40 CFR § 63.9890
What emission limitations must I meet?
June 9, 2020
(a) You must meet each emission limit in Table 1 to this subpart that applies to you.
(b) For each wet scrubber applied to meet any particulate matter, particulate matter less than 10 microns (PM10), chlorine, hydrochloric acid, or dioxins/furans emission limit in Table 1 to this subpart, you must maintain the hourly average pressure drop and scrubber liquid flow rate at or above the minimum level established during the initial or subsequent performance test.