San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

1 2008 PM2.5 Plan 

Quantification of Contingency Reductions for the 2008 PM2.5 Plan

Section 1: Introduction 

The San Joaquin Valley Air District’s (District) 2008 PM2.5 Plan is a 

comprehensive and innovative strategy demonstrating expeditious attainment of 

the U.S. Environmental Protection Agency’s (EPA) 1997 air quality standards for 

PM2.5 (particulate matter that is 2.5 microns or less in diameter). On November 

9, 2011, EPA approved this plan and related submittals, with the exception of the 

plan’s contingency measures1. This contingency disapproval triggers Clean Air 

Act (CAA) sanction clocks running from the effective date of the final Federal 

Register action (January 9, 2012). The goal of this document is to demonstrate 

sufficient contingency measure emissions reductions to meet federal 

requirements and stop the sanction clock. 

Contingency measures are extra emissions reductions that go into effect without 

further regulatory action2. In an attainment plan, the measures must be “extra” in 

the sense that the reductions are not accounted for in reasonable further 

progress (RFP) or in the attainment demonstration. The purpose of contingency 

measures is to continue progress in reducing emissions should the State 

Implementation Plan (SIP) need to be revised to meet a missed RFP milestone 

or correct continuing nonattainment. 

Contingency measure emissions reductions are demonstrated for the RFP 

milestone years and for the attainment year. The discussion in EPA’s PM2.5 

implementation rule suggests that the amount of contingency reductions should 

be equivalent to about one year of reductions needed for RFP3, although this is 

not embodied in regulatory requirements related to contingency measures (40 

CFR 51.1012 or in CAA §172(c)(9)). For the 1997 PM2.5 standard, this is based 

on the overall level of reductions needed to demonstrate attainment divided by 

the number of years between the base year (2005) and the attainment year 

(2014) (9-year timespan). Table 1 shows the resulting contingency need for 

each pollutant for the 2008 PM2.5 Plan. 

 

 

1

 EPA, Approval and Promulgation of Implementation Plans; California; 2008 San Joaquin Valley 

PM2.5 Plan and 2007 State Strategy; Final Rule. 76 Fed. Reg. 217, pg 69896-69926. (2011, 

November 9). Retrieved from http://www.gpo.gov/fdsys/pkg/FR-2011-11-09/pdf/2011-27232.pdf 

2

 Clean Air Act Section 172(c)(9), 40 CFR 51.1012. 

3

 EPA, Clean Air Fine Particle Implementation Rule [PM2.5 Implementation Rule]. 72 Fed. Reg. 

79, pp. 20586–20667. At 20642-43. (2007, April 25). Retrieved from 

http://www.gpo.gov/fdsys/pkg/FR-2007-04-25/pdf/E7-6347.pdf#page=1 
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

2 2008 PM2.5 Plan 

Table 1: Contingency Reductions Target (in tons per day, or tpd) 

Contingency Target = 

“One year’s worth of 

RFP”4

PM2.5 2.5 

NOx 31.6 

SO2 0.2 

Section 2: RFP milestone years 

RFP contingencies are used if planned emissions controls fail to reach the 

emissions targets specified in the SIP for RFP. The need to implement RFP 

contingencies is based on the emissions occurring in the RFP milestone year. 

For the 2008 PM2.5 Plan, the RFP milestone years are 2009 and 2012; however, 

EPA noted that only 2012 needed to be evaluated for purposes of correcting the 

contingency disapproval. If the 2012 RFP targets were met, then 2012 

contingency reductions are not needed. 

All control measure commitments from the 2008 PM2.5 Plan have been adopted 

by the District and ARB except one: Rule 4905 (Natural, gas-fired, fan-type 

residential central furnaces) is to be amended in 2014, but emissions reductions 

from this rule amendment were not quantified or credited in the 2008 PM2.5 

Plan. 

Table 2 is based on the most recent annual planning inventories available, from 

ARB’s 2011 RFP tables for the Valley with updates from EPA’s September 2011 

TSD. Since the actual 2012 emissions levels are at or below the approved RFP 

levels, RFP was met for 2012, and contingencies for the RFP year are not 

needed. 

Table 2: 2012 RFP Benchmarks5

Approved RFP Level Actual 2012 

emissions 

RFP benchmark met? 

