UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Supplemental

Technical Support Document

For

EPA’s Rulemaking

for the

South Coast Air Quality Management District 

portion of the 

California State Implementation Plan

CPV Sentinel Energy Project AB 1318 Tracking System –

Source-specific SIP Revision

Prepared by Laura Yannayon

Reviewed by Gerardo Rios

August 9, 2012
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I. BACKGROUND DISCUSSION

A. Timeline Summary of Actions Related to This Rulemaking

The South Coast Air Quality Management District (District) adopted the CPV Sentinel 

Energy Project AB 1318 Tracking System on July 9, 2010. The California Air Resources 

Board (CARB) submitted the CPV Sentinel Energy Project AB 1318 Tracking System to 

EPA as a source specific SIP (State Implementation Plan) revision on September 10, 2010. 

EPA issued a completeness letter on October 27, 2010, finding that the submittal had met the 

completeness criteria in 40 CFR Part 51 Appendix V. EPA proposed approval of the source 

specific SIP revision on January 13, 2011. On April 20, 2011, EPA responded to comments 

and finalized approval of the source specific SIP revision. (76 FR 22038) California 

Communities Against Toxics (CCAT) and Communities for a Better Environment (CBE)

filed a petition for review with the United States Court of Appeals for the Ninth Circuit. On 

July 26, 2011, CCAT filed their Opening Brief. CCAT and CBE’s Opening Brief set forth 

some detailed assertions regarding the quantification and surplus adjustments of the offset 

transactions in the AB 1318 Tracking System. The detailed arguments that CCAT and CBE 

included in their Ninth Circuit Opening Brief were not included in their comments on our 

proposed rulemaking.

On September 14, 2011, EPA filed a motion requesting the Court to remand the rulemaking 

to allow EPA to supplement the record and provide additional justification for our action. 

Although the Ninth Circuit summarily denied this motion, several months later after briefing 

and oral argument, the Court remanded the rulemaking to EPA for additional justification. 

The Court did not vacate the rule upon remand. This technical support document (TSD) 

supports EPA’s supplemental notice of Proposed Rulemaking action for the CPV Sentinel 

Energy Project AB 1318 Tracking System as a source specific SIP revision.

B. Summary of EPA’s April 20, 2010 Rulemaking

On April 20, 2010, EPA published a final rulemaking (76 FR 22038) approving the CPV 

Sentinel Energy Project AB 1318 Tracking System as a source-specific SIP revision to the 

South Coast portion of the California SIP. Please refer to our prior rulemaking for specific 

additional information. The SIP revision consists of enabling language and the AB 1318 

Tracking System. The SIP revision allows the District to transfer offsets for particulate

matter less than 10 microns in diameter (PM10) and one of its precursors, sulfur oxides (SOx),

from the District’s internal offset account to the AB 1318 Tracking System, for use by the

CPV Sentinel Energy Project. 

As part of that rulemaking, EPA evaluated whether the specific offsets included in the AB 

1318 Tracking System met the federal criteria of being real, quantifiable, surplus, permanent, 

and enforceable emission reductions. EPA’s evaluation was based on our review of the 

District’s supporting documentation, generally the “Offset Verification Forms” (OVF) and 

the attachments the District submitted for each offset included in the AB1318 Tracking 

System. Because the quantity of offsets placed into the Tracking System was greater than the 

amount of offsets required by the Sentinel Energy Project, EPA only reviewed the supporting 
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documentation for as many shutdown emission units as necessary to verify the needed 

quantity of offsets were provided. EPA explained the scope of our analysis by stating in the 

April 20, 2011, NFRM (Notice of Final Rulemaking) that “EPA reviewed the submitted 

documentation demonstrating that a sufficient number of these specific emissions credits 

being transferred meet the federal integrity criteria required by section 173 of the CAA.” 

C. Summary of EPA’s Current Rulemaking Action

In this Supplemental TSD, EPA is providing additional information regarding our prior 

determination that at least 118,120 lbs of PM10 and 13,928 lbs of SOx offsets meet the 

requirements of Section 173 as transferred by the District into the AB 1318 Tracking System. 

