40 CFR § 60.2725
May I conduct a repeat performance test to establish new operating limits?
June 9, 2020
(a) Yes. You may conduct a repeat performance test at any time to establish new values for the operating limits. The Administrator may request a repeat performance test at any time.
(b) You must repeat the performance test if your feed stream is different than the feed streams used during any performance test used to demonstrate compliance.