United States Environmental Protection Agency, Region 9 

Air Division 

Technical Support Document 

for 

EPA’s Notice of Proposed Rulemaking 

for the 

California State Implementation Plan 

San Joaquin Valley Unified Air Pollution Control District’s 

Rule 4320, Advanced Emission Reduction Options for Boilers, Steam Generators and Process 

Heaters Greater than 5.0 MMbtu/hr 

Prepared by: Idalia Perez 

August 19, 2010 
San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) 

Submitted Rule 

SJVUAPCD Rule 4320, Advanced Emission Reduction Options for Boilers, Steam Generators 

and Process Heaters Greater than 5.0 MMbtu/hr 

 Adopted: October 16, 2008 

 Submitted: March 17, 2009 

 Determined complete: April 20, 2009 

Previous Rule Submittals 

There are no outstanding submittals of Rule 4320. 

SIP-Approved Rule 

There is no SIP-approved version of Rule 4320. 

Rule Summary 

Rule 4320 limits NOx, SO2, PM10 and CO emissions from boilers, steam generators and process 

heaters with a total rated heat input greater than 5 MMBtu/hour. 

Rule 4320 provides three options for compliance: 

1. Comply with the NOx emission limits and PM control measures specified in the Rule; or 

2. Pay an annual NOx emissions fee to the District and comply with PM control measures; 

or 

3. Comply with the low-use requirements. 

The NOx limits in the Rule are as follow: (Std = standard schedule; Enh = enhanced schedule; 

SESIL = Staged Enhanced Schedule, Initial Limit; SESFL = Staged Enhanced Schedule Final 

Limit) 

Category NOx Limit Compliance 

Deadline 

A. Units with a total rated heat input > 5.0 MMBtu/hr to < 

20.0 MMBtu/hr, except for Categories C through G units

STD - 9 ppmv or 

0.011 lb/MMBtu 

ENH - 6 ppmv or 

0.007 lb/MMBtu

STD – 07/01/2012

ENH – 01/01/2014 

B. Units with a total rated heat input > 20.0 MMBtu/hr, 

except for Categories C through G units 

STD - 7 ppmv or 

0.008 lb/MMBtu 

ENH - 5 ppmv or 

0.0062 lb/MMBtu

STD – 07/01/2010

ENH – 01/01/2014

C. Oilfield Steam Generators 

C.1. Units with a total rated heat input > 5.0 MMBtu/hr to 

<20.0 MMBtu/hr

STD - 9 ppmv or 

0.011 lb/MMBtu 

ENH - 6 ppmv or 

0.007 lb/MMBtu

STD – 07/01/2012

ENH – 01/01/2014 

C.2. Units with a total rated heat input >20.0 MMBtu/hr STD - 7 ppmv or 

0.008 lb/MMBtu 

STD – 07/01/2010
SESIL - 9 ppmv or 

0.011 lb/MMBtu; 

SESFL - 5 ppmv or 

0.0062 lb/MMBtu

SESIL – 07/01/2012 

SESFL – 01/01/2014 

C.3. Units firing on less than 50%, by volume, PUC 

quality gas 

SESIL - 12 ppmv or 

0.014 lb/MMBtu 

SESFL - 9 ppmv or 

0.011 lb/MMBtu

SESIL – 07/01/2011

SESFL – 01/01/2014 

D. Refinery units 

D.1. Units with a total rated heat input > 5.0 MMBtu/hr 

to < 20.0 MMBtu/hr

STD - 9 ppmv or 

0.011 lb/MMBtu 

ENH - 6 ppmv or 

0.007 lb/MMBtu

STD – 07/01/2012

ENH – 01/01/2014 

D.2. Units with a total rated heat input >20.0 MMBtu/hr 

to < 110.0 MMBtu/hr 

STD - 6 ppmv or 

0.007 lb/MMBtu 

SESIL - 9 ppmv or 

0.011 lb/MMBtu

SESFL - 5 ppmv or 

0.0062 lb/MMBtu

STD – 07/01/2011

SESIL – 07/01/2012

SESFL – 01/01/2014 

D.3. Units with a total rated heat input > 110.0 

MMBtu/hr 

STD - 5 ppmv or 

0.0062 lb/MMBtu

STD – 06/01/2007

D.4. Units firing on less than 50%, by volume, PUC 

quality gas. 

