3091 County Center Drive, Suite 240

, Auburn, CA 95603 (530) 745

- 2330 Fax (530) 745

- 2373

www.placer.ca.gov/apcd Thomas J. Christofk, Air Pollution Control Officer



### MEMORANDUM

TO: Board of Directors, Placer County Air Pollution Control District

FROM: John Finnell

, Senior Air Pollution Control Engineer

AGENDA DATE: December 1 0, 2009

SUBJECT: Adoption of Amendments to Rule 233, Biomass Boilers (A ction/Public

Hearing )

Action Requested:

1) Conduct a Public Hearing regarding the proposed adoption of a mendments to
Rule 233, Biomass Boilers

.

2) A pprove and adopt all Findings and Recommendations found in Attachment # 2

and a pprove Resolution #0 9

- 12 (Attachment # 1) thereby adopting a mendments to
Rule 233, Biomass Boilers

.

Background:

The District Rules and Regulations include three boiler regulations. These regulations were intended to regulate nitrogen oxide ( NOx ) emissions. Since carbon monoxide (CO) emissions general ly have an inverse relationship to NOx, CO is also regulated.

Natural gas and oil fired boilers rated at greater than 5 million Btu per hour are subject to the requirements of Rule 231, Industrial, Institutional, and Commercial Boilers Steam

Ge nerators and Process Heaters. There are a number of facilities in Placer County which must meet the requirements of this rule

.

Suspension biomass b oilers at medium density fiberboard (MDF) plants are required to
meet Rule 232, Biomass Suspension Boilers

. This regulation only applies to SierraPine in

Rocklin.

Biomass boilers that are major sources of NOx and are not located at an MDF plant are required to meet the Rule 233, Biomass Boiler

. This rule applies to the Rio Bravo Rocklin

and Sierra Pacific Industries , Lincoln, facilities in Placer County.

There are technical issues making the NOx and CO standard difficult to achieve during

some startups and shutdowns. As a result, an a mendment was adopted on October 11,

2007 which allow ed alternate emission limits during startup and shutdown.Adoption of Amended Rule 233, Biomass Boilers

District Board of Directors Agenda Date: December 10, 2009 Page 2

The October 11, 2007

, rule amendment was forwarded to the California Air Resou r ces Board (CARB) for approval into the California State Im plementation Plan (SIP). This was approved by CARB and forwarded to the U.S. Environmental Agency (USEPA) for approval.

USEPA declined to approve the amendment as inconsistent with federal regulation and pol icy. Their objections were in two areas:

1. The 115 ppm limit for NO

x does not app ly during startup and shutdown. Instead

mass emission limits in the Permit to Operate would apply. Although these limits were already in place in the both the District Permit t o Op erate and federal Title
V, EPA has requested that the limitations be listed in the Rule itself.

2. The amendment must provide a demonstration that both the length of time of the startups and shutdown and the emissions wer e minimized as much as technologi cally feasible.

In acknowledgement of US EPA ’s intention to disapprove the October 11, 2007, amendment, the District requested the withdrawal of the amendment from SIP

consideration in a letter dated October 14, 2008.

Discussion:

As there are only two boilers, one a stoker boiler and one a circulating fluidized bed

boiler

, that this rule applies to Section 101 has been amended to address those specific types of boilers by changing the applicability section to read :

“ This rule appl ies to stoker and circulating fluidized bed boilers and steam generators which have a heat input rating of less than 500 million Btu per

hour and a potential to emit, as defined in Rule 502, NEW SOURCE
REVIEW, 25 tons or more of NO

x emissions and which have a primary energy source of biomass consisting of a minimum of 75 percent of the total annual heat input

. ”

Any new stoker or circulating fluidized boilers rated less than 500 million Btu per hour would have to meet the proposed rule requirements and also apply Best Available Control Technology (BACT) to be determined during the permitting process.

If other types of boilers were proposed for installation in Placer County, the equipment would fall under other existing boiler rules , or possibly a new regulation would be

considered.

Exemptions:

There are no changes to the Exemptions.Adoption of Amended Rule 233, Biomass Boilers

District Board of Directors Agenda Date: December 10, 2009 Page 3

Definitions:

Definitions of a circulating fluidized bed boiler and stoker boiler were added. The definition of shutdown was changed.

Standards:

Carbon monoxide emission limitations were added to Section 301.1. These limitations were previously required but existed only in the Permits to Operate for the two affected

facilities.

Section 302, Startup and Shutdown Provisions, was added to allow the limitations for NOx and CO to be established in terms of mass emissions during startup and shutdown

instead of the concentrat ion of 115 ppmv.

Mass emission limitations for NOx and CO during startup and shutdown were added to

Section 302.1.b. For a circula ting fluidized bed boiler, the proposed NOx limitations are 35 pounds per hour on a 24 hour average (and for curing of refractory on a 72 hour average) and CO limitations of 56 pounds per hour on a 24 hour average (and for curing

of re fractory on a 72 hour average). For a stoker boiler, the proposed NOx limitations are 37.6 pounds per hour on a 24 hour average and CO limitations of 56 pounds per hour on a 24 hour average.

Mass emissions limits are usually expressed as pou nds per hour or pounds per day and do not require a CO 2 correction . This re moves the issue of low CO 2 causing the corrected

NOx and CO values to be artificially high in some cases

.

The proposed amendment removes Section 302.1.c. which requires a limit on the number of startups and shutdow ns in a calendar year as a permit condition. These limitations are currently in the District Permits to Operate and are not believed to be needed in the Rule.

Fiscal Impact:

California Health and Safety Code Section 40728.5 required all air quality districts to consider and make public any findings relating to the cost effectiveness of implementing

an emission contr ol m easure. The proposed Rule 233 amendment does not impleme nt an
emission control measure but instead allows emission limits in mass emi ssion rates

instead of concentrations during startup and shutdown and will not have a fiscal impact on any facility, and is not subject to th e cost effectiveness mandate.

Public Outreach :

The hearing notice was published in the Auburn Journal and Press Tribune newspapers on

or before November 8, 2009

, in advance of the scheduled public hearing. No other public meetings were held. In lieu of public meetings the District staff e mailed notices and copies of the proposed amended rule to the affected pe rmitted sources of the District advising them directly of the proposed rule and of their opportunity to comment either inAdoption of Amended Rule 233, Biomass Boilers

District Board of Directors Agenda Date: December 10, 2009 Page 4

writing or before the District Board’s public hearing. Comments have been received and

some of the comments have been entered in the f inal proposed rule.

Recommendation:

The purpose of the Board Hearing is to consider public testimony regarding the rule and to consider whether the proposed rule amendment is to be adopted

.

Staff recommends and requests that the Board :

(1) A pprove and adopt all Findings and Recommendations found in Attachment # 2

,

(2) A dopt Resolution #0 9

- 12

, Attachment # 1, thereby adopt ing the proposed

amendment to Rule 233, Biomass Boilers , as shown in Exhibit I of the resolution

.

Attachment ( s ) # 1 : Resolution #0 9

- 12 , Adoption of Amendment to Rule 233, Biomass Boilers

,

and Exhibit I (P roposed Rule 233 , strikeout version )

#2 : Analysis and Findings Required for Rule Adoption

#3 : Staff Report, Rule 233, Biomass Boilers

### ATTACHMENT #1

SUBJECT:

R esolution # 09

- 12- 1

- BEFORE THE BOARD OF DIRECTORS 1

PLACER COUNTY AIR POLLUTION CONTROL DISTRICT 2

STATE OF CALIFORNIA 3

4

RESOLUTION NO :

_ 09

- 12

_ 5

6

In the matter of: Approve Resolution # 0 9

- 12 , thereby adopting the Placer County Air 7

Pollution Control District’s proposed Amendments to Rule 233, Biomass 8

Boilers , as Shown in Exhibit I 9

10

11

The following RESOLUTION was duly passed by the Board of Directors, Placer County Air 12

Pollution Control District, at a regular meeting held December 10 , 2009 by the following vote: 13

14

Ayes: Holmes, M.___

__ Ucovich

_____ Weygandt___

__ Holmes, J. ___ __ Barkle

___ __ 15

Nakata___

__ Hill___

__ Uhler

_____ Allard

_____ 16

Noes: Holmes, M.___

__ Ucovich

_____ Weygandt___

__ Holmes, J. ___ __ Barkle

___ __ 17

Nakata___

__ Hill___

__ Uhler___ __ Allard

_____ 18

Abstain: Holm es, M.___

__ Ucovich

_____ Weygandt___

__ Holmes, J. ___ __ Barkle

_____ 19

Nakata___

__ Hill___

__ Uhler___ __ Allard

_____ 20

21

Signed and approved by me after its passage. 22

23

______________________________Chairperson 24

25

Attest: 26

27

______________________________Clerk of said Board 28

29

30- 2

-

WHEREAS , Section 40001 of the Health and Safety Code of the State of California authorizes 1

the Placer County Air Pollution Control District, to adopt and enforce Rules and Regulations to 2

achieve and maintain ambient air quality standards wit hin the District; and 3

4

WHEREAS , Section 40702 of the Health and Safety Code of the State of California requires a 5

district to adopt rules and regulations and do such acts as may be necessary or proper to execute 6

the powers and duties granted; and 7

8

WHEREAS

, these proceedings were held in a public hearing and were properly noticed 9

pursuant to Section 40725 of the Health and Safety Code of the State of California; with any 10

evidence having been received concerning the proposed adoption of this Resolution and th is 11

