Independent Audit Program

An independent auditor visits each CASTNET site at least once every other year to perform a Field Systems Audit (FSA). Regulatory ozone monitoring sites are audited annually by an independent auditor or a local monitoring agency. Performance evaluation results are loaded into EPA's Air Quality System (AQS) database routinely.

PND165, WY panorama site photo

The Quality Assurance Project Plan (QAPP) and Standard Operating Procedures for the independent audits are available below. The quarterly and annual audit reports are also provided below.

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