SESIL - 12 ppmv or 

0.014 lb/MMBtu

SESFL - 9 ppmv or 

0.011 lb/MMBtu

SESIL – 07/01/2011

SESFL - 01/01/2014 

E. Units, from any Category, that were installed prior to 

1/1/2009 and limited by a Permit to Operate to an annual 

heat input >1.8 billion Btu/year but < 30 billion Btu/year. 

STD - 9 ppmv or 

0.011 lb/MMBtu

STD – At the next 

unit replacement but 

no later than 

01/01/2014

F. Units at a wastewater treatment facility firing on less 

than 50%, by volume, PUC quality gas. 

SESIL - 12 ppmv or 

0.014 lb/MMBtu

SESFL - 9 ppmv or 

0.011 lb/MMBtu

SESIL – 07/01/2011

SESFL – 01/01/2014

G. Units operated by a small producer in which the 

rated heat input of each burner is < 5 MMBtu/hr but 

the total rated heat input of all the burners in a unit is 

rated between 5 and 20 MMBtu/hr, as specified in the 

Permit to Operate, and in which the products of 

combustion do not come in contact with the products

of combustion of any other burner. 

STD - 9 ppmv or 

0.011 lb/MMBtu 

STD – At the next 

unit replacement but 

no later than 

01/01/2014 
The emission fee is the sum of an administrative fee and a fee based on the amount of emissions 

of the unit: 

Total Fee = Admin Fee + (Total Emission of unit/year) (Fee Rate) 

By January 1, 2010, operators must decide if they will comply with Rule 4320 by paying a fee or 

by complying with the NOx emission limits. The fee shall be paid by July 1 of each year for the 

previous year’s emissions. Operators of units for which an annual fee is paid must also meet 

RACT. 

Before January 1, 2014, a unit designated to comply with the NOx emission limits of the Staged 

Enhanced Schedule can be redesignated to comply with the Rule by paying an emission fee if: 

1. The unit meets the Initial NOx Limit (SESIL in Table above); 

2. Emission fees are paid at time of the application for redesignation, for all past 

emissions from the unit since January 1, 2009 through the calendar year prior to the 

calculation date; and 

3. The total annual fee is paid from that date forward. 

The PM control requirements include: 

1. Fire exclusively on gas; or 

2. Fire fuel with less than 5 grain of sulfur per 100 standard cubic feet; or 

3. Use emission control systems to reduce SO2 emissions by 95% or emit 9 ppm or less; 

and 

4. Refinery units must be in compliance by July 1, 2013. 

Low-use unit requirements apply to units with a heat input of 1.8 billion Btu/year or less. 

The Rule also includes start-up/shutdown provisions (Section 5.6), monitoring provisions 

(Section 5.7), requirements to demonstrate compliance (Section 5.8), recordkeeping 

requirements (Section 6.1), a list of test methods (Section 6.2), testing requirements (Section 

6.3), requirements for an emission control plan, a compliance schedule (Section 7.0) and 

calculation requirements (Section 8.0).

Effects on Emissions 

NOx Reductions

The District projects emission reductions for the two NOx compliance deadlines. The first 

estimates an emission reduction of 3.3 tons of NOx/day for compliance with the standard limits. 

This is a reduction of 46.5% from the calculated baseline of 7.1 tons of NOx/day. The 2007 

Ozone Plan had a 2011 baseline of 4.6 tons of NOx/day with a commitment to reduce emissions 

by 0.71 tons NOx/day or 15%. The District normalized the 46.5% reduction to the baseline in 

the ozone plan (4.6 tons/day) and calculated a normalized emission reduction of 2.1 tons per day. 

