Clean Air Markets Program Data UC Energy Institute University of California at Berkeley November 10, 2003 Martin Husk

Overview How emissions and heat input are monitored Monitoring system certification requirements and testing On-going quality assurance testing Contents of the Electronic Data Report Good afternoon. My name is Martin Husk, and along with my colleague Michele Wockenfuss, we will talk to you today about how and why the Clean Air Markets Division is undertaking a project to re-engineer its data systems. We will start by defining what re-engineering means, which will help put the discussion in context. Next, we will discuss the type of systems we had, and in some cases, still have at CAMD. Then I’ll let you know why we decided to re-engineer our data systems in the first place and discuss the project we undertook to review these systems and identify what changes need to be made. We will look at the vision for future systems that was developed from the review and how that vision will shape future CAMD data systems.

Overview Quality assurance standards Data availability Uses of the data Questions and answers Finally, we will talk about how CAMD planned and organized its re-engineering project. Then its on to the good stuff. Michele will discuss the one completed and two soon-to-be-completed projects, and will provide a demonstration of each. Then Michele will end the presentation by sharing some of our lessons learned and keys to help you have a successful re-engineering project.

How Emissions are Monitored Identify which pollutants require monitoring Identify which other parameters may require monitoring

How Emissions are Monitored Select the most appropriate monitoring type: Continuous Emissions Monitoring System (CEMS) Appendix D and E Low Mass Emissions Methodology (LME) Predictive Emissions Monitoring System (PEMS)

Continuous Emissions Monitoring System (CEMS) Part 72 defines it as equipment used to “sample, analyze, measure and provide…a permanent record of emissions.” CEMS consists of monitors installed in stacks and/or ducts, and a Data Acquisition and Handling System (DAHS). Measure emissions and heat input every 15 minutes.

Types of CEMS Conventional Extractive (Wet or Dry Basis Measurement) Hot Wet - Wet Basis Cool Dry with condenser near the CEMS Shelter - Dry Basis Cool Dry with condenser at the probe - Dry Basis Dilution Extractive (Wet Basis Measurement) In Stack Dilution Out of Stack Dilution In-situ (Wet Basis measurement in the stack) Point Path

Conventional Extractive CEMS

Conventional Extractive Systems Representative sample of the flue gas is continuously withdrawn from the stack, transported to a CEMS shelter and analyzed Components of an extractive system Probe Sample lines Filters Moisture removal system Pump Analyzer Extractive systems usually make measurements on a dry basis

Dilution Extractive CEMS (wet basis) Flue gas is diluted with clean dry air to lower the dew-point of the sample Eliminates the need for Heated sample lines Moisture removal system In Stack Dilution Critical Orifice is in the probe Sample Temperature is Stack Temperature Quicker response than out of stack dilution No temperature controls to maintain

In-Situ CEMS Point Path Electro-optical, or Electrochemical sensor Measurement over short distant (~cm) Path Light or sound is transmitted across the stack The interaction with the stack gas is related back to a gas characteristic

In-Situ CEMS Typical Applications: Opacity Measurement Stack Flow Path - Light Stack Flow Point - Differential Pressure (s-type Pitot) Path - Ultra-sonic (sound waves)

Alternatives to CEMS CEMS are required except for cases that qualify to use the following options: Appendix D - SO2 and Heat Input Monitoring Options Appendix E - NOx Emission Rate Estimation Procedures Low Mass Emissions - Estimation of SO2, NOx, and CO2 emissions and total heat input using: Default or site-specific emission factors, and Max. unit heat input or actual heat input from fuel usage data Predictive Emissions Monitoring - Estimation of NOx emissions using CEMS validation of estimation procedures

Appendix D Applicability Principle: Requires Monitoring of: May be used in lieu of SO2 and/or flow and diluent monitors to determine hourly SO2 mass emissions and/or heat input rate Gas and Oil fired units only Principle: Fuel Flow Rate * Sulfur content = SO2 emissions Fuel Flow Rate * Gross Calorific Value (GCV) = Heat Input Requires Monitoring of: Hourly Fuel Usage (fuel flowmeters) GCV and Sulfur content of the fuel (default SO2 emission rates allowed for gaseous fuels)

Appendix E May be used in lieu of a NOx-diluent CEMS for determining hourly NOx emission rate (lb/mmBtu) Applicable only to Gas and Oil-Fired Peaking Units If you qualify for Appendix E, you must use Appendix D to determine heat input rate

Appendix E Units that hold peaking status must continue to meet the peaking unit definition from year-to-year If a unit fails to meet the criteria it must install & certify a NOx CEM by December 31 of the year after the year for which the criteria are not met A unit may then only re-qualify by providing three consecutive years (or ozone seasons) of qualifying capacity factor data

How Appendix E Works The average NOx emission rate (lb/mmBtu) is determined from fuel specific NOx emission rate testing at four, equally spaced load levels The hourly heat input rate is determined using the fuel flow monitoring procedures of Appendix D The NOx Emission Rate is plotted vs. Heat Input Rate to create a baseline correlation curve The baseline correlation curve is programmed into the DAHS and is used to determine the hourly NOx emission rate corresponding to the heat input rate for each hour of operation

Operating Level 4 Operating Level 1 Operating Level 3 Segment 4 Segment 3 Operating Level 4 Operating Level 1 Segment 2 Operating Level 3 Segment 1 Operating Level 2

