The U.S. EPA, under the authority of the Clean Air Act (CAA), regulates emissions of toxic air pollutants and criteria air pollutants. These pollutants are generated by mobile sources, mainly automobiles, and by stationary sources such as utility plants, manufacturing facilities, refineries, and other commercial and industrial operations. Exposure to air toxics can increase a person’s risk of cancer and other serious health conditions, and criteria air pollutants can also affect health and the environment.
EPA establishes and implements science-based emission standards and guidelines that reduce releases of 187 air toxics, as well as criteria air pollutants such as particulate matter, sulfur dioxides, and ozone precursors including nitrogen oxides and volatile organic compounds. As EPA sets and periodically reviews the standards outlined in the Clean Air Act, it relies heavily on technology to ensure that these requirements are appropriate and that they are being met.
Supporting All Steps of the Rulemaking Process—From Promulgation to Implementation
For more than three decades, RTI has worked with the Sector Policies and Programs Division within EPA’s Office of Air Quality Planning and Standards to research and support development and implementation of emission standards and guidelines for air toxics and criteria pollutants emitted from stationary sources. We aid in all steps of the rulemaking process, from initial data gathering and analysis through the promulgation of final rules. We also assist in implementation of newly promulgated rules.
In this role, our experts are often called on to devise new and unique strategies or tools to assist in the regulatory development process.
Comprehensive Web-Based Survey Gathers Critical Data on Electric Utilities
Air pollution regulations that significantly reduce emissions without hindering economic growth depend on research grounded in industry-specific emissions and control strategy information. In the initial phases of rulemaking, using existing inventories and industry-specific questionnaires, we assist EPA in collecting and analyzing nationwide information about the subject industry, including
- Information on the production processes
- Data on emissions and emission sources
- Currently applied and potentially available control technologies
- Data on the cost of controls.
In a unique approach to nationwide data gathering, we prepared and implemented a web-based comprehensive, industrywide survey of the more than 500 coal- and oil-fired electric generating stations in the United States. We developed the web-based tool for respondents to submit survey responses and emissions data and operated a telephone hotline. The input interface we provided to respondents included built-in QA/QC checks, which substantially reduced the need to contact respondents for clarification of responses while maintaining data quality and timeliness.
We also developed a database interface to gather industry data from respondents using EPA’s Electronic Reporting Tool. We collected fuel analysis data, unit process parameters, and emissions data spreadsheets. We processed the survey responses into a relational database that included both facility-level and unit-specific equipment information, activity and emissions data for toxic and criteria air pollutants.
Standardizing the Process for Calculating Emission Limits
Once emissions inventory data have been collected for an industry, we help EPA determine appropriate technology-based emission limits. Several aspects of emissions data are important in the development of limits, including the size of the data set, the presence of outliers, the data distribution, and the amount of variability in the data.
Where the emission limits must reflect the CAA-specified maximum achievable control technology, our statisticians and environmental engineers have developed spreadsheet templates that help EPA standardize the process of calculating those limits. These templates support testing of the data distribution and calculation of an upper prediction limit. The statistical tools contained in these templates help EPA apply a standardized system of analyzing differing data sets as part of fulfilling its obligations under the CAA.
Advanced Protocols for Petroleum Refinery Emissions Inventories
For some rulemakings, sufficient emissions data may not be readily available to conduct the necessary analyses. EPA must then decide how it will obtain additional emissions data.
As part of collecting emissions data for the Petroleum Refinery Risk and Technology Review, our experts helped develop an Emission Estimation Protocol for Petroleum Refineries. This document provides guidance to refineries, as well as state and local agencies, for developing more comprehensive and accurate emissions inventories, particularly for specific air toxics that do not have emission factors in EPA’s AP-42 (Compilation of Air Pollutant Emission Factors).
RTI reviewed and compiled literature and source test data to develop tiered emission estimation methodologies and default emission factors for more than a dozen key sources associated with refineries. The draft protocol document was revised based on public comments, and a final version was published to support information collection during the Petroleum Refinery Risk and Technology Review.
Following an additional round of public comment, these documents were finalized and are available for states and refineries to use in calculating their emissions.
Rapid Analysis and Processing of Public Comments
On all EPA rulemaking projects, the publication of a proposed rule in the Federal Register is followed by a public comment period. We help EPA organize and summarize public comments so that it can respond to all comments. Under two recent projects—the Clean Power Plan for Existing Electric Utility Generating Units and the Greenhouse Gas Emissions Standards for New, Modified, and Reconstructed Electric Utility Generating Units—EPA received thousands of substantive public comments. To help process these comments, we used our internally developed Comment Handling and Response Manager (RTI-CHARM) software tool to efficiently categorize and aggregate groups of closely related comments into summaries for EPA to review and prepare responses.
Science-based Standards Support Improved Air Quality
Over the past three decades, emissions of criteria air pollutants and air toxics have decreased by more than 60 percent, while the U.S. population and gross domestic product have both increased. The air quality benefits associated with reduced emissions include improved health, longevity, and quality of life.
We support EPA efforts to develop regulations for dozens of industrial sectors. As the examples here illustrate, we provide innovative tools and unique strategies for collecting and analyzing industry-specific data to ensure emissions standards are based on sound science and thorough consideration of public input.