This projection satisfies the 2007 Ozone Plan commitment of 0.71 tons NOx/Day. The District 

also estimates an emission reduction of 3.9 tons NOx/day for the applicable enhanced limits. 

This would represent the maximum reductions which would be expected from Rule 4320 

implementation. 
SO2 Reductions

SJVUAPCD states that the majority of units would comply with Options 1 and 2 and expects no 

additional reductions from these units. District staff identified some units that may need to install 

and operate an emission control system reducing SO2 emissions by at least 95% to comply with 

Option 3. They estimate that this would result in emission reductions of 5.4 tons of SO2/day. 

Criteria for Rule Evaluation 

Generally, SIP rules must be enforceable (see section 110(a) of the Clean Air Act, hereafter 

CAA); must require Reasonably Available Control Technology (RACT) for major sources in 

nonattainment areas (see CAA section 182(a)(2)(A)); must not interfere with applicable 

requirements, including requirements concerning attainment (see CAA section 110(l)); and must 

not relax existing requirements in effect prior to enactment of the 1990 CAA amendments (see 

section 193). In addition, SIP rules must implement Reasonably Available Control Measures 

(RACM) for PM2.5 nonattainment areas (see CAA section 172(c)(1)). 

The SJVUAPCD regulates a severe ozone nonattainment area (40 CFR 81) and a PM2.5 

nonattainment area, thus, submitted Rule 4320 must fulfill RACT and RACM requirements. 

Guidance and policy documents that we used to define specific enforceability and RACT 

requirements include the following: 

• Issues Relating to VOC Regulation, Cutpoints, Deficiencies, and Deviations (the "Blue 

Book"), US EPA, OAQPS (May 25, 1988). 

• Guidance Document for Correcting Common VOC and Other Rule Deficiencies, EPA 

Region IX (August 21, 2001, the “Little Bluebook”).

• State Implementation Plans; General Preamble for the Implementation of Title I of the 

Clean Air Act Amendments of 1990, 57 FR 13498 (April 16, 1992); 57 FR 18070 (April 

28, 1992). 

• Clean Air Fine Particle Implementation Rule; Final Rule, 72 FR 20586 (April 25, 2007) 

• Determination of Reasonably Available Control Technology and Best Available Retrofit 

Control Technology for Industrial, Institutional, and Commercial Boilers, Steam 

Generators, and Process Heaters, CARB (July 18, 1991). 

http://www.arb.ca.gov/ractbarc/boilers.pdf

• Alternative Control Techniques Document-- NOx Emissions from 

Industrial/Commercial/Institutional (ICI) Boilers, US EPA 453/R-94-022 (March 1994). 

http://nepis.epa.gov/EPA/html/Pubs/pubtitleOAR.htm

• Alternative Control Techniques Document-- NOx Emissions from Utility Boilers, US 

EPA 452/R-93-008 (March 1994). http://nepis.epa.gov/EPA/html/Pubs/pubtitleOAR.htm

• Control Techniques for Sulfur Oxide Emissions from Stationary Sources, US EPA 450/3-

81-004 (April 1981). http://nepis.epa.gov/EPA/html/Pubs/pubtitleOAR.htm

• Because Rule 4320 includes a fee provision in Section 5, EPA considers this rule an 

economic incentive program subject to EPA’s guidance, “Improving Air Quality with 

Economic Incentive Programs,” US EPA, 452/R-01-001 (January 2001) 

http://www.epa.gov/ttncaaa1/t1/memoranda/eipfin.pdf

Rule Evaluation 
Enforceability, SIP Relaxation, RACT and RACM

Recordkeeping and other compliance provisions in the rule ensure that the requirements are 

adequately enforceable. Since this rule has not been previously incorporated in the SIP and it 

does not supersede an existing SIP-approved rule, the submitted rule does not relax the SIP and 

complies with CAA §110(l) and §193. 

