Section 61.33 - Stack sampling(a) Unless a waiver of emission testing is obtained under § 61.13 , each owner or operator required to comply with § 61.32(a) shall test emissions from the source according to Method 104 of appendix B to this part or according to Method 29 of appendix A to part 60. Method 103 of appendix B to this part is approved by the Administrator as an alternative method for sources subject to § 61.32(a) . The emission test shall be performed: (1) By May 28, 2014 in the case of an existing source or a new source which has an initial startup date preceding February 27, 2014; or(2) Within 90 days of startup in the case of a new source which did not have an initial startup date preceding February 27, 2014.(b) The Administrator shall be notified at least 30 days prior to an emission test so that he may at his option observe the test.(c) Samples shall be taken over such a period or periods as are necessary to accurately determine the maximum emissions which will occur in any 24-hour period. Where emissions depend upon the relative frequency of operation of different types of processes, operating hours, operating capacities, or other factors, the calculation of maximum 24-hour-period emissions will be based on that combination of factors which is likely to occur during the subject period and which result in the maximum emissions. No changes in the operation shall be made, which would potentially increase emissions above that determined by the most recent source test, until a new emission level has been estimated by calculation and the results reported to the Administrator.(d) All samples shall be analyzed and beryllium emissions shall be determined within 30 days after the source test. All determinations shall be reported to the Administrator by a registered letter dispatched before the close of the next business day following such determination.(e) Records of emission test results and other data needed to determine total emissions shall be retained at the source and made available, for inspection by the Administrator, for a minimum of 2 years.38 FR 8826, Apr. 6, 1973, as amended at 50 FR 46294, Nov. 7, 1985; 79 FR 11275, Feb. 27, 2014