UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX AIR DIVISION

Technical Support Document 

for 

EPA’s Evaluation of 

Best Available Control Measures and Most Stringent Measures 

for 

Fine Particulate Matter Emissions 

from 

Stationary and Area Sources 

in the 

San Joaquin Valley Air Pollution Control District 

Prepared by 

 Region 9 Air Division Rules Office 

January 2016 
2 

1. Summary of California’s Submittal 

Documents with information supporting California’s demonstration of BACM and 

MSM include: 

 

a. Appendix C of the 2015 PM2.5 Plan titled, “BACM and MSM for Stationary and 

Area Sources.” 

b. Chapter 8 of the 2015 PM2.5 Plan titled, “Commitment to Leave No Stone 

Unturned to Evaluate Additional Opportunities.” 

c. Email from Sheraz Gill (SJVAPCD) to Andrew Steckel (EPA), dated June 26, 

2015, forwarding additional analysis in electronic files titled, “AO Engine Retrofit 

Analysis,” “Wood-burning1,” and “Evaluation of Covers Lagoons Manure Piles for 

NH3.” 

These documents are summarized below. 

a. Appendix C of the 2015 PM2.5 Plan includes almost 300 pages of SJVAPCD 

analysis to demonstrate implementation of Best Available Control Measures 

(BACM) and Most Stringent Measures (MSM) for stationary and area sources. 

Section C.i provides background and identifies twelve adopted SJVAPCD 

regulations that achieve new emission reductions after 2012. 

Section C.ii summarizes SJVAPCD’s methodology for determining BACM and 

MSM based on EPA guidance. This includes: (1) develop a detailed emissions 

inventory; (2) model to identify significant and de minimis sources; (3) identify 

potential BACM and MSM in other SIPs or used in practice, and evaluate their 

technological and economic feasibility; (4) compare potential BACM/MSM 

against SJVAPCD’s existing adopted control measures; and (5) adopt and 

implement any potential BACM/MSM that is more stringent than SJVAPCD’s 

existing regulations or provide a reasoned justification for rejecting it. 

Section C.iii describes the organization of the rule by rule evaluation that follows 

in sections C.1 – C.41. Generally, this includes a discussion of the rule 

applicability, adoption/amendment history, affected sources, emissions inventory, 

regulatory evaluation, analysis of technological feasibility, cost effectiveness of 

potential additional BACM/MSM, and a summary of the findings. The inventory 

discussion lists annual and wintertime average PM2.5, NOx and SOx emissions for 

2012-2020. The regulatory evaluation generally considers federal and State 

guidance and rules and local rules at least from South Coast Air Quality 

Management District (SCAQMD), Bay Area Air Quality Management District 

(BAAQMD), Sacramento Metro Air Quality Management District (SMAQMD) and 

Ventura County Air Pollution Control District (VCAPCD). 
3 

Section C.iv explains that ammonia emission controls are not effective in 

significantly reducing PM2.5 concentrations, so SJVAPCD does not need to 

evaluate ammonia controls for BACM or MSM. Nonetheless, SJVAPCD 

performed a BACM/MSM evaluation for ammonia sources as described in 

sections C.iii and C.41 to demonstrate that existing requirements adequately 

implement BACM and MSM. 

Sections C.1 – C.41 provide SJVAPCD’s evaluation described in section C.iii for 

each category of sources. These range in detail from 1-2 page determinations 

that SJVAPCD found no more stringent requirements or potential additional 

BACM/MSM measures (e.g., section C.39 for tub grinding) to detailed analysis of 

more complex sources and associated requirements (e.g., 29 page analysis in 

section C.41 for SJVAPCD Rule 4570 regarding confined animal facilities). 

b. Chapter 8 of the 2015 PM2.5 Plan includes a general discussion of SJVACPD’s 

plans to continue evaluating all of its existing regulations for potential additional 

emission reductions. It also includes specific short-term commitments to 

evaluate three source categories and include any additional actions for reducing 

emissions in SJVAPCD’s 2012 PM2.5 SIP in fall 2016. These commitments 

address flares (Rule 4311), warm mix asphalt and conservation management 

practices (Rule 4550). 

c. In response to discussions between EPA and SJVAPCD staff, SJVAPCD 

provided additional analysis regarding agricultural engines, wood burning 

devices, and covering manure storage ponds and storage piles. The first 

document explains challenges with further lowering emission limits for existing 

spark-ignited agricultural engines. The second document discusses the 

emissions impact of SJVAPCD’s most recent revision to Rule 4901 regarding 

wood burning devices. The third document provides an evaluation of potential 

ammonia reductions from covering manure storage ponds and manure storage 

piles in the San Joaquin Valley. 

2. EPA’s General Evaluation of California’s Submittal 

For most stationary and area sources of direct PM2.5 and PM2.5 precursor emissions 

in the SJV, we believe the District’s analyses adequately demonstrate that the SIP 

for the SJV area provides for the implementation of BACM and MSM. For several of 

these source categories, EPA has evaluated additional control options as 

summarized in section 3 below. We selected these source categories because they 

emit relatively large amounts of direct PM2.5 or PM2.5 precursors and/or because 

SJVAPCD, CARB, EPA, and/or the public have recently identified potential 

additional control measures. Based on these various analyses, we have identified no 

additional control measures that have been demonstrated to be technically and 

economically feasible for implementation in the SJV area. 

 
4 

3. EPA’s Evaluation of Several Specific Rules 

SJVAPCD and CARB will need to develop additional SIPs in the next few years 

including a Serious Area PM2.5 Plan for the 2006 NAAQS and a Moderate Area 

PM2.5 Plan for the 2012 PM2.5 NAAQS. We expect that these additional attainment 

plans will build upon the BACM and MSM evaluations provided in the 2015 PM2.5

Plan and further in this TSD. To that end, we identify below several measures which 

SJVAPCD and CARB should analyze more fully in these future SIPs for potential 

additional emission reductions. 

a. Open Burning Rule 4103 

1. Overview 

Section C.1 (beginning page C-8) discusses SJVAPCD Rule 4103, Open 

Burning. Rule 4103 is designed to minimize impacts of smoke and other air 

pollutants from open burning of agricultural waste and other materials. The 

rule restricts the type of materials that may be burned and establishes other 

conditions and procedures for open burning in conjunction with SJVAPCD’s 

Smoke Management System (SMS).1 EPA last approved Rule 4103 as 

meeting Reasonably Available Control Technology (RACT) requirements in 

2012.2 

Permitted burns must comply with Rule 4103 provisions regarding, for 

example, moisture (e.g., Section 5.5.4 and 5.5.9), time of day (Sections 

5.5.11 and 5.5.12) and permits (Section 6.1). Under the SMS, SJVAPCD 

analyzes the daily impact of open burning on air quality in 103 zones in the 

SJV Air Basin and allocates daily burning allowances based on local 

meteorology, air quality conditions, atmospheric holding capacity, burning 

already approved in an area, impacts on downwind populations and other 

factors. 

Additionally, SJVAPCD implements portions of California Health and Safety 

Code (CH&SC) sections 41855.5 and 41855.6.3

 CH&SC section 41855.5 

requires SJVAPCD to prohibit specific crop categories from open burning 

according to a schedule, the final phase of which began on June 1, 2010. 

CH&SC section 41855.6 authorizes SJVAPCD to postpone the burn 

prohibition for specific crop categories if SJVAPCD determines that there is 

no economically feasible alternative means of eliminating the waste or 

 

1

 SJVAPCD also refers to its SMS as a “Smoke Management Program” (see “San Joaquin Valley Unified 

Air Pollution Control District Proposed Smoke Management Program: Rules, Policies, and Procedures to 

Comply with the California Code of Regulations Title 17 Smoke Management Guidelines for Agricultural 

and Prescribed Burning,” adopted June 20, 2002). 

2 See 77 FR 214, January 4, 2012. 

3 See Table 9-1, Final Staff Report and Recommendations on Agricultural Burning, lists prohibitions by 

specific crop type, approved into the SIP on 01/04/2012 (77 FR 214). 
5 

determines that there is no long-term federal or state funding commitment for 

the continued operation of biomass facilities in the San Joaquin Valley or 

development of alternatives to burning. 

SJVAPCD states that this rule implements BACM and MSM. The following 

are key points drawn from SJVAPCD’s analysis that support the District’s 

BACM/MSM determination. 

2. Comparison to Analogous Control Measures in Other Areas 

The District compares Rule 4103 to several other open burning rules in 

California.4

 SJVAPCD finds no other requirements more stringent than those 

in Rule 4103 but notes that SCAQMD Rule 444 restricts burning on 

residential wood combustion (RWC) curtailment days. The District explains 

that although Rule 4103 does not contain the same restriction, in practice 

SJVAPCD also generally limits burning on RWC curtailment days.5

 According 

to SJVAPCD, there are also no more stringent federal or state regulations or 

guidance such as contained in a Control Techniques Guidance (CTG), 

Alternative Control Techniques (ACT) documents, NSPS, NESHAP or MACT 

standard. Lastly, Rule 4103 is more stringent than other requirements as it is 

the only rule which prohibits burning of most agricultural crop categories. 

We are not aware of open burning programs in other areas that are more 

stringent than Rule 4103, considered as a whole. Although Rule 4103 does 

not specifically restrict burning on RWC curtailment days, as does SCAQMD 

Rule 444, on balance we find that Rule 4103’s general prohibitions on the 

burning of specific agricultural crops are more effective means for reducing 

PM emissions than targeted restrictions on RWC curtailment days. 

3. Technical and Economic Feasibility of Alternative Control Techniques 

As described above, the CH&SC requires SJVAPCD to prohibit specific crop 

categories from open burning unless the District determines that there is no 

economically feasible alternative means of eliminating the waste or 

determines that there is no long-term federal or state funding commitment for 

the continued operation of biomass facilities in the San Joaquin Valley or for 

the development of alternatives to burning. 

 

4 See 2015 PM2.5 Plan, Appendix C, beginning on page C-14, and including BAAQMD Regulation 5, 

SMAQMD Rule 407, VCAPCD Rule 56, and SCAQMD Rule 444. 

5

 Described in 2015 PM2.5 Plan, Appendix C on pages C-9 – C-10. It is difficult to quantify the emission 

reductions resulting from this type of provision, as banning open burning on RWC curtailment days could 

shift more waste to other days with more favorable meteorology, so overall there could be little change in 

the overall wintertime inventory. Any burning that occurs is subject to SJVAPCD’s SMS, which specifically 

allocates allowable burn acreage for 103 geographic zones, based on local meteorology to be protective

of the NAAQS, thereby minimizing impacts of added smoke emissions. We also do not expect additional 

emission reductions from this provision because SJVAPCD already implements it in practice. 
6 

Beginning on page C-12, the District discusses its prior feasibility analyses 

and the current status of biomass facilities. In addition, the 500-page staff 

report supporting SJVAPCD’s most recent revision to Rule 4103 includes 

over 150 pages of analysis detailing the economic and technical feasibility of 

prohibiting burning of each significant crop that was burned at the time.6 As a 

result of this analysis, SJVAPCD amended Rule 4103 in 2010 to incorporate 

CH&SC prohibitions and committed to review its determinations for any 

postponed burn prohibitions for crops and materials at least once every five 

years. As a condition of approval, CARB required an additional 2012 review 

to determine if additional reductions were feasible. The District prepared a 

2012 Report that examines the feasibility of alternatives for each remaining 

crop type allowed to burn. The report indicated no significant changes in the 

economic feasibility and no long-term federal or state funding commitments 

for the operation of biomass facilities.7 In 2015, the District again reviewed its 

determinations and found that since 2012, five out of eleven biomass power 

plants which previously accepted agricultural materials have ceased to 

operate, making additional postponements economically and technically 

unfeasible.8 On December 23, 2015, CARB concurred that the limited 

exemptions are appropriate through 2020.9 

4. Emissions Inventory 

SJVAPCD estimates open burning will contribute 2.39 tpd NOx, 3.41 tpd 

PM2.5, and 0.07 tpd SOx on an average winter day in 2020. This is above the 

District’s selected BACM/MSM significance threshold for PM2.5 and below the 

District’s selected significance threshold for NOx and SOx. 

5. Conclusions 

We believe that the current version of Rule 4103 requires all control 

measures for open burning activities in the San Joaquin Valley that are best 

available control measures considering technological and economic 

feasibility, for the reasons cited above as well as the following reasons: 

A. EPA has not established specific control standards for open burning 

activities. 

 

6 See Final Staff Report and Recommendations on Agricultural Burning, SJVAPCD, Revised July 21, 

2010. 

7 See 2012 Update: Recommendations on Agricultural Burning, May 2012, 14 pages. 

8 See Final 2015 Agricultural Burning Review, December 2015, 16 pages.

9 See Letter from Kurt Karperos, CARB to Samir Sheikh, dated December 23, 2015.
7 

B. SJVAPCD conducted an economic analysis of alternatives to open 

burning for each crop category and determined that for each crop category 

allowed some burning in Table 9-1, there is no economically feasible 

alternative means of eliminating the waste. While we encourage 

SJVAPCD to continue refining this analysis, we do not have information to 

contradict the conclusions at this time. 

C. SJVAPCD determined that there is no long-term federal or state funding 

commitment for the continued operation of biomass facilities in the San 

Joaquin Valley or development of alternatives to burning. We do not have 

information to contradict this conclusion at this time. 

D. SJVAPCD compared the control requirements in Rule 4103 with 

analogous rules in other local districts and states and we agree that Rule 

4103 is as stringent as or more stringent than those other rules. 

E. SCAQMD Rule 444(c)(25) prohibits open burning of agricultural crops on 

days when residential wood burning is prohibited. SJV explains that in 

practice the District prohibits open burning of agricultural crops on days 

when residential wood burning is prohibited. However, we recommend 

that SJVAPCD add this prohibition explicitly to SJVAPCD Rule 4103. 

Additionally, we believe Rule 4103 currently fulfills the requirements of MSM 

because we have compared the control requirements in Rule 4103 with 

analogous rules in other local districts and states and believe that Rule 4103 

is as stringent as or more stringent than those other rules. 

b. Boilers, Steam Generators, and Process Heaters Greater than 5.0 MMBtu/hr 

1. Overview 

Section C.7 (beginning page C-35) discusses two SJVAPCD rules for these 

sources. Rule 4306, Boilers, Steam Generators, and Process Heaters – 

Phase 3, establishes NOx emission limits and related operational 

requirements that all units must meet. Rule 4320, Advanced Emission 

Reduction Options for Boilers, Steam Generators, and Process Heaters 

Greater than 5.0 MMbtu/hr, establishes more stringent NOx emission limits 

but allows sources to pay an emission fee in lieu of compliance with the 

emission limits. SJVAPCD concludes that these two rules together 

implement BACM and MSM for this source category. 

Boilers, steam generators, and process heaters have significant variability in 

the technology, size, use and age of equipment, potential controls for various 
8 

pollutants,10 affected industry and regulatory strategies used by different 

agencies.11 As a result of this variability, the BACM/MSM demonstration for 

this category of sources is more complex than for some categories with less 

variability.12 However, the following summarizes key points drawn from 

SJVAPCD’s analysis that support the District’s BACM/MSM determination. 

2. Comparison of Rule 4306 to Analogous Control Measures in Other Areas 

Rule 4306 establishes mandatory NOx emission limits ranging from 5 - 30 

ppm (depending on boiler type, see Rule 4306, table 1). According to 

SJVAPCD, these limits are at least as stringent as state and federal 

regulations and guidance, including federal NESHAP, MACT and NSPS 

standards, and EPA ACT guidance. In addition, they are in the same range 

as analogous prohibitory rules from other nonattainment areas that generally 

have among the most stringent requirements in the country, including 

SMAQMD Rule 411 (9 – 30 ppm), SCAQMD Rule 1146 (5 – 25 ppm) and are 

generally more stringent than rules in Bay Area and Ventura. We generally 

agree with this analysis, but note that SCAQMD Rule 1146 is more stringent. 

In 2010, EPA approved Rule 4306 as fulfilling RACT requirements for NOx

under CAA section 182(b)(2).13 

3. Comparison of Rule 4320 to Analogous Control Measures in Other Areas 

Rule 4320 establishes NOx limits (5 – 12 ppm)14 lower than those in Rule 

4306 (5 – 30 ppm).15 However, sources may exceed these limits if they pay 

an emission fee described in Rule 4320 section 5.3. The only other traditional 

prohibitory rule that we are aware of with emission limits in the same range as 

4320 is SCAQMD Rule 1146. For example, in SJVAPCD Rule 4320, units 

above 20 MMBtu/hr have a limit of 7 ppm while in SCAQMD Rule 1146, units 

between 20 and 75 MMBtu/hr have a limit of 9 ppm (less stringent than Rule 

4320), but units above 75 MMBtu/hr have a limit of 5 ppm (more stringent 

than Rule 4320).16 SCAQMD Regulation XX (RECLAIM) also regulates units 

within the same size range as Rule 4320 but allows sources to comply with 

emission caps by purchasing RECLAIM Trading Credits (RTCs).17 According 

 

10 E.g., 2015 PM2.5 Plan, Appendix C, section C.7 discusses low temperature oxidation, EMx and SCONOx 

for NOx; and alternative fuels, baghouses, ESPs, wet scrubbers for PM2.5. 

11 E.g., different subcategories, different limits, SCAQMD’s RECLAIM program, etc. 

12 E.g., sections C.19 regarding sulfuric acid mist, and C.21 regarding residential water heaters.

13 See 75 FR 1715, January 13, 2010. 

14 See Rule 4320, Table 1.

15 See Rule 4306, Table 1. 

16 See SJVAPCD Rule 4320 Table 1, Category B and SCAQMD Rule 1146 Section (c)(1)(F). 

17 RECLAIM is a market incentive program designed to allow facilities flexibility in achieving emission 

reduction requirements for NOx and SOx using methods which include, but are not limited to: add-on 

controls, equipment modifications, reformulated products, operational changes, shutdowns, and the 

purchase of excess emission reductions. (Rule 2000, Section (a).) The Allocations of RECLAIM Trade 

Credits (RTCs) are based on historical throughput and emission factors for each source type (Rule 2002, 
9 

to information provided by SCAQMD, there are 1074 boilers that are subject 

to Rule 1146 and 230 non-refinery boilers subject to RECLAIM.18 Given that 

we do not know the rated heat input of these units and that the relative 

stringency between the rules varies with rated heat input, we cannot conclude 

that the lower NOx emission limits in Rule 1146 have been demonstrated to 

be technically and economically feasible for the wide variety of sources 

subject to Rule 4320. 

4. Technical and Economic Feasibility of Alternative Control Techniques 

SJVAPCD summarizes analysis of control technologies which could further 

reduce emissions, and explains why they are not demonstrated to be 

generally cost-effective at this time. This includes low temperature oxidation 

and EMx for NOx, and alternative fuels, ESP and wet scrubbers for direct 

PM2.5. For low temperature oxidation, the District concludes “the technology 

has not been achieved in practice and [is] cost prohibitive without significant 

subsidies.”19 The District states that EMx has only been used for turbines, not 

boilers.20 For ESP and wet scrubbers, the District calculated cost 

effectiveness of $44,997,329/ton of PM and $3,151,420,104/ton of PM, 

respectively.21 We do not have information at this time that contradicts the 

District’s conclusions. However, in the future, we recommend that SJVAPCD 

further analyze the technical and economic feasibility and the potential for 

additional emission reductions achievable by implementing the following 

measures. 

A. Rule 4320 Table 1 establishes “Standard Schedule” NOx emission limits 

for various subcategories of boilers (e.g., 9 ppm for oilfield steam 

generators with a RHI between 5.0 and 20.0 MMBtu/hr). SJVAPCD could 

consider requiring that all units within individual categories comply with the 

Standard Schedule limits instead of allowing them to pay fees and emit 

more. 

 

Section (d)(1)(A).) After every calendar quarter, facilities have to calculate their total emissions and hold 

any RTCs necessary to reconcile their allocations with their emissions. (Rule 2004, Section (b)(1)). 

Trading of RTCs is subject to requirements in Rule 2007. Rule 2011 describes all of the recordkeeping 

and reporting requirements for RECLAIM facilities and Rule 2010 ensures that “RECLAIM facilities which

exceed their Allocation provide compensating emission reductions.” (Section (a).) Therefore, neither 

SCAQMD’s RECLAIM program nor SJVAPCD’s Rule 4320 require that each source individually meet a 

specific NOx emission limit. However, SCAQMD has demonstrated that the emission reductions 

associated with the allocations in RECLAIM are enforceable, because sources that exceed the allocation

must obtain enforceable RTCs elsewhere. In contrast, SJVAPCD has not yet demonstrated that the 

emission reductions associated with the limits in Rule 4320 are fully enforceable. 

18 See Email from Kevin Orellana (SCAQMD) to Idalia Perez (USEPA), 7/21/15. 

19 See 2015 PM2.5 Plan, Appendix C, page C-39. 

20 See 2015 PM2.5 Plan, Appendix C, page C-39. 

21 See 2015 PM2.5 Plan, Appendix C, page C-42. 
10 

B. Rule 4320 Table 1 establishes “Enhanced Schedule” NOx emission limits 

for various subcategories of boilers (e.g., 6 ppm for oilfield steam 

generators with a RHI between 5.0 and 20.0 MMBtu/hr) which sources 

must meet if they elect to delay compliance with the Standard Schedule 

limits. SJVAPCD could consider requiring that all units within individual 

categories comply with the Enhanced Schedule limits, when feasible. 

C. Requiring a 2 ppm limit for refinery boilers larger than 110 MMBtu/hour, 

which SCAQMD determined was Best Available Retrofit Control 

Technology22 (BARCT) in 2015.23 In contrast, SJVAPCD Rule 4230 Table 

1 currently establishes a 5 ppm limit for these sources. 

