Direct PM Emissions 2.5 Data, Testing, and Monitoring Issues

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1 Direct PM Emissions 2.5 Data, Testing, and Monitoring Issues Ron Myers Measurement Policy Group SPPD, OAQPS

2 The Issues Collecting data needed for effective inventories and SIP development Selecting and prescribing appropriate test methods Improving monitoring in rules Implementing a transition period

3 Components of Direct PM 2.5 Filterable PM 2.5 Solid or liquid material at stack temperature and higher (measured at ~250 o to 320 o F) Stable in atmosphere and collected on ambient sampler Condensable PM 2.5 Vapor or gas at stack temperature Condenses to liquid or solid at stack exit Stable in atmosphere and collected on ambient sampler

4 Reasons to Consider Condensable PM Emissions 2.5 Condensable fraction of direct PM 2.5 can be significant 10 to 50 percent of PM 2.5 emissions depending on control measures, temperature, other source-specific specific conditions Combustion, metallurgical & wood product sources emit large quantities of vapors that condense to form PM 2.5 Acids (e.g., sulfuric acid from coal combustion) Neutralized acids (e.g., [NH 4 ] 2 [SO 4 ], NH 4 Cl ) Organic materials (e.g., alkanes, PAHs, PCBs, PCDDs, acids) Metals (e.g., As, Se, Sb, Pb compounds) A small fraction of point sources are responsible for the majority of condensable PM emissions

5 Inventories and PM Emissions 2.5 Filterable PM Historically only PM included in databases Some States include filterable PM 10 or PM 2.5 Condensable PM Current knowledge is spotty Some SIP databases fail to include PM cond (even when required) When PM cond included - calculated from emissions factors (e.g., AP-42) that are often based on incorrect test methods Inventories reflect database errors Federal inventory includes some adjustments Underestimate some sources contributions, overestimate others

6 Effect on SIP Regulations Most current regulations do not address PM cond Focus on filterable PM Force control technology towards filterable PM Some regulations do include PM cond, but with incorrect test methods Final rule creates a transition period Regulations addressing PM cond encouraged but not required Develop more precise and accurate PM cond emissions for inventories and rules

7 EPA Method 202 (Condensable PM Test Method) Sample collected in cold water Organic PM extracted with solvent Water & solvent evaporated Residue weighed Procedures Preferred Optional N 2 purge Evaporation 80 F Neutralize quantitatively by titration No purge 250 F Over neutralize, measure sulfate, assume SO 3 Impact 10-20X artifact Lose nitrates, chlorides Sulfate biased low, SO 3 biased high

8 Test Method Selection is Important for Measuring PM PMcond Variations of Method 202 commonly applied Method 202 can be (and often is) conducted incorrectly Without N 2 purge, dreaded artifacts can form (e.g., SO 2 gets trapped in water, reacts with other stuff to form psuedo-pm) Artifacts can be > PM cond by orders of magnitude Amount of artifact is source-specific specific and test- specific variable and unpredictable

9 EPA Activities to Resolve PM cond Test Methods Issues Recommending use of Method 202 with purge and use of condensable PM 2.5 (see Assessing improvements to Method 202 Apply technologies tested in Canada and US Reduce artifacts from ~10 mg to >2 mg Revise M202 in Appendix M More precise (no options) More accurate (reduce artifacts) Post on EPA/EMC web site in July 2007 Propose in 2007/2008 Promulgate 2008/2009

10 EPA PM Transition 2.5 Period Activities Recommending use of Method 201A (existing filterable PM 10 test method) with supplemental hardware for filterable PM 2.5 Revise Method 201A in Appendix M Add filterable PM 2.5 measurement Available now on EPA/EMC web site as CTM-040 Propose 2007/2008 Promulgate 2008/2009 Encourage stakeholder testing for Total PM 2.5

11 Other EPA Transition Period Activities Advance Dilution Sampling Method Promote ASTM Standard development process Assess speciation capacity Improve consistency mobile source methods Document benefits of improved monitoring Develop PM 2.5 CEMS Develop guidance on understanding and applying data uncertainty

12 April 2008 SIP expectations States are encouraged to evaluate and control sources of condensable PM 2.5 that may be important in attainment strategies However, emissions limits (e.g., RACT, RACM) in 2008 are not required to include condensable PM 2.5 If want credit for condensable PM 2.5 reductions, must ensure those reductions with enforceable emission limits

13 Your Direct PM SIP 2.5 Activities By transition period Collect information on PM 2.5 filterable and condensable Include PM cond at your option In new rules with appropriate test methods As supplemental testing with filterable PM Incremental cost $700 Populate emissions factors database Use Electronic Reporting Tool to document emissions tests ( )

14 Your Direct PM SIP Activities 2.5 Post 2011 PM 2.5 Use information obtained during transition period Improve direct PM 2.5 emissions inventory Revise control strategies Revise or establish new PM 2.5 limits Not necessary to REVISIT old limits Must incorporate condensable PM in NEW limits e.g. SIPs to make mid-course corrections SIPs for 2006 PM 2.5 standards Improve monitoring methods Improve management of short term emissions Start up/shut down/malfunction Continuous performance assessment

15 Important Monitoring Elements Indicator of performance Emission measurements Operating parameters Work practice Raw material or fuel content Monitoring technique Continuous emissions monitor High Sensitivity PM monitor Continuous opacity monitor Continuous parametric monitoring Monitoring frequency Averaging time

16 Summary - Direct PM Emissions 2.5 Issues Both filterable and condensable PM 2,5 are important components direct PM 2.5 Databases must address both for all sources to ensure effective control program Target significant sources Establish technologically correct regulations Test methods and monitoring must correspond with emissions limitations You get what you measure