40 CFR §63.8440

1. (a)For each affected kiln that is subject to the emission limits specified in Table 1 to this subpart, you must conduct a performance test before renewing your 40 CFR part 70 operating permit or at least every 5 years following the initial performance test.
2. (b)You must conduct a performance test when you want to change the parameter value for any operating limit specified in your OM&M plan.