5. Emission Fee as Deterrent 

The emission fee option in Rule 4320 provides compliance flexibility to 

sources with high emission control costs. Operators choosing this compliance 

option calculate fees annually based on permitted emission limits and fuel use 

during the year.24 SJVAPCD may directly enforce the requirement to pay the 

fee against regulated sources. As a result of EPA’s incorporation of Rule 

4320 into the SIP,25 EPA and citizens may also enforce these fee 

requirements against regulated sources pursuant to CAA §§113 and 304. 

The CAA explicitly allows states to use economic incentives as a tool to attain 

the NAAQS. See, for example, CAA §110(a)(2)(A), requiring that each SIP 

“include enforceable emission limitations and other control measures, means, 

or techniques (including economic incentives such as fees, marketable 

permits, and auctions of emissions rights)... as may be necessary or 

appropriate to meet the applicable requirements of [the Act]”. EPA has 

issued guidance on “financial mechanism economic incentive programs 

(EIPs),” among other kinds of economic incentive programs.26 As stated in 

EPA guidance, “Financial mechanism EIPs include fees or taxes on 

emissions... While financial mechanisms do not limit total emissions directly, 

they indirectly reduce emissions by increasing costs for high emitting 

activities.”27 Because the emission fee is a compliance option in the rule, we 

have considered this fee provision as part of our evaluation of the District’s 

 

22 Defined in the CA Health and Safety Code Section 40406 as “an emission limitation that is based on 

the maximum degree of reduction achievable, taking into account environmental, energy, and economic 

impacts by each class or category of source.” 

23 See presentation for SCAQMD NOx RECLAIM Working Group Meeting, April 29, 2015. Available on 

slide 7 at http://www.aqmd.gov/docs/default-source/rule-book/Proposed-Rules/regxx/noxreclaim_wgm_042915b.pdf?sfvrsn=2. 

24 See Rule 4320, Section 5.3. 

25 See 76 FR 16696, March 25, 2011.

26 Improving Air Quality with Economic Incentive Programs, EPA, January 2001 (2001 EIP Guidance). 

27 See 2001 EIP Guidance, Section 8.0, page 119. 
11 

BACM demonstration. We use the 2001 EIP Guidance as a policy framework 

to evaluate the fee provision’s effectiveness as a pollution deterrent. 

The 2001 EIP Guidance highlights several attributes of emission fees that 

may make them effective as financial mechanism EIPs,

28 including the 

following. 

A. Fees are levied on emissions or on an activity or commodity that is 

reasonably related to actual emissions or potential emissions. 

Rule 4320 requires calculation and payment of fees based on the relevant 

emission unit’s potential emissions as determined by permitted emission 

limits and actual fuel usage.29 Accordingly, the fee provisions of Rule 4320 

are levied on activities reasonably related to actual emissions. 

B. The fees are reasonable, but significant enough to motivate emission 

reductions. 

The cost of the emission fee in Rule 4320 relies on SJVAPCD Rule 9510, 

Indirect Source Review, adopted in 2005.30 At that time, the cost was set 

to increase twice, but only the “2008 and beyond” cost, set at $9,350/ton 

of NOx, was relevant to Rule 4320, which was adopted in 2008. The 

annual costs of this compliance option for a sample set of units is shown 

in Table B-1. When developing Rule 4320, SJVAPCD calculated cost 

effectiveness and the annualized cost over ten years for various 

representative retrofit scenarios, but not for every affected facility. 

Although the limits used in the District’s cost calculations presented in 

Table B-1 do not precisely represent all scenarios in Rule 4320, we use 

these annualized cost figures for comparison. We chose sample heat 

inputs to be comparable to the units for which SJVAPCD calculated cost 

effectiveness of retrofits,31 and to fall within the ranges of each category in 

Rule 4230 that had units at the time of rule adoption.32 33 

 

 

28 See 2001 EIP Guidance, Section 3.1(b), page 26.

29 See Rule 4320, sections 5.1 and 5.3. 

30 See Rule 4320 Section 5.3.1.4, and Rule 9510 Section 7.2.1. 

31 See SJVAPCD Rule 4230 Staff Report, Tables C-2 through C-7, October 16, 2008.

32 See SJVAPCD Rule 4230 Staff Report, Table B-2. 

33 The assumptions of operating capacity were also based on information available in Table B-2 of the 

Staff Report. The PTO limits were chosen to be the previously applicable emission limits consistent with 

the approach taken by the District to calculate emission reductions for the rule in Table B-2.
12 

Table B-1. Annual Cost of Compliance with Emission Fees and Emission Limitations 

 

34 Applicable limit in Rule 4306. 

35 Applicable “Standard Schedule” limit in Rule 4320. 

36 Emission Fee = (NOx emission limit in PTO)(assumed fuel)(9,350) + Administrative Fee. 

37 References are to Tables in Appendix C of Rule 4320 Staff Report, October 16, 2008. 

38 SJV did not provide information for units of this size and type.

Heat Input 

(MMBtu/hr) 

Capacity 

Factor 

Old 

limit

34

New 

limit

35

Annual 

Fee36 

Comparable 

Scenario 

Reference

37

 

Annualized 

Cost ($/yr) 

Cost 

Effectiveness 

($/ton NOx) 

General Category (Categories A and B in Rule 4320) 

10 0.50 15 9 $3,833 –

38

 – – – 

20 0.50 15 9 $7,666

Retrofit with 

SCR to 

decrease 

emissions 

from 15 

ppm to 5 

ppm 

C-3 $41,841 $80,930

30 0.50 9 7 $7,028 Retrofit with 

SCR to 

decrease 

emissions 

from 9 ppm 

to 5 ppm 

C-5 

$46,768 $148,470

100 0.50 9 7 $23,425 $60,255 $57,332

200 0.50 9 7 $46,850 $86,726 $41,259

Oilfield Steam Generator (Category C in Rule 4320) 

10 0.75 15 9 $5,750 – – – – 

20 0.75 15 9 $11,500 Retrofit with 

SCR to 

decrease 

emissions 

from 15 

ppm to 5 

ppm 

C-2 

$41,841 $53,988

30 0.75 15 7 $17,249 $46,768 $28,816

100 0.75 15 7 $57,498 $60,255 $15,546

200 0.75 15 7 $114,996 $86,726 $11,186

Oilfield Steam Generators firing < 50% PUC quality gas 

50 0.75 15 9 $28,749 – – – – 

Refinery units (Category D in Rule 4320) 

8 0.75 30 9 $89,200 Retrofit with 

ULNB to 

decrease 

emissions 

from 30 

ppm to 9 

ppm 

C-7 

$8,544 $12,400

15 0.75 30 9 $17,249 $12,477 $10,337

33.8 0.75 25 6 $33,470 $27,716 $9,988

92 0.75 25 6 $91,102 $54,166 $7,170
13 

Table B-1 estimates the annualized costs to comply with Rule 4320 

emission limits as ranging from $8,544 to $86,726, and the annual costs to 

comply instead through fees as ranging from $7,028 to $91,102. For units 

where the fee is higher than the cost of meeting the emission limits, this 

fee structure serves as a deterrent and encourages direct emission 

reductions by complying with the Rule 4230 emission limits. This is 

supported by data from CARB indicating that 472 of 1164 units (40.5%) 

are complying with the rule by paying a fee.39 If, in contrast, the fee had 

been set too low, we would expect many more sources would select the 

fee payment compliance option. 

Table B-1 suggests that the deterrent value of the fee varies among 

subcategories (e.g., by boiler size and capacity factor), as sometimes the 

fee is estimated to cost more than direct compliance and sometimes less. 

We recommend that SJVAPCD evaluate how sources are complying with 

Rule 4320 within each subcategory to determine whether changes are 

appropriate to the fee structure. If, for example, all oilfield steam 

generators between 20 – 30 MMBtu/hr comply with Rule 4320 by paying 

the fee, it might be because compliance with the emission limits is too 

costly, or it might be that the fee is too low to be a useful deterrent. We 

also note that this would be an appropriate evaluation to perform as part of 

a program evaluation as discussed in the EIP guidance.40

 

The District’s discussion of “Additional Emission Reduction Opportunities” 

(Section C.7) does not consider the possibility of increasing the emission 

fee to encourage more units to comply directly with the emission limits 

over time. The emission fee has not been increased since rule adoption 

and does not increase with inflation. We suggest SJVAPCD consider 

increasing fees over time to continue ensuring the deterrent effect. For 

example, SJVAPCD Rule 3170’s fee rate in section 5.1 is adjusted to the 

U.S. City Average Consumer Price Index for all-urban consumers, in 

accordance with CAA §502(b)(3)(B)(v). 

6. Emission Fee May Provide Emission Reductions 

Where a State relies upon a discretionary EIP in a SIP, EPA evaluates the 

programmatic elements of the EIP to determine whether the resulting 

emission reductions are quantifiable, surplus, enforceable and permanent, 

terms referred to as the integrity elements of EIPs. See 2001 EIP Guidance at 

Section 4.1. EPA has previously determined that certain incentives programs 

implemented by the District achieve emission reductions that meet these EIP 

integrity elements.41

 

 

39 See ARB 2015 PM2.5 Plan Staff Report, Appendix B, Section II.D, Compliance with Rule 4320. 

40 See 2001 EIP Guidance, Section 5.3(b) at page 73. 

41 See 79 FR 29327, May 22, 2014. 
14 

Regarding Rule 4320, SJVAPCD states that “these fees are used by the 

District to achieve cost effective NOx reductions through District incentive 

programs, the District’s Technology Advancement Program, and other routes” 

(see Appendix C, page C-35). SJVAPCD provided no further demonstration 

of what types of programs are funded and how these meet the EIP integrity 

elements. Because of this, emission reductions achieved by Rule 4320 may 

not be credited for attainment planning purposes at this time. 

Nonetheless, it appears that the fees collected under Rule 4320 are 

contributing to improved air quality by supporting SJV’s incentive funding 

programs. While we cannot quantify these reductions at this time, we believe 

these fees create an incentive to reduce pollution and thereby support the 

BACM determination for this source category. 

7. Emission Inventory 

The District states that emissions from boilers, steam generators, and 

process heaters greater than 5.0 MMBtu/hr are lower than the District’s 

selected BACM/MSM significance thresholds. (See page C-36.) Given the 

size of the inventory subject to Rules 4306 and 4230 (1.61 tpd of NOx in 2015 

and 1.36 tpd of NOx in 2020), the potential emission reductions from this 

category are relatively small. 

8. Conclusion and Recommendations 

For the reasons discussed above, we propose to find that Rule 4306 and 

Rule 4320 together establish BACM and MSM control requirements for this 

source category at this time. We recommend, however, that SJVAPCD 

continue evaluating the technical and economic feasibility of the following 

measures in the future: 

A. Require that all units within individual categories comply with Rule 4320 

“Standard Schedule” limits instead of allowing them to pay fees and emit 

more. 

B. Require that all units within individual categories comply with Rule 4320 

“Enhanced Schedule” limits, when available. 

C. Require that all units comply with SCAQMD Rule 1146 limits. 

D. Require a 2 ppm limit for refinery boilers larger than 110 MMBtu/hour. 

E. Require the emission fee to increase annually. 

F. Evaluate how sources are complying with the rule within each subcategory 

to determine whether changes are appropriate to the fee structure. 
15 

c. Flares 

 

1. Overview

Section C.11 (beginning page C-58) discusses SJVAPCD Rule 4311, Flares. 

Rule 4311, as adopted June 18, 2009, is designed to limit VOC, NOx, and 

SOx emissions from flaring by requiring specific operational practices. For 

example, Section 5.0 requires that flares in the Valley have automatic ignition 

systems and meet specified VOC and NOx emission limits. Beyond that, all 

refinery flares and other flares with capacity above five MMBtu/hour must 

submit a flare minimization plan (FMP) to evaluate equipment and potential 

preventative measures and demonstrate that the operator appropriately 

minimizes flaring. 

Flaring is primarily used to control emissions and as a safety device. 

SJVAPCD states that most flares in SJV operate as emergency control 

devices unlike, e.g., SCAQMD and BAAQMD which have significantly larger 

flares that operate as part of refinery processes.42 EPA approved Rule 4311 

as meeting VOC RACT requirements under CAA section 182(b)(2) in 2011.43 

SJVAPCD states that this rule implements BACM and MSM. The following 

are key points drawn from SJVAPCD’s analysis that support the District’s 

BACM/MSM determination. 

2. Comparison to Analogous Control Measures in Other Areas 

In section C.11, the District compares Rule 4311 to analogous requirements 

from several other California districts that generally have among the most 

stringent air pollution requirements in the country, including SCAQMD Rule 

1118, BAAQMD Rule 12-11 and 12-12, VCAPCD Rule 54, and Santa Barbara 

County Air Pollution Control District (SBCAPCD) Rule 359 and concludes, 

“Rule 4311 currently has in place the most stringent measures feasible to 

implement in the Valley and therefore meets or exceeds both BACM and 

MSM requirement for this source category.”44 SJVAPCD also concludes that 

Rule 4311 is as stringent as or more stringent than the applicable federal 

NESHAP, MACT, and NSPS and there are no applicable CTGs or ACTs.45

The operational requirements in section 5.0 of the rule include having a flame 

present when combustible gas is vented, automatic ignition or pilot flame on 

the flare, purge gas requirement, and ground level enclosed flare VOC and 

NOx limits. These requirements make the rule more stringent than VCAPCD 

Rule 54 and equivalent to SBAPCD Rule 359. In light of Rule 4311’s detailed 

FMP requirements, on balance Rule 4311 appears equally as stringent as 

 

42 See 2015 PM2.5 Plan, Appendix C, Section C.11, page C-60. 

43 See 76 FR 68106, November 3, 2011. 

44 See 2015 PM2.5 Plan, Appendix C, Section C.11, page C-84.

45 See 2015 PM2.5 Plan, Appendix C, Section C.11, page C-72.
16 

SCAQMD Rule 1118 and BAAQMD Rule 12-12. Our evaluation below 

focuses on two elements of SJVAPCD Rule 4311: (A) applicability of FMP 

and required contents of FMPs,46 and (B) monitoring requirements. We also 

address below in paragraph (C) a third element of Rule 4311, SO2

performance targets, which the District did not specifically address in section 

C.11. 

A. According to the District, SJVAPCD, SBCAPCD, SCAQMD, BAAQMD, 

and VCAPCD all require FMPs, but SCAQMD only requires it from 

facilities where emission targets are exceeded. All five districts require 

FMPs from refinery flares while SJVAPCD, SBCAPCD, and VCAPCD also 

require FMPs from other industrial flares. All five district rules require that 

similar information be included in submitted FMPs. They include, at a 

minimum, a description of the flare system and a description of emission 

reductions systems or activities. FMPs are specific to each source and 

these plans, along with associated causal analysis reports,47 require 

facilities to determine what measures are technically and economically 

feasible to reduce flaring events. SJVAPCD states that their flaring differs 

from other California districts as it mainly occurs in the oil and gas 

production industry. In contrast, BAAQMD, SCAQMD and SBCAPCD 

flaring occurs primarily in the petroleum refining industry which generally 

has higher emissions per flare.48 SJVAPCD states that this further 

supports why FMPs, rather than specific additional controls, are an 

appropriate control measure, as flaring conditions vary in different 

industries. 

B. SJVAPCD, SCAQMD, BAAQMD, SBCAPCD, and VCAPCD rules all 

require monitoring and recordkeeping of flaring events. SJVAPCD, 

SCAQMD, BAAQMD, and SBCAPCD additionally require reporting of 

flaring events to the local air district. The information required in the 

monitoring reports by the different rules is similar (e.g., volume and 

composition of flared gas), but the frequency with which these reports 

must be submitted varies. SJVAPCD and SBCAPCD require reports 

annually, SCAQMD quarterly and BAAQMD monthly. We note that 

 

46 SJVAPCD also completed a 39-page study on Rule 4311 and flares in 2014 which summarized and 

analyzed the flares in the District, their FMPs, annual monitoring reports, reportable events, and a 

comparison of Rule 4311 to other federal, state and local requirements. This study report provided the

total number (235) and types of flares in the district, the flares requiring FMPs (95), the emissions from 

reported flaring (347.4 MMscf), and identified measures in FMPs to minimize flaring. The report 

concluded “that flare operators are doing their due diligence to reduce emission from flaring in the Valley,” 

and “the District recommends no rulemaking action for Rule 4311.” There is no detailed discussion on 

emission reductions achieved in the district due to FMPs. Rule 4311 required sources to submit FMPs 

beginning in 2011 and to submit annual reports starting in 2012. At the time of the flares study, the

District had only evaluated 2011-2012 reports and not 2012-2013 reports. SJVAPCD, “Rule 4311 

(Flares) Further Study 2014,” September 16, 2014. 

47 See SJVAPCD Rule 4311 amended June 18, 2009 section 6.2.2.1. 

48 See 2015 PM2.5 Plan, Appendix C, Section C.11, page C-62. 
17 

SCAQMD and BAAQMD’s more frequent reporting requirements were 

designed primarily for large refineries, while SJVAPCD’s reporting 

requirements were designed for smaller sources. 

C. Rule 4311 Section 5.9 also establishes petroleum refinery SO2

performance targets of 1.5 tons per million barrels of crude processed 

after 2011 and 0.5 tons after 2017. SCAQMD Rule 1118 has analogous 

targets of 0.7 tons after 2010 and 0.5 tons after 2012. Therefore, by 2017, 

Rule 4311 and Rule 1118 will have the same performance targets.49

3. Technical and Economic Feasibility of Alternative Control Techniques

SJVAPCD summarizes analysis of control measures which could further 

reduce emissions,50 and explains why they are not demonstrated to be 

generally feasible at this time. Among the potential controls they considered 

are maximum monthly flared gas targets and requiring capture of the gas 

before it is flared. 

SJVAPCD’s analysis discusses two analogous rules which attempt to cap the 

amount of flared gas. SBCAPCD Rule 359 and the State of North Dakota’s 

Century Code 38-08-06.4 establish percentages of gas that can be flared of 

the total gas produced. In Rule 359, this percentage is averaged to 5% flared 

gas monthly and in North Dakota, the goal is 74% capture (26% flared). 

According to SJVAPCD, the actual volume of gas flared in SJV is already 

below 5%.51 SJVAPCD also states that the addition of transmission pipelines 

is the major possible measure to further capture gas and reduce flaring 

locally. However, most pipelines would not be installed by flare operators but 

by utility companies. SJVAPCD also states that requiring the oil and gas 

producers to construct transmission pipelines would be cost prohibitive and 

more stringent than any other district requirements.

52

 

We find the District’s analyses concerning the feasibility of additional flare 

control measures to be reasonable, especially in light of the District’s 

observation that the large majority of produced gas in SJV is already 

captured. 

4. Commitment for Further Analysis 

Chapter 8 of the Plan includes a commitment by the District to conduct a 

comprehensive review of submitted FMPs to identify effective flare 

minimization practices; to evaluate the technical and economic feasibility of 

 

49 See Staff Report for Rule 4311, SJVAPCD, June 18, 2009, page 16. 

50 See 2015 PM2.5 Plan, Appendix C, starting page C-79. 

51 See 2015 PM2.5 Plan, Appendix C, Section C.11, page C-80, Table C-11. 

52 See 2015 PM2.5 Plan, Appendix C, Section C.11, page C-84.
18 

implementing new and additional flare minimization practices at affected 

facilities; to have a draft report available for public review and comment by 

December 1, 2015; to develop a final report by March 31, 2016 after 

addressing public comments on these evaluations; and upon completion of 

these analyses, to work closely with affected operators to “evaluate and 

implement, when feasible, the most effective flare minimization practices 

through the FMP submittal and approval process under Rule 4311.”53

 

5. Emissions Inventory 

SJVAPCD states that emissions from flares are lower than the District’s 

selected BACM/MSM significance thresholds.54 Given the size of the 2015 

inventory subject to Rules 4311 (0.55 tpd NOx, 0.33 tpd SOx and 0.16 tpd 

PM2.5), the potential emission reductions from this category are relatively 

small. 

6. Conclusion and Recommendations

For the reasons discussed above, we propose to find that Rule 4311 

establishes BACM and MSM control requirements for this source category at 

this time. 

We support SJVAPCD’s commitment to evaluate the potential for further 

emission reductions through the review of submitted FMPs. SJVAPCD 

released a draft report of this evaluation dated December 3, 2015. The draft 

report recommended specific areas for further evaluation in 2016. EPA 

provided comments on the draft report on December 23, 2015, which 

included the following: 

A. Consider including a specific schedule or timeline in the study for completing the 

additional evaluations. 

B. Consider evaluating the smaller source flares and unreported flaring events in 

the 2016 further study. 

C. Consider explicitly identifying example facilities which currently utilize practices 

that the District intends to explore further. 

D. Consider adding further details regarding which petroleum industry processes 

are currently utilizing ultra low-NOx flares and which other industrial practices 

can potentially utilize these types of flares. 

 

 

53 See 2015 PM2.5 Plan, Chapter 8, Section 8.1, page 8-2.

54 See 2015 PM2.5 Plan, Appendix C, Section C.11, page C-60. 
19 

d. Solid Fuel Fired Boilers 

1. Overview 

Section C.13 (beginning page C-87) discusses the SJVAPCD rule for these 

sources. Rule 4352, Solid Fuel Fired Boilers, Steam Generators, and 

Process Heaters, establishes NOx emission limits and related operational 

requirements that all units must meet. SJVAPCD states that this rule 

implements BACM and MSM. 

The District states that there are 17 units subject to this rule located at 15 

facilities,55 consistent with the information provided as supplemental 

information to the SIP submittal and included in the docket for our action on 

Rule 4352.56 Based on information provided by the District in 2009, there are 

nine units burning biomass, two burning municipal solid waste (MSW) and six 

burning other solid fuels. 

The following are key points drawn from SJVAPCD’s analysis that support the 

District’s BACM/MSM determination. 

