EPA's (Environmental Protection Agency's) role in the quality assurance of ambient air-pollutant measurements

EPA's roll in the quality assurance of monitoring data is to assist monitoring agencies by providing those quality-assurance services or functions that (1) are common to most monitoring agencies and would be uneconomical to duplicate in each agency's program, (2) are too costly for individual monitoring agencies to carry out, (3) need to be uniform across the nation's monitoring agencies to facilitate universal data interpretation, comparison, evaluation, and common analysis, or (4) are more appropriately derived from a source independent from the monitoring agency. These functions are focused in three principle areas: (1) standardized and validated monitoring methods, (2) air monitoring guidance and technical assistance, and (3) assessment of the quality of monitoring data being obtained. These functions are discussed along with overview descriptions and summaries of results of specific EPA quality assurance programs including reference and equivalent methods, the Quality Assurance Handbook and other guidance documents, availability of various pollutant concentration standards, and assessment and reporting of the precision and accuracy of air monitoring data.