Yolo

- Solano Air Quality Management District

1947 Galileo Court, Suite 103

Davis, CA 95618
(530) 757

- 3650
www.ysaqmd.org



## PROPOSED AMENDMENTS TO RULE 2.34, STATIONARY GAS TURBINES

FINAL STAFF REPORT

October 2 4 , 201 4

Prepared by: Kyle Rohlfing, Associate Air Quality Engineer

Reviewed by: Frank DeMaris, Engineering ManagerTable of Contents Page

I. EXECUTIVE SUMMARY

................................ ................................ ................................ ............. 1

A. BACKGROUND

................................ ................................ ................................ ................ 2

II. DISCUSSION OF PROPOSED RULE 2.3 4 REQUIREMENTS

................................ ................... 3

III. COMPARISON TO OTHER APPLICABLE REGULATIONS AND REQUIREMENTS

........... 5

IV. IMPACTS OF THE PROPOSED RULE

................................ ................................ ...................... 1 0

V. ENVIRONMENTAL IMPACTS OF METHODS OF COMPLIANCE

................................ ....... 11

VI. REGULATORY FINDINGS

................................ ................................ ................................ ......... 12

VII. PUBLIC COMMENTS AND STAFF RESPONSES

................................ ................................ .... 1 3

VIII. REFERENCES

................................ ................................ ................................ .............................. 1 6

ATTACHMENT A PROPOSED AMENDMENTS TO RULE 2.3 4

, STATIONARY GAS

TURBINES ; STRIKE

- OUT UNDERLINE VERSION

ATTACHMENT B NOTICE OF EXEMPTION FROM CEQA GUIDELINES

ATTACHMENT C RESOLUTION NO. 14

- 08

ATTACHMENT D WRITTEN COMMENTS RECEIVEDFinal Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

I. EXECUTIVE SUMMARY

O n November 12 , 20 1 4 , the Yolo

- Solano Air Quality Management District (District) Board of

Director s will consider the proposed amendments to Rule 2.34, Stationary Gas Turbines. The rule applies to all stationary gas turbines rated 0.3 megawatts (MW) and larger.

The main revisions/requirements for Rule 2.34 will be:

1. Definitions have been stricken or added as appropriate.

2. References to efficiency have been removed from the rule as they are no longer required.

3. Limitations on emissions concentrations in short

- term excursions have been added to the

standards section of the rule.

4. Requirements for emissions control d uring start

- up and shut

- down periods have been

added.

5

. The compliance schedule section of the administrative requirements has been stricken as all new or currently permitted sources will be immediately subject to rule provisions.

6

. The emission cont rol plan section of the administrative requirements has been edited so that the section will also apply to proposed sources.

There is currently one permitted source within the District that will be subject to this revised rule. The rule revision was prompted by the application for an Authority to Construct for a new combined cycle power plant which has since been canceled. The revised rule will apply to any future proposals for installation of simple cycle or combined cycle gas turbine power plants. The revisions of the rule acknowledge the practical considerations of operating a combined cycle gas turbine power plant. The deletion of the efficiency multipliers from the standards section of the rule will result in lower permissible limits for oxides of nitrogen (NOx)

.

The District does not expect the proposed rule changes to have either a significant or a detrimental ef fect on the environment. Therefore, staff has prepared a Notice of Exemption (NOE) to satisfy the California Environmental Quality Act (CEQA) requirements. The NOE states that the adoption of these proposed rule amendments is exempt from the requirements of CEQA pursuant to Section 15308, Actions by Regulatory Agencies for Protection of the

Environment.

Page 1Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

A. BACKGROUND

Overview of source category

Stationary gas turbines are engines consuming liquid or gaseous fuels

, which produce mechanical power that can be used to perform mechanical work or can be converted into electrical power. After air is compressed in the compressor section of the engine, fuel is introduced and mixed with the air and then the mixture is ignite d in the combustor. The ex panding combustion gases exhaust through the turbine section of the engine, causing the turbine blades to spin and thus creating shaft power. The combustion of fuel by the stationary gas turbine results in the emission of five of the District’s criteria pollutants: carbon monoxide (CO), oxides of nitrogen (NOx), oxides of sulfur (SOx), volatile organic compounds (VOC), and particulate matter with an aerodynamic diameter equal to or less than ten microns (PM 10 ). Many stationary gas turbines utilize selective catalytic reduction (SCR) as an emissions control technology. This control technology results in the emission of ammonia , which can nega tively affect the respiratory system with acute and chronic exposures

.

In the simple cycle gas turbine power plant electrical powe r is created from the generator driven by the gas turbine. A later development in stationary power generation is the combined cycle power plant which utilizes additional components. The more complex combined cycle extracts

useful heat energy from the gas turbine exhaust with a heat recovery steam generator. The heat recovery steam generator then channels the ste am to drive a steam t urbine. The shaft power from

the steam turbine is used to drive an additional electric generator. The additional equipment of the combined cycle power plant results in a greater amount of time necessary to reach steady

state operatio n compared to the simple cycle process

.

Currently, CalPeak Power

- Vaca Dixon, LLC (CalPeak) is the only stationary gas turbine source subject to this rule operating in the District. This source consists of two simple cycle stationary gas turbines controlled with SCR. Because these are simple cycle turbines, the longer start

- up period proposed for combined cycle units will not apply.

Sources will be allowed temporary departures from emission limit compliance for periods of

short

- term excursions un der the proposed rule revisions; however, the turbines will be limited to a more restrictive NOx emission concentration limit for periods of steady state operation. Results of recently performed source tests show compliance with the revised applicable NOx emission

concentration limit s can be achieved.

Page 2Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

II. DISCUSSION OF PROPOSED RULE 2.34 REQUIREMENTS

Listed below are descriptions of the proposed revisions to Rule 2.34, Stationary Gas Turbines.

Section 100 General

Section 101

- Purpose: The purpose o f this rule is to limit NOx emission from stationary gas

turbines.

