On July 30, 2003, EPA issued the revised "Part 75 CEMS Field Audit Manual"which is designed to provide guidance to State and local regulatory agencies for conducting audits of CEM programs. The Introduction states that "EPA believes that a strong audit program is an essential component of an effective Part 75 compliance oversight program. Given the increased role of State and local agencies in Part 75 implementation, EPA has prepared this manual to assist agencies in implementing Part 75 and to ensure the ongoing integrity of the new NOx trading program."
The Manual includes an overview of the various CEM technologies (e.g., dilution-extractive, straight extractive, in-situ), instructions for evaluating electronic data reports (EDRs) using EPAs auditing software, guidelines for conducting on-site inspections, and procedures for observing CEMS performance tests such as daily calibrations and relative accuracy test audits. Appendix A of the "Part 75 CEMS Field Audit Manual" includes a series of example audit forms and check sheets. RMB notes that Appendix A also includes procedures for conducting a Level 3 type audit where a linearity check is conducted using calibration gases provided by the auditor.
Given the relatively high profile of the NOx Budget Program, especially in relation to ozone non-attainment issues, as well as the significant cost of NOx allowances, the issuance of this manual likely signals an increase in auditing activity by various regulatory agencies. Experience indicates that newly affected NOx Budget sources have found Part 75 compliance to be a significant challenge. Because the 2004 ozone season marks the beginning date for compliance with the NOx Budget Trading Program, sources may find it beneficial to conduct an objective, external audit to ensure that the CEM program is operating on a sound foundation.
In addition to program compliance, another important objective of an audit can be the evaluation of potential CEMS "biases" that may be attributing to the over-reporting of SO2 and/or NOx emissions. Due to the high cost of NOx allowances (ranging from $1,500 to $6000 per ton), over-reporting emissions can have significant cost impact. For information concerning RMBs auditing services please contact one of RMBs staff. A copy of EPAs "Part 75 CEMS Field Audit Manual" is available in our FTP Library.
RMB Consulting &