PM2.5 71 70 Yes 

NOx 336 336 Yes 

SOx 20 20 Yes 

 

 

4

 This data is consistent with EPA’s determination in its September 20, 2011 Technical Support 

Document and Responses to Comments, Final Rule on the San Joaquin Valley 2008 PM2.5 

State Implementation Plan, page 132. http://www.regulations.gov/#!documentDetail;D=EPA-R09-

OAR-2010-0516-0175

5

 Based on EPA’s September 2011 TSD, page 120. 

http://www.regulations.gov/#!documentDetail;D=EPA-R09-OAR-2010-0516-0175
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

3 2008 PM2.5 Plan 

Section 3: Attainment year 

Attainment contingencies are implemented if a region fails to attain a federal 

standard by the final attainment date6. The need to implement attainment 

contingencies is based on ambient air quality data as of the end of the attainment 

year. This is contrasted against RFP contingencies, which are needed if 

emissions reductions targets are not met. The District and ARB have already 

adopted all plan control measures that included emissions reductions 

commitments to assure that the emissions levels needed for attainment will be 

achieved in 2014. 

However, if EPA finds that an area fails to attain a standard on time, contingency 

reductions must be implemented automatically. An area often must adopt a new 

attainment plan, and sometimes other penalties apply as well, depending on the 

requirements associated with the standard in question. 

3.1 What Qualifies as a Contingency Measure? 

As noted in the introduction (Section 1 of this document), contingency measures 

are extra emissions reductions that go into effect without further regulatory 

action. The amount of contingency reductions should be equivalent to about one 

year of reductions needed for RFP7. The plan should contain trigger 

mechanisms and a schedule for the contingency measure implementation. 

Contingency measures can include measures already adopted and scheduled for 

implementation, as long as these measures are not relied on to provide 

emissions reductions needed to provide for RFP or expeditious attainment. 

Based on these general contingency requirements, the District is utilizing three 

types of contingency measures in this contingency quantification: 

• Surplus reductions from implementation of traditional regulations 

• Regulations with a contingency trigger 

• SIP-creditable incentive-based emissions reductions 

Each of these contingency measures was discussed in either Chapter 9 of the 

2008 PM2.5 Plan8or ARB’s resolution adopting the plan.9 As such, this 

 

6

 However, Clean Air Act Section 172(a)(2)(C) and EPA’s Fine Particle Implementation Rule allow 

for two one-year attainment date extensions in the event that there is “clean data” in the 

attainment year, but not in the preceding two years that also factor into the three-year average 

attainment determinations. 

7

 EPA, Clean Air Fine Particle Implementation Rule [PM2.5 Implementation Rule]. 72 Fed. Reg. 

79, pp. 20586–20667. At 20642-43. (2007, April 25). Retrieved from 

http://www.gpo.gov/fdsys/pkg/FR-2007-04-25/pdf/E7-6347.pdf#page=1 

8

 District’s (April 30, 2008) 2008 PM2.5 Plan, Chapter 9, pages 9-7 through 9-9. 

http://www.valleyair.org/Air_Quality_Plans/docs/AQ_Final_Adopted_PM2.5/13%20Chapter%209.

pdf 

9

 ARB (May 22, 2008). Resolution adopting the 2008 PM2.5 Plan, page 6. 

http://www.arb.ca.gov/planning/sip/sjvpm25/resolution_sjv08.pdf
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

4 2008 PM2.5 Plan 

document is not adding new contingency measures to the plan, but is more 

accurately quantifying the benefit of these measures to demonstrate that 

sufficient contingency reductions are being achieved. 

3.1.1 Surplus Reductions from Implementation of Traditional Regulations 

The year 2014 was modeled for attainment in the 2008 PM2.5 Plan. As the 

attainment contingency need would not occur until 2015 (since attainment would 

be based on air quality data collected through the end of 2014), the additional 

reductions occurring between 2014 and 2015 due to further implementation of 

adopted controls and fleet turn-over can serve as attainment contingencies 

(Table 3). ARB documented the emissions reductions occurring between 2014 

and 2015 in its May 18, 2011 letter to EPA, and EPA acknowledges this data in 

its contingency quantification in its TSD10. 