Section 102

- Applicability: Except as provided in sections 1 10 and 1 11 , this rule shall apply to all stationary gas turbines, 0.3 megawatt (MW) and larger.

Section 103

– Severability: If any provision, clause, sentence, paragraph, section or part of th is rule is for any reason judged to be unconstitutional or invalid, such judgment shall not affect or

invalidate the remainder of the rule.

Section 1 10

- Exemption

- Laboratory, Firefight ing/Flood Control, and Chemical Processing

Units: Except for the notification requirement of section 401.3

, the provisions of this rule will not apply to laboratory gas turbines used for research into the advancement of gas turbine technology,

turbines use d exclusively for firefighting and/or flood control, or che mical processing gas

turbines.

The revision of this rul e will e liminate the exemption for pipeline gas turbines that could have been g ranted at the Air Pollution Control Officer’s d etermination that emissions control technology is not technologically feasible, cost effective, or creates adverse environmental impacts.

Section 1 11

- Exemption

- Emergency Standby and Small Units: Except for the notification and

record

- keeping conditions of sections 401.3, 402, and 502. 2

, the provisions of this rule shall not apply to emergency standby stationary gas turbines operating less than 200 hours per calendar year, or units rated less than 4 MW operating less than 877 hours per calendar year.

Section 200 De finitions: T wenty

- o ne (2 1 ) terms have been defined for rule clarity.

Section 300 Standards

Section 301

- Emission Limits: Except for the start

- up period, shut

- down period, or up to four (4) consecutive fifteen minute periods during short

- term excursions , the gas turbine shall not be operated under conditions with NOx emissions (averaged over 15 minutes) in excess of the limi ts specified in Table 1. In response to public comments on the compliance ability of gas turbines burning alternative gaseous fuels, such as landfill, digester, and refinery gases, the District is revising Table 1 to restrict the emission limits associated with gaseous fuels to commercial natural and liquefied petroleum gases. As no existing gas turbine subject to the rule is fired on any of these alternative gaseous fuels, this revision is not a relaxation of the emission limits. Any future gas turbine proposing to fire alternative gaseous fuels will be subject to the requirement to use the best available control technology (BACT) unde r the District’s New Source Review rule,

which will include a case

- by

- case emission limit appropriate for that unit and fuel.

Page 3Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

TABLE 1. NOx Emission Concentration Limits



### Unit Size Compliance limit

NO

x , ppm @ 15% O 2

Megawatt Rating (MW) Gas A Liquid B

0.3 to Less Than 2.9 MW

and Units Greater Than or Equal to 4 MW That Operate Less Than

877 Hour/Year 42 65

2.9 to Less Than 10 MW 25 65

10.0 MW and Over 9 25

A. GAS INCLUDES ONLY COMMERCIAL NATURAL AND LIQUIFIED PETROLEUM GASES.

B. L IQUID INCLUDES KEROSINE, JET, AND DISTILLATE OIL . THE SULFUR CONTENT OF THE OIL SHALL BE LESS THAN 0.05%.

Section 301.1: This rule amendment limits the duration and NOx concentration of short

- term
excursions.

Section 301.2: This rule amendment limits the total amount of time allowed for short

- term excursions in a year.

Section 30 2 : This section has been added to require operation of emissions control devices during periods of turbine start

- up and shut

- down. This section wi ll require operation of SCR systems once the temperature of the catalyst media has increased to the minimum operation temperature either specified by the manufacturer or as previously established in source tests for a specific

source. The EPA requested th e rule should specify a minimum temperature at which SCR control should be initiated and supplied a range of 475

- 550 ° F. The District has agreed to set the minimum temperature for SCR control to the upper limit of this range. To determine a practical

emis sion limit during start

- up periods the District considered recent power plant projects reviewed by the California Energy Commission. Comparing maximum hourly emissions proposed during start

- up periods to the rated heat inputs of the gas turbines t he Distr ict

determined that 0.16 lb NOx /MMBtu is an appropriate limit for turbine emissions during startup for turbines combusting gas eous fuels . The District determined that this emission rate is equivalent to a NOx concentration of 43 ppmv @ 15% O 2 and proposed to make this limit

enforceable as an average over the duration of the startup period.

The District received public comments questioning the feasibility of the proposed startup limit for smaller gas turbines. These comments from a turbine man ufacturer indicated that a higher limit of 70 ppmv should be an attainable standard. As the purpose of the startup limit is to avoid a perceived loophole in the rule’s emission limits, the District has revised the proposed rule to include a startup limit o f 70 ppmv NOx at 15% O 2

.

The District found less recent data available for emissions during startup from turbines combusting liquid fuel. To avoid setting an unrealistically low limit for startup emissions th e District started with a NOx emissions factor of 0.88 lb NOx/MMbtu from the fifth edition of U.S.

EPA AP

- 42, Compilation of Air Pollutant Emission Factors as a maximum value. T his value was substituted in the equation to calculate the startup emission s exhaust concentration limit for liquid

fueled turbines along with the F factor for crude, residual, and distillate oils at 9,190 scf/MMBtu.

Page 4Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

0. 88 lb

MMBtu × 10 6 ÷ 46 lb

mole × 385 scf

mole ÷ 9 ,1 9 0 scf

MMBtu × � 20.9%

- 15% �

( 20.9% ) = 226 ppm@15% O2

Section 30 3 : Thi s section has been added to specifically require a stationary gas turbine owner/operator to install and operate continuous monitoring equipment. For units with ratings equal to or greater than 10 MW, the owner/operator will be required to install equipment that measures and records exhaust gas NOx concentrations.

Section 304 : This section has been added to require regular third

- party testing of emissions from affected turbines to determine complia nce with NOx emission concentration limits. For units with ratings equal to or greater than 10 MW, the owner/operator will also be required to conduct a regular Relative Accuracy Test Audit (RATA) to determine the reliability of measurements made by the c ontinuous emissions monitoring system.

