Presentation on theme: "New Source Review: Modeling and Offsets"— Presentation transcript:
1New Source Review: Modeling and Offsets November 2, 2005Judy B. YorkeYorke Engineering, LLCx25
2NSR 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; andAir Pollution Control
3NSR Modeling Demonstration SCAQMD Rule 1303 Appendix AScreening AnalysisIf hourly emissions are less than the values in Table A-1, the modeling requirement is satisfiedIf source does not pass screening analysis, detailed modeling is required
5Detailed Air Quality Modeling Create dispersion model using SCREEN3 or ISCST3Calculate highest pollutant concentration for receptors outside facility boundary1-hour averageAnnual averageDetermine ambient pollutant concentration by taking highest value from most recent 3 years dataAdd new concentration to ambient concentrationModeling satisfied if sum does not exceed values in Table A-2.
6TABLE A-2: Most Stringent AAQS Air ContaminantAveraging TimeMost Stringent Air Quality StandardNitrogen Dioxide1-hour Annual25 pphm* 5.3 pphm500 ug/m3 100 ug/m3Carbon Monoxide1-hour 8-hour20 ppm 9.0 ppm23 mg/m3 10 mg/m3Suspended Particulate Matter -<10um (PM10)24-hour Annual Geometric Mean50 ug/m3 30 ug/m3`Sulfate24-hour25 ug/m3* pphm = parts per hundred million
7NSR-Offsets Goal of Offsets Use emission reductions from existing sources to offset emission increasesReductions more than compensate for increases and result in a net air quality benefit
8Offset Ratio Generally, offsets are required at a 1.2-to-1 ratio Some variations, e.g.,:Priority ReserveOffset BudgetRECLAIM NOx/SOx
9Offset Exemptions Exemptions are identified in Rule 1304, for example: Qualifying Replacements;Emergency Equipment;Air Pollution Controls;Relocations;Facilities with a PTE below thresholds
10NSR-Offset Exemption Thresholds Offsets are required if facility exceeds:
11Cost of Offsets The cost of offsets vary with the demand… Examples of market prices, current bids/offers*:· Non-RECLAIM Emission Reduction Credits -o PM10 ~ $65,000/lbo ROG ~ $1,500/lbo CO ~ $7,800/lb· RECLAIM Trading Credits -o NOx ~ $ /lbo SOx ~ $1.35-$3.5/lb* From Christine Grandstaff of Cantor Fitzgerald ( )
12Generating ERCs Rule 1309 defines requirements to obtain ERCs Rule 1306 the emission decrease which may be consideredRequirements are very stringent
13To Obtain ERCs2 years of records demonstrating actual emissions must be providedActual emissions are discounted to current BACT emission rateDiscounted emissions are further cut by usage factor if operated less than 180 days/year.
14Summary Review carefully BACT determination Review offset and modeling applicability and requirementsCheck permit conditions carefullyGet help when you need help!