Table 3: Attainment Contingencies from Traditional Regulatory Reductions: 

additional reductions in 2015 (tpd) 

Contingency

NOx 21 

PM2.5 0 

SOx 3 

3.1.2 Regulations with Contingency Trigger 

The District’s 2008 Amendment to Rule 4901 (Wood Burning Fireplaces and 

Wood Burning Heaters) included a contingency provision (Section 5.6.5 of Rule 

4901) that would lower the mandatory wood burning curtailment threshold if the 

Valley fails to attain the 1997 PM2.5 standard by April 2015. The contingency, if 

implemented, would lower the curtailment level from a forecast 24-hour level 

PM2.5 level of 30 μg/m3 to 20 μg/m3. This would result in more “No Burn” days 

and more PM2.5 and NOx emissions reductions from residential wood 

combustion. The trigger for this measure is that the lower threshold would 

become effective 60 days after final EPA rulemaking that the Valley failed to 

attain the federal annual PM2.5 standard set in 1997 by the applicable attainment 

deadline (April 2015, based on 2012-2014 data). 

As part of the 2012 PM2.5 Plan adopted by the District Governing Board in 

December 2012, the District has made a local commitment to lower the wood 

burning curtailment in 2014, with implementation starting November 1, 2014. 

 

10 EPA, September 20, 2011 Technical Support Document and Responses to Comments, Final 

Rule on the San Joaquin Valley 2008 PM2.5 State Implementation Plan, page 135, “New” Post 

Attainment Year Reductions. http://www.regulations.gov/#!documentDetail;D=EPA-R09-OAR2010-0516-0175
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

5 2008 PM2.5 Plan 

This proactive strengthening of the rule does not change the status of the current 

Rule 4901 contingency, as these additional reductions were not relied upon to 

demonstrate attainment in the 2008 PM2.5 Plan. 

The emissions reductions that would be achieved by this contingency measure 

are based on the: 

• Total emissions reductions that would be achieved by Rule 4901, as an 

annual average day, under implementation of the contingency level 

• Minus the annual average emissions reduction plan commitment for Rule 

4901 in 2014 without the contingency, and which was accounted for in the 

RFP demonstration and the attainment plan modeling. 

Based on Tables 4 and 5 below, the emissions reduction attributable to the Rule 

4901 contingency is, as an annual average, 3.12 tpd of PM2.5 and 0.32 tpd of 

NOx. This is higher than estimates previously supplied to EPA and noted in its 

September 20, 2011 Technical Support Document, page 135. However, 

previous estimates were based on 2006 air quality data, whereas the analysis 

presented here is based on 2009-2013 air quality data (during which the 2008 

amendment to Rule 4901 has been fully implemented). Also, the previous 

estimate did not accurately account for the 2014 emissions reductions 

commitment from pre-contingency Rule 4901. 

This conservative calculation is just one way to calculate the contingency benefit. 

However, this calculation greatly understates the full impact of Rule 4901 “No 

burn” days, which reduce some of the most harmful species of particulates in the 

times and places where air quality is forecast to reach unhealthy levels. The 

contingency achieves the greatest benefit during the winter, when PM2.5 is 

highest. A Valley-wide no-burn day achieves a direct PM2.5 emission 

reduction of 16 tons. No other single regulation achieves this level of 

effectiveness. 

 
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

6 2008 PM2.5 Plan 

Table 4: PM2.5 emissions reductions, Rule 4901 contingency

Column 1 Column 2 Column 3 Column 4 

County 

 Total “No Burn” days 

at contingency level, 

based on 2009-2013 

wood-burning 

seasons 

Direct PM2.5 

emissions 

subject to the 

rule, tons/day

PM2.5 emissions 

prevented 

during 

contingency, 

tons 

(Column 2 x 

Column 3) 