 

2. Comparison to Analogous Control Measures in Other Areas 

Rule 4352 establishes NOx emission limits of 165 ppmv for MSW facilities, 90

ppmv for biomass and 65 ppmv for other solid fuels. SJVAPCD notes that 

these limits have been lowered significantly over time and are at least as 

stringent as state and federal regulations and guidance, including federal 

NESHAP, MACT and NSPS standards, and EPA ACT guidance. In addition, 

Section C.13 compares the emission limitations in Rule 4352 with analogous 

prohibitory rules from other nonattainment areas that generally have among 

the most stringent requirements in the country, including SMAQMD Rule 411, 

SCAQMD Rule 1146, and BAAQMD Regulation 9 Rule 7.57 This comparison 

is of limited use because SMAQMD has no affected facilities, and there are 

no sources complying with SCAQMD and BAAQMD’s more stringent 40 ppmv 

limits.58

However, we also note that there are three other non-attainment Districts in 

California with adopted regulations that apply to active biomass-fueled units: 

Yolo-Solano Air Quality Management District (YSAQMD), El Dorado County 

Air Quality Management District (EDAQMD) and Placer County Air Pollution 

Control District (PCAPCD). YSAQMD’s limit is 90 ppm corrected to 3% O2 on 

 

55 See 2015 PM2.5 Plan, Appendix C, page C-87.

56 See 77 FR 66548 (November 6, 2012). The District further adds that one biomass facility in Tracy and 

another in Mendota closed in October 2014 and January 2015 respectively. (See page C-90). It is unclear 

if this is accounted for in the 17 units. 

57 See 2015 PM2.5 Plan, Appendix C, pages C-88 to C-90.

58 See 77 FR 66548 (November 6, 2012) and supporting documents in the docket. 
20 

a 24-hour block average. EDAPCD’s limit is 115 ppm corrected to 12% CO2

on a 3-hour rolling average. PCAPCD’s limit is 115 ppm corrected to 12% 

CO2 on a 3-hour rolling average and 68 ppm corrected to 12% CO2 on a 24-

hour block average. These are all within the same range as SJVAPCD’s limit 

of 90 ppm corrected to 3% O2 on a 24-hour block average. 

Therefore, we generally agree with SJVAPCD’s determination that Rule 4352 

establishes among the most stringent limits as compared to other regulations 

for solid fuel fired boilers. EPA approved Rule 4352 as fulfilling ozone RACT 

in 2012.59 

3. Technical and Economic Feasibility of Alternative Control Techniques 

SJVAPCD summarizes analysis of control technologies which could further 

reduce emissions,60 and explains why they are not demonstrated to be 

generally cost-effective at this time. This includes analysis of direct PM2.5

controls and a conclusion that the best feasible controls, electrostatic 

precipitators (ESP) or baghouses, are already required in these sources’ 

permits. It also includes analysis of why other controls (including ESP, 

baghouses and scrubbers for SOx, and shorter start-up periods) are not 

technically and economically feasible. But mostly, it includes analysis of the 

potential for additional NOx controls by requiring selective catalytic reduction 

(SCR) for each of the three fuel-types and emission limits, summarized 

below. 

A. Biomass – SJVAPCD estimates cost-effectiveness of requiring SCR for 

biomass units at $54,342/ton NOx and states that the real costs may be 

higher. SJVAPCD’s analysis also discusses the societal benefit of burning 

biomass in a boiler by “providing a cleaner alternative to the open burning 

of agricultural waste and assisting with meeting landfill diversion goals”.61

SJVAPCD notes that two facilities have shut down in the last year, arguing 

that this is additional evidence that further control costs are not 

economically feasible. We do not have information that contradicts the 

validity of this technical and economic analysis and agree that burning 

agricultural waste in biomass facilities is environmentally beneficial.62

 

59 See 77 FR 66548, November 6, 2012. 

60 See 2015 PM2.5 Plan, Appendix C, starting page C-90. 

61 See 2015 PM2.5 Plan, Appendix C, page C-91. 

62 Note that the SJVAPCD BACT determination for DTE Stockton, LLC (ATC # N-645-36-0; Project# N1101175) concluded that 0.065 lb NOx/MMBtu (approximately 45 ppm) on a 24-hour block average, 

achieved with SCR, was BACT. Additionally, the facility is expected to be able to achieve 0.04 lb 

NOx/MMBtu but is currently in its 24-month evaluation period. We do not have information indicating that 

this technology is technically and economically feasible for implementation throughout the SJV at this

time, but the District should investigate the potential for additional NOx emission reductions from more 

widespread implementation of this technology throughout SJV. 
21 

B. MSW – SJVAPCD estimates cost-effectiveness of requiring SCR for MSW 

units at $30,806/ton NOx and states that the real costs may be higher. As 

a result, SJVAPCD determined that retrofitting MSW units is not cost 

effective, and that Rule 4352 implements Best Available Control 

Technology (BACT) for these sources. We note that MSW boilers, like 

biomass boilers, similarly provide an environmental benefit by helping to 

meet landfill diversion goals. We do not have information that contradicts 

the validity of SJVAPCD’s technical and economic analysis. 

C. Other Solid Fuel - SJVAPCD estimates cost-effectiveness of requiring 

SCR for other solid fuels at $59,769/ton NOx and states that the real costs 

may be even higher. Although we note that these cost-effectiveness 

estimates appear to rest on questionable economic and technical 

assumptions (e.g., a 10% interest rate and a 10-year equipment life),63 we 

do not have information at this time that contradicts the District’s 

conclusions. We recommend that the District reassess the economic and 

technical assumptions underlying its cost-effectiveness evaluation for this 

source category. We also recommend that SJVAPCD further analyze the 

potential for additional emission reductions through fuel switching at the 

six “other solid fuel” units to, for example, natural gas or liquid fuel. This 

could result in lower NOx, SOx and direct PM2.5 emissions. In 1993, EPA 

issued a memorandum “to provide guidance to States on the use of fuel 

switching to meet the NOx RACT requirements.64 This approach has also 

been suggested for achieving reductions of CO2 in EPA’s proposed 

“Carbon Pollution Emission Guidelines for Existing Stationary Sources: 

Electric Utility Generating Units.”65 We do not believe that the analysis 

performed to support the fuel switching recommendation in the 1993 EPA 

memorandum considered the additional environmental benefits of burning 

wastes in biomass and MSW boilers, so we are only recommending it 

regarding the “other solid fuels” at this time. 

4. Emission Inventory 

According to SJVAPCD, emissions from solid fuel fired boilers, steam 

generators, and process heaters (2.99 tpd of NOx in 2015 and 3.47 tpd of NOx

in 2020) are lower than the District’s selected BACM/MSM significance 

thresholds.66 

 

63 E.g., see comment letter from Andrew Steckel (EPA) to Jessi Fierro (SJVAPCD) on “Proposed Rule 

4352, Solid Fuel Fired Boilers (November 15, 2011),” dated 11/30/2011. 

64 Office Memorandum from Michael Shapiro, Acting Assistant Administrator for Air and Radiation, to 

Regional Offices, July 30, 1993, available at http://www.epa.gov/ttn/caaa/t1/memoranda/fuelsw.pdf. 

65See 79 FR 34830 at 34857 (June 18, 2014) (discussing CO2 emission reductions achievable through redispatch from steam EGUs to NGCC units). 

66 See 2015 PM2.5 Plan, Appendix C, page C-88. 
22 

5. Conclusion and Recommendations 

For the reasons discussed above, we propose to determine that Rule 4352 

implements BACM and MSM for this category at this time. We recommend, 

however, that SJVAPCD continue evaluating the technical and economic 

feasibility of the following measure in the future:

a. Consider the technical and economic feasibility of requiring those sources 

currently burning “other solid fuels” to switch to cleaner fuels, such as 

natural gas or liquid fuel. 

e. Glass Melting Furnaces 

1. Overview 

Section C.14 (beginning page C-102) discusses the SJVAPCD rule for these 

sources. Rule 4354, Glass Melting Furnaces, establishes NOx, VOC, SOx

and PM10 emission limits and related operational requirements that all units 

must meet. SJVAPCD states that this rule implements BACM and MSM. 

Specifically, the District states that the emission limits in Rule 4354 “require 

the installation of the best available NOx technology (i.e., oxy-fuel firing or 

SCR systems).”67

The following are key points drawn from SJVAPCD’s analysis that support the 

District’s BACM/MSM determination. 

2. Comparison to Analogous Control Measures in Other Areas 

Rule 4354 establishes mandatory NOx emission limits ranging from 1.5 – 3.7 lb 

NOx/ton glass and SOx emission limits of 0.9 to 1.7 lb SOx/ton glass, 

depending on glass product and averaging time.68 According to SJVAPCD, 

this rule has been improved many times and these limits are at least as 

stringent as state and federal regulations and guidance, including federal 

NESHAP, MACT and NSPS standards, and EPA ACT guidance.69 In 

addition, section C.14 compares the emission limits in Rule 4354 with 

analogous prohibitory rules from other nonattainment areas that generally 

have among the most stringent requirements in the country, including 

SCAQMD Rule 1117 (4.0 lb/ton)70 and BAAQMD Rule 9-12 (5.5 lb/ton 

 

67 See 2015 PM2.5 Plan, Appendix C, page C-102. 

68 1.5 lb/ton on a 30 day rolling average for container glass; 3.7 lb/ton on a 24-hour block average and 3.2 

lb/ton on a 30-day rolling for flat glass (standard); 3.4 lb/ton on a 24-hour block average and 2.9 lb/ton on 

a 30-day rolling for flat glass (enhanced). 

69 Ibid, pages C-103 and C-104. 

70 Comparison to SCAQMD Rule 1117 here is relevant but of limited use because Rule 1117 was last 

revised in 1984 and SCAQMD sources are subject to RECLAIM and have RTC allocations based on a 

2000/2005 1.2 lb/ton BARCT determination, less than allowed under Rule 1117. In addition, SCAQMD 

indicates that the two affected glass facilities in 2011 emitted a combined 0.30 tpd NOx, which is 
23 

averaged over a 3 hour period), and states that SJVAPCD “found no 

requirements that were more stringent than those already in Rule 4354.” 

In 2013, EPA approved Rule 4354 as fulfilling ozone RACT requirements 

under CAA §182(b)(2).71 

We are not aware of prohibitory rules for glass melting furnaces in other areas 

that are more stringent than Rule 4354. 

3. Technical and Economic Feasibility of Alternative Control Techniques 

SJVAPCD evaluates the possibility of lowering Rule 4354’s SOx limits for 

container glass melting furnaces consistent with SJVAPCD’s permit BACT 

limit from 0.9 and 1.1 lb SOx per ton of glass to 0.8 lb. SJVAPCD states that 

“[b]ecause emissions are averaged across furnaces, EPA requires that there 

be a 10% air quality benefit, meaning that the overall limit for multiple 

furnaces be 10% less than the limit for a single furnace.”72 The District also 

states that lowering the SOx limit in Rule 4354 to 0.8 lbs would “extend 

beyond BACT” and would not be feasible because of this requirement for a 

10% air quality benefit.73 

We note that the 10% “air quality benefit” factor the District refers to is not an 

EPA requirement but a recommended measure of environmental benefit for 

purposes of evaluating an economic incentive program.74 Although EPA 

continues to recommend that rules allowing for averaging of emissions across 

multiple units achieve added air quality benefits compared to rules that 

establish source-specific limits, this recommendation does not provide a basis 

for excluding a potentially feasible control measure from consideration as 

BACM or MSM. We encourage SJVAPCD to more specifically consider the 

technical and economic feasibility of lowering the SOx limit in the rule to 0.8 lb 

per ton of glass, with or without averaging across emission units. 

SJVAPCD also asserts that the NOx emission limits in Rule 4354 effectively 

require implementation of the best available NOx control in oxy-fuel firing or 

SCR systems. The District did not provide additional analysis regarding these 

and other potential control technologies to support this assertion, but at this 

time we do not have information contradicting it. In the most recent District 

staff report addressing emission limits in this rule, SJVAPCD identified three 

 

consistent with the 2000/2005 1.2 lb/ton assumption for BARCT. See NOx RECLAIM Working Group 

Meeting, April 29, 2015. Available on slide 8 at http://www.aqmd.gov/docs/default-source/rulebook/Proposed-Rules/regxx/nox-reclaim_wgm_042915b.pdf?sfvrsn=2

71 See 78 FR 6740, January 31, 2013. 

72 2015 PM2.5 Plan, Appendix C, page C-105. 

73 Id. 

74 See 2001 EIP Guidance, Section 4.3 (“All EIPs must demonstrate environmental benefit. This 

demonstration can show ... more emission reductions (of HAPs or criteria pollutants) than would have 

happened without the EIP”). 
24 

types of controls that might further reduce NOx emissions from this category, 

which should be further considered in the future:75

 

A. Using a different refining agent (raw materials). 

B. Changing the combustion process. 

C. Adding post combustion controls. 

We note that source-specific NOx BACT determinations for container glass 

facilities in the SJV have led to NOx limits of 1.3 lb/ton76, which are currently 

being implemented. Additionally, we recommend that SJVAPCD further 

analyze the potential for additional NOx control by lowering the emission level 

for container glass melting furnaces consistent with SCAQMD’s RECLAIM 

BARCT determinations.

77 RECLAIM regulates container glass furnaces in the 

SCAQMD, but allows sources to comply with their emission allowances by 

purchasing RTCs.78 SCAQMD’s BARCT determinations are the basis for 

establishing RTC allowances for each source. The 2000/2005 NOx BARCT 

determination79 of 1.2 lb/ton for container glass melting furnaces is more 

stringent than the analogous Rule 4354 limit and is already accounted for in 

current RTC allowances, while RECLAIM’s 2015 BARCT determination (80% 

reduction80) will further reduce available RTC allowances. We recommend 

that SJVAPCD analyze the feasibility of controls equivalent to those 

considered by SCAQMD in establishing BARCT. But at this time, absent 

information about how affected sources comply with the available RECLAIM 

compliance options, it is not clear that the lower NOx emission levels identified 

in SCAQMD’s 2015 BARCT determination are technically and economically 

feasible for glass melting furnaces in SJV.81

 In addition, we recommend that SJVAPCD further analyze the potential for 

additional NOx emission reductions by requiring flat glass sources to comply 

 

75 See Staff Report for Rule 4354, SJVAPCD, September 16, 2010, page 13. 

76 See e.g. Application # N-1662-2-17; Project # N-1141107, dated October 20, 2014. 

77 See Presentation for NOx RECLAIM Working Group Meeting, April 29, 2015. Available on slide 8 at 

http://www.aqmd.gov/docs/default-source/rule-book/Proposed-Rules/regxx/noxreclaim_wgm_042915b.pdf?sfvrsn=2.

78 See footnote 16 above. 

79 See Presentation for NOx RECLAIM Working Group Meeting, April 29, 2015. Available on slide 8 at 

http://www.aqmd.gov/docs/default-source/rule-book/Proposed-Rules/regxx/noxreclaim_wgm_042915b.pdf?sfvrsn=2.

80 See Presentation for NOx RECLAIM Working Group Meeting, April 29, 2015. Available on slide 8 at 

http://www.aqmd.gov/docs/default-source/rule-book/Proposed-Rules/regxx/noxreclaim_wgm_042915b.pdf?sfvrsn=2.

81 Although it appears that, on average, 2011 emissions from the two SCAQMD facilities was consistent 

with 2000/2005 BARCT, we do not have compliance information for each of the facilities at this time. See

NOx RECLAIM Working Group Meeting, April 29, 2015. Available on slide 8 at 

http://www.aqmd.gov/docs/default-source/rule-book/Proposed-Rules/regxx/noxreclaim_wgm_042915b.pdf?sfvrsn=2.
25 

with the Tier 4 “Enhanced Option” lower emission limits (3.4 lb/ton block 24-

hour average and 2.9 rolling 30-day average) that are provided in Rule 4354 

as an option in exchange for a delayed compliance deadline. 

4. Emission Inventory 

SJVAPCD states that NOx and PM2.5 emissions from glass melting furnaces 

are lower than the District’s selected BACM/MSM significance thresholds but 

the SOx emissions from this category are above the District’s selected 

BACM/MSM significance thresholds.82 SJVAPCD identifies only eight83

sources subject to this rule, but estimates their combined total emissions at 

4.08 tpd NOx in 2015 and 4.38 tpd in 2020; 0.36 tpd PM2.5 in 2015 and 0.40 

tpd in 2020, and 1.87 tpd SOx in 2015 and 1.98 tpd in 2020. 

 

5. Conclusion and Recommendations 

For the reasons discussed above, we propose to find that Rule 4354 

establishes BACM and MSM control requirements for this source category at 

this time. We recommend, however, that SJVAPCD continue evaluating the 

technical and economic feasibility of the following measures in the future: 

A. Requiring a NOx emission level of 1.2 lb/ton for container glass melting 

furnaces, consistent with SCAQMD’s 2000/2005 RECLAIM BARCT 

determination. 

B. Requiring a NOx emission level of 1.3 lb/ton for container glass melting 

furnaces, consistent with permitted limits in SJV. 

C. Requiring a NOx reduction of 80% reduction for container glass melting 

furnaces, consistent with SCAQMD’s 2015 RECLAIM BARCT 

determination. 

D. Requiring all flat glass units to comply with the Tier 4 “Enhanced Option” 

in Rule 4354. 

E. Further reducing NOx emissions by: (a) using a different refining agent

(raw materials); (b) changing the combustion process; and/or (c) adding 

post combustion controls. 

F. Requiring a SOx emission level of 0.8 lb/ton glass with reasonable

averaging, consistent with permit BACT. 

 

82 See 2015 PM2.5 Plan, Appendix C, page C-103.

83 According to the April 17, 2006 Rule 4354 Staff Report (at page C-4), there are three flat glass 

manufacturers, three container glass manufacturers, and two fiberglass manufacturers in SJV.
26 

f. Conservation Management Practices 

1. Overview 

Section C.15 (beginning page C-106) discusses SJVAPCD Rule 4550, which 

applies to on-field crop and animal operations.84 Rule 4550, Conservation 

Management Practices, establishes requirements for owner/operators to 

implement conservation management practices (CMPs) to control PM10. For 

each agricultural site, owner/operators must select and implement one CMP 

per category and submit a CMP application for District review and approval. 

For example, the cropland categories are land preparation/cultivation, harvest 

and other; and the dairy categories are corral/manure handling and overall 

management/feeding.85 In addition, all operations must implement at least 

one CMP for unpaved roads and one for unpaved vehicle/equipment traffic 

areas. In February 2006, EPA approved Rule 4550 as satisfying BACM 

requirements for the control of PM10.

86

The following summarizes key points drawn from SJVAPCD’s analysis that 

support the District’s BACM/MSM determination. 

2. Comparison to Analogous Control Measures in Other Areas 

According to SJVAPCD, Rule 4550 is the most stringent rule of its kind. The 

District compares Rule 4550 to rules from other air districts and states, 

including Imperial County Air Pollution Control District (ICAPCD) Rule 806,87

and Arizona Administrative Code (AAC) R18-2-610 and 611 (AgBMP 

Rules).88 SJVAPCD also states that Rule 4550 is more stringent than 

SCAQMD’s “agricultural best management practices program,”89 and 

SMAQMD Rule 215, although the 2015 PM2.5 Plan does not provide a 

comparative analysis for them. 

 

84 Adopted May 20, 2004, re-adopted August 19, 2004. 

85 Poultry Operations have three CMP categories and beef feedlots have two CMP categories. See Rule 

4550 “List of Conservation Management Practices,” August 19, 2004. 

86 See 71 FR 7683, February 14, 2006. 

87 EPA approved April 22, 2013, 78 FR 23677. 

88 EPA approved October 11, 2001 (66 FR 51869). The State of Arizona has since revised these rules to 

include additional requirements. The Governor’s AgBMP Committee is in the process of further revising 

these rules for submittal to EPA. See 2014 AgBMP Committee Meeting Agendas and Minutes, 

https://www.azdeq.gov/environ/air/plan/abmp.html.

89 SCAQMD Rule 403 Fugitive Dust, section (g) allows an exemption for agricultural crop operations 

provided that the owner implements the conservation practices specified in the Rule 403 Agricultural 

Handbook (for operations within the South Coast Air Basin) or the Rule 403 Coachella Valley Agricultural 

Handbook (for areas outside the South Coast Air Basin). The Agricultural Handbooks contain 

conservation practice requirements, with categories for active sites, inactive sites, farm yard areas, track 

out, unpaved roads and storage piles. Operations that do not implement the Agricultural Handbook 

requirements become subject to Rule 403 requirements.
27 

Rule 4550 includes several significant requirements that other rules cited do 

not contain. For example, in addition to requiring that owner/operators keep 

records of the selected CMPs, Rule 4550 requires that owner/operators 

submit a CMP application for SJVAPCD review and approval. The CMP 

application must include details regarding the CMPs selected, such as the 

extent and duration of CMP implementation and other information needed by 

the District to calculate emission reductions.90 In contrast, ICAPCD Rule 806 

does not have an application and approval process, although more specific 

requirements for CMP implementation are written into the rule definitions.91

Rule 4550 also requires owner/operators to maintain records for five years, 

including CMP applications and plans, confirmation of CMP implementation, 

and demonstrations for claimed exemptions.92 Rules in other areas have less 

stringent or no apparent recordkeeping requirements. 

