While a single public report with this exact alphanumeric string is not indexed, the components suggest the following technical context:

: A document tracking adherence to EPA Tier 3 or NSPS CI (Compression Ignition) standards for stationary equipment.

Knowing the industry (e.g., water district, mining, or healthcare) would help narrow this down. New Source Performance Standards (NSPS) | US EPA

If you are looking for a physical report, it is likely one of the following: