Discussion of the Best Available Retrofit Technology (BART) Guidelines and BART Modeling

Transcription

1 Discussion of the Best Available Retrofit Technology (BART) Guidelines and BART Modeling Regional/State/Local Modelers Workshop May 16, 2007 Todd Hawes, EPA OAQPS 1

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5 Rate To Achieve Natural Conditions in 60 Years (under 308) Example Baseline 30 (Visibility impairment in Deciviews) x x Required Analysis for 1st Implementation Period Natural 12 Ultimate CAA goal Long Term Strategy for Reasonable Progress BART is an independent part of Reasonable Progress Year 5

6 BART Terminology Source is BART-Eligible Source is exempt from BART 1 st round of CALPUFF modeling Source is Subject to BART BART = an emission limit resulting from a control technology analysis for sources Subject to BART 2nd round of CALPUFF modeling 6

7 Summary of the BART Process 1. ID BART eligible sources 2. ID which of those are subject to BART Reasonably anticipated to cause or contribute to any visibility impairment in Class I areas (e.g. CALPUFF modeling) 3. Determine the BART controls, if any 7

8 1. Identifying BART-Eligible Sources BART-Eligible if: Any emission units in one of the 26 (28) PSD categories (e.g. EGUs, industrial boilers, kraft pulp mills, refineries, portland cement plants,etc) Any units in existence on 8/7/77 and began operation on or after 8/7/62 Is the PTE of any visibility impairing pollutant, summed across all units, > 250 TPY? 8

9 The 26 BART Categories 1. Fossil-fuel fired steam electric plants > 250 million BTU/hr heat input 2. Coal cleaning plants (thermal dryers) 3. Kraft pulp mills 4. Portland cement plants 5. Primary zinc smelters 6. Iron and steel mill plants 7. Primary aluminum ore reduction plants 8. Primary copper smelters 9. Municipal incinerators capable of charging > 250 tons of refuse per day 10. Hydrofluoric, sulfuric, and nitric acid plants 11. Petroleum refineries 12. Lime plants 13. Phosphate rock processing plants 14. Coke oven batteries 15. Sulfur recovery plants 16. Carbon black plants (furnace process) 17. Primary lead smelters 18. Fuel conversion plants 19. Sintering plants 20. Secondary metal production facilities 21. Chemical process plants 22. Fossil-fuel boilers of more than 250 million BTUs per hour heat input 23. Petroleum storage/ transfer facilities exceeding 300,000 barrels 24. Taconite ore processing facilities 25. Glass fiber processing plants 26. Charcoal production facilities 9

10 2. Subject to BART Which BART Eligible Sources Are Subject to a BART control evaluation? Does the B-E Source Cause or Contribute to visibility impairment in a Class I area (i.e. is it Subject to BART)? Three Options for the Subject to BART test: State assumes that all BART-eligible sources will cause or contribute to visibility impairment at any Class I area all are Subject to BART State demonstrates all BART-eligible sources will not cause or contribute to visibility impairment at any Class I area grid modeling Exempt individual sources CALPUFF, model plants, permit limits 10

11 2. Subject to BART (cont.) Exemptions from BART: Modeled impact < contribution threshold ( dv) Model Plant SO2 + NOx < 500 TPY (PTE); facility > 50 km from Class I area SO2 + NOx < 1000 TPY (PTE); facility > 100 km from Class I area PM can be included with appropriate justification Permit limits < 250 TPY of visibility impairing pollutant Model plant Modeled impact less than threshold Limits must be made enforceable Install latest, greatest controls available No exemptions for >750 MW EGUs 11

12 2. Subject to BART (cont.) BART Exemptions by individual source modeling - Which Sources Cause or Contribute to Impairment? Set a contribution threshold (0.5 dv or lower) Run CALPUFF for all BART-eligible units at the Source; use max. 24-hr actual emission rates Compare results to the threshold Max. 24 hr impacts compared to natural background (20% best or annual); 98 th percentile value is used If the source impact threshold (e.g. 0.5 dv) then it is Subject to BART Otherwise, (e.g < 0.5 dv) source is exempt from BART Note a modeling protocol should be submitted to and approved by the State 12