Board having duly considered such evidence; and 12

13

WHEREAS , the District has considered the relative cost effectiveness of the measure as well as 14

other factors, as required by Health and Safety Code Section 40922, and made reasonable efforts 15

to determine the direct costs expected to be incurred by regulated parties pursuant to Health and 16

Safety Code Section 40703; and 17

18

WHEREAS, Portions of the Placer County Air Pollution Control District (PCAPCD) have been 19

designated as “se vere ” non

- attainment areas for th e federal 8

- hour ozone standard and non

20

attainment for the 1

- hour ozone standard pursuant to the Federal Clean Air Act Amendments of 21

1990 (FCAA): and 22

23

WHEREAS , the proposed rule is a rule change to address a technical issue with startup and 24

shutdowns of ap plicable biomass boilers and make it SIP approvable but not specifically an 25

emission control measure; it was listed in the District’s annual “Regulatory Measures List “ 26

pursuant to Health and Safety Code Section 40923. 27

28

29- 3

-

NOW, THEREFORE, BE IT RESOLVED , tha t this Board approves and adopts this Rule 233

, 1

Biomass Boilers

, as shown in Exhibit I

. 2

3

BE IT RESOLVED AND ORDERED that the Air Pollution Control Officer is hereby 4

authorized and directed to submit this adopted rule, in the form as required by the Califo rnia Air 5

Resources Board , on behalf of the Placer County Air Pollution Control District, and to p erform 6

such acts as are necessary to carry out the purpose of this resolution. 7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

### E XHIBIT I

RULE 233, BIOMASS BOILERS (Strikeout Version)Strikeout Version December 10, 2009

Placer County APCD 233

- 1 Rules and Regulations RULE 233 BIOMASS BOILERS

Adopted 10

- 6

- 94 ( Amended 10

- 11

- 07 , Amended 12

- 10

- 09 )

CONTENTS

100 GENERAL

101 APPLICABILITY

102 FEDERAL REGULATIONS

103 EXEMPTION, BOILERS, STEAM GENERATORS, AND PROCESS HEATERS

104 EXEMPTION, BIOMASS SUSPENSION BOILERS

105 EXEMPTION, MUNICIPAL SOLID WASTE

106 EXEMPTION, WASTE HEAT RECOVERY BOILERS

200 DEFINITIONS

201 BIOMASS

202 BIOMASS BOILER OR STEAM GENERATOR

203 BRITISH THERMAL UNIT

204 CIRCULATING FLUIDIZED BED BOILER

205 CURING STARTUP

20 6 4 HEAT INPUT

20 7 5 HIGHER HEATING VALUE (HHV)

20 8 6 MUNICIPAL SOLID WASTE

20 9 7 NO X EMISSIONS

2 10 08 PARTS PER MILLION BY VOLUME (PPMV)

2 11 09 RATED HEAT INPUT CAPACITY

2 12 1 0 RESPONSIBLE OFFICIAL

2 13 1 1 SHUTDOWN

2 14 12 STARTUP

215 STOKER BOILER

21 3 6 UNIT

21 4 7 WOOD

300 STANDARDS

301 LIMITATIONS

302 STARTUP AND SHUTDOWN PROVISIONS

400 ADMINISTRATIVE REQUIREMENTS

401 OPERATION AND MAINTENANCE PLAN

402 COMPLIANCE COSTS

403 CERTIFICATION

500 MONITORING AND RECORDS

501 RECORDKEEPING

502 CONTINUOUS EMISSIONS MONITORING

503 INITIAL COMPLIANCE TEST

50 4 TEST METHODS

50 5 CORRECTION OF EMISSION CONCENTRATIONSDecember 10, 2009 Strike out Version

Rules and Regulations 233

- 2 Placer County APCD 50 6 DURATION OF RECORDSStrikeout Version December 10, 2009

Placer County APCD 233

- 3 Rules and Regulations This Page Intentionally Left BlankDecember 10, 2009 Strike out Version

Rules and Regulations 233

- 4 Placer County APCD 100 GENERAL

101 APPLICABILITY: This rule applies to stoker and circulating fluidized bed boilers and steam generators which have a heat input rating of less than 500 million Btu per hour an d a potential to emit, as defined in Rule 502, NEW SOURCE REVIEW, 25 tons or m ore of NO

x emissions and which have a primary energy source of biomass consisting of a minimum of 75 percent of the total annual heat input.

102 FEDERAL REGULATIONS: Compliance with this rule shall not exempt a person from complying with any federal regulation promulgated pursuant to the Clean Air Act (42 U.S.C. Section 7401 et seq.).

103 EXEMPTION, BOILERS, STEAM GENERATORS, AND PROCESS HEATERS: This rule

shall no t apply to boilers, steam generators, and process heaters subject to Rule 231, INDUSTRIAL, INSTITUTIONAL, AND COMMERCIAL BOILERS, STEAM GENERATORS,
AND PROCESS HEATERS.

104 EXEMPTION, BIOMASS SUSPENSION BOILERS: This rule shall not apply to existing boilers and steam generators subject to Rule 232, BIOMASS SUSPENSION BOILERS.

105 EXEMPTION, MUNICIPAL SOLID WASTE: This rule shall not apply to combustion units whose primary purpose is to burn municipal solid was te, as defined in Section 20 6 8

.

106 EXEMPTION, WASTE HEAT RECOVERY BOILERS: The provisions of this rule do not apply to waste heat recovery boilers used to recover sensible heat from the exhaust of combustion turbines or unfired waste heat recovery boile rs used to recover sensible heat from the exhaust of any combustion equipment.

200 DEFINITIONS

201 BIOMASS: Any organic material not derived from fossil fuels, such as agricultural crop residues, bark, lawn, yard and garden clippings, leaves, silvicultu ral residue, tree and brush pruning, wood and wood chips, and wood waste, including these materials when separ ated

from other waste streams. Biomass does not include material containing sewage sludge, industrial sludge, medical waste, hazardous waste, or r adioactive waste.

202 BIOMASS BOILER OR STEAM GENERATOR: Any combustion equipment used in any industrial, institutional, or commercial operation designed to burn biomass to produce steam, heat water or other fluids, and/or produce electricity.

203 BRITI SH THERMAL UNIT (BTU): The amount of heat required to raise the temperature of one pound of water from 59 degrees F to 60 degrees F at one atmosphere.

204 CIRCULATING FLUIDIZED BED BOILER: A boiler that burns solid fuel in a moving suspension of inert materials, forced through upward blowing of air jets, and where the ash and inerts are captured and recirculated back into the moving fluidized bed.

205 CURING STARTUP: A startup which includes heating the boiler at predetermined rate and holding tempera ture at several points to allow for insulating materials to cure in the boiler refractory. A curing startup shall not exceed 96 hours.

20 4 6 HEAT INPUT: The chemical heat released due to fuel combustion in a boiler, using the higher heating value of th e fuel. This does not include the sensible heat of incoming

combustion air.Strikeout Version December 10, 2009

Placer County APCD 233

- 5 Rules and Regulations 20 5 7 HIGHER HEATING VALUE (HHV): The total heat liberated per mass of fuel burned (BTU per pound), when fuel and dry air at standard conditions undergo complete combustion and

al l resultant products are brought to their standard states at standard conditions. HHV shall be determined by one of the following test methods:

20 5 7 .1 ASTM E711 for biomass ; or

20 5 7 .2 ASTM D 240

- 87 or ASTM D 2382

- 82 for liquid hydrocarbon fuels; or

20 5 7 .3 ASTM D 1826

- 88 or ASTM D 1945

- 81 in conjunction with ASTM D 3588

- 89 for gaseous fuels.

20 6 8 MUNICIPAL SOLID WASTE: Household, commercial/retail, and/or institutional waste. Household waste includes material discarded by single or multiple residential dwellings, hotels, motels, and other similar permanent or temporary housing establishments or facilities. Commercial/retail waste includes material discarded by stores, offices, restaurants, warehouses, non

- manufacturing activities at industrial facilitie s, and other similar

establishments or facilities. Institutional waste includes material discarded by schools, hospitals, prisons, and government facilities and other similar establishments or facilities.

