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42 U.S.C. 7401 et seq.
57 FR 61992, Dec. 29, 1992, unless otherwise noted.
67 FR 45598, July 9, 2002, unless otherwise noted.
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At 91 FR 37274, June 22, 2026, as required by the Congressional Review Act and Public Law 119-14, the Environmental Protection Agency removed all amendments to subpart XXXX of part 63 published at 89 FR 94886, Nov. 29, 2024.
(a) You must monitor and collect data as specified in table 9 to this subpart.
(b) Except for periods of monitoring malfunctions, associated repairs, and required quality assurance or control activities (including, as applicable, calibration checks and required zero and span adjustments), you must monitor continuously (or collect data at all required intervals) while the affected source is operating. This includes periods of startup, shutdown, and malfunction when the affected source is operating.
(c) In data average calculations and calculations used to report emission or operating levels, you may not use data recorded during periods of monitoring malfunctions or associated repairs, or recorded during required quality assurance or control activities. Such data may not be used in fulfilling any applicable minimum data availability requirement. You must use all the data collected during all other periods in assessing the operation of the control device and associated control system.