At a minimum, the District must ensure that RACT will be implemented for appropriate sources 

subject to Rule 4320. Section 5.3.3 states: “Operators of units for which an annual fee is 

provided must also certify that the units meet federal RACT control measures at the time the 

annual fee is provided.” This provision alone is not sufficient to ensure that RACT will be 

implemented. However, Rule 4306, adopted October 16, 2008, implements RACT for this 

source category. EPA approved Rule 4306 on January 13, 2010 (75 FR 1715). Because sources 

have a separate obligation to comply with Rule 4306 (which does not allow payment of fees in 

lieu of compliance), the necessary regulatory framework is in place to ensure that RACT will be 

implemented for this source category. If, in the future, the District intends to rely on Rule 4320 

to implement RACT, the District would need to modify Rule 4320 to delete the provision which 

allows sources to pay fees in lieu of compliance or otherwise ensure RACT implementation. 

There is no specific guidance on what constitutes RACM for PM2.5 for this source category. 

According to an EPA report (US EPA 450/3-81-004), the most straightforward way to reduce 

SOx emissions, a PM2.5 precursor, is to burn fuels with low sulfur content. Rule 4320 

requirement that units burn gas or low sulfur fuel addresses this approach to reducing SOx 

emissions. For units burning fuel with higher sulfur content, Rule 4320 requires add-on controls 

to minimize SOx emissions. The combination of these two approaches (fuel switching or add-on 

controls) is appropriate to fulfill CAA RACM requirements regarding SOx. RACM requirements 

for NOx, another PM2.5 precursor are also fulfilled by Rule 4306, as discussed above regarding 

RACT. 

Emission Reductions Beyond RACT

The amount of emission reductions projected for Rule 4320 assumes compliance with the 

emission limits in section 5.2.3, although sources may pay fees instead of directly meeting these 

limits. SJVUAPCD’s staff report explains that the District will use these fees to purchase 

emission reductions more cost effectively than direct compliance with section 5.2.3, and thus 

will actually achieve more emission reductions if sources elect to pay fees. 

However, to ensure that all emission reductions purchased by the District are adequately surplus, 

quantifiable, enforceable, permanent and otherwise consistent with EPA’s EIP guidance, this 

component of the program must be fully described and included in a SIP submittal. The existing 

submittal of Rule 4320 does not include all necessary details on how creditable emission 

reductions will be achieved. We list below the minimum elements and supporting 

documentation needed, along with some suggestions on how this information may be provided: 

The submittal should describe and provide supporting documentation on: 

• How public input is/will be provided for in the development and implementation of the 

program. 
• The protocols and quantification methodology and procedures used to calculate emission 

reductions. The submittal may rely on and refer to relevant Moyer Program Guidelines 

or emissions quantification protocols that have been adopted by the SJVUAPCD 

Governing Board after a public process. 

• Criteria, policies and procedures to ensure that the reductions are surplus.1

• The potential source categories generating the emission reductions and the demonstration 

that the reductions are surplus. 

• The process to ensure that protocols are revised as appropriate to reflect new emission 

standards and emission factors, and that emission reductions thus continue to be surplus. 

• A real-time, transparent and publicly available system for tracking and evaluating 

program implementation. The purposes of the tracking system are at least the following: 

1. To help ensure that the program achieves actual emission reductions. 

2. To allow the District to compare actual reductions with projected emission 

reductions in the SIP in order to address any emission reduction shortfall 

expeditiously. 

3. To collect information for the District’s retrospective evaluation of program 

implementation.2 See EIP Guidance Section 5.3(b). 

4. To maximize transparency regarding use of public funds. 

5. To increase opportunities for technology transfer. 

• Real time information available through the tracking system should include3: 

1. Grant/Project Level 

 Name of grantee 

 Funding per grant per year 

 Activity and sources4

 that generate emission reductions, and the projected 

emission reductions by source 

 Actual reductions for the source and actual reductions for the project. 