Section 400 Administrative Requirements

Section 401

– Exemption Applicability : The owner/operator shall submit support documentation for any units exempt from the provisions of the rule per Sections 110 and 1 11 of the rule

.

Section 402

- Emergency Standby and Small Units: The o wner or operator of an exempt emergency standby or small unit shall notify the APCO in writing within seven days if the hour

per

- year limit is exceeded. If the limit is exceeded the exem ption shall be permanently withdrawn and within 30 days of the exceedance, an application for an Authority to Construct shall be submitted detailing a plan to meet the applicable limit of Section 301. This section shall not apply to public service units o perating during a state of emergency declared by the Governor

of the State of California.

Section 500 Report ing and Recordkeeping

Section 501

- Repo r t ing: The owner or operator shall maintain records for a period of five years. The owner or operator shall also submit to the APCO information demonstrating that the CEMS has data gathering and retrieval capability. Prior to the issuance of a Permit to Operate , the owner or operator shall submit information correlating the control system operating parameters to the associated NOx output. Source test information shall be provided annually regarding the exhaust gas NOx concentration.

Section 502

- Recordkeeping : Gas turbine operating logs shall be maintained that include, on a daily basis, the actual start

- up and stop time and total hours of operation. The information shall

be retained for a period of five years and shall be made available for inspection.

Section 600

- Test Methods:

Section 601: Oxides of Nitrogen (NOx) shall b e determined in accordance with U.S. Environmental Protection Agency ( EPA ) Method 7E or EPA Method 20.

Section 602: Oxygen (O2) shall be determined in accordance with California Air Resources

Board ( ARB ) Method 100 or EPA Method 3A.

Page 5Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

III. COMPARISON TO OTHER APPLICABLE REGULATIONS AND REQUIREMENTS

California Health and Safety Code (CH&SC) Section 40727.2 requires districts to perform a comparative alternative analysis of any new control standard. Specifically, the District is required to prepare a written analysis that identifies all existing federal air pollution control requirements, including, but not limited to emission control standards constituting best available

control te chnology (BACT) that applies to the same equipment or source type as the rule or regulation proposed for adoption or modification by the District. In addition, the analysis shall identify any other District rule or regulation that applies to the same equi pment or source type. The analysis shall compare the following specific elements:

A. New Source Performance Standards

Stationary gas turbine s with a 10 Million Btu per hour heat input rate at peak load (based on the higher heating value of the fuel fired) are subject to the requirements of the EPA’s New Source Performance Standards (NSPS) contained in 40 CFR Part 60, Subpart KKKK. Table 2 belo w presents a comparative analysis between specific elements of the proposed revised rule and the corresponding elements of t he existing federal regulation.

Table 2. Comparison of Proposed Rule Revision Emission Limits with NSPS 40 CFR, Part 60, Subpart K KKK

Turbine Rating District Rule 2.34 NOx Emission Limits, ppmv@15% O 2 Federal Regulation 40 CFR Part 60, Subpart

KKKK NOx Emission Limits, ppmv@15% O 2

˂ 10 MW fired on

Natural Gas 25 or 42 42

, 100, or 150

˂ 10 MW fired on fuel

other than Natural Gas 25 , 42, or 65 96 or 150

≥ 10 MW fired on

Natural Gas 9 or 42 * 15

, 25

, 42, 100 , or 150

≥ 10 MW fired on fuel

other than Natural Gas 9, 25, 42, or 65 * 42, 74, 96 , 100 , or 150

* The 42 and 65 ppmv NOx limit s in these categories only apply to turbines which are limited to operat ing for less than 877 hours/year

The standards for sulfur dioxide of 40 CFR Part 60, Subpart KKKK requires either that the emission of sulfur dioxide (SO 2 ) from any stationary gas turbine not exceed 0.90 pounds per

megawatt

- hour or that the fuel burned not contain potential sulfur emissions in excess of 0.060 pounds of SO 2 per million BTU. The subpart also contains alternative compliance limits for

turbines in a non

- continental area or if the EPA administrator finds both that the turbine is located in an area where natural gas is not available and that the removal of sulfur compounds would cause more environmental harm than benefit. District Rule 2.34 currently does not contain any

restrictions on sulfur oxides and the proposed amendments will not add any restrictions. Emissions of sulfur oxides from stationary gas turbines will be limited by other District rules and regulations as well as state

- level regulations on fuel sulfur content.

Page 6Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

Table 3. NOx Emission Monitoring Conditions

District Rule 2.34 Federal Regulation 40 CFR Part 60, Subpart KKKK

Requirement Application Requirement

- Monitoring system which continuously

monitors and records: a. Control system operating parameters; b. Elapsed time of operation; c. For units of 10 MW or greater, the

exhau st gas NOx concentrations correcte d to

ISO conditions at 15 percent oxygen on a dry basis. The NOx monitoring system shall meet requirements of 40 CFR Part 60, Appendix B, Spec. 2 or other systems that are acceptable to

the EPA. - Turbines with water or steam injection for NOx control - Continuous monitoring system for fuel consumption and ratio of

water/steam to fuel

OR

- Continuous emissions monitoring system (CEMS) with NOx and O 2 (or CO 2 ) monitors and fuel and

watt meters

Also

- For combined heat and power turbines equipped with CEMS monitoring, meters for useful recovered energy flow rate, temperature, and pressure

Turbines without water or steam injection for NOx control - Annual performance test (may be reduced to once every 2 years if results show NOx emissions equal

to or less than 75% of limit

OR

- Continuous emissions monitoring system (CEMS) with NOx and O2 (or CO2) monitors and fuel and

watt meters

OR

- Continuous parameter monitoring (parameters to be monitored dependent upon turbine design and control equipment)

Stationary gas turbines with a 10 Million Btu per hour heat input rate at peak load (based on the lower heating value of the fuel fired) and not regulated under Subpart KKKK are subject to the requirements of NSPS contained in 40 CFR Part 60, Subpart GG. Table 3 below presents a comparative analysis between specific elements of the proposed revised rule and the corresponding elements of the existing federal regulation.