13 3. Determine the Controls, if any (Subject to BART) If the source is not exempt - If the Source Causes or Contributes to Visibility Impairment then it is subject to BART Conduct an engineering review to determine a control technology to set an emission limit (BART) For each source, State must consider 5 factors: Controls already in place at the source Cost of compliance Remaining useful life Energy and nonair environmental impacts Visibility Test the fifth factor degree of visibility improvement as a result of control <CALPUFF> 13

14 3. Determine the Controls, if any (cont.) Fifth Factor (Visibility modeling) Run CALPUFF at pre-control and post-control emission rates for SO2, NOx, and PM2.5 (i.e. degree of improvement) The difference is the degree of visibility improvement expected by installing the control technology (use 24-hour maximum actual emission rates and compare the modeled impacts to natural conditions) No prescriptive limits for this step such as a comparison threshold Results can be weighted in a variety of ways Consider magnitude, frequency, and duration of impacts. Examples Worst case days, percentage change Season, threshold combinations 14

15 3. Determine the Controls, if any (cont.) Establishing the BART Limit State weighs the five factors and determines an emission limit (i.e. BART) based on control Example scrubber at 95% control Repeat process on each affected unit Pollutant by pollutant basis For each control technology option under review BART may equal No Control based on the five factor analysis Example there are existing controls on the unit and it would be cost prohibitive to control further Example no significant visibility improvement is shown 15

16 BART Process BART-eligible - One of 26 PSD categories -Date criteria: TPY PTE If not BART-eligible No BART If BART eligible Exemption Test -modeling single sources e.g. CALPUFF -model plants -Permit limits - no exemption for 750 MW EGU s If not exempt Subject to BART Analysis 1. Cost 2. Energy and non-air impacts of compliance 3. Existing control equipment 4. remaining useful life of source 5. Degree of visibility improvement - CALPUFF If exempt No BART Establish Controls -SO2 -NOx -PM No Bart, no controls 16

17 Guideline is binding for 750 MW power plants For EGU plants >750 megawatt (MW), CAA requires BART determinations to be made pursuant to EPA guidelines. Guidelines procedures mandatory for these sources Guidelines contain presumptive control levels for units 200 MW and above For EGU units >200 MW (not at 750 MW plants): encourage use of presumptive controls Because of evidence that such controls are cost effective All other source categories: guidelines are guidance only 17

18 BART Presumptive Limits for EGUs For coal-fired EGUs greater than 200 MW located at power plants greater than 750 MW SO2: 95% removal or an emission rate of 0.15 lb/mmbtu. NOx: lbs/mmbtu depending on boiler and coal type, In NOx SIP call area extend controls to year round Outside SIP call area current combustion controls State can set BART higher or lower if justified in the five factor analysis (unlikely in all but a few cases) 18

19 Effect of the CAIR on BART Affects only EGUs that participate in CAIR (in the East) Covers an EGU s BART obligation for NOx and SO2. CAIR = BART EGUs must still undergo a BART analysis for PM (may model PM only) 19

20 Alternatives to BART Alternative rule published Oct. 13, 2006 Must show Better than BART Allows trading Facility caps for BART and non-bart sources (bubbling) WRAP program 20

21 Question and Answer Documents Q/A Document, Additional Regional Haze Questions, ( revision) BART Exemption Q/A ( revision) Q & A s for Source by Source BART rule of July 6, 2005 ( Staff Draft) 21

22 Q & A s IMPROVE Equation Use of old or new is fine New equation - justification needed for adjusting CALPUFF results Exemption Threshold Justification needed CALPUFF Version VISTAS version ok for BART Consultation requirements Part of SIP; state to state and with FLMs 22

23 Finally.. Regional Haze SIPs are due December 17,

24 Questions Which States are doing their own modeling vs. sources vs. RPOs? How many States are using a threshold of 0.5 dv? How many sources using new IMPROVE vs. old for exemptions? How many States have started their BART determinations (BART exemptions)? What percentage of B-E sources are exempt? What percentage will be subject to controls? 24