SJVAPCD also states that Rule 4550 is more stringent in other ways. For 

example, the District states that Rule 4550 applies to crop and animal 

operations, while ICAPCD Rule 806 and Arizona Section 49-457 only apply to 

crops. We note, however, that ICAPCD has a separate Rule 420, Livestock 

Feed Yards, that regulates PM emissions from animal facilities,93 and the 

Arizona State Legislature revised A.R.S §49-457 to add requirements for 

dairy, beef cattle feedlot, poultry and swine facilities.94

SJVAPCD also states that Rule 4550 is equivalent or more stringent than 

ICAPCD Rule 806 regarding conservation tillage CMPs. Rule 806 encourages 

the use of conservation tillage by making the conservation tillage CMP 

equivalent to three CMPs, whereas, under Rule 4550, growers that choose 

the conservation tillage CMP must implement two additional CMPs (i.e., one 

in each of the harvest and other CMP categories). While Rule 4550 requires 

more CMPs in this instance, we recognize the value of incentivizing 

conservation tillage as a highly effective PM control and encourage the 

District to consider creating similar incentives to implement conservation 

tillage. Recent research shows the PM2.5 control efficiency (CE) for 

conservation tillage at 85-90%, with slightly higher CE for PM10.

95 In contrast, 

 

90 See Rule 4550 section 3.9. 

91 For example, ICAPCD Rule 806 and SCAQMD Rule 403 Agricultural Handbook set a minimum 

standard of 60% coverage for the “Cover Crop” CMP. In contrast, Rule 4550 describes “Cover Crop” as 

“Use seeding or natural vegetation/regrowth of plants to cover soil surface,” but does not specify whether 

implementation requires 100% coverage or something far less. Similarly, several Rule 806 CMPs 

specifically require the reduction of at least one ground or tilling operation (see, e.g., sections C.7, C.12, 

C.28). This minimum requirement is not specified in analogous Rule 4550 CMPs. 

92 See Rule 4550, section 6.5. ICAPCD Rule 806 has a two-year recordkeeping requirement and South 

Coast 403 Agricultural Handbook does not specify a timeframe for keeping records. 

93 Approved by EPA on February 26, 2003 (68 FR 8839).

94 See Arizona State Legislature, A.R.S.49-457, section P.1.e and P.5.a, available at 

http://www.azleg.gov/FormatDocument.asp?inDoc=/ars/49/00457.htm&Title=49&DocType=ARS. 

95 See California Spring 2008 Tillage Campaign: Data Analysis, Space Dynamics Laboratory, Utah State 

University Research Foundation, Document Number SDL/08-556, June 21, 2013. 
28 

a grower could comply with Rule 4550 by implementing three CMPs each 

with a 10% CE. In this case, the number of CMPs required by Rule 4550 

would be higher, but the overall PM control could be lower.96

 

In other respects, other programs include measures that Rule 4550 does not 

contain. For example, the ICAPCD and SCAQMD rules include mandatory 

windblown dust controls for inactive or fallowed land. ICAPCD Rule 860 

requires growers to minimize time that newly tilled soil is smooth and dry prior 

to planting, and to implement windblown dust controls for fallowed land.97

SCAQMD Rule 403’s Agricultural Handbook requires that owners cease 

activities and implement an additional windblown dust CMP when winds 

exceed 25 mph. It also requires windblown dust controls for inactive 

cropland.98 In contrast, windblown dust controls are an option in Rule 4550, 

but not a requirement. 

While the SJVAPCD, ICAPCD, SCAQMD and Arizona programs include 

many similar CMPs and requirements, a direct comparison between them is 

complicated by the different rule structures and great variability in the 

operations of the affected growers.99 For example, other rules differ in the 

number of required CMPs, treatment of windblown dust, treatment of 

conservation tillage and specificity of CMP definitions, among other things. 

We encourage SJVAPCD to consider all of these factors during its next 

rulemaking process on Rule 4550. On balance, however, we find that Rule 

4550 is at least as stringent as the analogous rules implemented elsewhere, 

in particular given its requirements concerning submittal and approval of 

applications and related compliance requirements.100 

 

 

96 We also note that other rules require more CMPs than Rule 4550, which requires five CMPs for each 

agricultural crop operation. In 2007, the Arizona Legislature revised Arizona Revised Statutes (A.R.S.) 

§49-457 in Section 14 of Senate Bill 1552 to require two Best Management Practices (BMP) for each 

category in a serious nonattainment area (a total of six BMPs). ICAPCD Rule 806 requires six CMPs for 

crop operations, and SCAQMD Rule 403’s agricultural handbook requires nine CMPs. In many cases, 

however, implementation of Rule 4550’s CMPs may be more effective because, for example, of the 

application review and approval process. 

97 See ICAPCD Rule 806, section E.6. 

98 Rule 403 Agricultural Handbook, Measures to Reduce Dust from Agricultural Operations in the South 

Coast Air Basin, South Coast Air Quality Management District, December 1998, See Sections II.1 Active 

Conservation Practices and II.2 Inactive Conservation Practices. 

99 The San Joaquin Valley has 992,479 acres of harvested cropland, as compared to 466,877 acres in 

Imperial County and 197,101 acres in Maricopa County (Arizona. 2012, Census of Agriculture, USDA, 

National Agricultural Statistics Service). Farmers in the San Joaquin Valley grow more than 250 crops.

See Vegetable Research and Information Center, San Joaquin Valley Agriculture, University of California 

Cooperative Extension, available at http://vric.ucdavis.edu/virtual_tour/sanjoq.htm. 

100 See Rule 4550, Section 6.1. 
29 

3. Technical and Economic Feasibility of Alternative Control Techniques 

SJVAPCD has evaluated two additional CMPs since 2004: misting and new 

almond harvesting equipment. The District explains that the study presented 

on misting to control PM10 generated by disking did not provide sufficient 

information to demonstrate the minimum 10% reduction in PM10, so it was not 

added to the CMP list. A 2010/2011 study showed that the use of newer 

almond harvesting equipment achieved significant PM10 reductions. However, 

the District did not revise the CMP lists in Rule 4550 as use of newer almond 

harvesting equipment is already listed under an existing CMP category. 

SJVAPCD also considered requiring windblown dust controls, but determined 

that they would not substantially impact the area’s PM2.5 design values for the 

following reasons: windblown dust events typically occur during the spring 

and fall seasons, and are less likely during summer and winter; PM2.5

concentrations rarely become elevated during wind events; PM2.5 values 

recorded during winter stagnation periods are usually much higher than those 

recorded during wind events; PM2.5 values are driven by winter-time 

concentrations due to organic carbon and formation of ammonium nitrate; and 

the geologic component of peak PM2.5 concentration is a fraction of the mass 

formed by secondary processes and other sources.101

Recently, the SJV has experienced recurring high wind dust events with 

numerous high wind dust flagged data for PM10 and PM2.5, some of which 

have also resulted in exceedances for PM2.5. Crustal/geologic material, while 

not the majority of PM2.5, represents a significant component of the total PM2.5

mass, especially in spring through fall.102 Based on the number of days that 

the District flagged for PM2.5 as being influenced by high wind, we 

recommend that SJVAPCD revisit the feasibility and effectiveness of requiring 

windblown dust controls on significant sources, including agricultural 

sources.103

4. Commitment for Further Analysis 

SJVAPCD has submitted a commitment to evaluate all feasible opportunities 

for additional emissions reductions, if any, through implementation of Rule 

4550 and other regulations.104 The District has committed to conduct this 

evaluation and to have a draft report available for public review and 

 

101 See 2015 PM2.5 Plan, Appendix C, page C-110. 

102 See 2015 PM2.5 Plan, Appendix C, page C-109. “Further review of Valley research on PM2.5/PM10

ratios shows a consistent mid-point estimate of 0.10.” 

103 From 2010-2014 (5 years), there were 36 days when one or more PM2.5 monitors were flagged as 

being influenced by high winds in SJVACPD. See September 4, 2015 USEPA Raw Data Qualifier 

Reports, Report Request ID: 1366988, Report Code: AMP360 and Report Request ID: 1366985, Report 

Code: AMP360. 

104 See 2015 PM2.5 Plan, Chapter 8, section 8.3. 
30 

commenting by May 31, 2016. After addressing public comments, the District 

commits to finalize this report by October 15, 2016. This evaluation will be 

conducted in close coordination with stakeholders, including agricultural 

industry representatives, ARB, EPA, NRCS, farm bureaus and others. 

5. Emissions Inventory 

The emissions inventory shows that farming operations are the largest source 

of direct PM2.5 emissions in the Valley. The District’s 2020 winter inventory of 

direct PM2.5 from farming operations (9.0 tpd) is 15.5% of the total direct PM2.5

emissions (58.1 tpd). The District’s 2020 annual average inventory of direct 

PM2.5 from farming operations (13.7 tpd) is 21.8% of the total direct PM2.5

emissions (62.8 tpd). However, the District states that these particulate 

emissions, which are geologic in nature, make up a relatively small portion of 

the overall PM2.5 concentrations.105

 

SJVAPCD estimates that Rule 4550 reduced PM10 emissions from 

agricultural operations by 24%, or 35.3 tpd in 2005, its first full year of 

implementation.106 & 107 The District assumes 10% of PM10 from agricultural 

sources is PM2.5.

108 Given this assumption, Rule 4550 would have reduced 

PM2.5 in the Valley by approximately 3.5 tpd in 2005. To estimate emission 

reductions from the Rule, SJVAPCD analyzed and assigned control 

efficiencies for each CMP menu option.109 For example, the menu for the 

unpaved roads category includes “Restricted Access,” and “Washed Gravel” 

CMPs, among others. SJVAPCD estimates 10% control efficiency for 

restricted access, and 46% for washed gravel.110 This is based on the 

District’s finding that application of gravel to unpaved roads is four times more 

effective in reducing particulate emissions as restricting access to unpaved 

roads. 

SJVAPCD states that even the highest cost CMPs in Rule 4550 are costeffective at $2,500/ton of PM10.

111 Therefore, there may be opportunities to 

further reduce PM10 and PM2.5 emissions from Rule 4550, particularly if less 

effective measures are eliminated or combined, so that the menu options are 

limited to the most effective control measures. We recognize that it took many 

 

105 See 2015 PM2.5 Plan, Appendix C, page C-109. 

106 See 2015 PM2.5 Plan, Appendix C, page C-106 (citing SJVAPCD, “Conservation Management 

Practices Program, Report for 2005,” January 19, 2006 (2005 CMP Report) at page 2, available at 

http://www.valleyair.org/farmpermits/updates/cmp_program_report_for_2005.pdf).

107 See Rule 4550, Section 7.0, Compliance Schedule: “Unless otherwise noted, all provisions of this rule 

shall be effective on and after May 20, 2004.” 

108 See 2015 PM2.5 Plan, Appendix C, page C-109. 

109 See 2005 CMP Report at page 6 and Appendix C, available at 

http://www.valleyair.org/farmpermits/updates/cmp_program_report_for_2005.pdf. 

110 See 2005 CMP Report, Appendix B, CMP Emissions Reduction Methodologies, Table 3. Unpaved 

Area and Road Control Efficiency, page 8. 

111 See SJV Rule 4550 Revised Final Staff Report, Appendix B, page B-10. 
31 

months to develop the existing CMP lists to ensure feasible options for the 

wide variety of affected crops and conditions in the Valley. Nonetheless, we 

encourage the District to reevaluate the available control measures given the 

extensive experience SJVAPCD and industry have had implementing Rule 

4550 since adoption and given the remaining emissions from this activity. 

 

6. Conclusion and Recommendations 

For the reasons discussed above, we propose to find that Rule 4550 

establishes BACM and MSM control requirements for this source category at 

this time. We appreciate SJVAPCD’s commitments to conduct further 

analysis112 and recommend that it include the following: 

A. Evaluate the use and effectiveness of each compliance option in the CMP 

lists, based on submitted CMP plans, compliance and enforcement 

records and reports, and other available documentation. 

B. Identify, for potential removal from the CMP lists, any CMPs that have 

minimal environmental benefits, based on the evaluations described 

above in 6.A. 

C. Identify, for potential addition to the CMP lists, new CMPs that may 

effectively reduce PM emissions from agricultural operations. 

 

D. Identify potential rule revisions to strengthen Rule 4550’s control 

requirements, including incorporating mandatory wind-blown dust control 

measures, provisions to require or incentivize the use of conservation 

tillage, and provisions that would make certain mitigation measures 

mandatory for certain types of sources. 

E. Identify, for potential revision to the CMP lists, minimum standards to 

strengthen the enforceability and/or efficacy of certain CMPs (e.g., “cover 

crop” must establish at least 60% coverage). 

F. For each potential revision identified in 6.B-F above, evaluate the 

technical feasibility of implementation in the SJV, and evaluate the costs 

of implementation in the SJV. 

G. For each potential revision identified in 6.B-F, calculate potential PM 

emission reductions from a specified baseline emissions inventory. 

 

 

112 See Chapter 8, section 8.3, Rule 4550 Conservation Management Practices. 
32 

g. Commercial Charbroiling

1. Overview 

Section C.16 (beginning page C-115) discusses SJVAPCD Rule 4692 as it 

relates to two types of commercial charbroiling devices: chain-driven and 

under-fired. SJVAPCD estimates chain-driven charbroilers account for 42% of 

its charbroiling inventory, and under-fired for 58%.

113 Air emissions from 

these operations include water vapor, VOCs and PM. SJVAPCD explains that 

larger PM particles and grease are typically captured by grease filters in 

ventilation hoods, and the remaining VOCs and PM2.5 are exhausted outside 

the restaurant unless a secondary control device is used. 

SJVAPCD explains that chain-driven charbroilers are semi-enclosed with 

mechanical chains that automatically move food through the cooking device. 

Rule 4692 requires that chain-driven charbroilers be equipped and operated 

with a catalytic oxidizer to oxidize VOCs and PM10 in the exhaust stream to 

CO2 and water vapor. SJVAPCD estimated that the originally adopted Rule 

4692 reduced PM2.5 emissions from chain-driven charbroilers by 84% and the 

September 2009 amendment expanded the rule’s applicability and reduced 

25% of the remaining PM2.5 chain-driven charbroiler emissions.114

Under-fired charbroilers operate differently than chain-driven charbroilers, and 

have a stationary cooking surface similar to a home barbecue with a heavyduty grill over gas burners, electric heating elements, or wood to cook the 

food. SJVAPCD states that controlling emissions from under-fired charbroilers 

has proven far more challenging and to date, no cost effective technologies 

have been demonstrated.115 

SJVAPCD concludes that Rule 4692 implements the most stringent control 

measures feasible at this time for both chain-driven and under-fired 

operations, and therefore satisfies both BACM and MSM for this source 

category. EPA approved Rule 4692 into the SIP in 2011.116 The following 

summarizes key points from SJVAPCD’s analysis that support the District’s 

BACM/MSM determination. 

 

113 See SJVAPCD 2012 PM2.5 Plan, December 20, 2012, Appendix D page D-112, available at 

http://www.valleyair.org/Workshops/postings/2012/12-20-

12PM25/FinalVersion/14AppendixDStationaryandArea.pdf. 

114 See 2015 PM2.5 Plan, Appendix C, page C-115. The 2009 amendment increased the number of 

regulated charbroilers by lowering the exemption threshold from 875 to 400 lb of meat cooked/week. 

115 Ibid. 

116 See 76 FR 68103, November 3, 2011. Rule 4692 is not subject to specific ozone RACT control 

requirements of CAA 182(b)(2) and (f) since it is not subject to a CTG and the SJVAPCD has no major 

VOC/NOx charbroiler sources. 
33 

2. Comparison to Analogous Control Measures in Other Areas 

Rule 4692 requires that chain-driven charbroilers be equipped and operated 

with a catalytic oxidizer with a control efficiency of at least 83% for PM10 and 

86% for VOC emissions. 

According to SJVAPCD, there are no federal CTG, ACT, NSPS, NESHAP, or 

MACT standards and no State regulations for this category. We agree there 

are no federal or California State regulations that specifically address PM 

emissions from this category. 

SJVAPCD also compared Rule 4692 to SCAQMD Rule 1138, Control of 

Emissions from Restaurant Operations; VCAPCD 74.25, Restaurant Cooking 

Operations; and BAAQMD Regulation 6 Rule 2, Commercial Cooking 

Equipment; and concluded that it found no requirements in SCAQMD Rule 

1138 or VCAPCD Rule 74.25 more stringent than those already in Rule 4692. 

We agree with this evaluation. 

Section C.16 states that BAAQMD, Regulation 6 Rule 2 regulates both chaindriven and under-fired charbroilers. For new and existing under-fired 

charbroilers with more than 10 ft2

 of cooking area, the BAAQMD rule limits 

emissions to 1 lb PM10 per 1,000 lb beef cooked. Restaurants are required to 

install an emission control device that is certified to comply with Regulation 6 

Rule 2. SJVAPCD points out, however, that a significant portion of under-fired 

charbroilers in the BAAQMD are below the applicability threshold for the size 

of grill and amount of food cooked and that “BAAQMD has been unable to 

enforce this rule because no control technologies have been certified.”117

Based on these evaluations, SJVAPCD concludes that Rule 4692 is 

effectively more stringent than the BAAQMD rule. 

Except as discussed above for BAAQMD, we are not aware of prohibitory 

rules for charbroilers in other areas that are more stringent than Rule 4692. 

3. Technical and Economic Feasibility of Alternative Control Techniques 

According to SJVAPCD, catalytic oxidizers that are effective for chain-driven 

charbroilers are not effective for under-fired charbroilers because the exhaust 

stream cools too much prior to reaching the catalytic oxidizer. The catalyst 

 

117 See 2015 PM2.5 Plan, Appendix C, page C-116. Also see BAAQMD Compliance Advisory, Under-fired 

Charbroilers: Upcoming Requirements, January 18, 2013, which states “At the present time, there are no

certified control devices available in the Bay Area. However, testing of several control devices is in

process.” Available at http://www.baaqmd.gov/~/media/files/compliance-andenforcement/advisories/restaurants/under-fired-charbroiler-advisory-final-1-18-13.pdf?la=en. 
34 

needs the exhaust stream to be maintained at a high temperature in order to 

operate effectively.118

 

SJVAPCD discusses the following control strategies as being potentially more 

effective for under-fired charbroilers: high efficiency particulate-arresting 

filtration systems, electrostatic precipitators, and wet scrubbers. However, 

SJVAPCD adds that in its December 2009 amendment of Rule 4692, these 

controls were determined to be unproven and extremely costly.119 SJVAPCD 

notes that technology has continued to develop since 2009 and it expects to 

begin demonstration of some of the above control technologies by mid-2015. 

It states that manufacturers of these emission controls estimate the initial 

capital costs of feasible control technologies will range from $40,000 to over 

$100,000, and monthly operation and maintenance costs will range from a 

few thousand to tens of thousands of dollars.120 The District states that it will 

examine all potential opportunities for further emissions reductions. 

We are not aware of cost effective emission reduction technologies for underfired charbroilers that have been demonstrated or achieved in practice. 

4. Commitment for Further Analysis 

Since 2009, SJVAPCD has attempted to test and demonstrate PM controls 

for under-fired charbroilers. In October 2009, SJVAPCD established its 

Charbroiler Incentive Program (ChIP), which allocated $500,000 to retrofit 

commercial under-fired charbroilers with VOC/PM10 controls.121 The District 

reported that even though the incentive program was extended to March 2011 

and outreach efforts were increased, no applications for funding were 

submitted.122 The District also partnered with SCAQMD, BAAQMD and EPA 

Region 9 to further research and evaluate control technologies and costs of 

various off-the-shelf and prototype PM control technologies for under-fired 

charbroilers. The University of California at Riverside’s Center for 

Environmental Research and Technology (CE-CERT) received funding of 

over $500,000 provided by SCAQMD, BAAQMD and EPA for screening tests 

and full protocol emissions testing. 

To date, CE-CERT has tested and provided preliminary emission test results 

for several technologies including: multiple stage rooftop filtration, in-hood two 

 

118 See 2015 PM2.5 Plan, Appendix C, page C-117. 

119 See 2015 PM2.5 Plan, Appendix C, page C-118, and Final Staff Report for Amendments to Rule 4692, 

Page 2 and Appendix C, October 8, 2009. SJVAPCD provides costs ranging from $37,500 to $104,000, 

with a cost effectiveness of $22,300 to $58,200 per ton of PM2.5 reduced. 

120 See 2015 PM2.5 Plan, Appendix C, page C-118. 

121 http://www.valleyair.org/recent_news/Media_releases/2010/News%20release%20-

%20Air%20District%20offers%20charbroiler%20incentives.pdf and 

http://www.valleyair.org/grant_programs/ChIP/ChIP%20Guidelines%20100308.pdf. 

122 See SJVAPCD 2012 PM2.5 Plan, December 20, 2012, Appendix D, page D-109.
35 

stage baffle filters, rooftop exhaust conditioning and inertial separation, 

electrostatic precipitator/activated carbon cells, and ceramic filtration with 

microwave regeneration.123

SJVAPCD’s 2012 PM2.5 Plan states that extending the applicability of Rule 

4692 to include under-fired charbroilers could further reduce PM2.5 by 20% 

(0.4 tpd), and as part of that plan, the District has committed to amend Rule 

4692 in 2016 to add requirements for under-fired charbroilers, with an 

anticipated compliance date of 2017.124

In June 2015, the SJVAPCD Governing Board approved $750,000 for its 

Restaurant Charbroiler Technology Partnership program to fund PM control 

technology demonstration projects for under-fired charbroilers at Valley 

restaurants.125 The District’s funding would include the full purchase cost, 

installation, operation, maintenance, and other costs such as modifications to 

existing system configurations and structural reinforcements. 

The Plan states that as part of its 2016 rule amendment process, the District 

will examine all potential opportunities for further emissions reductions from 

this source category.126 

5. Emission Inventory 

SJVAPCD provides a PM2.5 emissions inventory for commercial charbroiling 

sources subject to Rules 4692 (2.97 tpd PM2.5 in 2015 and 3.31 tpd PM2.5 in 

2020). No NOx or SOx emissions are listed for this category. 

6. Conclusion 

Rule 4692 implements the most stringent measures adopted or demonstrated 

to be technically and economically feasible for commercial chain-driven 

charbroilers. We are not aware of more stringent control measures for underfired charbroilers that have been achieved in practice.127

 

 

123 See Commercial Cooking Emissions Control, University of California, Riverside, June 11, 2015, 

available at http://www.aqmd.gov/docs/default-source/Agendas/aqmp/control-strategy-symposium/pm2-5-

welch.pdf?sfvrsn=2. 

