New Source Review: Modeling and Offsets

1. New Source Review:Modeling and Offsets November 2, 2005 Judy B. Yorke Yorke Engineering, LLC 949-248-8490 x25 JYorke@YorkeEngr.com

2. NSR Modeling Requirement • A demonstration that the new/modified source will not “cause a violation, or make significantly worse an existing violation…” of the NAAQS. • Exemptions are identified in Rule 1304, for example: • Replacements; • Emergency Equipment; and • Air Pollution Control

3. NSR Modeling Demonstration • SCAQMD Rule 1303 Appendix A • Screening Analysis • If hourly emissions are less than the values in Table A-1, the modeling requirement is satisfied • If source does not pass screening analysis, detailed modeling is required

4. Table A-1: Allowable Emissions

5. Detailed Air Quality Modeling • Create dispersion model using SCREEN3 or ISCST3 • Calculate highest pollutant concentration for receptors outside facility boundary • 1-hour average • Annual average • Determine ambient pollutant concentration by taking highest value from most recent 3 years data • Add new concentration to ambient concentration • Modeling satisfied if sum does not exceed values in Table A-2.

6. Air Contaminant AveragingTime Most StringentAir QualityStandard NitrogenDioxide 1-hourAnnual 25 pphm*5.3 pphm 500 ug/m3100 ug/m3 CarbonMonoxide 1-hour8-hour 20 ppm9.0 ppm 23 mg/m310 mg/m3 SuspendedParticulateMatter -<10um(PM10) 24-hourAnnual Geometric Mean 50 ug/m330 ug/m3` Sulfate 24-hour 25 ug/m3 TABLE A-2: Most Stringent AAQS * pphm = parts per hundred million

7. NSR-Offsets • Goal of Offsets • Use emission reductions from existing sources to offset emission increases • Reductions more than compensate for increases and result in a net air quality benefit

8. Offset Ratio • Generally, offsets are required at a 1.2-to-1 ratio • Some variations, e.g.,: • Priority Reserve • Offset Budget • RECLAIM NOx/SOx

9. Offset Exemptions • Exemptions are identified in Rule 1304, for example: • Qualifying Replacements; • Emergency Equipment; • Air Pollution Controls; • Relocations; • Facilities with a PTE below thresholds

10. NSR-Offset Exemption Thresholds Offsets are required if facility exceeds:

11. Cost of Offsets • The cost of offsets vary with the demand… • Examples of market prices, current bids/offers*: • ·Non-RECLAIM Emission Reduction Credits - • oPM10 ~ $65,000/lb • oROG ~ $1,500/lb • oCO ~ $7,800/lb • ·RECLAIM Trading Credits - • oNOx ~ $.75-2.5/lb • oSOx ~ $1.35-$3.5/lb * From Christine Grandstaff of Cantor Fitzgerald (949-240-4602)

12. Generating ERCs • Rule 1309 defines requirements to obtain ERCs • Rule 1306 the emission decrease which may be considered • Requirements are very stringent

13. To Obtain ERCs • 2 years of records demonstrating actual emissions must be provided • Actual emissions are discounted to current BACT emission rate • Discounted emissions are further cut by usage factor if operated less than 180 days/year.

14. Summary • Review carefully BACT determination • Review offset and modeling applicability and requirements • Check permit conditions carefully • Get help when you need help!