Planning and Modeling Branch
The Planning and Modeling Branch performs a variety of functions:
- Regulation development and revision;
- Tracking and responding to federal rulemaking;
- State plan development;
- Air quality modeling and increment tracking to support planning and permitting efforts;
- Administrative management within the air quality programs.
Regulations and SIP Development
Planning for new or modified air quality regulations is coordinated by the Planning and Modeling Branch. This includes drafting regulatory language, organizing workshops to collect input from the general public and industry representatives on proposed changes, and preparing materials for State Environmental Commission (SEC) hearings where proposed regulatory changes are heard.
Under the authority of Title I of the Clean Air Act (CAA), the U.S. Environmental Protection Agency (EPA) has developed and promulgated health-based air quality standards, National Ambient Air Quality Standards (NAAQS) that limit the maximum levels of certain pollutants in outdoor air. Each state is responsible for developing plans to demonstrate how those standards will be achieved, maintained, and enforced. These plans make up the state implementation plan (SIP). Required modifications to Nevada’s SIP are developed and coordinated with applicable agencies, affected industry and interested public.
The Regional Haze Rule [PDF] was promulgated by the Environmental Protection Agency (EPA) on July 1, 1999. The rule was designed to protect and improve the visibility in the country's national parks, forests and wilderness areas (Class I areas) whose visibility is impacted by manmade pollution. These areas include many of our best known and most treasured natural areas, such as the Grand Canyon, Yosemite, Yellowstone, Mount Rainier, Shenandoah, the Great Smokies, Acadia and the Everglades. There is one designated Class I area in Nevada, the Jarbidge Wilderness Area in the northeast corner of the state.
The Nevada Division of Environmental Protection (NDEP) has prepared a Regional Haze SIP demonstrating reasonable progress in reducing haze in the Jarbidge Wilderness Area and in Class I areas in neighboring states that may be impacted by emissions from Nevada. This SIP covers through 2018, the first benchmark year on the path to natural visibility by 2064. Comprehensive SIP revisions are required every ten years. 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.
PSD stands for “Prevention of Significant Deterioration.” PSD is a federally mandated construction permitting program for large sources (such as large mines, power plants, chemical plants, etc.). One of the significant components of the PSD program is the requirement to evaluate increment consumption. Increment is the maximum allowed increase in concentration of a pollutant, above a baseline concentration in an area. NDEP's two air bureaus Nevada Bureau of Air Quality developed the "Increment Tracking System" to manage increment.
Particulate matter (PM) is one of the six criteria pollutants regulated under the CAA. PM is a complex mixture of extremely small particles and liquid droplets and is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals and soil or dust particles. It can cause adverse health and environmental effects. EPA is concerned about particles 10 micrometers in diameter or smaller because those are the particles that generally pass through the throat and nose, subsequently entering the lungs, causing potentially serious health effects.