20 7 9 NO X EMISSIONS: The sum of nitric oxides and nitrogen dioxide in the flue gas, collectively expressed as nitrogen dioxide (NO 2 ).

2 0 8 10 PARTS PER MILLION BY VOLUME (PPMV): The ratio of the number of gas molecules of a given species, or group, to the number of millions of total gas molecules.

2 09 11 RATED HEAT INPUT CAPACITY: The heat input capacity, in million BTU per hour, specified on the nameplate of the combustion unit. If the combustion unit has been altered or modified such that its maximum heat input is different than the input capacity specified on the nameplate, and this alteration or modification has been approved by the Air Pollution Control Officer and made a limiting condition of operation, then the new maximum heat input shall be considered as the rated heat input capacity.

2 10 12 RESPONSIBLE OFFICIAL: An indiv idual with the authority to certify that a source complies with all applicable requirements, including the conditions of permits issued to

sources in accordan ce with Regulation 5, PERMITS. A "responsible official" means one of the following:

2 1 0 1 2 .1 For a corporation, a president, secretary, treasurer, or vice

- president of the corporation in charge of a principal business function, or any other person who performs similar policy or decision

- making functions for the corporation, or a duly authorized represe ntative of such person if the representative is responsible for the overall operation of one or more manufacturing, production, or operating facilities applying for or subject to a permit and either:

2 1 1 1 2 .1.1 The facilities employ more than 250 persons or have gross annual sales

or expenditures exceeding $25 million (in second quarter 1980 dollars); or

2 1 1 1 2 .1.2 The delegation of authority to such representative is approved in

advance by the Air Pollution Control Officer;

2 1 0 1 2 .2 For a partnership or sole proprietorship, a general partner or the proprietor, respectively; or

2 1 0 1 2 .3 For a municipality, state, federal, or other public agency, either a principal executive officer or a ranking elected official; orDecember 10, 2009 Strike out Version

Rules and Regulations 233

- 6 Placer County APCD

2 1 0 1 2 .4 For an acid rain unit subject to Title IV (Acid Deposition Control) of the Clean Air Act, the "responsible official" is the designated representative of that unit for any purposes under Title IV and Rule 507, FED ERAL OPERATING PERMITS

PROGRAM.

21 1 3 SHUTDOWN: A shutdown starts when fuel feed is curtailed and the unit begins cooling from the unit’s normal operating temperature, as specified by the manufacturer, and ends when

the unit is 150 degrees F steam flow is zero or less for at least one hour

, or 24 hours has elapsed since the start of the shutdown , or fuel feed resumes , whichever occurs first.

21 2 4 STARTUP: Th e period of time a unit is heated to the normal operating temperature, as specified by the manufacturer , following a shutdown

. A normal startup shall not exceed 24 hours. A curing startup shall not exceed 96 hours.

21 3 5 STOKER BOILER: A boiler that burns solid fuel on a stationary or moving grate located at the bottom of the furnace, and where the fuel is supplied and ash removed continuously.

21 4 6 UNIT: Any biomass boiler or steam generator as defined in Sections 202.

21 5 7 WOOD: Wood, wood residue, bark, or any derivative fuel or residue thereof, in any form, including but not limited to sawdust, sanderdust, wood chips, scraps, slabs, millings, shavings, and processed pellets made from wood or other forest residues.

300 STANDARDS

301 LIMITATIONS:

301.1 No person shall allow the discharge of NO

x and CO emissions into the atmosphere from a biomass boiler or steam generator in excess of the following standards, whichever is less stringent, excluding startup and shutdown con ditions:

a. An exhaust concentration of 115 parts per million (ppmv) corrected to 12 percent by volume stack gas carbon dioxide (CO 2 ) on a three

- hour average dry basis.

b. 50 percent of the uncontrolled NO

x emission concentration in the exhaust gas stream. A corresponding controlled concentration limit, expressed in ppmv corrected to 12 percent by volume stack gas CO 2 on a three

- hour average dry basis, shall be established in a Permit to Operate for the purp ose of demonstrating continuous compliance with the 50 percent emission reduction.

Type of Boiler NOx CO

Circulating Fluidized Bed

(<500 MMBtu/hour) 115 ppmv corrected to

12% CO2 (3 hour rolling average) 400

ppmv corrected to

12% CO2 (3 hour rolling average)

Stoker

(<500 MMBtu/hour) 115 ppmv corrected to

12% CO2 (3 hour rolling average) 1000

ppmv corrected to

12% CO2 (3 hour rolling average)Strikeout Version December 10, 2009

Placer County APCD 233

- 7 Rules and Regulations 302 STARTUP AND SHUTDOWN PROVISIONS

302.1 The emission limits of Section 301.1 shall not apply during startup or shutdown provided the following requirements are met:

a. 302.1.1 CO 2 emissions are 10 percent or less by volume stack gas on a one

- hour

average dry basis.

b. Emission units subject to this rule shall have mass emission limitations for

NOx and CO applicable to startup and shutdown established in permit(s) to operate by January 1, 2008, for existing facilities or in the initial Authority to

Construct for new facilities.

302.1.2 During startup and shutdown, the mass emissions of NOx and CO shall not

exceed the levels shown below : . The block averaging time starts at the beginning of either the startup or the shutdown.

Type of Boiler NOx CO

Circulating Fluidized Bed

(<500 MMBtu/hour) 35 pounds per hour (24 hour block average) 56

pounds per hour (24 hour block average)

35 pounds per hour (72 hour block average during curing of refractory startup ) 56

pounds per hour (72 hour block average during curing startup of refractory )

Stoker

(<500 MMBtu/hour) 37.6 pounds per hour (3 hour rolling average) 170

pounds per hour (3 hour rolling average)

302.1.3. A normal startup shall not exceed 24 hours. A startup which involves

curing of refractory shall not exceed 96 hours.

c. Emission units subject to this rule shall have a limit on the number of startups and shutdowns in a calendar year as a permit condition.December 10, 2009 Strike out Version

Rules and Regulations 233

- 8 Placer County APCD 400 ADMINISTRATIVE REQUIREMENTS

401 OPERATION AND MAINTENANCE PLAN: Any person installing an emission control device as a means of complying with the emission limitations of Section 301 s hall submit an Operation and Maintenance Plan with the application for Authority to Construct for the

emission control device.

401.1 The Operation and Maintenance Plan shall specify:

a 401.1.1

. Operation and maintenance procedures that will demonstrate continuous

operation of the emission control device during emission

- producing operations; and

401.1.2 b. Records that must be kept to document the operation and maintenance

procedures.

401.1.3. Each source must provide to the District a description of th e actions that

will be taken to minimize emissions during startup and shutdown events.

401.2 The records must comply with Sections 501, 502, and 504.

401.3 The Operation and Maintenance Plan shall be implemented upon approval by the Air

Pollution Control Officer.

4 01.4 Subsequent to the construction of any emission control device used for demonstrating compliance with the emission limitation of Section 301, a n Operation and Maintenance Plan shall be submitted or resubmitted in conjunction with any changes in the procedures addressed in the plan, or upon the request of the Air
Pollution Control Officer.

402 COMPLIANCE COSTS: A person operating a unit subject to this rule shall bear all expenses associated with compliance with the monitoring and reporting provisions of this rule.

403 CERTIFICATION: All reports submitted in accordance with this rule shall be signed by a

resp onsible official who shall certify the truth, accuracy, and completeness of the report.

500 MONITORING AND RECORDS

501 RECORDKEEPING: A person operating a unit subject to this rule shall keep the following

records for each unit:

501.1 Calendar date of record.

501.2 Number of hours the unit is operated during each day.

501.3 Boiler load.

501.4 Fuel types, including supplementary gaseous or liquid fuels.

501.5 Duration of startups and shutdowns.

501.6 Type and duration of maintenance and repairs.

501.7 Results of compliance tests.Strikeout Version December 10, 2009

Placer County APCD 233

- 9 Rules and Regulations

501.8 Three

- hour average NO x emission concentration (expressed as NO 2 and corrected to 12 percent by volume stack gas CO 2 ).

501.9 Three

- hour average CO emission concentration (corrected to 12 percent by

vol ume stack gas CO 2 ).

501.10 Startup and shutdown emissions reco r ds using averaging periods as required in
Section 302.1.

501.1 1 0 Identification of time periods during which NO x and CO emission limitations are exceeded, the reason for the exceedance, and a description of corrective action

taken.

501.1 2 1 Identification of time periods during which operating condition and pollutant emission data were not obtained, the reason for n ot obtaining this information, and a description of corrective action taken.