124 See SJVAPCD 2012 PM2.5 Plan, December 20, 2012, Chapter 5 page 5-22. This section also states 

that modeling shows reducing emissions from under-fired charbroiling by 20% in Kern County is 

necessary for attainment; also discussed in SJVAPCD’s 2015 PM2.5 Plan page C-119. 

125 See Action Summary Minutes, SJVAPCD Governing Board, Thursday, June 18, 2015, pages 5-7. 

http://www.valleyair.org/Board_meetings/GB/agenda_minutes/Minutes/2015/GB-Minutes_June.pdf. 

126 See 2015 PM2.5 Plan, Appendix C, page C-119. 

127 While BAAQMD has adopted a rule that is more stringent on paper, it does not define MSM as no 

sources have been shown to comply with it. 
36 

For the reasons discussed above, we propose to find that Rule 4692 

establishes BACM/MSM control requirements for this source category at this 

time. 

h. Internal Combustion Engines

1. Overview 

Section C.17 (beginning page C-120) discusses the SJVAPCD rule for these 

sources. Rule 4702, Internal Combustion Engines establishes NOx, CO, 

VOC, and SOx emission limits and related operational requirements that all 

units must meet. The rule contains separate emission limits for spark-ignited 

internal combustion (IC) engines used in agricultural operations (SI AO 

engines), spark-ignited IC engines used in non-agricultural operations (SI 

non-AO engines), and compression-ignited IC engines. For some engines, 

the rule also establishes more stringent limits, but allows sources to comply 

by paying a fee in lieu of meeting the lower limits. 

SJVAPCD concludes that Rule 4702, as amended November 2013, 

implements BACM and MSM for this source category. The following 

summarizes key points drawn largely from SJVAPCD’s analysis that support 

a BACM/MSM determination based on the 2013 amended version of Rule 

4702, which EPA proposed to approve into the California SIP on December 2, 

2015.128 EPA approved a prior version of Rule 4702 into the California SIP on 

January 10, 2008.129

2. Comparison to Analogous Control Measures in Other Areas 

A. Spark-Ignited Engines Used Exclusively in Non-Agricultural Operations 

(non-AO engines) 

Rule 4702, as amended January 2007, required all SI non-AO engines 

rated at >50 bhp to meet NOx emission limits ranging from 25 to 75 ppmv, 

as provided in Table 1 of the rule.130 In January 2008, EPA determined 

that Rule 4702 (as amended January 2007) implemented BACM/BACT for 

IC engines and approved the rule into the SIP.131 In August 2011, the 

District added to the rule a new Table 2 containing the same NOx emission 

limits as in Table 1 but also including a lower NOx emission limit of 11 

ppmv for all SI non-AO “rich-burn” and “lean-burn” engine types not 

specifically listed in Table 2.132 Table 2 of the rule, as amended August 

 

128 80 FR 75442 (December 2, 2015). 

129 73 FR 1819 (January 10, 2008). 

130 SJVUAPCD Rule 4702, as amended January 18, 2007, at section 5.1 and Table 1. 

131 73 FR 1819, January 10, 2008. 

132 SJVUAPCD Rule 4702, as amended August 18, 2011, at Table 2. 
37 

2011, specifically lists three types of rich-burn engines and three types of 

lean-burn engines, which remain subject to the NOx emission limits in 

Table 1 (ranging from 25 to 75 ppmv).133 All other SI non-AO engines 

rated at >50 bhp are subject to the 11 ppmv limit in accordance with the 

compliance schedule specified in Section 7.5 of the rule, unless the 

source operator either: (1) pays an annual fee to the District in accordance 

with sections 5.6 and 7.6 of the rule, or (2) elects to implement an 

alternative emission control plan pursuant to section 8.0 of the rule.134 In 

November 2013, the District revised Table 2 to add “waste gas fueled” 

engines to the list of lean-burn engines subject to a 65 ppmv NOx

emission limit but retained all other emission limits in Table 1 and Table 2 

as adopted August 2011.135 Thus, under the November 2013 version of 

Rule 4702, all SI non-AO engines rated at >50 bhp must, at minimum, 

comply with the NOx emission limits in Table 1 (which are identical to the 

applicable limits in the SIP-approved rule), and only those engine types 

not specifically listed in Table 2 are subject to the more stringent 11 ppmv 

NOx emission limit or an alternative compliance requirement.136 We are 

not aware of any emission limitation lower than 11 ppmv for spark-ignited 

IC engines that has been adopted and/or achieved in practice. The 

following Table H-1 compares the emission limits in Table 1 and Table 2 

of Rule 4702 to analogous limits implemented by other California agencies 

and contained in federal or state requirements or guidance. 

Table H-1: NOx emission limits for Non-AO Spark Ignited Engines 

Rich Burn Lean Burn Notes

District and 

Rule 

Amendment 

Year 

waste 

gas 

(ppmv) 

cyclic 

loaded 

/field 

gas 

(ppmv) 

all 

other 

(ppmv) 

two 

stroke, 

gaseous 

fueled 

(ppmv) 

all 

others 

(ppmv) 

 Additional 

notes 

SJV Rule 

4702 Table 1 

2011

50 50 25 75 65 

SJV Rule 

4702 Table 2 

2011

50 50 11 75 11 

can pay fee in 

lieu of control 

Bay Area 

2007 70 25 65 or 70 70 for waste gas 

 

133 Id. 

134 Id. at section 5.2.2. 

135 SJVUAPCD Rule 4702, as amended November 14, 2013, at Table 2. 

136 Id. at section 5.2.1; see also SJVUAPCD Rule 4702, as amended January 18, 2007, at section 5.1. 
38 

Rule 9-8

South Coast

Rule 1110.2 

2008

11 11 

Sacramento

Rule 412 

1995

50 (RACT) or 25 (BARCT) 

125 (RACT) or 65 

(BARCT) 

Feather 

River Rule 

3.22 

2014

90/25 150/65 

attainment/non

attainment 

Placer Rule 

242 

2003

90 150/300 

> 100 hp/ < 100 

hp 

Mojave Rule 

1160 

1994

50 140 

Ventura

Rule 74.9 

2005

50 25 45 or 125 

125 for waste 

gas 

San Diego 

Rule 69.4.1 

2000 125

(RACT) 

or 50 

(BARCT) 

50 

(RACT) 

or 25 

(BARCT) 

125 (RACT) or 65 

(BARCT) 

El Dorado

Rule 233 

2006

25 65 

Antelope 

Valley Rule 

1110.2 

2003

36 ppm or alternative using equation 

RACT/BARCT 

Guidance 

2001

50 

(BARCT) 

300 

(RACT 

and 

BARCT) 

50 

(RACT) 

or 25 

(BARCT) 

200 

(RACT 

and 

BARCT) 

125 

(RACT) 

or 65 

(BARCT) 

NSPS JJJJ 146 82 

lowest limits 

listed in this 

table, as there 

are different 

limits for 

different sized 

engines 

The emission limits in Table 1 and Table 2 of SJVUAPCD Rule 4702 are 

generally equivalent to or lower than analogous limits in other California 
39 

district rules, with the exception of SCAQMD Rule 1110.2, El Dorado Rule 

233, and Antelope Valley Rule 1110.2. Based on the comparison of Table 

1 limits (and associated analysis) to the other local, State and federal 

guidance and regulations, we propose to find that Rule 4702 implements 

BACT for NOx control. 

B. Spark-Ignited Engines used Exclusively in Agricultural Operations (AO) 

Rule 4702 contains separate limits for AO engines in Table 3 of the rule 

which are compared to several relevant analogous rules in Table H-2 

below: 

Table H-2: NOx Emission Limits for Agricultural Operation IC Engines 

District Amendment 

Year 

Rich Burn SparkIgnited IC Engine Lean Burn SparkIgnited IC Engine 

San Joaquin Rule 4702 2013 90 ppmv 150 ppmv 

South Coast Rule 1110.2 2008* 11 ppmv 11 ppmv 

Bay Area Rule 9-8 

Fossil/waste fuel 

2007 Exempts AO engines Exempts AO engines 

Sacramento Rule 412 1995* Exempts AO engines Exempts AO engines 

Feather River Rule 3.22 

Attainment/Nonattainment 

(exempts Ag sources 

emitting < 50% major 

source thresholds) 

2014 90/25 ppmv 150/65 ppmv 

Placer Rule 242 2003* Exempts AO engines Exempts AO engines 

Mojave Desert Rule 

1160.1 

2012 90 ppmv 150 ppmv 

* Indicates rule is in the SIP 

As shown in Table H-2, regarding spark-ignited AO engines, Rule 4702 is 

more stringent than other analogous California air district requirements 

except for SCAQMD and Feather River. With respect to the South 

Coast’s AO engine NOx limits, we note that the SCAQMD, like SJVAPCD, 

has provided economic incentive grants for agricultural engine retrofits 

and replacements in recognition of unique economic and technical 

circumstances in the agricultural industry.137

C. Compression-Ignited Engines 

Rule 4702 requires all compression-ignited engines to meet EPA’s Tier 3 

or Tier 4 emission standards for nonroad engines as stated in the rule’s 

Table 4. Certified engines must meet tier 3 or 4 standards, and non-

 

137 See SCAQMD Final Staff Report for Rule 1110.2, May 2005, Appendix B: Incentive Funding Available 

for Agricultural Engine Emission Reductions. 
40 

certified engines must meet tier 3, tier 4, or a numerical limit based on 

engine size. 

SCAQMD, BAAQMD and VCAPCD also set emission limits for these 

engines, but they are not directly comparable. Tier 3 and 4 generally 

require engine manufacturers to perform certification testing to 

demonstrate that engines meet gram/pollutant/kilowatt-hour standards 

based on engine power. These California rules, in contrast, require 

engines to meet part/million pollutant standards not dependent on power. 

To compare the requirements, we calculated ppmv emissions equivalent 

to tier 4 standards using a conversion factor for uncontrolled emissions 

from lean burn engines.138 This equates the tier 4 standards to 22 - 190 

ppmv NOx corrected to 15% oxygen. These limits are lower than 

BAAQMD and VCAPCD’s limits except for engines above 740 bhp, and 

higher than SCAQMD’s limits. The Tier 3 standards address combined 

non-methane hydrocarbon and NOx emissions, and are not directly 

comparable to the BAAQMD, VCAPCD and SCAQMD rules. However, 

SJVUAPCD Rule 4702 does establish comparable NOx limits for noncertified engines greater than 500 bhp. Rule 4702’s NOx limit (80 ppmv) is 

equal to VCAPCD’s Rule 74.9 (80 ppmv), lower than BAAQMD’s Rule 9-8 

(110 ppmv), and higher than SCAQMD’s Rule 1110.2 (11 ppmv). 

Tier 4 engines are certified to meet EPA’s most recent emission standards 

for compression ignited nonroad engines.139 For the non-certified 

compression ignited engines smaller than 750 bhp that are required to 

meet Tier 3 certification standards, we note that the Tier 4 NOx emission 

standards are identical to the Tier 3 NOx standards for all engines except 

for model years 2014 or later, which are subject to more stringent Tier 4 

NOx limits.140 We are unaware of control measures for compression 

ignited engines more stringent than EPA’s tier 4 certification standards. 

3. Technical and Economic Feasibility of Alternative Control Techniques 

SJVAPCD summarizes its analysis of control technologies which could 

reduce emissions to below the levels identified in Table 1 and Table 3 of the 

rule.141 The analysis considered implementing NOx limits of 11, 25, and 65 

 

138 EPA Alternative Techniques Document – NOx emissions from Stationary Reciprocating IC engines, 

EPA, July 1993, page 4-11. 

139 40 CFR part 1039. 

140 For further information on EPA’s emission standards for nonroad compression-ignition engines, see 

http://www.epa.gov/otaq/standards/nonroad/nonroadci.htm. 

141 See 2015 PM2.5 Plan, Appendix C, starting page C-125. 
41 

ppmv for various types of engines. SVJAPCD also analyzed the costs of 

retrofitting SI non-AO engines to meet the lower limits.142

A. Non-AO Spark-Ignited Engines 

SJVAPCD concluded that controls down to 11 ppmv are not technically 

feasible at this time for SI non-AO waste gas-fueled (rich-burn) engines as 

the variability in the fuel can potentially damage add-on controls. This is 

supported by SCAQMD’s Rule 1110.2 compliance delay143 for meeting the 

11 ppmv emission limit for landfill and digester gas fueled engines. 

According to SJVAPCD, for similar reasons, it is not generally technically 

feasible for SI non-AO cyclic-loaded, field-gas-fueled (rich-burn) engines 

to install add-on controls. Specifically, according to SJVAPCD, the cyclic 

conditions varies the exhaust temperatures which is not ideal for add-on 

controls. 

According to SJVAPCD, some SI non-AO lean-burn engines can be 

retrofitted or replaced with selective catalytic reduction (SCR) based 

systems, and some SI non-AO rich-burn engines can be retrofitted with 

NSCR, but while these engines can technically be retrofitted to meet 11 

ppmv, such retrofits may not always be economically feasible.144

 

SJVAPCD estimated costs for retrofitting and replacing limited use leanburn SI non-AO engines. While SCR is technically feasible for these 

engines, the district concluded that they are not economically feasible 

because the cost effectiveness is $66,086/ton NOx for retrofitting limited 

use lean-burn SI non-AO engines and $77,564/ton NOx for replacing such 

engines. SJVAPCD also evaluated retrofitting limited use rich-burn SI 

non-AO engines and stated that this may be technically infeasible or 

would require substantial additional costs, and calculated a cost 

effectiveness of $66,015/ton NOx. 

SJVAPCD also estimates the retrofit costs for SI non-AO rich and lean 

burn engines ranging in power from 80 - 5,500 bhp.145 Annualized retrofit 

costs range from $8,790 - $1,104,181 and estimates of cost effectiveness 

range from $11,873 - $4,284,064/ton NOx. Based on this information, 

SJVAPCD concluded that retrofit and replacement of engines to meet the 

lower emission limits is technically and economically feasible for some 

engines, but not all. As a result, the District added an option in Rule 4702 

 

142 See Staff Report for Rule 4702, Appendix C, SJVAPCD, August 18, 2011. 

143 See SCAQMD Rule 1110.2 as amended on September 7, 2012 Table III-B. 

144 See 2015 PM2.5 Plan, Appendix C, page C-132. 

145 See Staff Report for Rule 4702, Appendix C SJVAPCD. 
42 

to pay a fee in lieu of compliance with the 11 ppmv NOx limits in Table 

2.146

Although the new emission limits in Table 2 are not enforceable because 

of the option to pay fees in lieu of compliance with the limits (section 

5.2.2.2), section 5.2.2.2.1 clearly requires that all engines in the fee 

program “shall have actual emissions not greater than the applicable limits 

in Table 1 during the entire time the engine is part of the fee payment 

program.” The NOx limits in Table 1 are identical to the control 

requirements in the SIP-approved version of Rule 4702 (see Rule 4702 as 

amended January 18, 2007, section 5.1.1). We find SJVAPCD’s analyses 

concerning the feasibility of additional control measures for SI non-AO 

engines reasonable. 

B. AO Spark-Ignited Engines 

SJVAPCD evaluated various scenarios and associated cost-effectiveness 

for controlling below Rule 4702’s emission limits of 90 ppmv for rich-burn 

SI AO engines and 150 ppmv for lean-burn SI AO engines, including those 

summarized in Table H-3. 

Table H-3: Cost Effectiveness ($/ton NOx reduced) for Spark Ignited AO Engines147

Emission 

limits 

Rich-Burn Lean-Burn 

Retrofit Replacement Retrofit Replacement

11 ppmv No analysis 59,754 55,118 76,209 

25 ppmv No analysis 69,521 No analysis No analysis 

65 ppmv No analysis No analysis No analysis 42,146 

SJVAPCD evaluated the costs for replacing spark ignited rich-burn AO 

engines to meet 11 and 25 ppmv limits. SJVAPCD did not analyze costs 

of retrofitting existing rich-burn SI AO engines to meet these limits 

(although it did evaluate retrofitting costs for the limited use rich-burn SI 

non-AO engines in the same Appendix C). The District calculated the 

costs for replacing lean-burn SI AO engines to meet the 11 and 65 ppm 

limits and the costs for retrofitting these engines to meet the 11 ppmv limit. 

The District did not evaluate the costs of retrofitting lean-burn SI AO 

engines to meet a 65 ppmv limit. 

According to SJVAPCD, retrofitting SI AO engines is economically 

challenging for the following reasons.148 

 

146 SJVAPCD Rule 4702, as amended November 14, 2013, at section 5.2 and Table 2.

147 See 2015 PM2.5 Plan, Appendix C, Section C.17, pages C-132 - C-139. 

148 “AO engine Retrofit analysis” attachment to email from Sheraz Gill (SJVAPCD) to Andy Steckel 

(USEPA), dated June 25, 2015. 
43 

1. Adding controls requires greater engine power output and associated 

cost. This additional cost augments higher energy needs and costs for 

many of these engines associated with the California drought. 

2. Because existing engines used in agricultural operations have been in 

service for many years, adding control devices would require 

expensive engine overhaul or rebuild. 

3. Lower emission limits create a narrower margin of compliance. The 

AO engines would need to ensure engines are properly maintained to 

ensure compliance with the lower emission limits. This can be 

particularly challenging for the older engines. 

4. Add-on control systems must be custom designed to each engine, and 

installing controls on an engine that does not run smoothly can 

damage existing equipment. 

5. Larger catalysts used for the lower emission limits are expensive to 

replace. 

6. Agricultural operators cannot pass increased production costs to 

consumers because they compete on an international basis. 

Therefore, costs of retrofitting puts them at an economic disadvantage. 

We find SJVAPCD’s analyses concerning the feasibility of additional 

control measures for SI AO engines reasonable. 

C. Compression-Ignited Engines 

While the district did not discuss compression ignited engines in section 

C.17, Rule 4702 requires all compression-ignited engines to meet EPA’s 

Tier 3 or Tier 4 emission standards for nonroad engines. Certified engines 

must meet tier 3 or 4 standards, and non-certified engines must meet tier 

3, tier 4, or a numerical limit based on engine size. Tier 4 engines are 

certified to meet EPA’s most recent emission standards for compression 

ignited nonroad engines.149 For the non-certified compression ignited 

engines smaller than 750 bhp that are required to meet Tier 3 certification 

standards, we note that the Tier 4 NOx emission standards are identical to 

the Tier 3 NOx standards for all engines except for model years 2014 or 

later, which are subject to more stringent Tier 4 NOx limits.150 We are 

 

149 See 40 CFR part 1039. 

150 For further information on EPA’s emission standards for nonroad compression-ignition engines, see 

http://www.epa.gov/otaq/standards/nonroad/nonroadci.htm. 
44 

unaware of control measures for compression ignited engines more 

stringent than EPA’s tier 4 certification standards. 

4. Emission Inventory 

Section C.17 discusses the emissions impact of this rule. SJVAPCD 

estimates 2015 annual average emissions for the category of 0.40 tpd PM2.5, 

9.21 tpd NOx, and 0.09 tpd SOx. According to SJVAPCD, total emissions 

from IC engines are lower than the District’s selected BACM/MSM 

significance thresholds.151 

5. Conclusion and Recommendations 

For the reasons discussed above, we propose to find that the emission limits 

in Table 1, Table 3, and Table 4 of Rule 4702 as amended on November 14, 

2013 and related compliance requirements implement BACM and MSM for 

this source category at this time. We recommend, however, that SJVAPCD 

consider the technical and economic feasibility of the following measures: 

A. Removing Tables 1 and 3 and requiring all spark-ignited IC engines to 

comply with the emission limits in Table 2 of the rule. 

B. Structuring the emission fee in section 5.6 to increase annually. The 

District’s discussion of “Additional Emission Reduction Opportunities” 

(Section C.7) does not consider the possibility of increasing the emission 

fee to encourage more units to comply directly with the emission limits 

over time. The emission fee has not been increased since rule adoption 

and does not increase with inflation. We suggest SJVAPCD consider 

increasing fees over time to ensure that it is effective as a pollution 

deterrent. For example, Rule 3170’s fee rate in section 5.1 is adjusted to 

the U.S. City Average Consumer Price Index for all-urban consumers, in 

accordance with CAA §502(b)(3)(B)(v). 

C. Revising the fee structure in section 5.6 of the rule by evaluating source 

compliance within each engine subcategory. We recommend that 

SJVAPCD evaluate how sources are complying with Rule 4702 within 

each subcategory to determine whether changes are appropriate to the 

fee structure. If, for example, all rich burn SI engines with a rated brake 

horsepower smaller than 600hp comply with Rule 4702 by paying the fee, 

it might be because compliance with the emission limits is too costly, or it 

might be that the fee is too low to be a useful deterrent. We also note that 

this would be an appropriate evaluation to perform as part of a program 

evaluation as discussed in the EIP guidance.152

 

 

151 See 2015 PM2.5 Plan, Appendix C, Section C.17, page C-121. 
45 

i. Stationary Gas Turbines

1. Overview 

Section C.18 (beginning page C-142) discusses the SJVAPCD rule for these 

sources. Rule 4703, Stationary Gas Turbines, establishes NOx limits and 

related operational requirements for all units larger than 0.3 MW. These units 

are mainly operated in oil and gas production and utilities, with some also 

found in manufacturing and government. SJVAPCD states that this rule 

implements BACM and MSM. The following summarizes key points drawn 

from SJVAPCD’s analysis that support the District’s BACM/MSM 

determination. 