Fresno 85 5.40 459.34 

Kern (Valley portion) 78 3.58 278.93 

Kings 69 0.52 35.95 

Madera 65 1.90 123.70 

Merced 55 1.43 78.87 

San Joaquin 49 3.51 172.04 

Stanislaus 74 3.07 227.18 

Tulare 67 2.29 153.10 

Total tons of direct PM2.5 prevented 1529.1 tons 

As an annual average day (divide by 365) 4.2 tpd 

Minus the annual average emissions reductions commitment accounted 

for in the EPA’s TSD11

-1.08 

Rule 4901 Contingency Benefit, annual average 3.12 tpd

Table 5: NOx emissions reductions, Rule 4901 contingency

Column 1 Column 2 Column 3 Column 4 

County 

 Total “No Burn” days at 

contingency level, 

based on 2009-2013 

wood-burning seasons 

Direct NOx 

emissions 

subject to the 

Rule, tons/day 

NOx emissions 

prevented 

during 

contingency, 

tons 

(Column 2 x 

Column 3) 

Fresno 85 0.57 48.37 

Kern (Valley portion) 78 0.37 28.47 

Kings 69 0.05 3.52 

Madera 65 0.23 14.63 

Merced 55 0.14 7.92 

San Joaquin 49 0.35 16.95 

Stanislaus 74 0.31 22.64 

Tulare 67 0.28 19.03 

Total tons of direct NOx prevented 161.53 

As an annual average day (divide by 365) 0.44 

Minus the annual average emissions reductions commitment accounted for 

in the EPA’s TSD12

-0.12 tpd 

Rule 4901 Contingency Benefit, annual average 0.32 tpd

 

 

11 EPA, Technical Support Document and Responses to Comments, Final Rule on the San 

Joaquin Valley 2008 PM2.5 State Implementation Plan, page 93 (2011, September 20). 

http://www.regulations.gov/#!documentDetail;D=EPA-R09-OAR-2010-0516-0175

12 Ibid. 
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

7 2008 PM2.5 Plan 

3.1.3 SIP-Creditable Incentive-Based Emissions Reductions 

The District’s successful incentive-based measures have been reducing pollutant 

emissions above and beyond reductions being achieved through traditional 

regulations. Historically, EPA has not granted credit for incentive-based 

reductions for use in SIPs to meet Clean Air Act obligations. New District Rule 

9610 will establish appropriate mechanisms for the District to take SIP credit for 

eligible incentive programs achieving surplus, quantifiable, and enforceable 

emissions reductions. Once given credit, SIP-creditable, incentive-based 

emissions reductions will be used alongside regulatory measures to meet federal 

Clean Air Act requirements, such as requirements for contingency reductions. 

These criteria and the District incentive programs that meet these criteria are 

more fully discussed in draft District Rule 9610 and the accompanying staff 

report. 

The 2013 Annual Demonstration Report shows emissions reductions being 

achieved across several applicable incentive programs. A total of 10.9 tpd of 

NOx and 0.44 tpd of PM2.5 is available for contingency through Carl Moyer, Prop 

1B, and NRCS. This total amount of reductions surpasses the amount needed in 

this quantification:4.15 tpd of NOx reductions and 0.10 tpd of PM2.5 

reductions of SIP-creditable incentive based emissions reductions. 

Under Section 7.0 of Proposed Rule 9610, the District must make several 

commitments for each SIP submission in which the District relies on Rule 9610 

reductions: 

• Identify incentive program guidelines (as specified in Section 3.0) 

used to generate projected SIP-creditable emission reductions. 

(Section 7.1) 

The District is using guidelines specifically included in Section 3.1 of Rule 

9610, the 2013 Annual Demonstration Report, and the Manual of 

Procedures. 

• Identify emission reductions not to exceed the amount projected to 

be achieved through the use of secured or reasonably anticipated 

incentive program funding and the estimated availability of emission 

reductions projects and willing participants, based on historical 

participation and estimates of remaining equipment. (Section 7.2) 

Whereas some SIP commitments will be based on projections of expected 

funding and participation, the SIP-creditable incentive-based emissions 

reductions for this contingency demonstration relies only on alreadyexecuted, legally binding contracts. Therefore, the emissions reductions 

commitment here does not exceed the amount achieved through actual 

incentive program funding and actual program participation. 
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

8 2008 PM2.5 Plan 

• Be specifically adopted by the District as a part of the SIP and 

accounted for in the annual demonstration report as SIP-creditable 

emission reductions are achieved through provisions of this rule. 

