|(a) Compliance with the nitrogen oxides emission specifications in §117.4005 of this title (relating to Emission Specifications) must be determined by the performance testing procedures specified in 40 Code of Federal Regulations (CFR) Part 60, Appendix A, Method 7, or an equivalent method approved by the executive director. Method 7A, 7B, 7C, or 7D may be used in place of Method 7. If Method 7C or 7D is used, the sampling time must be at least one hour. (b) Performance testing must be conducted in accordance with the procedures specified in 40 CFR §60.8. (c) Any continuous emissions monitoring systems (CEMS) or predictive emissions monitoring systems (PEMS) required by §117.4040 of this title (relating to Continuous Demonstration of Compliance) must be installed and operational prior to conducting performance testing under subsections (a) and (b) of this section. Verification of operational status must, at a minimum, include completion of the manufacturer's written requirements or recommendations for installation, operation, and calibration of the device or system. (d) Testing conducted before June 23, 1994, may be used to demonstrate compliance with the standard specified in §117.4005 of this title if the owner or operator of an affected facility demonstrates to the executive director that the prior performance testing at least meets the requirements of subsections (a) - (c) of this section. The executive director reserves the right to request performance testing or CEMS or PEMS performance evaluation at any time.