Page 7Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

Table 4. Comparison of Proposed Rule Revision Emission Limits with NSPS 40 CFR,

Part 6 0, Subpart GG

Turbine Rating District Rule 2.34 NOx Emission Limits, ppmv@15% O 2 Federal Regulation 40 CFR Part 60, Subpart GG

NOx Minimum Emission Limits, ppmv@15% O 2

0.3 to Less Than 2.9

MW

And Units Greater Than or Equal to 4 MW That Operate

Less Than 877

Hour/Year 42 or 65 75 or 150

2.9 to Less Than 10.0

MW 25 or 65 150

10.0 MW and Over 9 or 25 75 or 150

The NOx emission limits presented for Subpart GG reflect the most stringent emission lim its which can

be increase d to higher levels with a n adjustment factor calculated from the manufacturer’s rated heat rate at the manufacturer’s rated peak load and a NOx emission allowance for fuel

- bound nitrogen.

The federal regulation requires that if a nonzero emission al lowance for fuel

- bound nitrogen is used in the calculation of the applicable NOx emission limit in Subpart GG , the owner or operator of the turbine shall monitor the nitrogen content of the fuel combusted by the approved methods.

The standards for sulfur dioxide of 40 CFR Part 60, Subp art GG require that the emission of sulfur dioxide from any stationary gas turbine not exceed 0.015 percent by volume at 15 percent excess oxygen on a dry basis. The regulation also requires the fuel fired in a stationary gas turbine shall not contain

sul fur in excess of 0.8 percent by weight. District Rule 2.34 currently does not contain any restrictions on sulfur oxides and the proposed amendments will not add any restrictions. Emissions of sulfur oxides from stationary gas turbines will be limited by other District rules and regulations as well as state

- level regulations on fuel sulfur content.

Both 40 CFR Part 60, Subpart GG and District Rule 2.34 require monitoring of the emission unit to demonstrate compliance with the applicable emissions standard s. The federal regulation requires monitoring of the total sulfur content of the fuel combusted in the turbine. This monitoring becomes elective if the owner or operator can demonstrate by approved means that the fuel being fired in the

turbine meets the definition of natural gas given in the regulation. District Rule 2.34 has not contained

, and the rule revision will not add

, any limitations on sulfur dioxide emissions , so the District rule includes no requirement to monitor the fuel sulfur content

.

Page 8Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

T able 6. NOx Emission Monitoring Conditions

District Rule 2.34 Federal Regulation 40 CFR Part 60, Subpart GG

Requirement Application Requirement

- Monitoring system which continuously

monitors and records: a. Control system operating parameters; b. Elapsed time of operation; c. For units of 10 MW or greater, the exhaust gas NOx concentrations correcte d to

ISO conditions at 15 percent oxygen on a dry basis. The NOx monitoring system shall meet requirements of 40 CFR Part 60, Append ix B, Spec. 2 or other systems that are acceptable to

the EPA - Turbines with water or steam injection for NOx control - Continuous monitoring system for fuel consumption and ratio of

water/steam to fuel

- Construction, reconstruction, or

modification after Oct 3, 1977 but before July 8, 2004 - May as alternative install continuous emissions monitoring system (CEMS) with NOx and O 2 (or CO 2 ) monitors

- Construction, reconstruction, or modification after Oct 3, 1977 but before July 8, 2004 without water or steam injection - CEMS not requried

- Turbine constructed after July 8, 2004 with water or steam injection - Either continuous monitoring of fuel consumption and ratio of water/steam injection or use of

NOx CEMS

- Turbine constructed after July 8,

2004 without water or steam injection - May elect to, but not required to, operate NOx CEMS

- May elect to, but not required to, perform continuous parametric monitoring

- Periodic testing is an another acceptable monitoring system

- Parameters to be continuously monitored to show compliance with acceptable emission rates shall be monitored during the initial source test

to establish acceptable values and ranges

B. R easonably Available Control Technology

The revisions to this ru le would establish for steady

- state operation the same NOx emission limits as those currently established for stationary gas turbines by the Sacramento Metropolitan Air Quality Management District, which are equal to or lower than the applicable standards established by the federal government under 40 CFR 60 Subpart KKKK and well below the lowest applicable standards required by Subpart GG. Many determinations of Best Available Control Technology (BACT) made by other districts in California and by state ag encies in other states of the country have shown that the application of various control technologies

, including

low

- NOx combustors and SCR

, result in emissions well in compliance with the proposed rule

revision. These determinations demonstrate that the proposed rule emission limits are achievable.

The District showed the existing rule satisfies RACT in a 2006 RACT Sta te Implementation Plan and the pr oposed revised rule will be as stringent in controlling emiss ions

. The CalPeak peaking power plant in Vacaville complies with the rule to satisfy RACT. The Permit to Operate for

CalPeak includes two limits on the emission concentration of NOx. This source is limited to emit NOx in no higher concentration than 3.0 ppmv corrected to 15% O2 on a 3 hour rolling average and 12 ppmv corrected to 15% O2 for 15 minute averages except for certain periods of operation

when the source is exempt from one or both of these limits. This source has demonstrated ability

Page 9Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

to operat e in compliance with the lower emission limits of the proposed revision accepting that a source will be exempt from compliance with the rule emissions concentration standards during periods of shutdown and short

- term excursions as defined in the rule and that separate limits have been established for periods of startup

.

