air toxics rule changes (pursuant to session law 2012-91) north carolina division of air quality air...

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

North Carolina Division of Air Quality

Air Toxics Rule Changes Stakeholder MeetingMarch 20, 2013

Air Toxics – Summary of SL 2012-91

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 – Section 1

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


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)


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

5

Recommendations for Rule Changes

1. Develop an additional set of emissions thresholds for pollutants coming from unobstructed vertical stacks

2. Exempt natural gas and propane fired boilers

3. Exempt emergency engines4. Eliminate SIC call5. Clarify use of actual rate of emissions6. Remove the term “unadulterated wood”

from rules

1. Develop additional toxic permitting emission thresholds

Develop an additional set of emissions thresholds for pollutants coming from unobstructed vertical stacks◦Additional thresholds approximately 1.2-4 times higher than current thresholds

◦Health based standards stay the same.

Impact:Fewer facilities modeling


TPERs calculated from AAL based on dispersion modeling parameters

AAL* (1/(Cmax * averaging time factor)) * hours in averaging period =TPER


Cmax is maximum emission rate derived from dispersion model using conservative input parameters

◦ 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= 0.9306 grams/sec◦ Averaging Time Factor: Annual=0.1, Daily=0.6

2. Exempt natural gas and propane fired boilers

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.

Impact: Up to 150 facilities have sources that may

qualify for this exemption.

2. Exempt natural gas and propane combustion units

Reviewed emissions profile all TAPs from combustion of natural gas and propane

Using emissions estimation spreadsheets, back calculated what heat input would would result in emission rate that would exceed an existing TPER

Result: Benzene was controlling pollutant exceeding TPER at 450 million BTU/hr

3. Exempt emergency engines

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.Impact: Up to 150 facilities have sources that may

qualify for this exemption.

3. Exempt emergency engines

Reviewed emissions profile 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 daily and hourly at 4843 horsepower

4. Eliminate SIC call

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.

5. Clarify use of actual rate of emissions

Clarify in the rule to ensure that DAQ is implementing it consistently.

6. Remove term “unadulterated wood” from rules

Elimination of this term will prevent confusion with definitions for combustion sources in federal rules.

Comments? Please submit written comments by April

4, 2013 to:

[email protected]

Draft Rules:http://www.ncair.org/rules/toxics/Toxics_3-13-2013.pdf

Rules:http://www.ncair.org/rules/rules/Sec1100.shtml andhttp://www.ncair.org/rules/rules/SecQ0700.shtml

Next Steps

Stakeholder meeting Draft rule to AQC Public hearing request – EMC Comment period begins Public hearing Comment period ends EMC adoption RRC review/approval Effective date Effective date w/ General Assembly review

3/20/137/10/137/11/138/15/138/30/13

10/15/131/9/14

2/20/143/1/14

Mid-2014

North Carolina Division of Air QualityMike Abraczinskas

Deputy Director

[email protected] 919-707-8447

North Carolina Division of Air QualityJoelle Burleson

Planning


North Carolina Division of Air QualityDon van der Vaart

Permits Section Chief


air toxics rule changes (pursuant to session law 2012-91) north carolina division of air quality air...

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