 The emission reduction calculation for each source, including 

information/assumptions on baseline emissions. 

 Start date of project and duration the reductions will be claimed for credit 

2. Funding Source/Rule Level 

 Amount of funds collected or provided from the funding source/rule 

 Amount of funds spent 

 Actual emission reductions achieved 

 The SIP commitment, by year, on projected emission reductions 

 

1

 EPA’s guidance, “Improving Air Quality with Economic Incentive Programs” (EIP Guidance) defines surplus in 

sections 4.1(a) and 4.1(b). The EIP Guidance is available at: 

http://www.epa.gov/ttn/oarpg/t1/memoranda/eipfin.pdf 

2

 Prohibitory rules that include fee provisions are economic incentive programs subject to the EIP Guidance. As 

such, implementation of each rule should be evaluated. For example, the program evaluation should include 

evaluation of the District’s original purpose for the fee provision, how the fee provision affected compliance within 

the source category, whether the fee provision had the desired effect, whether the fee rate was appropriate to 

accomplish the District’s objectives, and whether there are any recommendations to improve the program. 

3

 “Funding source/rule level” means for example the Carl Moyer Program, Rule 9510, Rule 4320, and other

prohibitory rules which allow sources to pay fees in lieu of compliance with the emissions requirement. 

4

 If the activity was changing heavy-duty diesel engines, the “source” is a specific engine. 
 Comparison of projected with actual emission reductions5

 

3. Overall Incentive Program Summary Level 

 Amount of available funds 

 Funds spent each year 

 Actual emission reductions achieved annually 

 The SIP commitment, by year, on projected emission reductions 

 Comparison of projected with actual emission reductions 

• The audit and enforcement program that ensures implementation of grantees’ contractual 

obligations. 

• Annual reporting to EPA (where the public had the opportunity to review and comment 

on the draft report) which includes: 

o amount of funds spent for each funding source, 

o amount of emission reductions achieved versus projected for each funding source 

(see footnote 5), 

o discussion of any quantification or surplus issues that arose during the year and 

how the issues were resolved, 

o description and timing of measures to address any shortfalls in emission 

reductions, and 

o summary of inspections, audits, non-compliance findings, enforcement actions, 

and resultant penalties and remedies. 

We understand that SJVUAPCD intends to document the amount of reductions from sources that 

already comply with the emission limits. This is possible because Rule 4320 provides a deadline 

which has passed for sources to notify the District of their intent to pay fees in lieu of complying 

with the limits. To the extent that SJVUAPCD provides documentation of sources meeting the 

emission limits, it is appropriate to credit Rule 4320 with emission reductions separate from the 

fee component discussed above. 

Suggested Rule Improvements 

EPA recommends that the SJVUAPCD make the following improvements in the next revision of 

Rule 4320: 

1. The term normal operations in Section 5.8.2 should be clearly defined in the Rule or the 

Rule should state that it must be defined in the permit to operate. 

2. Ensure compliance with all provisions of EPA’s EIP Guidance in order to fully credit 

emission reductions for this rule as discussed in the Rule Evaluation section above. 

3. After January 1, 2011, take into consideration the condensable fraction of direct PM2.5 

emissions per EPA's Fine Particulate Rule, 40 CFR part 51, subpart Z (see 51.1002(c)). 

Recommendation 

Rule 4320 is enforceable, strengthens the SIP and is consistent with RACT and RACM 

requirements. Therefore, EPA staff recommends approval of SJVUAPCD submitted Rule 4320 

 

5

 The District may choose to compare projected emission reductions with actual emission reductions at the Overall 

Incentive Program Summary Level instead of the Funding Source or Rule Level. 
for incorporation into the California Applicable SIP. However, it is not appropriate to fully 

credit emission reductions for this rule without additional submitted materials described above. 

Attachments 

1. Submitted Rule 4320 

2. SJVAPCD Staff Report