Data Acquisition and Handling System (DAHS) Emissions Compliance and Regulatory Audit Recipe for Large Combustion Units Equipped with Continuous Emission Monitoring Systems (CEMS) and Continuous Opacity Monitoring Systems (COMS)

摘要

A Data Acquisition and Handling System (DAHS) stores monitored and calculated Continuous Emission Monitoring Systems (CEMS) and Continuous Opacity Monitoring Systems (COMS) emissions data from stationary combustion sources (e.g. combustion turbines, boilers and reciprocating internal combustion engines) and is used for alarming, recordkeeping and reporting purposes. There are numerous vendors that provide DAHS software packages capable of satisfying facility air program compliance requirements. As federal, state and local air quality regulations and air permits continue to develop, the ongoing challenge to implement new DAHS configurations as well as to appropriately quality assure and update existing configurations in a timely manner is becoming more difficult. DAHS configurations can seem labyrinthine and may include hundreds of database channels especially for facilities with Title V air operating permits and facilities subject to federal air regulations such as 40 CFR Parts 60, 63, 75 and/or 98. Due to the complexity of DAHS configurations and ever changing air emissions compliance programs, best practice is to perform periodic DAHS audits to identify potential configuration problems that could lead to either under- or over-reporting of analyzer downtime, excess emissions events and/or mass emissions within required quarterly, semiannual or annual air emissions compliance reports. Identifying and addressing DAHS configuration problems proactively may help avoid or mitigate potential enforcement actions. This paper presents a general process that can be used to perform DAHS reviews/audits of any DAHS software package, highlighting the importance of accurate and concise DAHS data flow diagrams and DAHS configuration summaries that are typically not provided by DAHS vendors. Lessons learned will also be presented through extensive experience gained by performing DAHS audits, preparing DAHS specifications as well as supporting facilities with ongoing DAHS/CEMS/COMS air management support.