This TSD and Attachment A provide more detailed explanations of our evaluation of those 

specific offsets we have determined meet the CAA Section 173 integrity requirements. EPA 

reviewed each OVF submitted by the District as part of the source-specific SIP revision. In 

some cases, EPA made additional adjustments, as shown in the column labeled “Verified 

Emissions 8/9/12” of Attachment A, to ensure emissions were quantified and surplus 

adjusted properly. Some examples of these adjustments, are (1) determining the appropriate 

percentage of PM to be attributed to PM10, (2) refining the surplus adjustment to account for 

new emission factors (EF) applied to certain rules as of the date the District issued the 

permit, or (3) ensuring that the same representative period was used for all shutdown 

equipment at a facility. A discussion of each emission unit for which EPA made an 

adjustment is provided in Section II. below.

Attachment A of this TSD lists each of the emission units for which EPA has determined the 

offset integrity criteria have been met. The information provided in Attachment A includes 

the company name, equipment description, application number, year of shutdown, date for 

Year 1 and Year 2 data, emissions from Year 1 and Year 2, annual average emissions, 

emissions verified for the December 29, 2010 TSD, and emissions verified for this August 9, 

2012 TSD. 

II. EVALUATION

A. Evaluation of Quantification Offset Criteria 

EPA has determined that the offsets listed in Attachment A are quantifiable as required by 

Section 173. For the shutdown equipment listed, the offsets are quantifiable because the 

District provided OVFs that evaluate the emission data prior to shutdown in addition to other 

supporting information. 

EPA concurs with the District’s evaluation, except as noted below in this TSD, for all of the 

offsets listed in Attachment A. (See also TSD dated December 29, 2010, Section V.B.2.) 

EPA made the following revisions for two sources to ensure the offsets were properly 

quantified. 
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1. Quantification: Adjustments to Account for PM10 Portion of Reported PM

The District’s Annual Emission Report (AER) collects data on particulate matter (PM) 

emissions. The offsets needed for the Sentinel Energy Project are for PM10 emissions. 

Therefore, as part of the offset verification process, the District needed to determine what 

portion of the reported PM emissions were also PM10 emissions. For emission units 

combusting natural gas, the District correctly determined that 100% of the PM emissions 

are PM10 or smaller emissions. This quantification is based on historical source test data 

for various natural gas combustion operations, as established in EPA’s AP-42 EFs for 

natural gas combustion sources.1 For non-combustion emission units, the District 

correctly determined that 50% of the PM emissions are assumed to be PM10 emissions or 

smaller. This quantification is based on PM and PM10 source test data from various 

aggregate processing operations as compiled in EPA’s AP-42 Section 11.19.2 Thus for 

some of the non-combustion emission units, such as the equipment shut down at 

Chandler Aggregates, the calculated “Annual Average” emissions were multiplied by 

50% to determine the amount of PM10 emissions that would be available as offsets. The 

District’s 50% PM10 adjustment for non-combustion emissions units was not always 

clearly detailed on the OVF’s, however EPA has verified that the offsets from each noncombustion emissions unit were properly adjusted as shown in Attachment A. 

AAA Glass Corporation operated a glass manufacturing facility. Furnace #1 (A/N 

C41204) was shutdown in 2001, while Furnace #2 (A/N 222144) was shutdown in 2005. 

The AER’s for each of these emission units separately quantified the amount of PM 

emissions coming from the burning of natural gas to heat the furnace (a combustion 

emission unit), and from the operation of the furnace itself (a non-combustion emission 

unit). As stated above, based on EPA’s AP-42, 100% of the PM emissions from the 

combustion of natural gas are properly quantified as PM10 offsets. The District also 

applied this assumption to the PM emissions from the furnace. However, based on ARB

speciation profiles for glass manufacturing facilities, only 98% of the PM emissions from 

these non-combustion units (i.e., the furnaces) are PM10.

3 Therefore, EPA adjusted the 

amount of PM10 offsets from both furnaces to reduce the quantities by two percent. 

Adjusting the PM emissions from the two furnaces by 98% resulted in a 26 lbs reduction 

of reported PM10 offsets from this facility.

2. Quantification: Adjustments to Account for Most Representative Baseline Year

For Diamond Pacific Products EPA noted that different shutdown and baseline years had 

been used for associated equipment at the facility. The following table shows the 

Diamond Pacific Products data in the Attachment A spreadsheet for PM10 emissions. 