2. Comparison to Analogous Control Measures in Other Areas 

Section C.18 compares the emission limitations in Rule 4703 with other 

regulations, concluding that SJVAPCD “found no requirements that were 

more stringent than those already in Rule 4703.”153 Rule 4703 establishes 

mandatory NOx emission limits ranging from 5 - 25 ppm.154 According to 

SJVAPCD, these limits are at least as stringent as state and federal 

regulations and guidance, including federal NESHAP, MACT and NSPS 

standards, and EPA ACT guidance. In addition, according to SJVAPCD, they 

are more stringent than analogous prohibitory rules from other nonattainment 

areas that generally have among the most stringent requirements in the 

country, including SMAQMD Rule 413 (9 – 42 ppm), SCAQMD Rule 1134 (9 

– 25 ppm), and VCAPCD (9 – 42 ppm). In 2009, EPA approved Rule 4703 as 

fulfilling ozone RACT requirements under CAA section §182(b)(2).155 

We generally agree with the District’s demonstration that Rule 4703 contains 

emission limits that are at least as stringent as other regulations for stationary 

gas turbines. 

3. Technical and Economic Feasibility of Alternative Control Measures 

SJVAPCD states that “comparisons of this rule with the District, BAAQMD, 

and SCAQMD BACT requirements showed that some BACT emissions limits 

[in permits] are more stringent than Rule 4703 limits,” but concludes that more 

stringent limits are not cost effective for all sources.156 According to the 

District, lower limits can only be achieved by controls that are installed in new 

 

153 See 2015 PM2.5 Plan, Appendix C, pages C-143 to 144. 

154 Depending on turbine type, see Rule 4703, Table 5-3. 

155 See 74 FR 53888, October 21, 2009. 

156 See 2015 PM2.5 Plan, Appendix C, page C-145. 
46 

units and that “requiring the installation of entirely new turbine systems is 

extremely expensive and not cost effective.” 

SJVAPCD evaluated the possibility of employing SCR for units larger than 3 

MW and concluded that it is not economically feasible. SJVAPCD also 

evaluated the potential of EMx, and concluded that more demonstration 

projects using the technology are needed before it can be expected to be 

deployed generally throughout the SJV.157 We do not have information at this 

time that contradicts the District’s technical and economic analysis. 

We note the SCAQMD has recently determined BARCT to be 2 ppm for 

stationary turbines.158 SCAQMD’s RECLAIM program regulates turbines from 

various industries within the South Coast air basin, but allows sources to 

comply with allocations by purchasing RTCs.159 The BARCT determinations 

are the basis for the RTC allowances, and the 2015 BARCT determination will 

impact future RTC allowances. This latest BARCT determination was 

completed within the last year and it is not yet clear whether SCAQMD 

sources will comply with it by reducing emissions or by buying RTCs. 

We do not have information indicating that the 2 ppm BARCT limit is 

technically and economically feasible for implementation in the SJV at this 

time. We recommend that SJVAPCD evaluate the potential for additional NOx

emission reductions from this source category through implementation of 

controls consistent with SCAQMD’s BARCT determination. 

4. Emission Inventory 

According to SJVAPCD, total emissions from stationary gas turbines are 

lower than the District’s selected BACM/MSM significance thresholds.160

Given the size of the inventory subject to Rule 4703 (e.g., 2.77 tpd NOx in 

2015 and 2.81 tpd NOx in 2020), the potential emission reductions from this 

category are relatively small. 

5. Conclusion and Recommendations 

For the reasons discussed above, we propose to determine that Rule 4703 

implements BACM and MSM for this category at this time. We recommend, 

however, that SJVAPCD continue evaluating the technical and economic 

feasibility of the following measures in the future: 

 

157 See 2015 PM2.5 Plan, Appendix C, Starting page C-145 regarding SCR and page C-150 regarding 

EMx. 

158 See Presentation for SCAQMD NOx RECLAIM Working Group Meeting, April 29, 2015. Available at 

on slide 7 and 8 at http://www.aqmd.gov/docs/default-source/rule-book/Proposed-Rules/regxx/noxreclaim_wgm_042915b.pdf?sfvrsn=2.

159 See footnote 16 above. 

160 See 2015 PM2.5 Plan, Appendix C, page C-143. 
47 

A. Requiring the RECLAIM 2015 BARCT emission limits of 2 ppm NOx. 

j. Wood Burning Fireplaces and Wood Burning Heaters – 

1. Overview 

Section C.20 (beginning page C-156) discusses SJVAPCD Rule 4901, Wood 

Burning Fireplaces and Wood Burning Heaters. Rule 4901 is designed to limit 

emissions of PM, including PM2.5 and PM10, and other pollutants generated by 

the use of wood burning fireplaces, wood burning heaters and outdoor wood 

burning devices. The rule establishes requirements for the sale/transfer, 

operation and installation of wood burning devices and on the advertising of 

wood for sale within the San Joaquin Valley. 

On September 30, 2015, we proposed to approve the 2014 version of Rule 

4901 as meeting the BACM/BACT requirements for PM2.5 (80 FR 58637). Our 

proposal relied, in part, on the District’s analyses

161 and our comparison of 

Rule 4901 with measures presented in the EPA document Strategies for 

Reducing Residential Wood Smoke162 and with other state and local wood 

burning rules.163 More information on this rule and our evaluation can be 

found in the Technical Support Document for that action (“Rule 4901 TSD”).164

 

Rule 4901 and the Check Before You Burn program165 implemented by the 

District provides for a comprehensive residential wood smoke program that 

incorporates all the elements outlined in EPA’s Strategies for Reducing 

Residential Wood Smoke, including a wood burning curtailment program 

(Paragraph 5.6-5.10), opacity and visible emission limits (Paragraphs 5.6.1.2.4 

and SIP-approved Rule 4101166), requirements regarding wood moisture 

content (Paragraphs 5.1.3 and 5.4), removal of uncertified wood burning 

stoves upon home resale (Paragraph 5.2.2), restrictions on wood burning 

devices in new construction (Paragraph 5.3), restrictions on the installation of 

wood burning fireplaces (Paragraphs 5.3.2.1 and 5.3.2.3), requirement that all 

wood burning stoves sold or transferred within the District meet current NSPS 

certification standards (Paragraphs 5.1.1 and 5.1.2), a wood burning changeout program167 and education and outreach.168

 

 

161 See 2015 PM2.5 Plan, Section C.20, beginning page C-156; Final Staff Report for Amendments to the 

District’s Residential Wood Burning Program, dated September 18, 2014 (“Rule 4901 Staff Report”) and 

the email from Sheraz Gill (SJVAPCD) to Andrew Steckel (USEPA), dated June 25, 2015. 

162 See Strategies for Reducing Residential Wood Smoke, EPA-456/B-13-001, March 2013.

163 See Rule 4901, Technical Support Document, EPA, August 2015, Attachment 1. Major Components of 

Various Residential Wood Burning Rules. 

164 See Rule 4901, Technical Support Document, EPA, August 2015. 

165 Including, e.g., links titled “What are Episodic Curtailments” and “Register your Residential Wood 

Burning Device” found on SJVAPCD’s Check Before You Burn web page: http://valleyair.org/rule4901/. 

166 Rule 4101, adopted February 17, 2005, approved August 11, 2005 (70 FR 46770). 

167 See ARB 2015 PM2.5 Plan Staff Report, page15 and http://valleyair.org/grants/burncleaner.htm
48 

SJVAPCD states that Rule 4901 and associated programs implement 

BACM/BACT and MSM. Below are key points drawn from SJVAPCD’s 

analysis and our September 30, 2015 proposed rulemaking that support the 

District’s BACM/MSM determination. 

2. Comparison to Analogous Control Measures in Other Areas 

According to SJVAPCD, Rule 4901 is at least as stringent as analogous rules 

in other areas. In our proposed rulemaking on Rule 4901, we compare Rule 

4901 with analogous rules in other districts and states169 and propose that 

Rule 4901 requires BACM/BACT for wood burning devices in the San Joaquin 

Valley considering technological and economic feasibility. Below, we examine 

several provisions in detail. 

A. Tiered Mandatory Wood burning Curtailment

One of the most effective ways to reduce wintertime smoke is a 

curtailment program which restricts use of woodstoves and fireplaces on 

days that are conducive to buildup of PM concentrations.170 Some 

communities implement a voluntary curtailment program (e.g., Butte 

County Air Quality Management District (BCAQMD), FRAQMD, and 

PCAPCD),171 while others implement a mandatory curtailment program 

(e.g., SCAQMD Rule 445, BAAQMD Regulation 6.3, SMAQMD Rule 417, 

Washoe County Rule 040.051, and Washington Administrative Code, 

Section 173-433). 

Rule 4901 paragraph 5.6 includes a mandatory two-tiered curtailment 

program. During a Level One Episodic Wood Burning Curtailment, which 

is declared when the PM2.5 concentration is forecasted to be between 20-

65 μg/m3, operation of wood burning fireplaces and unregistered wood 

burning heaters is prohibited, but properly operated, wood burning heaters 

that meet certification requirements and have a current registration with 

the District may be used. During a Level Two Episodic Wood Burning 

Curtailment, which is declared when the PM2.5 concentration is forecasted 

to be above 65 μg/m3 or the PM10 concentration is forecasted to be above 

135 μg/m3, operation of any wood burning device is prohibited. 

The District estimates that uncertified wood burning devices account for 

over 95% of wood smoke emission in SJV.172 SJVAPCD states that Rule 

4901 is the most stringent rule in the nation because it is the only one to 

 

195 See http://valleyair.org/rule4901/ and Rule 4901 Paragraph 5.1.3. 

169 See Rule 4901, Technical Support Document, dated August 2015, Attachment 1. Major Components 

of Various Residential Wood Burning Rules. 

170 See Strategies for Reducing Residential Wood Smoke, EPA-456/B-13-001, March 2013. 

171 Due to their voluntary nature, voluntary curtailment provisions are generally not included within District 

Rules. 

172 See Rule 4901 Staff Report, Appendix B page B-7. 
49 

ban uncertified, high-polluting devices when the PM2.5 concentration is 

forecasted to be above 20 μg/m3

.

173 SJVAPCD projects that reducing the 

forecast threshold from 30 to 20 μg/m3increases the total number of

curtailment days over an average wood burning season to 53-85 out of 

120 wood burning season days per year, depending on the county.174

By comparison, SCAQMD Rule 445 includes a mandatory curtailment of 

all devices when the 24-hour average PM2.5 concentration is forecasted 

above 30 μg/m3. SMAQMD Rule 421 declares a voluntary curtailment 

when the 24-hour average PM2.5 concentration is forecasted to be 

between 25-31 μg/m3, a Stage 1 Mandatory curtailment when between 31-

35 μg/m3, and a Stage 2 Mandatory Curtailment when above 35 μg/m3

.

During a Sacramento Stage 1 curtailment, certified wood burning heaters 

and pellet fuel wood burning heaters are allowed to operate. During a 

Stage 2 Mandatory Curtailment, operation of all wood burning devices is 

banned. 

While SCAQMD Rule 445 bans all burning above 30 μg/m3 and SMAQMD 

bans all burning above 35 μg/m3, SJVAPCD states that adding a small 

amount of additional emissions from registered clean burning devices when 

concentrations are between 30-65 μg/m3 will be overwhelmingly 

compensated for by decreased emissions from dirty devices when 

concentrations are between 20-30 μg/m3. The District states that reducing 

emissions when concentrations are forecasted to be 20-30 ug/m3 will 

reduce the build-up of emissions which occurs during long periods of 

stagnation experienced in the wintertime in the Valley.175 

Additionally, only certified devices registered with the District are allowed to 

burn during a Level One curtailment. Registration with SJVAPCD requires 

a registration fee and an inspection every 3-years by a certified wood 

burning professional to assure the device meets certification requirements 

and is installed and operated correctly. Given these requirements, the 

District states that only a limited number of residents will take advantage of 

this registration process.176 As a worst case scenario, the District assumed 

that 24% of all existing uncertified devices would transition to cleaner 

burning devices and register with the District, leading to a total increase of 

average wood burning season emissions between 20-65 μg/m3 by 0.22 tpd 

PM2.5. The District notes that to date, through the Burn Cleaner incentive 

program, over 80% of replacements have resulted in installation of a 

natural gas-fired unit rather than a cleaner wood burning device. Natural 

gas-fired units have negligible PM2.5 emissions and are not subject to Rule 

4901. The District states therefore that a more reasonable estimate would 

 

173 See email from Sheraz Gill (SJVAPCD) to Andrew Steckel (USEPA), dated June 25, 2015. 

174 See Rule 4901 Staff Report, page 20. 

175 See Rule 4901 Staff Report page 19. 

176 See email from Sheraz Gill (SJVAPCD) to Andrew Steckel (USEPA), dated June 25, 2015. 
50 

be to assume 20% of the 0.22 tpd would occur, leading to a 0.044 tpd 

increase in emissions when concentrations are between 20-65 μg/m3

. 

Further, the District states that when compared to the 3.33 tpd of direct 

PM2.5 emission reductions from lowering the curtailment threshold, and the 

additional 2.04 tpd estimated reduction from the transition to cleaner units, 

this 0.044 tpd increase in emissions is insignificant.177 We agree that 

reducing the curtailment threshold from 30 to 20 μg/m3

 for uncertified 

devices along with registration requirements for certified devices makes the 

Rule 4901 curtailment program at least as stringent as or more stringent 

than these and other analogous programs. 

B. Ban of wood devices and fireplaces in new development 

Some areas may choose to control emissions by banning installation of 

any wood burning devices in new construction (e.g., SCAQMD Rule 444), 

only allowing wood burning appliances that meet EPA certification 

requirements (e.g., PCAPCD Rule 225 and BAAQMD Regulation 6-3), or 

restricting the number and density of new wood burning appliances in a 

given area (e.g., SJVAPCD Rule 4901 and Washoe County 040.051). 

Rule 4901, Paragraph 5.3 limits the number of wood burning devices that 

can be installed in new residential developments. In areas denser than 

two dwellings/acre, no wood burning fireplaces are allowed and a 

maximum of two certified units are allowed. In less dense areas, one wood 

burning fireplace or certified wood burning heater is allowed per dwelling. 

SCAQMD Rule 445 amended May 3, 2013, paragraph (d)(1), bans 

permanent installation of any wood burning devices in new development. 

SJVAPCD states, however, that this requirement is not applicable to areas 

where there is no existing infrastructure for natural gas within 150 feet of 

the property line or those 3,000 feet above sea level. Therefore, 

SJVAPCD states that Rule 4901 is more stringent than Rule 445 as it 

does not exempt any homes at any elevation.178 Given this lack of any 

exemptions in Rule 4901, it is reasonable to conclude that Rule 4901 is at 

least as stringent as SCAQMD Rule 445. 

C. Provisions regarding the use and sale of unseasoned wood 

Burning wet wood reduces the temperature so combustion is less 

complete and emits more PM. Several studies suggest burning 

unseasoned wood can increase PM emissions from 13%-factor of 2 or 

more.179 Several District and State rules explicitly list unseasoned wood as 

 

177 See email from Sheraz Gill (SJVAPCD) to Andrew Steckel (USEPA), dated June 25, 2015. 

178 See Rule 4901 Staff Report, page 30. 

179 See e.g.,“Residential Wood Combustion Technology Review Volume 1. Technical Report” (EPA600/R-98-174a), December 1998 and J. S. Kinsey, P. H. Kariher, and Y. Dong, “Evaluation of Methods 
51 

a prohibited fuel type (e.g., BAAQMD 6.3, PCAPCD 225, Washoe 

040.051, Maricopa County P-26, WA 173-433), ban the sale of 

unseasoned wood seasonally (e.g., SCAQMD Rule 445), or require a 

label identifying if wood is seasoned or unseasoned (e.g., BAAQMD 6.3, 

Washoe 040.051). 

Rule 4901 does not expressly prohibit the sale or use of unseasoned 

wood. However, by prohibiting emissions as dark or darker in shade than 

No. 1 on the Ringelmann Chart (i.e. 20% opacity), SJVAPCD Rule 4101 

serves the same purpose as prohibiting the use of unseasoned wood 

because even well-designed wood burning devices will produce high 

opacity when burning unseasoned wood. Additionally, paragraph 5.4 of 

Rule 4901 includes a seasoned wood labeling restriction and paragraph 

5.1.3 requires retailers to provide information on proper fuel selection and 

use. Furthermore, SJVAPCD encourages the use of seasoned wood 

through its Check Before You Burn Program.180 We agree with the District 

that these requirements collectively prevent the use of unseasoned wood. 

However, we recommend including additional requirements regarding 

seasoned wood for clarity the next time the rule is revised as described 

below. 

3. Technical and Economic Feasibility of Alternative Control Techniques 

As described above, Rule 4901 incorporates all elements outlined in EPA’s 

Strategies for Reducing Wood Smoke and includes comparable provisions 

available in other analogous rules. We are not aware of other economically 

and technically feasible measures for reducing residential wood smoke that 

have been implemented in other areas. 

4. Emissions Inventory 

SJVAPCD estimates wood burning devices will contribute 0.94 tpd NOx, 8.35 

tpd PM2.5, and 0.15 tpd SOx on an average winter day in 2020. This is above 

the District’s selected BACM/MSM significance threshold for PM2.5 and below 

the District’s significance threshold for NOx and SOx.

181

 

SJVAPCD estimates that the 2014 revisions to Rule 4901 will directly reduce 

1.1 tpd PM2.5 for the 2020 annual average and 2.2 tpd for the 2018 winter 24-

hour average.182 CARB assigns an additional 0.5 tpd reductions by 2020 for 

 

for the Physical Characterization of the Fine Particle Emissions from Two Residential Wood Combustion 

Appliances”, Atmospheric Environment, 43 (2009) 4959–4967. 

180 See letter from Sheraz Gill, SJVAPCD to Andrew Steckel, EPA Region IX, dated July 20, 2015. 

181 See 2015 PM2.5 Plan, Appendix C, Section C.20, page C-157 

182 The Rule 4901 Staff Report projects 3.33 tpd direct PM2.5 reductions from reducing the burn threshold 

from 30 to 20 μg/m3. It also projects increased emissions from additional registered devices between 20 

and 65 μg/m3 at 0.065 tpd, so the net reduction is 3.27 tpd (Rule 4901 Staff Report, Appendix B pages B11 - B-12). SJVAPCD staff confirmed that these estimates are based on a 120-day wood burning season 
52 

the annual standard and 0.7 by 2018 for the winter 24-hour standard, as a 

result of additional homeowners replacing high-emitting fireplaces and stoves 

with low-emitting certified devices.183 The 2014 Rule 4901 revisions 

encourage these device replacements by allowing registered certified devices 

to operate on days with air quality projected between 20 – 65 μg/m3, while all 

other fireplaces and stoves can operate only on days projected below 20 

μg/m3

.

184 If approved into the SIP, these provisions become federally 

enforceable, and it is reasonable to assign them future emission reductions 

for CAA planning purposes. In this case, individual homeowners are not 

required to reduce emissions by upgrading their wood-burning devices, but 

the federally enforceable rule encourages change-outs by allowing registered 

and certified devices to burn on many more days than non-registered/certified 

devices.185 This is somewhat analogous, for example, to assigning future 

emission reductions for CAA purposes for SJVAPCD Rule 9410 (employee 

trip reduction). This rule similarly does not require individuals to reduce 

emissions by, for example, carpooling and using mass transit, but similarly 

establishes structures that make such lower emitting activity more likely. 

California’s estimate of future emission reductions from wood-burning device 

change-outs encouraged by the rule relies on a survey of homeowners which 

found that 29% of Valley residents would be willing to replace their wood 

burning fireplace or heater if they could use it more often than currently 

allowed.186 As a result, the 0.5 and 0.7 tpy emission reduction estimates 

assume that 20% and 14% devices will be upgraded by 2020 and 2018 

respectively.187 ARB estimates that in 2005, there were about 200,000 wood 

burning fireplaces and about 18,000 uncertified wood burning stoves in use in 

the Valley.188

 

 

(8/13/15 phone conversation between Sheraz Gill, SJVAPCD, and Andy Steckel, EPA). With ratios of 

120/365 days for the annual average and 120/180 days for the six-month winter average, 3.27 tpd 

converts to 1.1 tpd PM2.5 for the 2020 annual average and 2.2 tpd for the 2018 winter 24-hour average. 

183 ARB’s staff report (Release Date: April 20, 2015, page 9, Tables 1 & 2) assigns 1.6 tpd direct PM2.5

reductions by 2020 for the annual standard and 2.9 tpd for the 2018 winter 24-hour standard. SJVAPCD 

staff confirmed that the difference between these estimates and SJVAPCD’s previous estimates of 1.1 

and 2.2 tpd is due to increase device change-outs encouraged by the 2014 rule revisions. 1.6 – 1.1 = 0.5 

tpy. 2.9 – 2.2 = 0.7 tpy. 

184 See Rule 4901, Paragraph 5.6. 

185 SJVAPCD projects unregistered devices can burn on average 35-67 days/winter season and 

registered devices can burn 114-120 days/winter season depending on the county (Rule 4901 Staff 

Report, Appendix B, pages B-9 – B-10). 

186 See Rule 4901 Staff Report, Appendix-B, page B-13. 

187 Rule 4901 Staff Report, Appendix-B, page B-15 estimates that a net wood burning day average 

emission reduction of 1.82 tpd PM2.5 if 24% of residents change-out their devices. This corresponds to an 

annual and winter day average emission reduction of 0.6 tpd and 1.21 respectively. 

188 See ARB Miscellaneous Processes Methodologies — Residential Fuel Combustion, Section 7.1, 

Residential Wood Combustion, February 2013 Methodology and Appendices, Appendix A, Table A-1, 

page 7.1A-2; Table A-4, page 7-1A-10; and Table A-4, page 7-1A-13. 
53 

5. Conclusions and Recommendations 

For the reasons cited above, we propose to find that Rule 4901 requires all 

BACM for wood burning devices in the SJV considering technological and 

economic feasibility. Additionally, we propose to find that Rule 4901 

implements MSM because it is as or more stringent than analogous local, 

state and federal rules and guidance. 