C

. Best Available Retrofit Control Technology

The Sacramento Federal Non

- Attainment A rea is classified by the EPA to be in severe

nonattainment of the 8

- hour national ambient air quality standard for ozone

. According to Section 40920 of the California Health and Safety Code

, a district with severe air pollution shall, to the extent necessary to meet the requirement that a district design a plan to achieve and maintain air quality standards by the earliest practicable date, include in the district plan all measures required for moderate and serious nonattainment areas. One of the measures for

districts with serious air pollution is the use of the Best Available Retrofit Control Technology (BARCT) for existi ng permitted stationary sources. The only existing stationary gas turbines subject to the rule are operated by CalPeak Power and have the potential to emit 0.06 t ons per day

of NOx. The Yolo

- Solano Air Quality Management District has not relied on the application of BARCT for stationary gas turbines as a means to achieve ambient air quality standards in the

2012 Trien nial Assessment and Plan Update

. BARCT is not required and this rule does not

establish BARCT.

IV. IMPACTS OF THE PROPOSED RULE

Emissions Impacts

As previously stated

, there is currently only one permitted source within the District that will be subject to the provisions of the revised rule. CalPe ak has demonstrated ability to meet the NOx emission concentration standard of the revised rule. Although an exemption for short

- term excursions will allow the NOx emission concentration to be exceeded for short periods of time, additions to the rule requ ire that the average emission s for any six hour period containing a short

term excursion comply with the NOx emission limitation, and short

- term excursions will be

limited to no more than ten hours per year. The limitations to the short

- term excursions provision

will ensure that NOx emissions will not increase as a result of the revisions to this rule. The longer start

- up period for combined cycle stationary gas turbine power plants will not result in higher NOx emissions from a relaxation of reg ulation of such sources since the longer start

- up period reflects the practical limitations of operating combined cycle power plants. The elimination of the thermal stabilization period emission s lim its exemption has been replaced by exemptions for periods of start

- up and shut

- down; however, with the added requirement to operate control equipment during such periods and an added start

- up limit the proposed revisions

will not result in a relaxat ion of the emissions control from the existing version of the rule currently in the State Implementation Plan

.

Cost Effectiveness

CH&SC Section 40703 requires the District, in the process of adopting any regulation, to consider and make public its findings rela ted to the cost effectiveness of a control measure. Cost effectiveness for rulemaking purposes is calculated by dividing the cost of air pollution controls required by the rule by the amount of air pollution reduced.

Since there are no reductions expecte d from the proposed amendments to this rule and no additional air pollution controls are expected, no cost effectiveness calculations are required.

Page 10Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

Socioeconomic Impacts

CH&SC Section 40728.5(a) requires the District, in the process of adopting any rule or regulation, to consider the socioeconomic impact if air quality or emission limits may be significantly affected. However, districts with a population of less than 500,000 persons are exempt from the provisions of Section 40728.5(a). The Dis trict’s population is estimated to be approximately 331

, 600

, well below the 500,000 person threshold. Therefore, a socioeconomic analysis for this rulemaking is not required.

Incremental Cost Effectiveness

CH&SC Section 40920.6 requires an assessment of the incremental cost

- effectiveness f or proposed regulations related to ozone, Carbon Monoxide (CO), Sulfur Oxides (SOx), Nitrogen Oxides (NOx), and their precursors. Incremental cost

- effectiveness is defined as the difference in

control costs divided b y the difference in emission reductions between two potential control options that can achieve the same emission reduction goal of a regulation. Rule 2.34 only

contains limitations on NOx emiss ions. Since the revised rule does not require any additional air pollution controls not already required by other District rules and regulations, no cost

effectivene ss calculations are required.

Impacts to the District

The currently operating source has already demonstrated emissions that will be in compliance

wit h the applicable NOx emission limitation of the rule. Additional record

- keeping will be required of sources to demonstrate compliance with rule provisions for periods of short

- term
excursions from NOx emission compliant operation. It is anticipated that the proposed rule will have little to no impact on staff workload at the District. It is expected that any additional work load can be absorbed within the District’s engineering division.

V. ENVIRONMENTAL IMPACTS OF METHODS OF COMPLIANCE

Calif ornia Public Resource Code Section 21159 requires the District to perform an environmental analysis of the reasonably foreseeable methods of compliance. The analysis must include the following information for the proposed amendments to Rule 2.34:

1. An anal ysis of the reasonably foreseeable environmental impacts of the methods of compliance.

2. An analysis of the reasonably foreseeable mitigation measures.

3. An analysis of the reasonably foreseeable alternative means of compliance with the rule or regulation.

Table 1 lists all reasonably foreseeable compliance methods, the environmental impacts of those methods, and measures that could be used to mitigate the environmental impacts.

Page 11Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

TABLE 7. Environmental Impacts, Mitigation Measures, and Alternatives

Compliance

Methods Reasonably Foreseeable Environmental Impacts Reasonably Foreseeable Mitigation

Measures

Water/Steam Injection, Low NOx Combustion,

and Selective

Catalytic

Reduction Air Quality Impacts: Reduc ed NOx emissions but potential for ammonia emissions from use of selective catalytic

reduction

Installation of Continuous Emissions Monitoring System (CEMS) and regular source testing to ensure rule compliance and minimize ammonia

emission Water Impacts: Potential for increased consumption of water for water/steam injection as emissions control

Human Health Impacts: Improved human health in the District by reduction in emission of precursor to ground level

ozone

Solid Waste Disposal Impacts: Small

increase in solid waste from SCR catalysts that cannot be reactivated or otherwise recycled

This analysis demonstrates the adoption of amendments to Rule 2.34 will not have a significant

effect on the environment or humans due to unusual circumstances. In addition, the proposed amendment of Rule 2.34 is an action taken to protect the environment. Therefore, staff ha s determined that the project is categorically exempt from the requirements of the California

Environm ental Quality Act (CEQA) pursuant to Section 15308, Actions by Regulatory Agencies

for Protection of the Environment. Staff ha s prepared a Notice of Exemption (NOE) to meet the CEQA Guidelines (Attachment B) for submittal to the County Clerk for Yolo Coun ty, and the Clerk of the Board of Supervisors for Solano County.