502 CONTINUOUS EMISSIONS MONITORING

502.1 A person operating a unit subject to this rule shall install, calibrate, operate, and maintain a Continuous Emissions Monitoring System (CEMS) in accordance with applicable requirements of Appendices B and F of Title 40 Code of Federal Regulations Part 60 (40 CFR 60).

502.2 The CEMS shall include equipment that measures and records the following:

502.2.1 a

. Continuous exhaust gas NO x and CO concentrations corrected to 12

percent by volume stack gas CO 2 dry basis.

502.2.2 b

. Average NO x and CO concentrations calculated on a three

- hour average

basis.

502.3 A person operating a CEMS shall submit an excess emissions and monitoring system s performance report to the Air Pollution Control Officer within 30 days after the end of each calendar quarter in accordance with 40 CFR 60, Section 60.7(c) and (d) and Section 60.13.

502.4 The enhanced monitoring requirements of Sections 113 and 114 of the Federal Clean Air Act shall take precedence over the requirements of this Section for facilities subject to Rule 507, FEDERAL OPERATING PERMIT PROGRAM.

503 INITIAL COMPLIANCE TEST

503.1 An initial compliance test shall be conducted within 60 days of achieving the maximum firing rate at which the unit will be operated, but not later than 180 days after initial startup.

503.1.1 Each emission test run shall be conducted while the unit is operated within

10% of the maximum steady

- state steam production rate. No emission test shall be conducted during startup, shutdown, or under breakdown conditions for the purpose of the initial compliance test.

503.1.2

. The initial compliance test shall be conducted for NOx and CO using the

test methods specified in Section 504.December 10, 2009 Strike out Version

Rules and Regulations 233

- 10 Placer County APCD

503. 2 At least sixty (60) days prior to the initial compliance test, a written test plan detailing the test methods and procedures to be used shall be submitted for approval by the
Air Pollution Control Officer. The plan shall cite the test methods to be used for the determination of compliance with the emission limitations of this rule. The plan shall provide the proposed procedures for the characterization of the representative

biomass materials to be burned d uring testing.

50 4 CORRECTION OF EMISSION CONCENTRATIONS: NO

x and CO concentrations may be corrected to 8 percent by volume stack gas O 2 instead of 12 percent by volume stack gas
CO 2 if approved by the Air Pollution Control Officer in a Permit to Operate.

50 5 3 TEST METHODS: A person conducting source tests shall use the following test methods:

503.1 Nitrogen Oxides (NO X ): ARB Test Method 100, Title 17, CCR, Section 94114,

Procedu res for Continuous Emission Stack Sampling , or EPA Test Met hod 7E,

40 CFR 60, Appendix A. A violation determined by any of these test methods shall

constitute a violation of this rule.

503.2 Carbon Monoxide (CO): ARB Test Method 10, Title 17, CCR, Section 94109, Determination of Carbon Monoxide Emissions from Stationary Sources , or ARB Test Method 100, or EPA Test Method 10, 40 CFR 60, Appendix A. A violation determined by any of these test methods shall constitu te a violation of this rule.

503.3 Carbon Dioxide (CO 2 ): ARB Test Method 100, Title 17, CCR, Section 94114, Procedures for Continuous Emission Stack Sampling , or EPA Test Method 3A,

40 CFR 60, Appendix A.

50 6 4 DURATION OF R ECORDS : All records maintained pursuant to this rule shall be retained for at least two years from date of entry, with the exception that sources subject to the requirements of Rule 507, FEDERAL OPERATING PERMIT PROGRAM, shall reta in records at least five years. Records shall be made available for inspection by the Air Pollution Control Officer upon request.

### ATTACHMENT #2

SUBJECT:

ANALYSIS AND FINDINGS REQUIRED FOR RULE ADOPTIONANALYSIS AND FINDINGS REQUIRED FOR RULE ADOPTION

1 The following Analysis and the subsequent Findings are intended to address the requirements set forth in the Health and Safety Code relating to adoption of a new District Rule, as well as other

State statutes referenced herein.

1. Cost

- Effectiveness of a Control Measure

California Health & Safety Code (H&S) Section 40703 requires a District to consider and make public “the cost

- effectiveness of a control measure”. As the proposed rule does not impose new requirements but allows alternative emission limi ts during startup and shutdown , it is not a control

measure and no analysis is needed. There will be are no direct impacts to any operations that may be propo sed by an applicant/Permittee.

2. Socioeconomic Impact

H& S Section 40728, in relevant part, requires the Board to consider the socioeconomic impact of any new rule if air quality or emission limits are significantly affected. Since proposed Rule 233,

Biomass Boilers allows the use of alternative emission limits in mass emission rates instead of concentration only during startup and shutdown. The new emission limitations will allow or will not cause emission increases on a daily, quarterly or annual basis. T he proposed rule will not affect air quality or emissi on limitations in Placer County. The evaluation set forth in H&S Section 40728

is not needed.

3. California Environmental Quality Act (CEQA)

The p roposed Rule Amendment is not an activity that may cause a direct or reasonably foreseeable indirect physic al effect in the environment therefore not considered a “project”, as defined by

Section 21065 of the California Public Resource Code and Section 15 378(b)(4)&(5) of the CEQA guidel ines. A CEQA analysis is therefore not necessary.

4. Findings

H&S Code Section 40727 requires the PCAPCD, b efore adopting, amending, or repealing a rule or regulation, to “make findings of necessity, authority, clarity, consistency, nonduplication, and reference. These proposed findings are as follows:ANALYSIS AND FINDINGS REQUIRED FOR RULE ADOPTION

2 A. Necessity

– The amen dment to the rule is need ed to fix a technical requirement which was not identified in the previous rule development to address issues which occur during startup and shutdown

. B. Authority

– The proposed rule is not prohibited by any p rovision of law or state or federal regulation, and is therefore permissible.

C. Clarity

– The regulation is in substantial accord with the original rule but the amendment allows alternate limits at certain specified times which are startup and

shutdown most indemnification agr eements and is therefore found to be easily understood by the persons directly affected by it.

D. Consistency

– The regulation is in harmony with, and not in conflict with or contradictory to, existing statutes, court decisions, or state or federal regulation s.
E. Nonduplication

– The regulation does not impose the same requirements as an existing state or federal regulation.

F. Reference

– All statutes, court decisions, and other provisions of law used by PCAPCD in interpreting this regulation is incorporated into this analysis and this finding by

reference.

### ATTACHMENT #3

SUBJECT:

Staff Report RULE 233, BIOMASS BOILERS

### PLACER COUNTY

AIR POLLUTION CONTROL DISTRICT



# STAFF REPORT

RULE 2 33

BIOMASS BOILERS

PROPOSED AMENDMENTS

DECEMBER 1 0 , 2009Staff Report

– Rule 233, Biomass Boilers

Page 1

BACKGROUND

The Federal Clean Air Act, as amended in 1990, required a doption of source specific regulations

for major sources of nitrogen oxides (NO

x ) pursuant to Section s 182(b)(2)(C) and 182 (f). These sections required the adoption of Reasonable Available Control Technology (RACT) rules. In addition, the California Clean Air Act transport mitigation provisions required the adoption of Best Available Retrofit Control Technology (BARCT) for sources compromising 75% of the

actual NO

x emission inventory in the District.

Biomass boilers were affected by this requirement. There are currently three facilities with biomass boilers in Placer County: Rio Bravo

- Rocklin, Sierra Pacific Industries, and SierraPine

Ltd. Rule 232, Biomass Suspension Boilers , applies to SierraPine Ltd. Rule 233, Biomass

Boilers

, applies to Rio Bravo

- Rocklin which operates a fluidized bed b iomass boiler and to Sierra Pacific Industries which operates a stoker biomass boiler.

Rule 233, Biomass Boilers , was adopted on October 6, 1994 and subsequently approved in the California State Implementation Plan (SIP).

The rule limit ed NO

x emission to the least stringent of 115 ppmv corrected to 12% CO 2 or 50%

of the uncontrolled emission concentration in the boiler exhaust. Th e 115 ppmv limitation corresponds to the limitation in Sierra Pacific Industries Prevention of Significant Deterioration
(PS D) permit issued by the U.S. Environmental Protection Agency (EPA). This emission limitation reflected a determination by the U.S. EPA that the selective non

- catalytic reduction system used to control NO

x constituted Best Available Control Technology (BACT). Therefore this control technology and limitation would also represent RACT and BARCT which are less stringent requirements than BACT

.

