; and (ii) sources of air pollutants. (9) Indirect source The term indirect source has the meaning given the term in section 110(a)(5)(C) of the Clean Air Act ( 42 U.S.C. 7410(a)(5)(C) ). (10) Major source The term major source has the meaning given the term in section 501 of the Clean Air Act ( 42 U.S.C. 7661 ). (11) Reference method The term reference method has the meaning given such term in section 50.1 of title 40, Code of Federal Regulations, as in effect on the date of enactment of this Act. (12) Relevant committees of Congress The term relevant committees of Congress means— (A) the Committee on Environment and Public Works of the Senate; and (B) the Committee on Energy and Commerce of the House of Representatives. 4. Compendium of air quality monitoring technologies and uses of air quality insights Not later than 1 year after the date of enactment of this Act, and annually thereafter, the Administrator shall update the Air Sensor Toolbox of the Environmental Protection Agency or an equivalent online, publicly available compendium— (1) to describe all types of common air quality monitor technologies, which may include— (A) Federal Reference Method or Federal Equivalent Method monitors; (B) mobile monitoring platforms; (C) low-cost stationary monitors; (D) satellite sensors and surface monitors; (E) fenceline monitoring instruments; (F) high-resolution cameras; and (G) other technologies, as determined to be appropriate by the Administrator; (2) to describe the uses of the data associated with the types of common air quality monitor technologies described under paragraph (1); (3) to update and describe the advantages of monitoring technologies with respect to different air quality management applications, which may include— (A) the costs and ease of purchase, installation, operation, and maintenance of monitors; (B) air pollutant or air pollutants monitored; (C) spatial resolution; (D) temporal resolution; (E) frequency of data collection by monitors; (F) data quality and data processing needs