(a) Before August 7, 2019, for each existing source and each new or reconstructed source for which construction or reconstruction commenced after October 18, 2002, but before May 4, 2018, you must be in compliance with the emission limitations in this subpart at all times, except during periods of startup, shutdown, or malfunction. On and after August 7, 2019, for each such source you must be in compliance with the emission limitations in this subpart at all times. For new and reconstructed sources for which construction or reconstruction commenced after May 3, 2018, you must be in compliance with the emissions limitations in this subpart at all times.

(b) Before August 7, 2019, for each existing source, and for each new or reconstructed source for which construction or reconstruction commenced after October 18, 2002, but before May 4, 2018, you must always operate and maintain your affected source, including air pollution control and monitoring equipment, according to the provisions in § 63.6(e)(1)(i). On and after August 7, 2019 for each such source, and after February 8, 2019 for new and reconstructed sources for which construction or reconstruction commenced after May 3, 2018, at all times you must operate and maintain any affected source, including associated air pollution control equipment and monitoring equipment, in a manner consistent with safety and good air pollution control practices for minimizing emissions. The general duty to minimize emissions does not require you to make any further efforts to reduce emissions if levels required by the applicable standard have been achieved. Determination of whether a source is operating in compliance with operation and maintenance requirements will be based on information available to the Administrator which may include, but is not limited to, monitoring results, review of operation and maintenance procedures, review of operation and maintenance records, and inspection of the source.

(c) Before August 7, 2019, for each existing source, and for each new or reconstructed source for which construction commenced after October 18, 2002, but before May 4, 2018, you must develop a written startup, shutdown, and malfunction plan according to the provisions in § 63.6(e)(3). For each such source, a startup, shutdown, and malfunction plan is not required on and after August 7, 2019. No startup, shutdown, and malfunction plan is required for any new or reconstructed source for which construction or reconstruction commenced after May 3, 2018.