NO

x emissions are measured by a continuous emission monitoring system (CEMS) installed in

the stack. The conce ntration is corrected or normalized to 12% CO2 so that one boiler may be compared to another. It is also corrected so that an operation can not introduce additional outside air into the boiler solely to lower the concentration. The correction is a simple calculation as

follows:

NO

x corrected to 12% CO2 = NO

x measured x 12 % / CO 2 % measured

However, an issue arises when CO 2 levels are low. Since the value is in the denominator of the
formula, the corrected value for NOx concentration will be increased. For example if CO 2 drops from normal operating levels of 10 to 12 percent down to 6 percent, the NO

x concentration

corrected value will be 12/6 or 2 times the measured value. This may cause the corrected NOx

concentration value to be an exceedence , if t here is a concentration emission limit that is based on steady

- state operations

.

In a d dition to the intentional dilution of the exhaust gases which the CO 2 correction ad j usts for by increasing the corrected NO

x concentration value, l ow CO 2 levels and sub sequent high NOx

concentration values can occur if too much diluant air is added, such as occurs when the combustion process is interrupted or combustion is just beginning. The problem occurs primarily during startup and shutdown.Staff Report

– Rule 233, Biomass Boilers

Page 2

As will be discussed in detail later in this document, U.S. Environmental Agency (U

. S

. EPA) policies on Startups, Shutdowns, and Malfunctions provides for excess emissions during startup

or shutdown needs to be addressed

. A n amendment was adopted on October 11, 2007 which allowed alternate emission limits during startup and shutdown to be conditions of the Permit to Operate for the boilers

.

The October 11, 2007

, rule amendment was forwarded to the California A ir Resources Board (CARB) for approval into the California State Implementation Plan (SIP). This was approved by

CARB and forwarded to the U.S. E PA for approval.

U.S. EPA declined to approve that amendment into the SIP as inconsistent with federal regulation and policy. Their response was contained in an email in Attachment # 1

. The main objections were in two areas:

1. The 115 ppm limit for NO

x does not apply during startup and shutdown. Instead mass

emission limits in t he Permit to Operate would apply. Although these limits were already in place in the both the District Permit to Operate and federal Title V, EPA has requested

that the limitations be listed in the Rule itself.

2. The amendment must provide a demonstration that both the length of time of the startups

and shutdown and the emissions wer e minimized as much as technologically feasible.

In acknowledgement of U.S. EPA intention to disapprove the October 11, 2007, amendment, the District request ed the withdrawal o f the amendment from SIP consideration in a letter dated
October 14, 2008.

DISCUSSION OF PROPOSED RULE AMENDMENT

As t here are only two boilers , one a stoker boiler and one a circulating fluidized bed boiler that this rule applies to

, Section 101 has be en amended to address those specific types of boilers by changing the applicability section to read

This rule applies to stoker and circulating fluidized bed boilers and steam generators which have a heat input rating of less than 500 million Btu per hour and a potential
to emit, as defined in Rule 502, NEW SOURCE REVIEW, 25 tons or more of NO

x emissions and which have a primary energy source of biomass consisting of a minimum of 75 percent of the total annual heat input

.

Any new stoker or circulating flu idized boilers rated less than 500 million Btu per hour would

have to meet th e proposed rule requirements and also apply Best Available Control Technology (BACT) to be determined during the permitting process.

If other types of boilers were proposed for i nstallation in Placer County, the equipment would fall under other existing boiler rules, or possibly a new regulation would be considered.

Section 200, Definitions, has been amended to add definitions of circulating fluidized bed

boilers

, stoker boilers and a curing startup

.Staff Report

– Rule 233, Biomass Boilers

Page 3

Changes were also made to the startup and shutdown definitions. A shutdown starts when fuel feed is curtailed and the unit begins cooling from the unit‟s normal operating temperature, as specified by the manufacturer, and ends whe n steam flow is zero or 24 hours has elapsed since

the start of the shutdown , whichever occurs first.

A boiler only has one purpose, and that is to generate steam. The steam c an be used for various reasons, including electric generation. When boiler conditions that do not allow for steam generation are reached, the boiler's operation is terminated. This point represents a useful

indicator for the end of a "shutdown". Boiler s team flow is easily measured and is continuously monitored and recorded in the control room by the plant operator.

The steam flow was chosen instead of temperature because steam flow is more indicative of the operational condition of the boilers with re gard to the end of a shutdown versus a temperature

measurement. In addition, because steam flow is likely to cease before any likely temperature threshold that might be used to indicate a shutdown condition such as 150 degrees Fahrenheit or

a “cold” shutd own at ambient temperature, the period of time defined as a shutdown using a zero steam flow threshold versus a temperature threshold is shortened. For example, Rio Bravo indicates that steam flow goes to zero at a boiler temperature of approximately 750 degrees F. At that time the biomass fuel is completely consumed and emissions are negligible. ( See Attachment

# 4 : Memo from Rio Bravo. ) Therefore using zero steam flow to denote the end of a shutdown effectively reduces the possible period of time d uring which alternative emission limits for shutdown may be used. In addition, the alternative emission limits proposed for shutdowns are only effective when the CO2 level is reduced to below 10% due to the shutdown conditions of

reduced combustion.

Hist orically, a shutdown under which the alternat ive emission limits would be used occur s in about approximately one

- third of the shutdowns. Both facilities affected by this rule are limited by permit conditions to sixty (60) per year. One facility, Rio Bra vo, reported two (2) qualifying shutdowns where alternative limits would have been used for a combined fourteen (14) hours and the other affected facility reported thirteen (13) shutdowns where alternative limits would have been used for a total of sixty

- t hree (63) hours.

A startup is defined as the period of time a unit is heated to the normal operating temperature, as specified by the manufacturer

. A normal startup shall not exceed 24 hours. A curing startup shall

not exceed 96 ho urs.

S ection 301, Limitations, which addresses limitations during normal operation, has been changed

to add a carbon monoxide ( CO ) for each type of boiler. These limitations currently exist in the Permits to Operate for each facility.Staff Report

– Rule 233, Biomass Boilers

Page 4

TABLE 1

- NOx and CO Emission Limitations

Type of Boiler NOx CO

Circulating Fluidized Bed 115 ppmv corrected to 12%

CO 2 (3 hour rol ling average) 400 ppmv corrected to 12%

CO 2 (3 hour rolling average)

Stoker 115 ppmv corrected to 12%

CO 2 (3 hour rolling average) 1000 ppmv corrected to 12%

CO 2 (3 hour rolling average)

To address EPA's concerns in effort to make the amendment SIP ap provable, this rule amendment

includes the mass emission limitations in pounds per hour as follows in Section 302, Startup and

Shutdown Provisions.

Table 2 Startup and Shutdown Emission Limitations

Type of Boiler NOx CO

Circulating Fluidized Bed 35

p ounds per hour (24 hour block average) 56 pounds per hour (24 hour block average)

35 pounds per hour (72 hour block average during curing of refractory) 56 pounds per hour (72 hour block average during curing of refractory )

Stoker 37.6 pounds per hour (3 hour rolling average) 170 pounds per hour (3 hour rolling average)

A normal startup will be limited to 24 hours. A startup which involves curing of refractory may not exceed 96 hours. A shutdown will also be limited to 24 hours.

Section 302.1 req uired emissions units subject to this rule to have a limit on the maximum number of startup and shutdowns allowed in a calendar year as a permit condition. Currently both facilities affected by this rule have these limits in their permits and this section should be removed as it is no longer needed.

MINIMIZING EMISSIONS AND DURATION OF STARTUP AND SHUTDOWN

U.S. EPA policy requires a demonstration that both the length of time of the startups and

shutdown and the emissions are minimized as much as technolo gically feasible. (See Attachment

# 2 )

As discussed earlier, high NO

x concentrations may occur when the combustion process is interrupted or combustion is just beginning during startup and shutdown because of the correctionStaff Report

– Rule 233, Biomass Boilers

Page 5

to 12% CO2 and the ammonia inj ection NOx control are not effective

. Th e proposed rule

amendment minimiz es emissions at these times by :

1. P rohibiting the exceedences of the same pounds per hour limitations that were in the facility permits for normal operations. T he se pound per hour li mitations for both facilities

are more restrictive than the concentration limitation of 115 ppmv @12% CO 2

.

2. Emission s may go to zero if the shutdown requires maintenance inside the boiler. This is the case when the affected facilities need to repair tube leaks or conduct semi

- annual

maintenance. Typically the repair times last one to two days. Semi

- a nnual maintenance

lasts approximately seven days. For example

, if the boiler is normally averaging 30 pounds per hour of NOx , but is down for 7 days, there would 5, 040 pounds less NOx

emissions.

For Rio Bravo's circulating fluidized bed boiler, the normal operating limitation of 115 ppm NOx

corrected to 12% CO 2 equates to 83.6 pounds per hour. The proposed NOx limit during startup

and shutdown is 35 pounds per hour. The normal operating limit of 400 ppm CO corrected to 12%

CO 2 equates to 176.9 pounds per hour. The proposed CO limit during startup and shutdown is 56 pounds per hour.