Low Mass Emissions Methodology (LME) Procedure that may be used in lieu of CEMS and the Appendix D and E methodologies to report SO2, NOx, and CO2, emissions and Heat Input Gas-fired and oil-fired units only DAHS is not required -- EDR reports can be generated using EPA’s MDC (or any other) software Emissions limitations Annual NOx limit: NOx < 100 tons/year Ozone season NOx limit: NOx < 50 tons/control period SO2 limit < 25 tons/year (ARP units only)

Predictive Emissions Monitoring Systems (PEMS) May be used in lieu of a NOx monitoring system Consists of PEMS software and a DAHS Software “predicts” what the NOx emissions will be for each hour, based on comparison testing with CEMS

Monitoring System Certification Requirements and Testing CEMS Testing: Gas Monitors 7-day calibration error check Linearity check Cycle time test RATA/Bias test Flow Monitors 3 load RATA and Bias tests

7-day Calibration Error Test Measure calibration error of each pollutant monitor while unit is combusting fuel once each day for 7 consecutive operating days

Linearity Check 3 point check of linearity of each pollutant monitor while unit is combusting fuel at conditions of typical stack temperature and pressure Low (20 - 30% of span) Mid (50 - 60% of span) High (80 - 100% of span)

Cycle Time Test Determine time it takes for 95% of step change to occur going from: a stable zero gas value to stack emission value, and a stable high calibration gas value to stack emission value The cycle time is the slower of the two responses

Relative Accuracy Test Audit (RATA) Compares CEMS measurements to appropriate EPA reference method Conduct a minimum of 9 valid runs May discard up to 3 runs but must report all runs performed Recommended that RATA not be commenced until completion of other required certification tests

Bias Test Statistical test that evaluates RATA data to determine if a low bias exists in the CEMS measurements, and to determine need for calculating a Bias Adjustment Factor (BAF)

Monitoring System Certification Requirements and Testing Appendix D Fuel Flowmeter Accuracy Test is generally required annually Fuel Flow-to-Load Ratio or Gross Heat Rate-to-Load evaluation may be used as a quarterly check of the fuel flowmeter accuracy Can be used to extend the interval between fuel Flowmeter Accuracy tests to up to 5 years

Monitoring System Certification Requirements and Testing Appendix E: The NOx emission rate testing must be repeated once every 5 years Appendix D fuel flowmeter QA required

On-going Quality Assurance Testing for CEMS Daily Calibration Error Test Daily Interference Check (flow monitors only) Quarterly Linearity Check Quarterly Flow-to-Load Ratio (flow only) Quarterly Leak Checks (differential pressure flow systems) Relative Accuracy Test Audit (RATA) Bias Test (SO2, NOx, and flow monitors only)

Calibration Error Checks Measure the calibration error of each pollutant monitor while the unit is combusting fuel by injecting a known calibration gas into the system at the point of sample collection Zero Gas (0 - 20% of span) High Gas (80 - 100% of span) or Mid Gas (50-60%) For initial certification, a CEMS must meet a tight calibration standard for 7 consecutive operating days For ongoing QA, daily calibration error checks are required

Interference Check Daily QA check required for stack flow monitors Diagnostic check that confirms that monitor is ready for use

Flow-to-Load Ratio Test Quarterly evaluation of a stack flow monitor’s accuracy A baseline comparison of the hourly ratio of flow rate to unit load (Q/L) and a reference Q/L determined during the last flow RATA test

Leak Check Quarterly QA check for differential pressure type flow monitors Confirms the absence of leaks in the connections and lines

SO2 Monitoring

NOx Monitoring

Contents of the Electronic Data Report (EDR) EDR required each quarter or during Ozone Season Collection of EDR data is fundamental to verifying program EDR Files contain the following items: Facility information As-monitored emissions data (measured in ppm)

Contents of the Electronic Data Report (EDR) EDR Files contain the following items: Operational data (operating time, heat input) Calculated mass emissions and heat input data Monitoring Plan Quality assurance/test data Certification records

Quality Assurance Standards Extensive QA process for EDR data “Instant Feedback” based on ETS data checking Audit process feedback provided after all data are submitted

Quality Assurance Standards ETS data checking in two stages File Summary: checks general format and integrity of file. File Content: checks the data within the file recalculate all hourly data hourly sums vs. aggregates monitoring plan checks Over 150 checks performed on EDR data

Quality Assurance Standards Audit Process is run to evaluate the monitoring plan, and QA and test data Process is run after the end of each reporting period Feedback Emailed to sources Resubmissions of EDR data often required

Data Availability EDR data are submitted during the month after each calendar quarter “As reported” EDR files posted on the CAMD web site 20 days after the end of each reporting period Summary Emissions Reports posted on CAMD web site 20 days after the end of each reporting period

Data Availability Annual and Ozone Season data posted on Data and Maps web site page after program compliance is determined Hourly, monthly and quarterly posted on Data and Maps web site page after program compliance is determined Resubmitted EDR files are updated to the Data and Maps page each quarter

Uses of the Data EPA uses of the data Annual Acid Rain Program and NOx Budget Program Compliance Public access through web site Provide to other government agencies Compare to other agencies’ data

Uses of the Data Your uses of the data What EPA data do you use? How do you access the data? What analyses are performed based on EPA data? Are there other pieces of data you need for your analyses?

Questions and Answers