This action proposes corrections and updates to test methods and performance specifications for air emission sources subject to 40 CFR parts 60 and 63. The revisions include corrections to testing provisions that contain inaccuracies, updates to outdated test methods, clarifications, and the addition of alternative testing procedures the agency has deemed acceptable to use. For example, we would propose that Method 1 be revised to clearly specify the number of traverse points that must be used for sampling and velocity measurements once a directional flow-sensing probe procedure has been used to demonstrate that an alternative measurement site is acceptable. In Method 7, the word “should” would be changed to “shall” in the last sentence of section 10.1.3 because the difference between the calculated concentration values and actual concentrations are required to be less than 7 percent for all standards. This action is developed every two years to keep rules up-to-date and to ensure that compliance testing and monitoring are done correctly.