 1 See AP 42, Fifth Edition, Volume I, Chapter 1: External Combustion Sources, pg 1.4-3 2 See AP 42, Fifth Edition, Volume I, Chapter 11: Introduction to Mineral Products Industry. Table 11.19.2 

Emission Factors for Crushed Stone Processing Operations

3 California Emission Inventory and Reporting System (CEIDARS), Particulate Matter (PM) Speciation Profiles: 

See http://www.arb.ca.gov/ei/speciate/dnldopt.htm#specprof
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Equipment 

Description App. #

Year 

ShutdownYear 1 

Data

Year 1 

(lbs/yr)

Year 2 

Data

Year 2 

(lbs/yr)

Annual 

Average

(lbs/yr)

Verified 

Emissions 

12/29/101

(lbs/yr)

Verified 

Emissions 

8/9/122

(lbs/yr)

Bulk Load Truck 

(1 Rack) Grain 289836 2004 04-05 72 03-04 311 191.4 96 NA

Bulk Load Truck 

(1 Rack) Grain

EPA Revision 289836 2004 03-04 311 02-03 403 356.8 NA 178

Livestock Feed 

Rolling And 

Steam Flaking 289835 2005 04-05 1,155 03-04 12,774 6,964.4 3,482 NA

Livestock Feed 

Rolling And 

Steam Flaking

EPA Revision 289835 2005 03-04 12,774 02-03 10,370 11,572.0 NA 5,786

The supplemental documentation provided with the OVF’s showed the facility AER data 

for reporting years 2000-2001 through 2004-2005 for each piece of equipment in the 

process line. (The reporting year begins on July 1st of each year. For example, the 2000-

2001 reporting year begins on July 1, 2000 and ends on June 30, 2001 and is referred to 

as the 00-01 reporting year.) After consultation with the District, EPA determined that the 

facility had surrendered their permits in November 2004, and thus had only operated a 

few months during the 04-05 reporting period, which began on July 1, 2004. Therefore 

that period was not representative of normal operations in that it did not represent annual 

emissions from the equipment. Therefore, as shown above, EPA revised the Year 1 and 2 

data for the emission units shown above to reflect the most recent two years for which 

complete annual operating data was available. This adjustment increased the amount of 

credited offsets from the Bulk Load Truck from 96 to 178 lbs and from the Livestock 

Feed Rolling and Steam Flaking from 3,482 lbs to 5,786 lbs. 

B. Evaluation of Surplus Offset Criteria 

EPA has determined that the offsets listed in Attachment A are surplus as required by Section 

173. (See also TSD dated December 29, 2010, Section V.B.3.) EPA made the following 

revisions for four sources to ensure the offsets were surplus at the time of use (i.e. when the 

permit was issued for the Sentinel Energy Project). 

1. Surplus: Adjustments to Account for Additional Rule 1157 Requirements

Each of the facilities listed below shut down equipment subject to Rule 1157 – PM10

Emission Reductions from Aggregate and Related Operations. Rule 1157 was adopted by 

the District in January 2005. At rule adoption, the District calculated a baseline inventory 

for each facility subject to the rule and established EFs for each phase of operations at a 

facility, such as loading and unloading activities, hoppers and surge bins, conveyor 

transfer points, crushers, screens, milling equipment, and truck load-outs. An industry 

association, the California Mining Association, challenged Rule 1157 and the litigation 

resulted in a settlement. Pursuant to the settlement agreement, in December 2006 the 

District revised the facilities’ baseline inventories and the EFs used for emission units 
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operating in compliance with Rule 1157 requirements.4 Based on the settlement 

agreement, the District published new PM EFs to provide guidance to sources subject to 

Rule 1157 when calculating their emission inventories.5

The following shutdown facilities included in the AB 1318 Tracking System would be 

subject to the requirements of Rule 1157 if they were still operating: Chandler 

Aggregates, Oldcastle Westile, Elsinore Ready-Mix, and Whitewater Rock and Supply. 

For each of these facilities, in consultation with the District, EPA revised the systemwide controlled EF for each facility based on the new June 2007 EFs guidance for 

sources subject to Rule 1157. Please see Attachment B of this TSD, which includes the 

additional information provided by the District. 

Chandler Aggregates

Chandler Aggregates operated an aggregate processing system consisting of numerous

hoppers, feeders, crushers, screens, and conveyors to produce various sizes of aggregate

products. The facility used a system wide controlled PM10 EF of 11.87 lbs/1,000 tons of 

throughput in its AER for the reporting periods of 03-04 and 04-05. Using the revised 

Rule 1157 EFs, the District calculated a new system wide controlled PM EF of 12.52 

lbs/1,000 tons of throughput for this facility. Since the new Rule 1157 EF is higher than 

the EF used to quantify the AB 1318 Tracking System offsets, EPA has not made any

additional adjustment to ensure the offsets have been surplus adjusted. The verified 

emissions were not adjusted to reflect the higher 12.52 lbs/1,000 tons of throughput EF.