For Sierra Pacific Industries ‟ stoker boiler, the normal operating limit ation of 115 ppm NOx

corrected to 12% CO 2 equates to 60.6 pounds per hour. The proposed NOx limit during startup

and shutdown is 3 7.6 pounds per hour. The normal operating limit of 1000 ppm CO corrected to 12% CO2 equates to 227.5 pounds per hour. The p roposed CO limit during startup and shutdown

is 170 pounds per hour.

These calculations are shown in Attachment # 3.

U.S. EPA prepared a Policy Clarification guidance memorandum 1 (1982

- 1983 timeframe) that presented a policy for SIPs regarding excess emissions during malfunctions, startup, shutdown,

and maintenance. Interpretat ion of this policy allowed for enforcement discretion at national levels for emission exceedances during startup and shutdown (SU/SD) events. During a review of SIPs,

U.S. EPA observed several provisions that appeared to be inconsistent with the orig inal policy.

The 1999 U.S. EPA Memorandum by Steven Herman and Robert Perciasepe “State Implementation Plans (SIPs): Policy Regarding Excess Emissions During Malfunctions, Startup, and Shutdown” was prepared and distributed to the control authorities

. It was intended to take the opportunity to clarify several issues of interpretation and reaffirm and supplement the original policy. Various issues were discussed, including specific emission limits for startup and shutdown events, the “affirmative def ense” concept, and how modifications to SIPs could occur and meet the requirements described in the 1999 U.S. EPA memorandum.

The main question of interpretation that has arisen regarding the original policy is whether a State may go beyond an “enfor cement discretion” approach and include in its SIP a provision that
would, in the context of an enforcement action for excess emissions, excuse a source from penalties if the source can demonstrate that it meets certain objective criteria (an “affirmative

1 Kathleen Bennett, Assistant Administrator for Air, Noise and Radiation dated September 28, 1982 and February 15, 1983.Staff Report

– Rule 233, Biomass Boilers

Page 6

defense”). The 1999 memorandum clarifies that States have the discretion to provide such a defense to actions for penalties brought for excess emissions that occur during certain malfunction, startup, and shutdown episodes.

In general, because excess emi ssions that occur during these periods are reasonably foreseeable, they should not be excused. However, EPA recognizes that, for some source categories, even the best available emissions control systems might not be consistently effective during startup o r shutdown periods. In areas where no single source or small group of sources has the potential to cause an exceedance of the NAAQS or PSD increments, these startup and shutdown periods may

be addressed in the standards. This can be done through narrowly

- tailored SIP revisions that take into account the potential impacts on ambient air quality caused by the inclusion of these excess

emissions. In these instances, as part of its justification of the SIP revision, the State should analyze the impact of the potential worst

- case emissions that could occur during startup and shutdown periods.

U.S. EPA recognizes that there are several approaches that may be used to incorporate excess emission provisions into SIPs so that they can in turn provide greater certa inty to the regulated community. The main approaches are:
Enforcement Discretion, and/or

General Affirmative Defense Provision

In order to provide the most certainty to the regulated community, a SIP revision using a general affirmative defense provision meeting the requirements of the EPA Policy on Excess Emissions During Malfunctions, Startup, and Shutdown can be pursued. This is a more definitive approach, and thus does not rely on “agency enforcement discretion” for each event.

This amendme nt to Rule 233 is an opportunity to amend this Rule to include specific emission limits and conditions for startup and shutdown events in accordance with the United States Environmental Protection Agency ( U.S. EPA ) 1999 Memorandum , in regard to settin g standards satisfying affirmative defense provisions

. Accordingly, a justification discussion of how each of the seven points described in the memorandum is met is provided in the following paragraphs.

The normal operating emission limits for NOx and CO expressed as a concentration will not apply during narrowly defined startup and shutdown periods . I nstead, alternative emission limits in pounds per hour for startup and shutdown will apply and will be defined in the SIP amendment. To align with the EPA Policy, it must be demonstrated that the revision meets the following requirements:

U.S. EPA Policy Requirements:

1. Requirement: The revision must be limited to specific, narrowly

- defined source categories using specific control strategies (e.g., cogenerat ion facilities burning natural gas and using selective catalytic reduction)

.

Justification Discussion: The Rule 233 SIP revision applies only to the following source category:

Stoker and fluidized bed bo ilers and steam generators which have a potential t o emit, as defined in
Rule 502, N ew Source Review , 25 tons or more of NOx emissions and which have a primaryStaff Report

– Rule 233, Biomass Boilers

Page 7

energy source of biomass consisting of a minimum of 75 percent of the total annual heat input

. This rule applies to two facilities which utilize s elective n on

- c atalytic r eduction (SNCR) to control

NOx emissions. These systems inject ammonia into the boilers.

2. Requirement: Use of the control strategy for this source category must be technically infeasible during start

- up or shut

- down periods

.

Just ification Discussion: The NO

x control technology (either SCR or SNCR) requires a specific operating temperature range in order to function. Therefore, the NO

x emission control system is technically limited during periods of start

- up and shut

- down periods when the boiler is not within the temperature range.

The SNCR process does not operate at low system temperatures (less than 1,400°F) and functions best at temperatures between 1,600°F and 1,800°F. During a startup, the combustion system is

fired on natu ral gas (NG) or other similar startup fuel until the primary fuel can begin to be introduced into the system. Once the temperature of the combustion system reaches the normal operating temperature (and thermal equilibrium), ammonia injection begins, which allows for the

non

- catalytic NOx reduction reactio ns to occur.

If a mmonia is injected before the system reaches the normal operating temperature, significant emissions of ammonia (ammonia slip) occur as the ammonia is not reduced by conversion to nitroge n and water prior to exiting the stack.

In addition, due to the combustion process characteristics, the CO emissions undergo significant variation until the flame stability improves. Generally, the flame stability improves as fuel flow

increases and the system temperature rises. Once the system reaches thermal equilibrium, CO emissions are controlled by stable flame characteristics, which promote CO emissions that are in compliance with normal operations permit limits.

During a shutdown, the ammonia inj ection continues until the temperature of the system drops below the normal operating range for the SCR or SNCR control process to occur. The ammonia

flow is then shut

- off to eliminate ammonia slip. Thus

, during a shutdown, the NOx control system

can not be used to control NOx emissions throughout the complete shutdown cycle.

Furthermore

, during a shutdown the combustion process characteristics vary and thus the flame stability can degrade sufficiently to cause high CO emissions before the fuel (either primary fuel or NG/propane/or other similar stabilization fuel) is completely shut off

.

3. Requirement: The frequency and duration of operation in startup or shutdown mode must be minimized to the maximum extent practicable

.

Justification Discussi on: This requires implementation of narrowly defined periods for startup and shutdown which are unique to each boiler type. A startup commences when fuel is first introduced

into the combustion unit. A startup ends when the combustion unit reaches normal operating temperatures as defined for each specific combustion unit. Typically for a woodfired boiler startup internal temperatures must not be raised more than 100 degrees F per hour or damage may occur

to the boiler tubes. Initial preparation and firi ng takes several hours plus raising temperature fromStaff Report

– Rule 233, Biomass Boilers

Page 8

70 degrees to 1250 degrees F takes another 12 hours. A startup will not last longer than 24 hours (96 hours for a concrete curing startup).

The reason for a curing startup length of 96 hours i s that this represents the length of time required to cure the refractory when it is poured in the combustor area.

The startup temperatures are controlled by the amount of fuel introduced into the boiler.

By definition, a shutdown commences when fuel load is reduced in preparation for shutting fuel

flow off and the boiler begins cooling from normal operating temperature. It ends when one of the following occurs: (1) the re is no steam flow

, ( 2 ) more than 24 hours has el apsed since the start of

shutdown. The duration is 24 hours to allow for sufficient time for most systems to cool down sufficiently so that the boiler system can be safely entered for maintenance purposes.

The number of startup and shutdown events must be limited for each facility to ensure that the emissions from these narrowly defined startup and shutdown events are minimized and accounted for in the ambient air modeling scenarios.

The number of startup and shutdown events for each facility over the course of a year is depe ndent on many factors including:

Type of facility (peaker facility, base load facility, utility boiler, independent power producer, etc.) Type of fuel used (biomass from urban sources, biomass from agricultural sources,
biomass from forests, biomass from i ndustrial sources, etc.) Boiler and facility design (Stoker boiler, circulating fluidized bed, bubbling bed,
etc.) If the facility has a power purchase agreement (PPA) Age of facility Is original fuel still available? Does available fuel meet all origina l design criteria? Or are there additional constituents that may cause problems in system? Does available fuel meet all pollution control equipment design criteria? Or are there additional constituents that may cause problems in system?