We recommend the following additional recommendations for next time the 

rule is revised. For more information, see the Rule 4901 TSD189: 

A. While the provisions in paragraph 5.6.1.2.4 and SIP-approved Rule 4101 

replicate wood moisture requirements, for clarity we recommend revising 

Rule 4901 to add unseasoned wood to the list of prohibited fuel types in 

paragraph 5.5, ban the sale of unseasoned wood within the District, and 

revise the advertising requirement in paragraph 5.4 to require clearly 

labelling all wood sold in the District as seasoned or unseasoned. 

B. Many agencies include a continuous limit on opacity within their wood 

burning rule. While a continuous opacity limit is included in SJVAPCD 

Rule 4101, we recommend also adding an opacity limit into the body of 

SJVAPCD Rule 4901 to improve compliance and enforceability. See, for 

example, BAAQMD Regulation 6-3 paragraph 6-3-302, and PCAPCD 

Rule 225 paragraph 304.2. 

C. Consider requiring that homes that qualify for the “sole source of heat” 

exemption described in Paragraph 5.6.3.2 (outside of power outage 

conditions) maintain a properly operated device that meets at minimum 

EPA Phase II emission limits. 

D. Consider revising section 5.1 to prohibit installation of wood burning 

fireplaces in all existing and new development unless they meet 

equivalent EPA emission limits in 40 CFR part 60, subpart AAA for 

certified wood burning devices. 

E. The town of Laguna Beach, for example, requires that any “major 

remodel” to a single-family residence, retrofit any existing wood burning 

fireplace to comply with U.S. EPA Phase II emission limits by using a 

qualified retrofit insert, converting the existing wood burning fireplace to 

gas-only use or other approved device. Consider whether this requirement 

would be feasible in the San Joaquin Valley. 

 

189 See Rule 4901, Technical Support Document, EPA, August 2015. 
54 

Recommendations to program implementation: 

F. Fireplaces are generally decorative and used sparingly (once per week), 

while wood burning heaters are used more regularly for heating. Changing 

out a fireplace to an EPA-certified stove that may be used more frequently 

could result in greater emissions. Consider providing incentive funding for 

wood burning fireplaces change-out to gas fireplaces only. 

G. Consider adding a second “Report a Violation” button under the heading 

“No Burning Unless Registered,” at 

http://www.valleyair.org/aqinfo/cbyb.htm, and including a map of 

registered devices. As it stands, it is unclear how citizens can report a 

violation during this critical period. 

k. Paved and Unpaved Roads

1. Overview 

Section C.28 (beginning page C-194) discusses SJVAPCD Rule 8061, Paved 

and Unpaved Roads. Rule 8061, as amended August 19, 2004, is designed 

to limit PM, PM2.5 and PM10 emissions by requiring control measures and 

establishing design criteria for new and existing public and private paved and 

unpaved roads. Specific requirements include: 

A. Paved roads 

1. Requirements for paved shoulders constructed on new or modified 

paved roads with projected annual average daily vehicle trips (AADT) 

of 500 or more. 

2. Requirements for medians constructed on paved roads with a 

projected AADT of 500 or more. 

3. Requirements to prioritize the use of PM10-efficient street sweepers. 

4. Requirements to remove mud/dirt from travel lanes and paved 

shoulders; to restrict vehicles from traveling over mud/dirt until the 

material can be removed from travel lanes following a 

wind/storm/water erosion and runoff; and to implement dust minimizing 

practices during removal of mud/dirt. 

B. Unpaved roads 

1. Requirements to limit visible dust emissions (VDE) on unpaved road 

segments with 26 or more AADT to 20% opacity and to comply with 
55 

the requirements for stabilized unpaved roads by application and/or 

reapplication/maintenance of watering, uniform layer of washed gravel, 

chemical/organic dust stabilizer/suppressants, roadmix, paving or any 

other method that is demonstrated to limit VDE to 20% opacity and that 

meets the conditions of a stabilized unpaved road. 

2. Prohibition on the construction of new unpaved roads within an urban 

area. 

3. Requirements for identifying and paving unpaved roads within urban 

and rural areas. 

For existing unpaved public roads in urban and rural areas, Rule 8061 

requires city, county or state agencies to submit, by 2005, a list of all 

unpaved roads including data on the length of, and AADT on each 

unpaved road segment. The rule further requires agencies to pave an 

average of 20% annually of all unpaved roads up to a maximum of five 

cumulative miles by January 1, 2010. Also, by April of each year, 2006 

through 2010, city, county or state agencies are required to submit to 

the District the total number of unpaved road miles which were paved 

and the percentage of cumulative miles paved.190 Section 5.2.4 

contains similar requirements to pave or stabilize the unpaved 

shoulders of existing paved public roads. 

4. Requirements for identifying and paving unpaved shoulders in urban 

and rural areas. 

5. Requirements for establishing and posting maximum speed limits on 

unpaved roads. 

EPA approved Rule 8061 as satisfying BACM for PM10 in 2006.191

SJVAPCD’s 2015 evaluation concludes that Rule 8061 implements the most 

stringent measures feasible in the Valley and that the rule continues to meet 

or exceed BACM.192 The following are key points drawn from SJVAPCD’s

analysis that support the District’s BACM/MSM determination. 

2. Comparison to Analogous Control Measures in Other Areas 

In Section C.28, the District compares Rule 8061 to the following 

analogous fugitive dust requirements from other California and Nevada 

regulatory agencies that generally have among the most stringent air 

 

190 Rule 8061, section 5.2.3 

191 See 70 FR 51303 (NPR, August 30, 2005), 71 FR 8461 (NFR, February 17, 2006), and EPA’s 

associated technical support document for this action. 

192 2015 PM2.5 Plan, Appendix C, Section C.28, page C-196.
56 

pollution requirements in the country, and SJVAPCD concludes that it 

“found no requirements that were more stringent than those already in 

Rule 8061.”193

 

• SCAQMD Rule 1156, Further Reductions of Particulate Emissions 

from Cement Manufacturing Facilities, March 6, 2009. 

• SCAQMD Rule 1157, PM-10 Emission Reductions form Aggregate and 

Relation Operations, September 8, 2006. 

• SMAQMD Rule 403, Fugitive Dust, August 3, 1977. 

• VCAPCD Rule 55, Fugitive Dust, June 10, 2008. 

• Clark County Department of Air Quality Section 91, Fugitive Dust from 

Unpaved Roads, Unpaved Alleys, and Unpaved Easement Roads, 

April 15, 2014; and Section 93, Fugitive Dust from Paved Roads and 

Street Sweeping Equipment, April 15, 2014.194

According to SJVAPCD, Rule 8061 is also at least as stringent as State 

and federal regulations and guidance including the General Preamble for 

Title 1 of the CAA, the Fugitive Dust Background Document and Technical 

Information for BACM,195 and NSPS, NESHAP and MACT standards. We 

note, however, that Section C.28 provides little support for the District’s 

conclusions regarding BACM/MSM for this category. 

Table K-1 provides our comparison of the rules identified above with Rule 

8061. 

Table K-1 Paved and Unpaved Roads Rule Comparison 

 

193 2015 PM2.5 Plan, Appendix C, Section C.28, pages C-195 – 196.

194 2015 PM2.5 Plan, Appendix C, Section C.28, page C-194. 

195 57 FR 13498, EPA-450/2-92-004, 2015 PM2.5 Plan, Appendix C, Section C.28, pages C-194 – 195.

196 Rule 8061 exempts agricultural operations, but Rule 8081 Agricultural Sources establishes 

requirements to limit fugitive dust from agricultural sources. 

Rule Paved Roads Opacity Unpaved Roads Exempts

AADT AADT Require 

ments 

SJ 8061 

(paved/ 

unpaved 

roads) 

500-3000 

>3000 

● 4’ shoulder 

paved/stabilized 

● 8’ shoulder 

paved/stabilized 

20% >26 25mph Agricultural 

operations – 

but see Rule 

8081196

SC 1156 n/a 20% n/a ● 35mph Suppressant 
57 

3. Technical and Economic Feasibility of Alternative Control Techniques 

The District considered requiring control measures on paved and unpaved 

roads with less than 26 AADT. SJVAPCD’s analysis indicates that most 

PM emissions are from unpaved roads above 26 AADT, which are already 

subject to the Rule 8061 requirements. Additionally, emissions from 

unpaved roads are lowest in the winter months, when the District’s PM2.5

24-hour exceedances occur. For these reasons, SJVAPCD states that 

 

197 SC 1157 applies to paved roads at aggregate handling facilities. The 60 AADT applies to trucks exiting 

a facility on any day. SJ Rule 8041 contains requirements for track-out and applies analogous 

requirements to sites > 150 vehicle trips/day or > 20 vehicle trips/day by vehicles with 3 or more axles. 

198 SC 1186 PM10 Emissions from Paved and Unpaved Roads and Livestock Operations establishes 

requirements to reduce PM from vehicular travel. This rule is not discussed in SJ’s 2015 Appendix C, but 

appears relevant to the evaluation. 

(cement 

plants) 

haul road 

● 15mph 

other road 

not required if 

AADT< twice a 

day & 15 mph 

SC 

1157197

(aggregat

e/related 

ops) 

>60 

<60 

● sweep internal 

roads after shift 

● sweep/water 

internal roads at end 

of day 

20% Stabilize 

internal haul 

roads 

Unpaved 

roads if AADT 

< twice a day 

& < 15 mph 

SC 

1186198

(paved/ 

unpaved 

roads) 

500-3000 

>3000 

● 4’ paved shoulder 

● 8’ paved shoulder 

n/a >avg annual 

AADT of all 

unpaved 

roads 

15mph Unpaved 

roads above 

3000 feet with 

< 500 AADT 

SM 403 

(fugitive 

dust) 

n/a n/a n/a n/a Ag 

VC 55 

(fugitive 

dust) 

n/a 20% >20 15mph ● Ag 

● < 20 AADT 

unpaved 

service road 

● >20 AADT if 

4” of low silt 

matl/gravel 

applied 

CC 91 

(unpaved 

roads) 

n/a n/a 20% >150 Implement 

measures 

for 1

/3

unpaved 

road miles 

Private 

driveways 

CC 93 

(paved 

roads) 

<3000 

> 3000 

● 4’ shoulder 

paved/stabilized 

● 8’ shoulder 

paved/stabilized 

20% n/a n/a Private 

driveways 
58 

lowering the AADT threshold will not achieve additional emission 

reductions. 

During adoption of Rule 8061, the District was also asked to strengthen 

(and clarify) the requirement for cities and counties to pave an average of 

20% annually of all unpaved roads up to a maximum of 5 cumulative miles 

between 2005 and 2010. In response, SJVAPCD stated that this is not 

feasible given the financial hardship it would cause in some 

jurisdictions.199

SJVAPCD’s 2015 PM2.5 Plan stated that the District received only one 

significant comment related to Rule 8061 – to consider providing 

incentives to discourage new unpaved roads.200 The District’s response 

stated, “Rule 8061 already limits fugitive dust emissions from paved and 

unpaved roads by implementing control measures and design criteria.”201

We note that Rule 8061 prohibits the construction of any new unpaved 

road in an urban area unless the road meets the definition of a temporary 

unpaved road. We are not aware of this or other additional measures that 

are technically and economically feasible for sources in the District. 

4. Emissions Inventory 

SJVAPCD estimates 7.98 tpd PM2.5 in 2015 and 8.69 tpd in 2020 from 

paved and unpaved roads subject to Rule 8061. No NOx or SOx emissions 

are expected for this category. 

5. Conclusion and Recommendations 

For the reasons discussed above, we propose to determine that Rule 

8061 implements BACM and MSM for this category at this time. We 

recommend, however, that SJVAPCD continue evaluating the technical 

and economic feasibility of the following measures in the future: 

a. SJVAPCD should provide the number of unpaved roads and shoulders 

paved in meeting the Rule 8061 paving requirements in Sections 5.2.3 

and 5.2.4 through 2010 similar to Maricopa County.202 SJVAPCD’s 

 

199 “Responses to Comments on the Proposed Amendments to Regulation VIII,” SJVAPCD, August 19, 

2004. 

200 2015 PM2.5 Plan, Appendix H, page H-3.

201 Ibid.

202 Maricopa County reported that from November 2009 – December 2013, public unpaved roads 

decreased 232 miles and private unpaved roads decreased 273 miles. 

https://www.azmag.gov/Documents/AQTAC_2014-12-04_2013-Unpaved-Roads-Inventory-for-theMaricopa-County-PM10-Nonattainment-Area-Presentation.pdf. 
59 

website provides forms to report incremental progress regarding these 

requirements,203 but we were unable to find the results of the progress.

 

b. Consider revising sections 5.2.3.1.2, 5.2.3.1.3, 5.1.4.1.2 and 5.2.4.1.3 

to require paving/stabilizing additional roads and shoulders beyond the 

existing requirements for 2005-2010 currently in the rule. 

c. Consider requirements to reduce the speed limit from 25 mph to 15 

mph on unpaved roads similar to SCAQMD Rule 1186, VCAPCD Rule 

55 and CAPCOA BACM recommended practices.204 

l. Asphalt/Concrete Operations

1. Overview 

Section C.35 (beginning page C-218) discusses SJVAPCD rules related to 

these sources. This includes Rule 2201, New and Modified Stationary Source 

Review; Rule 4101, Visible Emissions; Rule 4301, Fuel Burning Equipment; 

Rule 4309, Dryers, Dehydrators, and Ovens; and Rule 4641, Cutback, Slow 

Cure, and Emulsified Asphalt, Paving and Maintenance Operations. Rule 

2201 discusses permit requirements for new and modified sources, Rule 

4101 establishes opacity limits for a wide range of activities, and Rule 4301 

establishes emission limits for any fuel burning equipment except air pollution 

control equipment. Rule 4309 establishes specific and more stringent NOx

emission limits for asphalt/concrete plants than Rule 4301205, and Rule 4641 

establishes VOC limits for cutback and emulsified asphalt. SJVAPCD 

concludes that these rules together implement BACM and MSM for this 

source category. 

 Section C.35 discusses various asphalt technologies including cold mix (rapid 

cure, medium cure, slow cure and emulsified), hot mix and warm mix; and 

achieved-in-practice controls. It also presents an inventory of PM2.5, NOx, SOx

and VOC emissions associated with asphalt manufacturing mineral 

processes. 

The following summarizes key points from SJVAPCD’s analysis that support 

the District’s BACM/MSM determination. 

 

203 https://www.valleyair.org/busind/comply/PM10/compliance_PM10.htm. 

204 http://www.capcoa.org/ag-clearinghouse/beef/unpaved-roads/

205 Rule 4301, (amended December 17, 1992), limits SO2, NOx and PM from units whose primary purpose 

is to produce heat or power by indirect heat transfer. Rule 4301 is similar to rules in other districts and 

acts as a backstop if a source specific rule does not apply. 
60 

2. Comparison of Rules 2201, 4101, and 4309 to Analogous Control Measures 

in Other Areas 

Rule 4309 establishes mandatory NOx and CO limits for dryers, dehydrators 

and ovens firing on gaseous or liquid fuel with a total heat input of 5.0 

MMBtu/hr or greater. Asphalt/concrete plants that exceed this threshold, for 

example, are subject to NOx limits of 4.3 ppm (gaseous fuel) and 12.0 ppm 

(liquid fuel). SJVAPCD found no NSPS or NESHAP requirements more 

stringent than these and other requirements in Rules 2201, 4101 and 4309. 

According to SJVAPCD, there are no state regulations applicable to this 

source category and no analogous rules from BAAQMD, SMAQMD or 

VCAPCD. SJVAPCD also evaluated SCAQMD Rule 1157, PM10 Emission 

Reductions from Aggregate and Related Operations, and SCAQMD Rule 403, 

Fugitive Dust, and found no SCAQMD requirements more stringent than 

those in SJVAPCD Rules 4101, 2201 and 4309.206

 

The District states that EPA has not issued federal guidance documents 

covering NOx or CO emissions for existing asphalt plants such as a CTG or 

an ACT document. In May 2007, EPA approved Rule 4309 as fulfilling ozone 

RACT requirements under CAA section 182(b)(2).207 EPA has also approved 

Rules 2201, 4101 and 4301 into the SIP.208

We are not aware of more stringent PM or NOx requirements implemented in 

other California districts for asphalt plants. We note that Rule 4101 only 

regulates opacity, and the NSPS and NESHAP contain both opacity and PM 

limits. Although opacity is often used as an indicator of PM emissions, we are 

not aware of a means to generally correlate opacity and PM limits for 

asphalt/concrete operations. 

3. Rule 4641 Controls Cutback Asphalt VOC Emissions

209

Cutback and emulsified asphalts are “cold mix” asphalts typically used for 

small projects. Generally, cutback asphalt emits more VOC than other asphalt 

technologies and is no longer used by Caltrans. Rule 4641 prohibits the 

manufacture or use of rapid and medium cure asphalt and establishes VOC 

emission limits of 0.5% for slow cure cutback asphalt and 3% VOC for 

emulsified asphalt. It exempts the use of medium cure asphalt when the high 

temperature for the 24-hours following application is forecast below 50o F. 

 

206 See 2015 PM2.5 Plan, Appendix C, Pages C-219 and C-220.

207 See 72 FR 29886, May 30, 2007. 

208 See Rule 2201: 79 FR 55637, September 17, 2014. Rule 4101: 70 FR 46770, August 11, 2005. Rule 

4301: 64 FR 26876, May 18, 1999. 

209 Rule 4641 regulates VOCs but not NOx or PM. While it is not directly relevant to BACM/MSM, we are 

providing a brief discussion of the rule here for background purposes. 
61 

SJVAPCD notes that the use of cutback asphalt emits VOCs, which do not 

contribute significantly to local PM2.5 formation. 

In March 2010, EPA approved Rule 4641 as fulfilling ozone RACT 

requirements under CAA §182(b)(2).210

 

We believe Rule 4641 is similar to rules in other air districts and is generally 

consistent with EPA’s CTG and model rule for cutback asphalt. 

4. Technical and Economic Feasibility of Alternative Control Techniques 

SJVAPCD’s analysis states that most traditional hot mix asphalt (HMA) 

mixtures are manufactured and compacted at above 300

oF, and that these 

high temperatures produce greenhouse gases and other criteria and 

hazardous air pollutants. The District notes that emissions are minimized by 

achieved-in-practice controls meeting Rule 4101 opacity limits. 

SJVAPCD discusses warm mix asphalt (WMA), a newer technology which is 

produced at temperatures 25 - 90oF lower than HMA. WMA’s benefits include 

improved performance, energy savings, and fewer combustion emissions by 

reducing the fuel needed to heat the asphalt. SJVAPCD’s analysis cites a 

U.S. study indicating typical fuel savings of 15 - 25%, which would similarly 

reduce NOx. European studies report NOx emission reductions in using WMA 

instead of HMA from 58 - 70%.211 

The District notes that U.S. use of WMA has grown steadily but, despite the 

technological feasibility of WMA substituting for HMA, the cost of converting 

equipment remains a barrier and certain applications may not be suitable for 

WMA. SJVAPCD further states that some WMA processes use organic or 

chemical additives that may be accommodated using existing plant and 

production technology, but also adds that WMA technologies may require 

more finesse in controlling the process.212 As a result, “more research into the 

capital costs associated with converting production equipment to handle 

WMA and other feasibility issues is still needed to fully determine whether 

WMA would be feasible and cost effective to require for all Valley asphalt 

production facilities.”213

 

At this time, we are not aware of any other state or local agency that 

requires214 the use of WMA. As noted by SJVAPCD, reduced fuel usage is 

 

210 See 75 FR 10690, March 9, 2010.

211 See 2015 PM2.5 Plan, Appendix C, Table C-36, page C-223. 

212 See 2015 PM2.5 Plan, Appendix C, Page C-221. 

213 See 2015 PM2.5 Plan, Appendix C, Page C-225. 

214 Discussions with the Federal Highway Administration (FHWA) indicates that rather than requiring the 

use of WMA, many states allow WMA as an option to HMA. FHWA stated that in evaluating this option, 

an asphalt contractor needs to consider factors such as ambient temperature, placement temperature, 
62 

one benefit of WMA. WMA studies also report the potential for reduced NOx, 

VOC and PM2.5 emissions.215

 

5. Commitment for Further Analysis 

The District states that emissions from asphalt usage is extremely small but 

has submitted a commitment to evaluate and promote the use of WMA and 

have a draft report available for public review and comment by December 1, 

2015. This includes evaluating opportunities to further encourage 

transportation and county agencies to continue transitioning from HMA to 

WMA as feasible, and evaluating potential outreach and education 

opportunities for encouraging project developers and construction managers 

to increase WMA use.216 We note that Texas and Nevada have previously 

summarized some WMA cost information.217 

6. Emission Inventory 

SJVAPCD states that PM2.5, NOx, and SOx emissions from asphalt/concrete 

operations occur during the mineral processes, and that asphalt mixing and 

application processes only emit VOCs.218 It further states that these 

emissions are lower than the District’s selected BACM/MSM significance 

thresholds.219 Given the size of the asphalt/concrete inventory subject to 

Rules 4309 and 4641 (0.22 tpd NOx and 0.89 tpd PM2.5 in 2015 and 0.25 tpd 

NOx and 1.01 tpd PM2.5 in 2020), the potential emission reductions from this 

category are relatively small. 

7. Conclusion and Recommendations 

For the reasons discussed above, we propose to find that Rules 4101 and 

4309 together establish BACM and MSM control requirements for this source 

category at this time. 

 

wind speed and haul distance between the asphalt plant and the job site. Personal communications 

Stanley Tong (EPA Region 9) and Mathew Corrigan (FHWA), February 9, 2015. 

