EMTIC BULLETIN SUBJECT: Clarification of "Not Observed" Conditions for Topside Leak Inspections by Method 303 The document entitled "Questions and Answers" and dated December 10, 1993, was distributed by EMB and was intended as guidance on the application of Method 303, Appendix A to Part 63. Questions number 12 has created some confusion leading to misinstruction of Method 303. Question number 12 stated that the only time offtakes and lids are counted as "not observed" is when the observer cannot see them due to some obstruction to view, such as fugitive emissions or the larry car. An example Percent Leaking Lids (PLL) calculation was given based on this premise. The answer to question 12 is incorrect in that Method 303 specifically allows other "not observed" conditions. For the topside port inspection, Section 5.3.2.2 classifies lids involved in charging operations as "not observed". These are accounted for as Pno in Equation 303-9. For the offtake system inspection, Section 5.4.5 classifies standpipe caps open for decarbonization as "not observed". These are accounted for as Tno in Equation 303-11.