T he affected fac ilit ies are b usiness es , and thus it is in their best interest to be in “normal operations” as much as possible, and not in the process of shutting

- down, starting

- up , or in an

outage. G oing through a shutdown and startup cycle frequently is not in the inte rests of the facility

and will be avoided to the greatest extent possible. Accordingly, market forces and finances will limit the viability of each facility if shutdowns and startups occur too frequent l y.

A permitted number of startup and shutdow n events may be derived from the anticipated number of startups and shutdowns required for the individual facility due to equipment variations and operating characteristics which are inherent to the individual design of each facility. Operations

includes: scheduled maintenance, forced outages, utility dispatch, breakdowns and malfunctions.

After reviewing all of the above factors and other performance related concerns, the number of

startup s and shutdown s are limited by permit conditions to provide a “n ot to exceed limit”Staff Report

– Rule 233, Biomass Boilers

Page 9

although the actual number of startups and shutdowns will likely be much less and dictated by the desire of each facility to minimize the loss of revenue that outages represent. For cap purposes, Rio Bravo is limited to twenty ( 20 ) in a quarter and no more than sixty ( 60 ) in a year that exceed the normal operating emission limits. Sierra Pacific Industries is limited to fifty (50) per year.

4. Requirement: As part of its justification of the SIP revision, the state should analyze the p otential worst

- case emissions that could occur during startup and shutdown periods

.

Justification Discussion: The worst case emissions were reviewed

. The concentrations in the exhaust gas increase but the pounds per hour averaged over the periods shown in Table 2 are not expected to be exceeded. This indicates there are no impacts.

The emissions from each facility during a startup and shutdown period ramp s

- up to and ramp s

down from the normal operating conditions and permit limits. For example, during startup, the emission control system (NO

x ) is not functioning and the combustion characteristics are poor (CO), thus, the NOx emissions and CO emissions are high in terms of concentration at the onset of

a startup event. The NOx emissions are high because there is no control of emissions and the combustion process results in localized temperatures high enough to cause the N2 to NOx reaction

to occur. The CO emissions are high because the poor combustion conditions do not facilitate complete combust ion. This is a result of many factors including poor mixing, high localized temperatures, and low temperatures on average in the combustor region.

As the startup process continues, the startup fuel flow rate is increased with the result allowing steadily climbing average temperatures in the combustor, improving mixing characteristics, and

overall better combustion characteristics to occur. This causes lower CO emissions due to the more complete burnout of the startup fuel. When the system heats up suffi ciently, the NOx cont rol system will begin operating, this usually occurs near the end of a startup event for facilities that

use selective non

- catalytic reduction (SNCR), because the optimum operating temperature range

for the NO

x control system is 1,500° F to 1,850°F.

Due to the nature of the combustion process, the startup emission limits are less likely to be exceeded the longer that the startup lasts and the longer the averaging period. However during the initial phases of a startup, any emission limi ts are likely to be exceeded for a short period of time because of the lack of effective pollution control techniques. For example, CO emissions will spike during initial phases of startup. As the startup progresses, the concentration of CO in the

exhaus t gases will drop to the normal operating levels.

Likewise the NOx emissions will spike during the startup event, but due to the nature of combustion process, and prior to initiating ammonia injection to begin th e SNCR reaction.

5. Requirement: All possible steps must be taken to minimize the impact of emissions during start

- up and shut

- down on ambient air quality

.

Justification Discussion: Each source must provide to the District a description of the actions that will be taken to minimize emissions during startup and shutdown events. These will be incorporated into their Permit.Staff Report

– Rule 233, Biomass Boilers

Page 10

The startup and shutdown emission limits that were chosen for CO and NO

x are the same limits

that each facility complies with during normal operations but with a longer averaging period for the circulating fluidized bed boilers

. The startup and shutdown limits (lbs/h ou r) are derived from

the curre ntly existing daily limits (lbs/day) that are in the PTO. The intent is to limit a facility to the same hourly emission rate, however allow for the emission spikes that occur during all startup

and shutdown combustion events. The averaging period for circulating fluidized bed boilers for normal startup and shutdown events is a block 24 hour period, with the total startup and shutdown

event not to exceed 24 hours.

The startup emission limit that was chosen for CO and NO

x for a curing startup event is also the same limits that the facility complies with during normal operations but with a longer averaging period for circulating fluidized bed boilers

. The intent is to limit the facility to the same hourly
emission rate, however

, allow for emission spike s that occur during the curing event. Since a curing event can last for a period longer than 24 hours depending on how much, which refractory areas, and what type of concrete are re

- poured a longer averaging period is required. Quantity, location, and ty pe of concrete can all affect the total curing time. The reason for this is that the curing process normally consists of heating the boiler system at a pre

- determined rate and holding the system temperature constant at several points to allow for the conc rete to dry and „set‟. Different quantities of concrete, areas repaired, and type of concrete all can affect the temperature curve and the temperature duration levels used during the curing process. The averaging period for a curing startup is thus minim ized to a block 72 hour period, with the total curing startup not to

exceed 96 hours.

U.S. EPA has issued startup and shutdown emission limits with block averages in other permits. The twenty

- four or seventy

- two block averaging periods represent nor mally expected startup or

shutdown events. The block averaging period hours will be flagged in the CEMS data and will facilitate identifying and counting of each event. The CEMS averaging calculations will include

valid data hours.

A facility is min imizing emissions by following the manufacturer‟s startup and shutdown procedures, which minimizes the “wear and tear” on the system. Deviating from these operational practices will increase maintenance costs, increase downtime for a facility, increase the number of startups and shutdowns, and increase the annual emissions from startup and shutdown events. The emission limits presented represent good engineering practice when the system is not at equilibrium (and therefore emitting hi gher CO levels than during normal operations) and the NOx air pollution control is not functioning due to technical constraints (and therefore emitting higher NOx levels than normal operations).

6. Requirement: At all times, the facility must be operated in a manner consistent with good practice for minimizing emissions and the source must have used best efforts regarding planning, design, and operating procedures to meet the otherwise applicable emission limitation

.

Justification Discussion: Sources will be required in their Permit to be operated in a manner consistent with good practice for minimizing emissions, and the source must have used best efforts regarding planning, design, and operating procedures to meet the otherwise applicable

emission limita tions.Staff Report

– Rule 233, Biomass Boilers

Page 11

It should be understood that the facilit ies are business es , and thus it is in their best interest to attain “normal operations” as soon as possible. Generating electricity at design conditions is the most

efficient and cost effective scenari o.

7. Requirement: The owner or operator’s actions during startup and shutdown periods must be documented by properly signed, contemporaneous operating logs, or other

relevant evidence.

Justification Discussion: Sources must demonstrate that actions are bei ng taken during startup and

shutdown events to minimize emissions. This will be a requirement in their permit, and can be achieved in several ways: by maintaining operating logs, identifying periods of startup and shutdown in the CEMs, reported in quarter ly and annual reports, and implementing site specific Plant Operating Procedures (POP), following manufacturer recommendations/guidelines during these periods.

The manufacturer‟s recommended operating practices and POPs can be discussed with agency

pers onnel to describe how the plant operations minimized emissions during startup and shutdown

events.

On a case by case basis, the source can also offer other relevant evidence that describes these

actions for District consideration.

RACT Evaluation

The RACT/BACT/LAER database contains case

- specific information on the "Best Available" air pollution technologies that have been required to reduce the emission of air pollutants from stationary sources (e.g., power plants, steel mills, chemical plants, etc.). This information has been provided by State and local permitting agencies. The Clearinghouse also contains a regulation data base that summarizes EPA emission limits required in New Source Performance Standards (NSPS), National Emission Standards for Ha zardous Air Pollutants (NESHAP), and Maximum Achievable Control Technology (MACT) standards. The database information pertains to normal operations of the facilities as can be seen because the facilities have pollution control equipment that does not oper ate at ambient and low temperatures (startup temperatures). Please note that the

list reviewed has not been confirmed to be “demonstrated”.

The RACT/BACT/LAER database was reviewed for comparison purposes and the following

information was identified:

Th e lbs/hr CO emission limit for Rio Bravo's circulating fluidized bed boilers (CFBs) equates to

0.16 lbs/MMBtu. The lbs/hr CO emission limit for Sierra Pacific Industries stoker boilers equates

to 0.59 lbs/MMBtu. The CO emission limit for facilities permi tted since 1990 ranged from 0.1 lbs/MMBtu to 0.63 lbs/MMBtu, with most of the units (10 of 14) in the range 0.3 ≤ x ≤ 0.5 lbs/MMBtu. Two units had CO emission limits slightly lower than the 0.16 lbs/MMBtu presented

in this revision. However, in one case, the system was required to have a CO oxidation catalyst
(RBLC ID OH

- 0307) and in the other case (RBLC IDNH

- 0013), the averaging period was 24

hours above 50% load. Interestingly, one other facility was required to install a CO oxidation catalyst, though the emission limit was 0.3 lbs/MMBtu. In the vast majority of the data reviewed,Staff Report

– Rule 233, Biomass Boilers

Page 12

the control technology for CO emissions was described as “good combustion practices” and/or “combustor design.”