VI. REGULATORY FINDINGS

Section 40727(a) of the CH&SC requires that prior to adopting or amending a rule or regulation,

an air district’s board make s findings of necessity, authority, cla rity, consistency, nonduplication, and reference. The findings must be based on the following:

1. Information presented in the District’s written analysis, prepared pursuant to CH&SC Section 40727.2;

2. Information contained in the rulemaking records pursuant to CH&SC Section 40728; and

3. Relevant information presented at the Board’s hearing for adoption of the rule.

The required findings are:

Necessity: The rule amendment is required in order to limit emissions of NOx from stationary gas

turbines w hile accepting the additional technical difficulties in achieving emissions compliance at

Page 12Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

startup for combined cycle gas turbine power plants versus simple cycle power plants . (CH&SC Section 40727(b)(1)).

Authority: The District is authorized to adopt rules and regulations by CH&SC, Sections 40001, 40702, 40716, 41010 and 41013. (CH&SC Section 40727(b)(2))

Clarity: District staff have reviewed the proposed rule and determined that it can be easily understood by the affected industry. In addition, the record contains no evidence that the persons directly affected by the rule cannot understand the rule. (CH&SC Section 40727(b)(3)).

Consistency: The District has compared the proposed rule to federal New Source Perform ance Standards (40 CFR Part 60) Subparts GG and KKKK for stationary turbines as well as possible revisions to Subpart KKKK for which implementation is pending

. The proposed rule does not

conflict with

, and is not contradictory to, existing statutes , court decisions, or state or federal regulations. (CH&SC Section 40727(b)(4)).

Non

- Duplication: The proposed rule does not duplicat e any state laws or regulations regarding the attainment and maintenance of state and federal air quality limits. (CH&SC Section 40727(b)(5)).

Reference : The District is not implementing, interpreting, or making specific any statute, court decision, or other provision of law by amending Rule 2.34. (CH&SC Section 40727(b)(6)).

VII. PUBLIC COMMENTS AND STAFF RESPONSES

Staff held a public workshop on January 1 5 , 201 4 , to discuss the proposed amendments to Rule

2.34. Notification was sent to surrounding Air Districts, City Managers within the District, building/planning/community development departments within the Distri ct, all city and county libraries within the District, all Board members, and all permitted/proposed sources. The workshop notice was published in The Davis Enterprise, The Woodland Daily Democrat , and the Vacaville Reporter newspapers on January 8, 2014

. A copy of the public workshop notice, the draft staff report, and draft rule language, was posted on the District’s web page.

A. Public W orkshop

- January 15 , 20 1 4

No comments pertaining to the proposed rule revisions were received during the public workshop or during the public comment period that ended on January 29, 2014

. On February 6, 2014, the U.S. EPA submitted two comments pertaining to the rule.

Comment 1. Nicole Law of the U.S. EPA commented that the definition of “short

- term
excursions” in the draft rule language creates a less stringent exemption from NOx emission limit compliant operation than the exemption given in the Sacramento Metropolitan Air Quality Management District’s Rule 413, and

asked that the District consider further limit ing the exemption for such

excursions

.

Response 1. The definition of “short

- term excursions” was revised to state that such

excursions are short term departures from compliant operation for turbines with a rated output greater than 100 MW, which are part of a combined cycle process

, due to specified causes

.

Page 13Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

Comment 2

. Nicole Law of the U.S. EPA also commented that the rule needed to place emission limits on turbines during periods of start

- up and shut

- do wn, either with numerical emission limits or a requi rement that control equipment be operational during periods of start

- up and shut

- down. As part of the comment she provided a link to an EPA proposed rule addressing start

- up , shut

- down, and malfunction provisions of rules included in State Implementation Plants (SIPs) at: http://www.epa.gov/oar/urbanair/sipstatus/emissions.html

.

Response 2

. The District notes that the proposed rule is a call for SIP revisions from certain specified r egions not including any air district in California. EPA did not provide in the comment any suggestions for specific emission limits during periods of

start

- up and shut

- down . Although this rule does not propose specific emission limits for stationary gas turbines during start

- up and shut

- down events, any unit subject to this rule will also be subject to the daily, quarterly, and annual

emission limits of its Permit to Operat e , including all startup/shutdown

emissions

. District permits include emission limits which are determined by the type of emission unit permitted, the proposed operation of the source, and the requirements of however many different District rules the sour ce is subject to. No revision to the rule language is proposed.

B. Additional Regulatory Notice

After receiving written comments from U.S. EPA resulting from the notice performed prior to the

p ublic w orkshop , the District revised the proposed rule language. Before moving to a p ublic

h earing the District sent the revised rule language and updated staff report to U.S. EPA for another review period on March 6, 2014. On April 18, 2014 the U.S. EPA submitted additional

written comments pertaining to t he rule.

Comment 1. Andrew Steckel of the U.S. EPA commented on the District’s contention that even if the rule did not contain specific emission limits for period of start

- up and

shut

- down, emissions units subject to the rule would still have permit lim its which restrict emissions from such units on a daily, quarterly, and annual basis. Mr. Steckel stated that while such permit limits might fulfill Clean Air Act requirements they are not approved into the SIP. He suggested revising rule provisions to r equire controls during start

- up and shut

- down either with numerical emission limits or operational requirements.

Response 1. Proposed Rule 2.34 has been revised to add start

- up/shut

- down operating standards. This section requires Selective Catalytic Reduc tion control systems

operate once the temperature of the catalyst media reaches the minimum temperature for operation recommended by the manufacturer or as demonstrated

in source tests. The secti on also requires other emissions control devices to operate continuously during start

- up and shut

- down events.

Comment 2. Mr. Steckel also recommended that the District demonstrate the revised rule fulfills Clean Air Act requirements regarding continuous emission limitations, RACT, and SIP relaxations.

