Planning and Modeling Branch - Regional Haze and BART
Regional Haze
US EPA Proposes Full Approval of Nevada's Regional Haze SIP, June 22, 2011 [PDF].
Overview
In 1977, Congress amended the Clean Air Act establishing a national goal to protect visibility in Class I federal areas -- national parks, forests and wilderness areas. The amendments called for the “prevention of any future, and the remedying of any existing, impairment of visibility in mandatory Class I federal areas which impairment results from manmade air pollution.” In 1979, EPA promulgated a list of 156 mandatory Class I areas in which visibility was determined to be an important factor. In Nevada, there is one designated Class I area, the Jarbidge Wilderness Area in the northeast corner of the state.
 Jarbidge Wilderness Area, Summer Season |
 Jarbidge Wilderness Area, Fire Event |
In 1980, EPA promulgated regulations to address visibility impairment that is "reasonably attributable" to a single source or group of sources. On July 1, 1999, the Regional Haze Rule [PDF] was promulgated by EPA. The intent of the regional haze rule is to improve visibility over a period of 60 years in all 156 mandatory Class I areas across the country. It requires each affected state to develop and adopt an implementation plan that will improve the haziest days and protect the clearest days at each mandatory Class I area in the state with a goal of returning to natural visibility conditions by the year 2064.
Comprehensive SIP revisions are required every 10 years. The initial planning period of the Regional Haze Rule is 2008 through 2018. A key component of the Regional Haze Rule is the requirement to install and operate the best available retrofit technology (BART) for qualifying older, existing sources of visibility impairing pollutants. Each plan must provide a comprehensive analysis of natural and man-made sources of haze in each mandatory Class I area in the state and contain strategies to control anthropogenic emissions that contribute to haze. The plan must also address the transport of haze across state boundaries.
Most of the technical work for regional haze SIPs in the western states was done through the Western Regional Air Partnership (WRAP). The WRAP is a collaborative effort of tribal governments, state governments and various federal agencies to develop the technical and policy tools needed by western states and tribes to comply with EPA's regional haze regulations. WRAP activities are conducted by a network of committees and forums composed of WRAP members and stakeholders, representing a wide range of viewpoints.
An EPA pamphlet explains what regional haze is and where it comes from. More information and educational materials on regional haze are found on the IMPROVE website. The IMPROVE website has information on visibility science, regional haze workshops and Class I area maps, as well as links to regulations.
Best Available Retrofit Technology (BART) Requirements
BART requirements apply to facilities built between 1962 and 1977 (the 15-year period prior to enactment of the 1977 prevention of significant deterioration rules) that have the potential to emit more than 250 tons a year of visibility-impairing pollution. Those facilities fall into 26 categories, including utility and industrial boilers, and large industrial plants such as pulp mills, refineries and smelters. Many of these facilities previously have not been subject to federal pollution control requirements for these pollutants.
The Regional Haze Rule requires the state to determine which facilities in the state are eligible for BART determinations. Once it is determined that a facility is BART-eligible, the state must determine whether it may reasonably be anticipated that the facility will cause or contribute to any impairment of visibility in any mandatory Class I area. If so, then the facility, or applicable source within the facility, is subject to BART. EPA’s Regional Haze Regulations and Guidelines for Best Available Retrofit Technology Determinations , published in the July 6, 2005 Federal Register, provides direction to the state on how to determine BART for sources.
BART Visiblity Modeling
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NDEP determined which Nevada facilities were BART-eligible. At the request of Nevada, the WRAP’s Regional Modeling Center (RMC) conducted air quality modeling to assess which BART-eligible sources were subject to a full BART determination. Modeling was conducted for all BART-eligible sources, except the Nevada Cement Company, which exercised the option to produce their own assessment. BART exemption modeling was performed in accordance with the WRAP RMC "Protocol for BART Exemption Screening" (2006) and the April 2007 explanation of changes using the CALPUFF modeling system (Version 6.112). Links to these documents and others are provided below. The modeling domain included all mandatory Class I areas within 300 km of the BART–eligible sources. |
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A summary of the BART exemption modeling resultsfor Nevada’s BART-eligible sources is found at the WRAP RMC. Nevada Cement Company's report and protocol may be viewed at “Source-Specific BART Exemption Modeling Report: Nevada Cement Company - Fernley Plant,”and “Source-Specific BART Modeling Protocol: Nevada Cement Company - Fernley Plant,” respectively (below). Three BART-eligible sources in Nevada were determined not to be subject to from BART requirements: NV Energy’s Sunrise Generating Station, Chemical Lime Company and Nevada Cement Company.
BART Determinations
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Four Generating Stations in Nevada, comprising of 10 unites, are subject to BART: NV Energy's generating stations at Tracy (units 1, 2 and 3), Fort Churchill (units 1 and 2) and Reid Gardner (units 1, 2 and 3); and Southern California Edison's (SCE) Mohave Generating Station (units 1 and 2). NDEP prepared BART determination reports for three NV Energy facilites. Links to NDEP'S determination reports are found below: |
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NDEP'S determination reports build on the BART reports submitted to NDEP by NV Energy. The SCE report for Mohave is accepted as Nevada's BART determination. Links to the BART reports submitted to NDEP by the facilities are provided below:
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Regional Haze SIP
NDEP has preapred a regional haze state implementation plan (SIP) demonstrating reasonable progress in reducing haze in the Jarbidge Wilderness Area and in Class I areas in neighboring states that may be impacted from emissions from Nevada. Nevada's SIP covers the initial planning period of the Regional Haze Rule, 2008-2018. SIP Transmital Letter [PDF] and Attachment [PDF] .
Current analysis shows that visiblity impairment at the Jarbidge Wilderness Area is primarily due to natural emissions of smoke and dust due to wildfire and windblown dust. However, implementation of BART and other Clean Air Act components of the regional haze plan to reduce 2018 anthropogenic emissions by tens of thousands of tons annually from Nevada sources including industrial, transportation and urban emissions, resulting in visibility improvements in the Jarbidge Wilderness Area and other Class I Areas.