The lbs/hr NO

x emission limit for the Rio Bravo's CFB equates to 0.098 lbs/MMBtu. The lbs/hr

NO

x emission limit for the Sierra Pacific Industries stoker boiler equates to 0.13 lbs/MMBtu. The

NO

x emission limit for facilities permitted since 1990 ranged from 0.075 lbs/MMBtu to 0.6 lbs/MMBtu, with most of the units ( 13 of 17) in the range 0.1 ≤ x ≤ 0.3 lbs/MMBtu. One unit had

a NO

x emission limit slightly lower than the 0.098 lbs/MMBtu presented in this revision. However, in this case (RBLC ID NH

- 0013), the averaging period was 24

- hours.

T he existing emission limits for the normal operations meet RACT/ BA R CT. Additionally the proposed startup and shutdown limits presented in this Rule 233 amendment also meet the

RACT /BARCT requirements and do not represent a relaxation of current emission limits because the same pou nd/hour limitations apply.

DISCUSSION OF PROPOSED RULE AMENDMENT

Applicability:

The amendment changes the applicability to stoker and circulating fluidized bed boilers and steam generators with a heat input of less than 500 million Btu per hour. T hese are the two types of boilers operated in Placer County to which this rule currently applies.

Exemptions:

There are no changes to the Exemptions.

Definitions:

Definitions of a circulating fluidized bed boiler

, stoker boiler and curing startup were added. The definitions of startup and shutdown were amended.

Standards:

Carbon monoxide emission limitations were added to Section 301.1.

Mass emission limitations for NO

x and CO during startup and shutdown were added to Section

302.1. For a circulat ing fluidized bed boiler, the proposed NOx limitations are 35 pounds per hour on a 24 hour average (and for curing of refractory on a 72 hour average) and CO limitations of 56 pounds per hour on a 24 hour average (and for curing of refractory on a 72 hour average). For a stoker boiler, the proposed NO

x limitations are 37.6 pounds per hour on a 24 hour average and CO

limitations of 170 pounds per hour on a 24 hour average

.

The proposed amendment removes Section 302.1.c. which require d a limit on the numb er of startups and shutdowns in a calendar year as a permit condition.Staff Report

– Rule 233, Biomass Boilers

Page 13

Administrative:

There are no changes to the Administrative Requirements.

Monitoring and Records:

Section 501.5 was changed to require records of the duration of each startup and sh utdown.

Section 501.10 was added to require records of the startup and shutdown emissions.

FINDING S

FINDING DEFINITION REFERENCE
Authority The District is permitted or required to adopt, amend, or repeal the rule by a provision of law or a state or federal regulation. California Health and Safety Code,
Section 40702 and Section 41010;
1990 Federal Clean Air Act, Section 110(a)(2)(H) and Section 182(d). Necessity The District has demonstrated that a
need exists for the rule, or for its

amendment or repeal. It is necessary for the District to adopt this rule in order to fulfill the requirements of the Federal Clean

Air Act Amendments of 1990 and seek SIP approval. Clarity The rule is written or displayed so that its meaning can be easily

understood b y the persons directly affected by it. There is no indication at this time

that the rule is not written in such a manner that the person affected by the rule can easily understand it. Consistency The rule is in harmony with, and not

in conflict with or co ntradictory to, existing statutes, court decisions, or state or federal regulations. The District has found that the rule is consistent with existing state and federal guidelines.

Non

- duplication The rule does not impose the same requirements as an existi ng state or federal regulation, unless the District finds that the requirements are necessary or proper to execute the powers and duties granted to, and imposed upon the District. NSPS, Subpart Da and Db apply to these boilers but the requirements are

less stringent than Rule 233.

Reference Any statute, court decision, or other provision of law that the District implements, interprets, or makes specific by adopting, amending, or repealing the rule. An example of

this would be the 1988 EPA State Implementa tion Plan call to revise

District rules. This rule is being proposed because of the requirements of the Federal

Clean Air Act Amendments of 1990.Staff Report

– Rule 233, Biomass Boilers

Page 14

SUMMARY

This amendment has been proposed to address comments from U.S. EPA and to make Rule 233,

Biomass B oilers , SIP approvable. The amendment places requirements that are currently in the Permits to Operate for two facilities in Placer County into this rule.

A ttachments (s) # 1: EPA Comments on 2007 Amendment to Rule 233

# 2: 1999 U.S. EPA Policy

# 3: Calculations

# 4: Rio Bravo Memorandum

### ATTACHMENT # 1

SUBJECT:

EPA Comments on 2007 Amendment to Rule 233

### ATTACHMENT # 2

SUBJECT:

1 999 U.S. EPA Policy

### ATTACHMENT # 3

SUBJECT:

CalculationsRio Bravo Rocklin

- Circulating Fluidized Bed Boiler

NOx Calculations (Enter numb er in cell with blue text)

ppm corrected to 12% CO2 115 typical %CO2 during normal operation 12.23 ppm actual = 117.20

dscfm =dry standard cubic feet per minute= 98,023 SV = specific molar volume = 379.5 @ 60 degrees F

Qsd = flowrate dscfm

MW = NOx = 46

lbs/hr = ppm x 10^

- 06[MW]/SV x Qsd x

60 lbs/day

83.6 NOx lbs/hr 2005.3 lbs/day

Input 356.8 MMBtu/hr

lbs/MMBtu= 0.23

CO Calculations (Enter number in cell with blue text)

ppm corr ected to 12% CO2 400 typical %CO2 during normal operation 12.23

ppm = 407.67 dscfm=dry standard cubic feet per minute= 98,023 SV = specific molar volume = 379.5 @ 60 degrees F

Qsd = flowrate dscfm

MW = CO 28

lbs/hr = ppm x 1 0^

- 06[MW]/SV x Qsd x

60 lbs/day

176.9 CO lbs/hr

Input 356.8 MMBtu/hr

lbs/MMBtu= 0.50Sierra Pacific Industries

- Stoker Boiler

NOx Calculations (Enter number in cell with blue text)

ppm corrected to 12% CO2 115
typ ical %CO2 during normal operation 17.23 ppm actual = 165.12 dscfm=dry standard cubic feet per minute= 50,427 SV = specific molar volume = 379.5 @ 60 degrees F

Qsd = flowrate dscfm

MW = NOx = 46

lbs/hr = ppm x 10^

- 06[MW]/SV x Qsd x

60 lbs/day

60.6 NOx lbs/hr 1453.4 lbs/day

Input 356.8 MMBtu/hr

lbs/MMBtu= 0.17

CO Calculations (Enter number in cell with blue text)

ppm corrected to 12% CO2 1000 typical %CO2 during normal operation 12.23

ppm = 1019.17 dscfm=dry standard cubic feet per minute= 50,427 SV = specific molar volume = 379.5 @ 60 degrees F

Qsd = flowrate dscfm

MW = CO 28

lbs/hr = ppm x 10^

- 06[MW]/SV x Qsd x

60 lbs/day

227.5 CO lbs/hr

Input 356.8 MMBtu/hr

lbs/MMBtu= 0.64

### ATTACHMENT #4

SUBJECT:

Rio Bravo Memorandum

### M EMORANDUM

DATE: November 24, 2009

TO: John Finnel l

FROM: Dr. Ted Guth, Maggie Estrada, Jack Snider

SUBJECT: Rio Bravo Roc klin

CC: Response to EPA Questions re: Rule 233



### John: Please convey these thoughts to the person at EPA asking questions.

1. Steam flow goes to zero during every shutdown.

2. Steam flow goes to zero at a boiler temperature of approximately 750°F.

3. Wh en the boiler temperature falls to approximately 750°F, the fuel is

completely consumed and stack emissions cease.

4. When the boiler is at approximately 750°F, a “warm startup” can occur. It

is estimated that the “warm startup” scenario occurs after about one

- third of

Rocklin‟s controlled shutdowns. Conversely, a “cold startup” occurs after

approximately two

- thirds of Rocklin‟s controlled shutdowns.

5. During a maintenance outage, the boiler temperature will drop to between

140°F and ambient to allow maint enance crews to safely enter and perform

work within the boiler. Following a maintenance outage, a boiler “cold

startup” would occur.

### 6. The type and length of maintenance performed (inside or outside of the

boiler) will determine whether a boiler “warm sta rtup” or “cold startup” is

necessary. A “warm startup” is always preferred, since it is the most

efficient due to the least amount of heat lost and minimizes the stack

emissions and the startup time.