for prescribed fire projects (Story and Dzomba, 2005) which can be downloaded from the USFS R1 air quality website at The decision analysis in the procedure document was not used in lieu of the Smoke Impact Spreadsheet (SIS) model (Air Sciences, 2003) which updates the modeling specified in the USFS R1 guidance. The SIS model uses an excel spreadsheet to link to the FOFEM5 model for broadcast burn fuel loading, the Consume model for pile burn emissions, and the CalPuff model for dispersion modeling. The SIS model was run for the BCLMP prescribed burn mode and for treatment units with pile burning. Air quality mitigation measures are listed in Chapter 2 (Table 2.14). Modeling assumptions include: Section 3.13 Air Quality 3-277

8 Conditions were developed from default fire behavior conditions in FOFEM. FOFEM used an SAF 237 Ponderosa pine type to estimate smoke emissions for the treatments in ponderosa pine stands. In grassland types, SRM 309 Idaho Fescue- Western Wheatgrass was used. Because not all of the area in each treatment will be burned, the project acres for smoke production have been corrected to reflect this effect. For information on area burned by treatment type, refer to Section 3.2 Fuels. Broadcast and understory burn analysis assumed a near maximum operational feasibility of 300 acres per day. Mechanical piles (12 x 30 x 60 ) are landing piles, which were assumed to be burned at the rate of 30 piles per day. Hand piles (8 x 8 x 6 ) are landing piles were modeled at 20 piles per acre on 12.5 acres or 250 piles/day. The SIS model FOFEM5 component was used for the understory burns while the Consume Pile Wizard was used for the pile burns. The SIS model then used CALPUFF model simulations in excel spreadsheets considering emissions and meteorology to estimate PM 2.5 concentrations. Model results include: Table : Alternative A - Smoke Impact PM 2.5 Estimates. Treatment Acres Acres/ Minimum Type Day Tons Total Tons Per Day Ambient Distance (Miles) UB 1, MP 1, BB 5, HP 1, Total 9, UB = Underburn; MP = Machine pile; BB = Broadcast burn; HP = Hand pile Table : Alternative B - Smoke Impact PM 2.5 Estimates. Treatment Acres Acres/ Minimum Type Day Tons Total Tons Per Day Ambient Distance (Miles) UB MP BB HP Total UB = Underburn; MP = Machine pile; BB = Broadcast burn; HP = Hand pile Section 3.13 Air Quality 3-278

9 Table : Alternative C - Smoke Impact PM 2.5 Estimates. Treatment Acres Acres/ Minimum Type Day Tons Total Tons Per Day Ambient Distance (Miles) UB MP BB HP Total UB = Underburn; MP = Machine pile; BB = Broadcast burn; HP = Hand pile The modeling results include projected emissions from all of the units, which range from a total of 447 tons (Alt A) to 418 tons under Alt C of PM 2.5 for prescribed burns. The burning would be implemented over 3 to 7 years, so any 1-year of emissions would likely not exceed 100 tons. Direct effects of the burns include particulate emissions. The understory and broadcast burns are expected to produce a centralized plume due to a concentrated burn area while pile burns result in multiple plumes, which consolidate into a central plume. Pile burns would be done in the fall while the broadcast burns would be done primarily in the spring. Underburns could be done in the spring or fall. Actual concentrations would be about 5- greater depending on the background concentrations of PM 2.5. Projected PM 2.5 emissions are below the 35- PM 2.5 standard a half- from all burn units. The minimum ambient distance is the spacing from the burn the public would have access to the air when outside of a vehicle. Access to the air triggers the 24-hour average PM standard. All burns would disperse to low concentrations beyond 5 s. Spring burns would likely occur during a period of more wind dispersion than fall under story or pile burning, due to longer spring daytime length, and higher mixing heights. The under story and pile burn smoke plume would likely also disperse to the north and east. Outside of the minimum ambient distances the smoke concentrations are expected to be within NAAQS and State of Montana air quality standards. BCLMP burns would be coordinated with the Montana/Idaho State Airshed Group ( The operations of the Montana/Idaho State Airshed Group are critical to minimize cumulative smoke/pm 10 air quality impacts. The State Airshed Group, Monitoring Unit in Missoula, evaluates forecast meteorology and existing air quality statewide by individual airshed and specifies restrictions when smoke accumulation is probable due to inadequate dispersion. Indirect effects would include some localized visibility reduction from the plumes. Some reduction in visibility driving along the Highway 212 could occur in narrow bands during under story or pile burning. Dispersion of the plumes would be expected to quickly mix the project smoke to insignificant visibility impact levels. Section 3.13 Air Quality 3-279

10 Due to prevailing wind direction and dispersions, prescribed fire activities should not impact the Northern Cheyenne Indian Reservation (Class 1 Airshed) or Lame Deer, MT (nonattainment for PM 10 ). Both of these areas are located to the west of the BCLMP area. B. CUMULATIVE EFFECTS ON AIR QUALITY On the Ashland RD, current and reasonably foreseeable events considered potential smoke producing projects include: - ThreeMile Stewardship Project - Fifteen Elk Landscape Management Project - Timber Creek Project - Private land fuel reduction - Wildfire Suppression - Cow Creek Fuels Reduction Project - Liscom Butte Fuels Reduction Project - Home Creek Fuels Reduction Project - Campground Maintenance - Poker Jim Prescribed fire Air resources are somewhat unique in that the past impacts to air quality are not usually evident or cumulative. The BCLMP emissions would be cumulative only with the local emission sources described in the affected environment occurring at the time of burning. Cumulative effects for air quality are very limited since there are very few sources of emissions in the analysis area. C. FOREST PLAN CONSISTENCY OF PROPOSED ACTION ALTERNATIVE This alternative would be consistent with the Forest Plan as it proposes to follow reporting and air quality management direction to maintain air quality standards. IV. EFFECTS OF NO ACTION ALTERNATIVE ON AIR QUALITY A. DIRECT & INDIRECT EFFECTS ON AIR QUALITY In the short run, the air quality effects from the No Action alternative are less than the action alternatives since the emissions from the pile, jackpot, under-story, and broadcast burning would not occur. In the long run, the No Action alternative would not reduce the amount of fuels in the treatment areas. Wildfire has the potential to result in extensive smoke and air quality impacts from PM 2.5 and PM 10 emissions. Section 3.13 Air Quality 3-280

11 B. CUMULATIVE EFFECTS ON AIR QUALITY Air resources are somewhat unique in that the past impacts to air quality are not usually evident or cumulative. The No Action alternative does not propose any prescribed burning treatments, so the project area would not add to additional air quality impacts. Emissions from a wildfire would be cumulative with local and regional emission sources described in the affected environment occurring at the time of burning. Cumulative effects would likely be the same as disclosed in the direct and indirect effects and are constrained by the air quality mitigation measures described in Chapter 2 (Table 2.14). C. FOREST PLAN CONSISTENCY OF NO ACTION ALTERNATIVE Air quality in the project area currently meets or exceeds standards required by federal and state laws and regulations, and as such complies with the Forest Plan. However, this alternative would not take any action to reduce the likelihood of the analysis area experiencing an uncontrolled wildfire, which would produce PM 2.5 and PM 10 emissions likely to exceed air quality standards at the time of the event. Section 3.13 Air Quality 3-281