215 See Frank, Bob, et. al., Warm Mix Asphalt (WMA) Emission Reductions and Energy Savings, National 

Center for Asphalt Technology, September 6, 2011; and Miller, Timothy D., et.al., Sustainable Asphalt 

Pavements: Technologies, Knowledge Gaps and Opportunities, Modified Asphalt Research Center, 

February 20, 2009. 

216 See 2015 PM2.5 Plan, Chapter 8, Section 8.2, page 8-3. 

217 See Button, J.W., Estakhri, C., Wimsatt, A., A Synthesis of Warm-Mix Asphalt, Texas Department of 

Transportation, FHWA/TX-07/0-5591-1, Table 7 (page 47), http://tti.tamu.edu/documents/0-5597-1.pdf

and Hand, A.J.T., Green Pavement Construction, April 23, 2009, Nevada T2 Center, slides 58 and 95 

estimate WMA equipment capital costs to be $25 to $100K per plant. The capital costs could be partially 

offset by reduced fuel usage to produce WMA. 

http://www.t2.unr.edu/T2%20WMA%20&%20RAP%20042309.pdf. 

218 The blue haze generally observed with HMA is condensable organics (which we believe is 

condensable PM2.5) and is generally not observed with WMA. FHWA WMA Technologies Brochure. 

219 See 2015 PM2.5 Plan, Appendix C, Page C-218. 
63 

We support and encourage the District’s commitment to work with 

stakeholders to evaluate and promote the use of WMA. SJVAPCD released a 

draft report of this evaluation dated December 1, 2015. The draft report 

summarizes stakeholder input on the advantages and challenges of 

promoting lower emissions asphalt processes and paving in the District. On 

December 23, 2015, EPA provided comments on the draft report, including 

the suggestion that some of the challenges could be opportunities to develop 

WMA best practices. In addition to our comment letter, we recommend the 

District evaluate the following additional suggestions in its discussions with 

stakeholders on how to best promote WMA: 

A. Include in a WMA best practices document, guidance, similar to that being 

considered by the Texas DOT,220 on projects where WMA should be 

encouraged, such as those with limited financial startup impacts, large 

paving projects (e.g., greater than 10,000 tons), and overlay projects with 

significant crack seal in the existing pavement. 

B. If Rule 4641 is revised to incorporate PM controls, SJVAPCD should also 

evaluate VOC reduction opportunities such as regulating asphalt release 

agents.221

C. Evaluate the potential to adopt requirements for permitted PM control 

devices at HMA plants similar to SCAQMD Rule 1155.222 

D. Evaluate whether it is feasible and productive to incorporate additional 

emission limits in SJVAPCD rules for new and/or existing sources in 

SJVAPCD that are similar but not covered by: 

 

1. NSPS, 40 CFR 60: Subpart OOO, Standards of Performance for 

Nonmetallic Mineral Processing Plants; Subpart I, Standards of 

Performance for Hot Mix Asphalt Facilities; and Subpart UU, Standards 

of Performance for Asphalt Processing and Asphalt Roofing 

Manufacturing. 

2. NESHAP, 40 CFR 63: Subpart LLLLL, Asphalt Processing and Asphalt 

Roofing Manufacturing for Major Sources; and Subpart AAAAAAA, 

 

220 Personal communications Stanley Tong (EPA Region 9) and Robert E. Lee (Texas DOT – 

Construction Division), February 18, 2015. 

221 SCAQMD is considering regulating mold release products (including asphalt release agents) for early 

2016. See Control Measure Forecast, June 5, 2015, Proposed Rule 1161, page A-3, and personal 

communications Stanley Tong (EPA Region 9) and Mike Morris (SCAQMD), June 23, 2015; 

http://www.aqmd.gov/docs/default-source/Agendas/Governing-Board/2015/2015-jun5-015.pdf?sfvrsn=2; 

study: http://www.irta.us/reports/Finalscaqmdmoldrelrept.pdf. 

222 See Particulate Matter (PM) Control Devices, May 2, 2014. Available at 

http://www.aqmd.gov/docs/default-source/rule-book/reg-xi/rule-1155.pdf?sfvrsn=4
64 

Asphalt Processing and Asphalt Roofing Manufacturing for Area 

Sources. 

m. Confined Animal Facilities 

1. Overview 

Section C.41 (beginning page C-240) discusses SJVAPCD Rule 4570, 

Confined Animal Facilities (CAFs), which applies to large dairy, poultry, beef 

cattle feeding and swine CAFs. The rule requires operators to implement 

measures to control VOC emissions for each major stage of operation, 

including feeding, silage, milking (dairy), housing, waste management and 

waste storage/application. According to the District, Rule 4570 was developed 

to limit VOC emissions, but also reduces ammonia emissions through 

mitigation measures for nutritional management, increased cleaning and 

removal of manure and litter from housing areas, and land incorporation of 

manure and litter.223 

 

EPA approved Rule 4570 as meeting RACT for VOC control in 2012.224

SJVAPCD states that Rule 4570 also implements BACM and MSM. The 

following are key points drawn from SJVAPCD’s analysis that support the 

District’s BACM/MSM determination. 

 

2. Comparison to Analogous Control Measures in Other Areas 

SJVAPCD states that there is no CTG, ACT, NSPS, NESHAP or other 

relevant federal regulations or guidance for CAFs. SJVAPCD compares the 

requirements in Rule 4570 with analogous prohibitory rules from other areas, 

including SCAQMD Rules 223 and 1127, BAAQMD Rule 9-10, SMAQMD 

Rule 496, VCAPCD Rule 23, ICAPCD Rule 217, Butte County Rule 450 and 

the State of Idaho Administrative Procedures Act Rule 58.01.01 (Idaho rule). 

It concludes that SJVAPCD Rule 4570 is more stringent than these other 

rules. For example, the District states that Rule 4570’s applicability thresholds 

are more stringent than those in SCAQMD Rule 233 and the Idaho rule.225 In 

addition, SJVAPCD strengthened Rule 4570 in 2010 by adding and changing 

certain measures, and making certain mitigation measures mandatory, 

whereas other rules have not been similarly updated.

226

 

 

223 See 2015 PM2.5 Plan, Appendix C, Pages C-240 to C-243. See also C-241, footnote 121 - Appendix F, 

Ammonia Reductions Analysis for Proposed Rule 4570 (Confined Animal Facilities), SJVAPCD, June 15, 

2006. 

224 77 FR 2228, January 17, 2012. 

225 See 2015 PM2.5 Plan, Appendix C, Page C-244, C-263. See 

http://adminrules.idaho.gov/rules/current/58/0101.pdf 

226 See 2015 PM2.5 Plan, Appendix C, Page C-247.
65 

The District provides a detailed comparison of Rule 4570 and the Idaho 

rule.227 The Idaho rule is based on a “points” system while Rule 4570 requires 

a minimum number of management practices for each CAF operation. These 

different structures make it difficult to compare these two rules directly. Rule 

4570 may be more prescriptive in requiring implementation of a certain 

number of management measures. In contrast, the Idaho rule assigns points 

to each measure listed in the rule and requires operators to implement 

measures that, combined, have at least 27 points.228 It appears that in some 

respects, Rule 4570 contains more stringent provisions than the Idaho rule 

(e.g., rule applicability threshold, and provisions for temporary 

suspension/substitution, testing and records retention). On the other hand, 

the Idaho rule contains options (e.g., chemical amendments, lagoon 

nitrification/de-nitrification systems, lagoon covers, tunnel ventilation with 

biofilter, and incorporation of manure within 24 hours of land application) that 

are not included in Rule 4570. It is not clear whether these control options are 

commonly implemented in Idaho or available or appropriate for use in the 

SJV. 

We generally agree with the District’s demonstration that Rule 4570 

establishes the most stringent control measures for ammonia emissions 

compared to other CAF regulations. 

3. Technical and Economic Feasibility of Alternative Control Techniques 

SJVAPCD analyzed additional potential control measures and did not identify 

any shown to be economically and technically feasible for SJVAPCD sources 

at this time. SJVAPCD discusses episodic application of sodium bisulfate 

(SBS) on manure at dairies, which converts a greater fraction of ammonia to 

non-volatile ammonium.229 The ammonium combines with sulfate to form 

ammonium sulfate, which remains in the manure or corral. However, 

SJVAPCD explains that there are potential adverse impacts of SBS 

application on worker safety and health, cattle heath, water quality, and on 

overall cost and cost-effectiveness. It references SCAQMD’s 2012 AQMP to 

argue that SBS effectiveness may be limited to specific SCAQMD dairies and 

may not be feasible for implementation in the Valley at this time. SJVAPCD 

also evaluated the use of covers to reduce ammonia from lagoons and solid 

manure storage piles.230 The District found no definitive evidence that lagoon 

covers would control ammonia emissions, and cited several studies indicating 

that anaerobic lagoons might increase ammonia emissions.231 It also cites 

 

227 See 2015 PM2.5 Plan, Appendix C, Page C-262. 

228 For a detailed explanation of the point system, see IDEQ, “Scientific Basis for the control of Ammonia 

from Dairy Farms Best Management Practices,” July 18, 2006, available at 

http://www.deq.idaho.gov/media/635665-58_0101_0502_scientific_basis_final.pdf 

229 See 2015 PM2.5 Plan, Appendix C, section C.41.IV, page C-267. 

230 See Email from Sheraz Gill (SJVACPD) to Andy Steckel (USEPA), dated June 25, 2015. 

231 Ibid, Evaluation of Covers Lagoons Manure Piles for NH3.docs. 
66 

cost and safety concerns related to covering manure piles that are not 

completely dry. 

We generally agree with the District’s conclusion that Rule 4570 establishes 

the most stringent control measures for ammonia emissions from CAFs that 

can feasibly be implemented in the SJV at this time. 

4. Emissions Inventory 

CAFs are the largest source of ammonia emissions in SJV, at 197.9.0 tpd 

(2015 winter average), or 61.8% of the total ammonia emissions in the SJV 

(320.4 tpd, 2015 winter average).232 The 2015 PM2.5 Plan (Appendix C) 

states that Rule 4570 reduced ammonia emissions by over 100 tpd but does 

not specifically explain the basis for this emission reduction estimate.233

More recently, CARB estimated that Rule 4570 reduced 2012 baseline 

emissions by 73 tpd, from 323.8 to 250.9 tpd.234

 

5. Conclusion and Recommendations 

Based on these evaluations, we propose to find that Rule 4570 implements 

BACM and MSM for CAF operations at this time. We recommend, however, 

that: 

H. The District periodically evaluate all available air pollution control 

measures for ammonia emissions from CAFs that may be technically and 

economically feasible for implementation in the SJV. This evaluation 

should include specific consideration of the control efficiencies and cost 

effectiveness of potential measures to reduce ammonia emissions from 

CAFs. 

 

I. CARB and the District clarify the assumptions and calculations used to 

estimate emissions and emission reductions from CAFs. 

n. Compost Operations 

1. Overview 

Section C.41 (beginning page C--272) discusses SJVACPD rules related to 

compost operations. This includes Rule 4565, Biosolids, Animal Manure, and 

 

232 See Appendix B: Emissions Inventory, Table B-5. 

233 For example, the 2015 PM2.5 Plan references Appendix F of SJVAPCD’s 2006 Rule 4570 staff report, 

but Appendix F does not specify the relevant emissions inventory and does not reflect the current version 

of Rule 4570.

234 Email from Gabe Ruiz (CARB) to Nancy Levin (USEPA), dated September, 3, 2015. 
67 

Poultry Litter Operations, and Rule 4566, Organic Material Composting. Rule 

4565 establishes requirements for facilities that landfill, land apply, compost 

or co-compost biosolids, animal manure or poultry litter. Rule 4566 

establishes requirements for facilities that stockpile and compost greenwaste 

and foodwaste materials. EPA approved Rules 4565 and 4566 as meeting 

RACT for VOC control in 2012.235

Rule 4565 was designed to control VOC emissions from biosolids, animal 

manure, and poultry litter composting and co-composting operations, but 

SJVAPCD states that the controls have the co-benefit of reducing ammonia 

emissions and assumes in its analysis that ammonia control efficiencies 

achieved by these control measures are the same as the estimated VOC 

control efficiencies.236 Facilities with throughputs less than 100,000 wet

tons/year must implement class one measures such as scraping or sweeping 

where compostable material is mixed, screened or stored, covering active or 

curing compost piles within three hours of turning, and maintaining minimum 

oxygen concentrations in active and curing compost piles. Larger facilities 

must implement class two measures requiring add-on controls or alternative 

measures demonstrating at least 80% control efficiency, such as conducting 

active or curing composting in aerated static piles or in-vessel composting 

systems that are vented to a control device, most commonly a biofilter.237

Rule 4566 establishes requirements to limit VOC emissions from facilities that 

stockpile or compost greenwaste and/or foodwaste. The District states that 

Rule 4566 has the co-benefit of also limiting ammonia emissions and 

assumes in its analysis that ammonia control efficiencies achieved by these 

control measures are the same as the estimated VOC control efficiencies.238

 

The required control measures for windrow or compost piles include turning 

(windrows only) and watering (for throughput less than 200,000 tpy); turning 

(windrows only), watering and covering with finished compost (for throughput 

between 200,000 but less than 750,000 tpy); and an APCO and EPAapproved mitigation measure demonstrating 80% reduction in VOC 

emissions, such as venting emissions to a biofilter, for larger operations. 

SJVAPCD states that Rules 4565 and 4566 implement BACM and MSM for 

ammonia from compost operations. The following are key points drawn from 

SJVAPCD’s analysis that support the District’s BACM/MSM determination. 

 

 

235 77 FR 7112, November 29, 2012. 

236 See 2015 PM2.5 Plan, Appendix C, Pages C-276 - C-277. 

237 See SJVAPCD Rule 4565, Section 5.3. 

238 See 2015 PM2.5 Plan, Appendix C, Pages C-272-C-273. 
68 

2. Comparison to Analogous Control Measures in Other Areas 

A. Biosolids, Animal Manure and Poultry Litter Composting/Co-composting 

Operations 

According to SJVAPCD, there is no national CTG, ACT, NSPS, NESHAP 

or MACT regulations or guidance for biosolids, animal manure or poultry 

litter composting/co-composting operations. SJVAPCD states that Rule 

4565 is as stringent as SCAQMD Rule 1133.2, the only other rule it found 

that regulates similar types of operations, and summarizes the following 

significant differences between these rules. Rule 4565’s more stringent 

threshold for applicability is 100 tpy of biosolids, animal manure or poultry 

litter, while Rule 1133.2’s threshold is 1,000 tpy. SCAQMD Rule 1133.2 

requires in-vessel composting with 70% control efficiency for existing 

facilities and 80% for new facilities, while SJVAPCD Rule 4565 requires 

10% - 80% control efficiency based on annual throughput. SJVAPCD 

states that the lower efficiencies are sometimes appropriate because invessel composting (class two) is not cost-effective for smaller or medium 

facilities. SJVAPCD estimates that the cost effectiveness of implementing 

class two measures for small size facilities (100 to 20,000 tpy throughput) 

ranges from $392,597 to $870,266 per ton VOC reduced. For medium 

sized facilities, (20,000 – 100,000 tpy throughput) the range is $48,262 to 

$150,312 per ton VOC reduced.239 In addition, SJVAPCD states that 

SCAQMD does not have any “unsubsidized facilities” within the size range 

where SCAQMD Rule 1133.2’s 70-80% requirement appears more 

stringent than SJVAPCD 4565’s 10-80% requirement.240 

B. Greenwaste and Foodwaste Composting Operations 

SJVAPCD states that there is no national CTG, ACT, NSPS, NESHAP or 

MACT requirements or guidance for greenwaste and/or foodwaste 

composting operations. SJVAPCD compares Rule 4566 with SCAQMD 

Rule 1133.3, the only other rule it found that regulates similar types of 

compost operations. Both rules require similar types of control, but 

SCAQMD Rule 1133.3 has lower thresholds. For example, SJVAPCD 

Rule 4566’s threshold for 80% control is greenwaste and/or foodwaste 

throughput of 750,000 tpy, while Rule 1133.3’s analogous threshold is 

5,000 tpy foodwaste. However, SJVAPCD states that SCAQMD does not 

have any compost facilities subject to the 80% control requirement, so the 

difference in thresholds is not meaningful. In addition, SJVAPCD states 

 

239See Appendix C, Costs and Cost Effectiveness Analysis for Revised Proposed New Rule 4565 

(Biosolids, Animal Manure, and Poultry Litter Operations), SJVUAPCD, March 30, 2007, Table 2, page C6. 

240 See Final Staff Report, Revised Proposed New Rule 4565 (Biosolids, Animal Manure, and Poultry 

Litter Operations), SJVUAPCD March 30, 2007, Table 2: Significant Differences, page 11. 
69 

that the thresholds in Rule 4566 are based on cost effectiveness and 

socioeconomic studies conducted for conditions in SJV.241

 

We generally agree with the District’s demonstration that Rules 4565 and 

4566 establish among the most stringent control measures for ammonia 

emissions from compost facilities compared to other regulations. 

3. Technical and Economic Feasibility of Alternative Control Techniques 

SJVAPCD evaluated other potential controls for reducing ammonia emissions 

from greenwaste/foodwaste and biosolids/animal manure/poultry litter 

compost sources, but did not find any that have been demonstrated to be 

feasible in SJV at this time. SJVAPCD estimates that the cost effectiveness of 

implementing a finished compost cover and watering system ranges from 

$2,393 to $2,525, but that this cost would not be feasible for operations that 

process less than 200,000 tpy, based on a 10% of profits threshold.242,243 It 

estimates that the cost effectiveness for implementing engineered controls 

ranges from $4,724 to $7,802 per ton VOC reduced, but that the cost to 

implement the system would not be economically feasible for operators who 

process less than 750,000 tpy of throughput, based on a 10% of profits 

threshold. Although EPA does not endorse the District’s use of a “10% of the 

industry’s profit” test for economic feasibility, we agree with the District’s 

conclusion that additional controls for composting operations are not 

economically feasible for implementation in the SJV area at this time, 

particularly in light of financial risks to the composting industry caused by the 

relatively low cost of landfilling and the lack of financial incentives for nonlandfilling alternatives such as composting and anaerobic digestion.244 We 

find it appropriate to consider the environmental benefits of composting 

operations,245 including diversion of material from landfills,246 in evaluating the 

feasibility of additional controls for this source category. 

 

241 See Appendix C at pg. C-274; Final Staff Report, Revised Proposed New Rule 4566 (Organic Material 

Composting Operations), SJVAPCD August 18, 2011, pages 15 and 31; and Appendix C, Cost 

Effectiveness Analysis for Revised Proposed New Rule 4566, SJVAPCD, August 18, 2011.

242 See Appendix C, Cost Effectiveness Analysis for Revised Proposed New Rule 4566, SJVAPCD, 

August 18, 2011, C-12. 

243 See Appendix D. Socioeconomic Analysis, Revised Proposed New Rule 4566 (Organic Material 

Composting Operations), August 18, 2011, section 5.2, page 15. 

244 See California Department of Resources Recycling and Recovery (CalRecycle), “Composting and 

Anaerobic Digestion” (June 18, 2013 Draft) at pg. 9, available at: 

http://www.calrecycle.ca.gov/Actions/Documents%5C77%5C20132013%5C900%5CComposting%20and

%20Anaerobic%20Digestion.pdf. 

245 See, e.g., http://www.epa.gov/composting/benefits.htm. 

246 Section 41780 of the California Public Resources Code requires each city and county to divert 50 

percent of all solid waste through source reduction, recycling, and composting activities, and section

41780.01 states that “it is the policy goal of the state that not less than 75 percent of solid waste 

generated be source reduced, recycled, or composted by the year 2020, and annually thereafter.” 
70 

Additionally, SJVAPCD has funded a demonstration project, through its 

Technology Advancement Program, that could potentially significantly reduce 

VOC, ammonia and other emissions at large greenwaste and/or foodwaste 

composting facilities. This prototype “extended aerated stack pile (eASP) 

method” substitutes diesel-powered loaders with electronic conveyor systems 

to build piles, uses solar-powered blowers to replace diesel-powered windrow 

turners, and uses finished compost biofilter covers.

247 The pilot study 

analyzes the advantages and drawbacks of the system, and concludes that 

the solar-powered eASP with a biofilter compost cap may be a viable method 

for commercial-scale composting.248 The study authors note that this 

demonstration project is the first test of this technology and recommend 

further testing and evaluation to assure results on an industry-wide basis.249

 

As with the solid fuel-fired boilers discussed above, we note that there are 

other environmental benefits of composting operations, including diversion of 

material from landfills, which should be considered in evaluating the feasibility 

of additional controls on composting operations in these rules. 

We generally agree with the District’s conclusion that Rule 4565 and Rule 

4566 establish the most stringent control measures for ammonia emissions 

from compost facilities that can feasibly be implemented in the SJV at this 

time. 

4. Emissions Inventory 

SJVAPCD estimates ammonia emissions from compost sources regulated by 

Rule 4565 and 4566 at 9.0 tpd (2015 annual average). 

5. Conclusion and Recommendations 

Based on these evaluations, we propose to find that Rule 4565 and Rule 

4566 implement BACM and MSM for composing operations at this time. We 

recommend, however, that the District periodically evaluate all available air 

pollution control measures for ammonia emissions from compost facilities that 

may be technically and economically feasible for implementation in the SJV. 

This evaluation should include specific consideration of the control 

efficiencies and cost effectiveness of potential measures to reduce ammonia 

emissions from these facilities. We also recommend that SJVAPCD continue 

its analysis of eASP to determine whether this control method is feasible for 

the compost industry in the Valley. 

 

247 See 2015 PM2.5 Plan, Appendix E, page E-15. 

248 See Greenwaste Compose Site Emissions Reductions from Solar-Powered Aeration and Biofilter 

Layer. Report from the contract team, May 14, 2013, available at 

http://www.valleyair.org/Grant_Programs/TAP/documents/C-15636-ACP/C15636_ACP_FinalReport.pdf 

249 Ibid., Appendix A, page 14 of 21.