Air Toxics Rule Changes (pursuant to Session Law 2012-91)

1. Air Toxics Rule Changes(pursuant to Session Law 2012-91) North Carolina Division of Air QualityJuly 2013 Environmental Management Commission

2. AAL – acceptable ambient level • GACT – generally available control technology • MACT – maximum achievable control technology • SIC – standard industrial classification • TAP – toxic air pollutant • TPER – toxic permitting emission rate Acronyms

3. Section 1 • Exempts sources subject to certain federal regulations • Codifies “Director’s Call” provision Section 2 • Requires rule amendments Section 3 • Requires review of rules and their implementation Section 4 • Requires reports on implementation of this act Air Toxics – Summary of SL 2012-91

4. Exempts from the State air toxics rules sources of toxic air pollutants subject to certain federal regulations, including: • National Emission Standards for Hazardous Air Pollutants (NESHAPs), 40 CFR Part 61 • Maximum Achievable Control Technology (MACT) standards, 40 CFR Part 63 • Generally Available Control Technology (GACT) standards, 40 CFR Part 63 • Subject to case-by-case MACT, 112(j) of the Clean Air Act Air Toxics – Section 1

5. When DAQ receives a permit application for a new or modified source or facility that would result in a net increase in toxic air pollutants: • Requires DAQ to determine if the toxic air emissions would pose an unacceptable risk to human health… and if it does, the Division Director would make a written finding and require a permit application that eliminates the unacceptable risk… (for all practical purposes this is the existing Director’s Call provision) Air Toxics – Section 1

6. Requires DAQ to review the State air toxics rules and their implementation to determine whether changes could: • Reduce unnecessary regulatory burden • Increase the efficient use of DAQ resources while maintaining protection of public health • Conduct the review in consultation with interested parties • Report the results of the review and include recommendations to the ERC by 12/1/12 Air Toxics – Section 3

7. Develop an additional set of emissions thresholds for pollutants coming from unobstructed vertical stacks • Exempt natural gas and propane fired boilers • Exempt emergency engines • Eliminate SIC call • Clarify use of actual rate of emissions • Remove the term “unadulterated wood” from rules Recommendations for Rule Changes

8. Develop an additional set of emissions thresholds for pollutants coming from unobstructed vertical stacks • Additional thresholds approximately 1.3-4.8 times higher than current thresholds • Health based standards stay the same. 1. Develop additional toxic permitting emission thresholds

9. TPERs calculated from AAL based on dispersion modeling parameters • AAL* (1/(Cmax * averaging time factor)) * hours in averaging period =TPER 1. Develop additional toxic permitting emission thresholds

10. Cmax is maximum emission rate derived from dispersion model using conservative input parameters • Emission rate – 1 lb/hr • Physical stack height=5.0 meters • Stack gas temperature=293 degrees Kelvin • Stack gas velocity=1.0 m/s • Stack diameter=1.0 m • Resulting Cmax= 0.9497 grams/sec • Averaging Time Factor: Annual=0.1, Daily=0.6 1. Develop additional toxic permitting emission thresholds

11. US EPA has exempted certain gas-fired combustion units from federal air toxics rules. Another federal rule only prescribes work practice standards on affected units. • Toxic air emissions from these sources are well below the TPERs. 2. Exempt natural gas and propane fired combustion sources

12. Reviewed emissions profiles for all TAPs from combustion of natural gas and propane • Using emissions estimation spreadsheets, back calculated what heat input would result in emission rate that would exceed an existing TPER • Result: Benzene was controlling pollutant exceeding TPER at 450 million BTU/hr 2. Exempt natural gas and propane fired combustion sources

13. US EPA federal air toxics rules apply to all emergency engines and only prescribe work practice standards. • Used temporarily in emergency situations. • Small. • Few hours of operation. • Peak shaving engines are not considered emergency engines. 3. Exempt emergency engines

14. Reviewed emissions profiles for all TAPs from combustion of diesel fuel in emergency engines • Using emissions estimation spreadsheets, back calculated through iterative process what size unit exceeds an existing TPER • Result: Formaldehyde controlling pollutant for hourly emissions at 4843 horsepower 3. Exempt emergency engines

15. 15A NCAC 02Q .0705 provides a mechanism for the Director to require all facilities under the same four-digit Standard Industrial Classification (SIC) to submit an application to comply with the NC air toxics rules. • The existing Director’s Call rule and SL 2012-91 provide adequate authority to address any unacceptable risks to human health from any facility. 4. Eliminate SIC call

16. Clarify in the rule to ensure that DAQ is implementing it consistently. 5. Clarify use of actual rate of emissions

17. Elimination of this term will prevent confusion with definitions for combustion sources in federal rules. 6. Remove term “unadulterated wood” from rules

18. Repeal 15A NCAC 02Q .0705, Existing Facilities, due to elimination of last MACT/GACT provision. • Repeal of 15A NCAC 02Q .0714, Wastewater Treatment Systems at Pulp and Paper Mills, due to obsolete requirements and implementation schedules. Additional Rule Changes

19. Calculation error in original recommendation identified by SAB • Old AAL = 2.8 x 10-11 fibers/mL • New AAL = the 2.8 x 10-6 fibers/mL • Old TPER = 1.9 X 10-6 lb/year • New TPER = 5.7 x 10-3 lb/year • No impact – no facilities in NC Asbestos AAL and TPERCorrection

20. Average 94 permit applications per year submitted to DAQ • Section 1 - 34 facilities/year • Recommendation 1 – 16 facilities/year • Recommendation 2 – 20 facilities/year • Recommendation 3 – 15 facilities/year • No impacts estimated for recommendations 4, 5 and 6 Impacts

21. Reduced facility data collection costs • Reduced facility modeling costs • $147,000 savings per year • Increased DAQ staff time due to unacceptable risk determinations • $6400 opportunity cost per year Fiscal Impacts