(Section 7.3) 

The District adopted the use of incentive program reductions for 

contingency as part of the SIP in the 2008 PM2.5 Plan. And now, this 

Rule 9610 emissions reductions commitment is to be adopted by the 

District as part of the SIP at the June 2013 public hearing, and is 

specifically accounted for in the 2013 Annual Demonstration Report. 

• State that if either the District or EPA finds that there is a SIP 

shortfall for a particular year, the District will adopt and submit to 

EPA, by specified dates, substitute rules and measures that will 

achieve equivalent emission reductions as expeditiously as 

practicable and no later than any applicable implementation deadline 

in the Clean Air Act or EPA’s implementing regulations. (Section 7.4) 

Whereas some SIP commitments will be based on projections of expected 

funding and participation, the SIP-creditable incentive-based emissions 

reductions for this contingency demonstration relies only on alreadyexecuted, legally binding contracts. Since the reductions relied upon in 

this contingency quantification and documented in the 2013 Annual 

Demonstration Report are based on legally-binding contracts and 

corresponding already-implemented emissions reductions, there is no 

shortfall. In fact, the 2013 Annual Demonstration Report quantifies more 

than double the total emissions reductions needed for this contingency 

demonstration. In addition, contracts executed between now and the end 

of 2014 will provide additional emissions reductions for 2015. The 

District’s ongoing project tracking of executed agreements ensures that no 

shortfall results as these projects continue to be implemented. The 

District would remedy any shortfall in a timely manner, per Section 7.4. 

 

3.2 Sufficient Contingency Reductions 

Areas like the Valley that have significant nonattainment challenges have 

developed several generations of aggressive and far-reaching emission 

reduction measures to meet various Clean Air Act requirements. The result of 

this “no stone left unturned” policy is that when viable emission reductions are 

identified, they are implemented to contribute to expeditious attainment. 

Reductions are not usually held in reserve to be used only if an area fails to meet 

a milestone. As a result, contingency measure demonstrations in the Valley 

have been a challenge, historically. 
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

9 2008 PM2.5 Plan 

However, this document has outlined three types of contingency measures being 

used to meet the contingency reductions required for the 2008 PM2.5 Plan: 

• Surplus from traditional regulations (see Section 3.1.1) 

• Regulations with contingency trigger (see Section 3.1.2) 

• SIP-creditable incentives (see Section 3.1.3) 

Table 6 shows how these approaches together generate enough emissions 

reductions to meet the contingency reductions required for this plan. 

Table 6: Demonstration of Sufficient Contingency Reductions

2015

PM2.5

Contingency reductions required 2.5

Demonstration of contingencies achieved 

Surplus from traditional regulations 0.0

Regulations with contingency trigger (Rule 4901) 3.12

SIP-creditable incentives (up to 0.44 tpd available) 0.10

Subtract PM2.5 reductions, trade for NOx* -0.72

Total contingency reductions achieved 2.5

Contingency need met? Yes

NOx

Contingency reductions required 31.6

Demonstration of contingencies achieved

Surplus from traditional regulations 21.0

Regulations with contingency trigger (Rule 4901) 0.3

SIP-creditable incentives (up to 10.9 tpd available) 4.15

Substitute PM2.5* 6.48

Total contingency reductions achieved 31.93

Contingency need met? Yes

SOx

Contingency reductions required 0.2

Demonstration of contingencies achieved

Surplus from traditional regulations 3.0

Regulations with contingency trigger 0.0

SIP-creditable incentives 0.0

Total contingency reductions achieved 3.0

Contingency need met? Yes

* 1 ton of direct PM2.5 emissions reductions is equivalent to 9 tons of 

NOx reductions in the 2008 PM2.5 Plan. See Appendix A to this 

contingency quantification document
San Joaquin Valley Unified Air Pollution Control District June 20, 2013

PM2.5 Contingency Quantification 

10 2008 PM2.5 Plan 

Appendix A 

9:1 Trading Ratio, NOx:PM2.5 

ARB provided the following “Attachment 3” to EPA on May 18, 2011 to document 

inter-pollutant trading ratios that depict the relative effectiveness of reductions in 

different precursors contributing to ambient PM2.5 levels in the San Joaquin 

Valley Air Basin (as well as South Coast). In the 2008 PM2.5 Plan, as approved 

by EPA, the 9:1 trading ratio was used only for transportation conformity 

purposes13, because that was the need at that time. However, the analysis 

generating this trading ratio was based on the emissions inventory as a whole, 

and not just mobile source emissions, as described in “Attachment 3.” Since 

EPA has already accepted this non-source-specific demonstration, the resulting 

trading ratio is available for use beyond transportation conformity. 