Response 2. The District feels the addition of operational standards for periods of start

- up and

shut

- down adequately addresses the requirement for continuous emission

Page 14Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

limitations and the concern over SIP relaxations. The requirement for RACT has been previously addressed in this staff report.

The District made further revisions to the proposed language and staff report and returned them to U.S. EPA for review on May 19, 2014. On June 4, 2014 the U.S. EPA submitted additional written comments pertaining to the rule.

Comment 3. Andrew Steckel again commented on the proposed language for start

- up/shut

down periods and suggested that some type of numerical limit should be established for emissions during start

- up periods and for initiation of SCR

emissions control

.

Response 3. The District reviewed recent power plant projects reviewed by the California Energy Commission to develop a practical limit for start

- up emissi ons. The District also accepted the upper limit of a range of temperature values supplied by EPA as the minimum temperature to activate SCR control.

Comment 4. Mr. Steckel also asked for the staff report to explain how the replacement of a

thermal stabi lization period exemption to emission limits by the start

- up/shut

down exemption would not relax the State Implementation Plan.

Response 4. This explanation is given in a discussion of the potential emissions impacts of the

rule revisions in Section IV o f this report.

C

. Public Hearing Notice Period

Subsequent to the public workshop and addressing the comments, District staff released the amended rule language and prepared a public hearing notice for the hearing which will be held

November 1 2 , 201 4 . The notice was sent to all the same parties which received the public workshop notice. The heari ng notice was also published in The Davis Enterprise, The Woodland Daily Democrat, and the Vacaville Reporter newspapers . A copy of the public hearing noti ce and updated documents (proposed staff report and proposed rule language), were posted on the District’s web page. In response to the notice, the District received the following comments:

Comment 1

. Nicole Law of US EPA indicated that the proposed rule was acceptable and EPA

had no further comments.

Response 1

. Comment noted.

Comment 2

. Mr. Anthony Pocengal with Solar Turbines Inc. submitted a comment letter stating that the proposed 43 ppmv NOx limit during startup may not be attainable for all turbines, particularly the smaller units manufactured by Solar. He proposed that the startup limit by revised to 70 ppmv.

Response 2

. The District notes that the proposed startup limit is derived fro m mass

- based limits associated with larger turbines and agrees that smaller units may not follow the same emissions profile during startup as a larger unit. Furthermore, the District recognizes that data regarding actual NOx concentrations during startup

o f turbines are extremely limited and that, in establishing an emission limit that will apply during startups, care must be taken to ensure that an unattainable standard is not established. The District is enacting a numerical limit on startup

Page 15Final Staff Report

– Rule 2.34, Stationary Gas Turbines October 24 , 2014

NOx emissions to close a perceived loophole in the rule, rather than with the intention of producing any actual emission reductions. Therefore, the District will revise the proposed NOx startup limit to 70 ppmv at 15% O 2 as suggested.

Comment 3

. Mr. Pocengal also comm ented that the requirement to begin operating SCR as soon as it will be effective, and no later than 550 °F, will be sufficient to ensure startup emissions are minimized, so a numerical limit is not necessary.

Response 3

. See comments 1 and 3 from the add itional regulatory notice and the associated

responses . The District has previously argued that emissions will be minimized by operational requirements like the minimum SCR activation temperature requirement. Recent litigation has led EPA to begin requirin g the closure of perceived loopholes in SIPs created by startup and shutdown exemptions from

emission limits. Therefore, some sort of numerical cap on NOx emissions during startup is required for SIP approval of the rule.

Comment 4

. Mr. Pocengal also comm ented that the proposed rule defines “gas” fuels to include natural gas, landfill gas, and digester gas, but that landfill and digester gases have compositions and qualities that can vary substantially. As the fuel characteristics can vary substantially fr om natural gas, the resulting emissions can potential ly be much higher, especially if contaminants in the fuel gas will interfere with common emission reduction and control devices. Mr. Pocengal proposes that such alternative gaseous fuels be subject to se parate, higher

emission limits or evaluated on a case

- by

- case basis.

Response 4

. The District agrees that it can be inappropriate to subject a unit fired on such alternative gaseous fuels to the same emission limit that the same unit can meet

when fired o n a commercially

- available gaseous fuel of consistent quality and properties. Since there are no turbines in the District subject to this rule and operating on alternative gaseous fuels, the District is revising the definition of gaseous fuels to include o nly commercial natural gas and liquefied petroleum gas. Any future unit operating on an alternative gaseous fuel will be subject to

BACT and evaluated on a case

- by

- case basis.

Comment 5

. Mr. Pocengal also commented that ISO correction is unnecessary for t urbines equipped with dry low

- NOx burners.

Response 5

. Both the current and the proposed rule include frequent references to ISO conditions, and this terminology is an integral part of the emission standards.

References to ISO conditions will not be deleted.

The District incorporated the above comments, as determine d appropriate. A copy of the updated documents (final staff report and final rule language) were provided to the Governing Board prior to the hearing and posted on the District’s web page.

VI I I. R EFERENCES

- AP 42 Compilation of Air Pollution Emission Facto rs , Fifth Edition, Section 3.1

, Stationary

Gas Turbines, Published April, 2000

Page 16ATTACHMENT A

PROPOSED RULE 2.34, STATIONARY GAS TURBINES

STRIKE

- OUT UNDERLINE VERSIONATTACHMENT B

NOTICE OF EXEMPTION FROM CEQA GUIDELINES

## Notice of Exemption

To: ■ County Clerk County of Yolo 625 Court Street, Room 105 Woodland, CA 95695 □ County Clerk Solano County

600 Texas Street Fairfield, CA 94533

From: Yolo Solano Air Quality Management District 1947 Galileo Court, Suite 103 Davis, CA 95616

Project Title: Revision of Rule 2.34

- Stationary Gas Turbines

Project Location: Yolo Solano Air Quality Management District

Project Description The revision of Rule 2.34 will lower the NOx emission limits of various categories of stationary gas turbines. The revision will also introduce

separate start

- up period exemptions from the emission limits for simple cycle and combined cycle turbine power plants.