 

13 ARB, 2011 PM2.5 SIP Revisions, Appendix D: Transportation Conformity Budgets, page 2 

(2011, March 29). Retrieved from http://www.arb.ca.gov/planning/sip/sjvpm25/appd.pdf
Attachment 3 

Precursor Effectiveness 

In order to understand the relative effectiveness of reductions in different precursors 

contributing to ambient PM2.5, staff of the Air Resources Board (ARB) and the South 

Coast Air Quality Management District (SCAQMD) conducted air quality modeling 

sensitivity runs using the modeling conducted for the attainment demonstrations. These 

relative effectiveness ratios were used to guide control strategy development as well as 

to normalize the benefits of multiple precursors so they can be reflected in terms of a 

single equivalent precursor. This method also provides a uniform metric for tracking 

progress relative to the attainment emissions targets. Documentation on the 

methodologies used for calculating the effectiveness ratios in each area is provided 

below. 

South Coast 

A description of the methodology used by SCAQMD staff is provided in Appendix C of 

ARB'S staff report on the SCAQMD 2007 State Implementation Plan which can be found 

at: 

San Joaquin Valley 

In order to evaluate precursor effectiveness, ARB staff focused on the response in the 

Bakersfield metropolitan area where the highest PM2.5 concentrations in the San 

Joaquin Valley occur. Staff conducted two grid-based modeling sensitivity runs where 

the NOx and primary PM2.5 emissions were reduced, one at a time, by 10% relative to 

the future-year modeled attainment scenario. From these sensitivity runs we calculated 

a future year modeled design value reflecting the further 10% emission reduction 

assumptions. The difference between the attainment scenario (before 10% reduction in 

emissions) and adjusted (after 10% reduction in emissions) design values were then 

compared. Table 1 shows results for NOx and primary PM2.5 emission reductions as 

well as the efficacy of reducing primary PM2.5 relative to that for NOx. 

The lS' column of Table 1 lists the Bakersfield area monitoring sites and the 2" column 

contains the monitored 2006 design value for those sites. The 3rd column contains the 

2014 modeled design values taking into account all of the reductions in the attainment 

strategy. The 4Ih and 5'h columns list the adjusted 2014 design values with additional 

10% emissions reductions for NOx, and primary PM2.5, respectively. The 6'h column 

lists the effectiveness of controlling primary PM2.5 relative to that of controlling NOx. This 

analysis showed that controlling primary PM2.5 is approximately nine times more 

effective than controlling NOx based on the average across the three Bakersfield area 

sites. 
Attachment 3 

The precursor effectiveness values were calculated by determining the difference 

between the modeled 2014 attainment design value (3rd column) and the design value 

of the sensitivity run (4th or 5th col~~mns). This difference was then divided by the 

tonnage of each precursor corresponding to a 10% domain-wide reduction in emissions 

to develop the respective precursor effectiveness ratios. 'The PM2.5 effectiveness value 

was then divided by the NOx effectiveness value to determine a relative ratio (6th 

column). 

Table 1: The effectiveness of precursor controls on the 2014 design value. 

Site Measured 

2006 

Design Value 

(uglm3) 

Modeled 

2014 

Design Value 

With 

SIP 

Attainment 

Strategy 

(uglm3) 

Modeled 

2014 

Design Value 

With 

Additional 

10% NOx 

Reduction 

(uglm3) 

Modeled 

2014 

Design Value 

With 

Additional 

10% PM2.5 

Reduction 

(uglm3) 

Effectiveness 

Relative to 

NOx 

Site 1 

(Bakersfield-California 

Site 2 

(Bakersfield-Planz) 

Site 3 

(Bakersfield-Golden) 

18.5 

18.9 

18.6 

14.3 

14.7 

14.4 

- 

14.1 

14.6 

14.2 

13.6 

14.0 

13.7 

8.7 

9.3 

8.6