Name of Public Agency Approving Project: Yolo Solano Air Quality Management District

Name of Person or Agency Carrying Out Project: Yolo Solano Air Quality Management District

Exempt Status:

□ Ministerial

□ Emergency Project

■ Categorical Exemption (CEQA Guidelines Section 15308, Action by Regulatory Agency for Protection of the Environment)

□ Statutory Exemption

Reason why project is exempt: The revision of Rule 2.34 is an action taken to protect the environment and is therefore exempt from CEQA because it constitutes a Class 8 categorical exemption pursuant to CEQA

Guidelines 15308.

Lead Agency Contact Person Mat Ehrhardt, Air Pollution Control Officer Telephone Number (530) 757

- 3650

Signature: Date: Title:

## Notice of Exemption

To: ■ County Clerk County of Yolo 625 Court Street, Room 105 Woodland, CA 95695 □ County Clerk Solano County

600 Texas Street Fairfield, CA 94533

From: Yolo Solano Air Quality Management District 1947 Galileo Court, Suite 103 Davis, CA 95616

Project Title: Revision of Rule 2.34

- Stationary Gas Turbines

Project Location: Yolo Solano Air Quality Management District

Project Description : The revision of Rule 2.34 will lower the NOx emission limits of various categories of stationary gas turbines. The revision will also introduce separate start

- up period exemptions from the emission limits for simple cycle and combined cycle turbine power plants.

Name of Public Agency Approving Project: Yolo Solano Air Quality Management District

Name of Person or Agency Carrying Out Project: Yolo Solano Air Quality Management District

Exempt Status:

□ Ministerial

□ Emergency Project

■ Categorical Exemption (CEQA Guidelines Section 15308, Action by Regulatory Agency for Protection of the Environment)

□ Statutory Exemption

Reason why project is exempt: The revision of Rule 2.34 is an action taken to protect the environment and is therefore exempt from CEQA because it constitutes a Class 8 categorical exemption pursuant to CEQA

Guidelines 15308.

Lead Agency Contact Person : Mat Ehrhardt, Air Pollution Control Officer Telephone Number : (530) 757

- 3650

Signature: Date: Title:ATTACHMENT C

RESOLUTION NO. 14

- 08

### RESOLUTION NO. 14

- 08

RESOLUTION AMENDING YOLO

- SOLANO AIR QUALITY MANAGEMENT

DISTRICT RULE 2.34

WHEREAS , California Health and Safety Code section 40702 provides that an air quality management district shall adopt rules and regulations as may be necessary or proper to execute the powers and duties granted to, and imposed upon, the district by Division 26 of the

Health and Safe ty Code; and

WHEREAS , Health and Safety Code section 40727 provides that before adopting, amending, or repealing a rule or regulation, a district board shall make findings of necessity, authority, clarity, consistency, nonduplication, and reference, based upon information developed pursuant to section 40727.2, information in the rulemaking record maintained pursuant to section 40728, and relevant information presented at the public hearing required by section 40725; and

WHEREAS , section 15308 of the CEQA Guidelines provides that actions taken by regulatory agencies as authorized by state law to assure the maintenance, restoration, or enhancement of the environment where the regulatory process involves procedures for protection of the environment, are categ orically exempt from CEQA review (Class 8 Categorical Exemption); and

WHEREAS , the purpose of amending Rule 2.34, Stationary Gas Turbines is to reduce gas turbine emission limits, require emissions control during turbine start

- up, and establish a practica l start

- up period for combined cycle power plants.

NOW, THEREFORE, BE IT RESOLVED that the Board of Directors of the Yolo

Solano Air Quality Management District hereby finds, authorizes, directs and declares as

follows:

1. The Board of Directors has considered and hereby adopts by reference the staff report prepared in this matter

.

2. The Board of Directors makes the following findings pursuant to Health and Safety Code

section 40727:

a. Necessity: Information in the District = s rulemaking record maintaine d pursuant to Health and Safety Code section 40728 demonstrates a need for amending District Rule 2.34;

b. Authority: Health and Safety Code section 40702 permits the District to amend District Rule 2.34;

c. Clarity: District Rule 2.34 as amended is written so t hat its meaning can be easily understood by the persons directly affected by it;

d. Consistency: District Rule 2.34 as amended is in harmony with, and not in conflict with or contradictory to, existing statutes, court decisions, or state or federal regulation s;

e. Nonduplication: District Rule 2.34 as amended does not impose the same

### requirements as an existing state or federal regulation;

f. Reference: By adopting District Rule 2.34, the District meets the requirements of Health & Safety Code Sections 40702.

3. The B oard of Directors finds that the District has complied with the procedural requirements set forth in Chapters 6 and 6.5 of Part 3 of Division 26 of the Health and Safety Code.

4. The Board of Directors finds that amending District Rule 2.34 is an action taken by a regulatory agency as authorized by state law to assure the maintenance, restoration, or enhancement of the environment where the regulatory process involves procedures for protection of the environment, and is therefore categorically exempt from CEQA review as a Class 8 Categorical Exemption.

5. The Board of Directors hereby amends District Rule 2.34, Stationary Gas Turbines, as set forth in Exhibit 1 (Attachment A of the Staff Report), which is attached and incorporated by reference. The amendmen t is effective November 12, 2014.

PASSED AND ADOPTED by the Board of Directors of the Yolo

- Solano Air Quality Management District this 12th day of November, 2014, by the following vote:

Ayes:

Noes:

Absent:

Abstain:

Dilenna Harris, Chair

Board of Directors

Yolo

- Solano Air Quality Management District

Attest: Approved as to Form:

Denise Almaguer,

Board Clerk Hope Welton, District CounselATTACHMENT D

COMMENTS RECEIVED