Oldcastle Westile

Oldcastle Westile, Inc. operated a cement slurry system and sand handling systems to

produce concrete roof tiles. EPA notes that the District used two different EFs in the 

AER’s to determine baseline emissions. The reason two different EFs were used was 

because the District published new PM EFs, pursuant to the Rule 1157 settlement 

agreement, for specific process equipment at Asphalt, Cement, Concrete and Aggregate

Product Plants in June 2007. To ensure the reported quantity of PM10 offsets reflect any 

reductions otherwise required by Rule 1157, EPA recalculated the baseline emissions for 

both AERs using the reported throughputs and the revised June 2007 Rule 1157 EFs. As 

shown in Attachment A, this resulted in the credited quantity of offsets being reduced 

from 981 to 358 lbs. Only 358 lbs of offsets were credited for this source. 

Elsinore Ready-Mix

Elsinore Ready-Mix operated a concrete batch plant (A/N 139185) and an aggregate

handling system (A/N 229108) to produce various sizes of aggregate products. This

facility reported PM emissions for the concrete batch plant and aggregate handling

systems in their AERs using an EF of 10 lbs/1,000 tons of throughput and 2 lbs/1,000

tons of throughput, respectively. 

 4 See Attachment C. Letter from Barry R. Wallerstein to Malcolm C. Weiss, Subject: Rule 1157 – PM10 Emission 

Reductions from Aggregate and Related Operations, dated December 15, 2006. 

5 See Attachment D. South Coast AQMD document entitled “Particulate Matter (PM) Emission Factors For 

Processes/Equipment at Asphalt, Cement, Concrete and Aggregate Product Plants” dated June 2007.
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For the concrete batch plant the facility used a system wide controlled PM EF of 10 

lbs/1,000 tons of throughput in its AER for the reporting period of 00-01. Using the 

revised Rule 1157 EFs, the District calculated a new system wide controlled PM EF of 

9.68 lbs/1,000 tons of throughput for this facility. As shown in Attachment A, this 

resulted in the credited quantity of PM10 offsets being reduced from 1,290 to 1,248 lbs. 

Only 1,248 lbs of offsets were credited for this facility.

The aggregate handling system is made of numerous pieces of equipment. If only 3 of the 

main pieces of equipment are reviewed, the jaw crusher and two screens, the revised Rule 

1157 EF from June 2007 for these devices is 4.71 lbs/1,000 tons of throughput, which is 

significantly more than the 2 lbs/1,000 tons EF used to report emission in the AER for 

this process line. Since the new Rule 1157 EF is higher than the EF used to quantify the 

amount of PM10 offsets, EPA has not made any additional adjustment to ensure the 

offsets have been surplus adjusted. The verified quantity of offsets in Attachment A are, 

therefore, lower than what would have been allowed by Rule 1157 for this facility. 

Whitewater Rock and Supply

Whitewater operated two separate rock crushing and processing lines. AER data for these 

operations was only reported for year 06-07, the year prior to shutdown; therefore the 

quantity of emission reductions was based on this single year of reported emission data. 

To ensure the reported offsets reflect any emission reductions otherwise required by Rule 

1157, the baseline emissions were recalculated using the reported throughputs and the 

revised Rule 1157 EFs.5 As shown in Attachment A, this resulted in the credited quantity 

of offsets being reduced from 2,821 to 95 lbs for A/N 120515, and from 2,015 to 68 lbs

for A/N 03115E. The reason for the significant difference in the quantity of offsets is 

because the facility used uncontrolled EFs in its AER. The quantified offsets were 

allocated between the two lines based on the capacity of each rock crushing processing 

line, which is correct because both lines are closed and the total PM10 offsets are the 

same, regardless of how they are allocated.

C. Evaluation of Permanent and Enforceable Offset Criteria

EPA has determined that the offsets listed in Attachment A meet CAA Section 173’s 

requirements to be permanent and enforceable because the owner or operator surrendered 

the permits to the District. It is illegal under SCAQMD Rule 203 for any source to emit 

any amount of an air pollutant without a valid permit, unless the source is specifically 

exempted from this requirement under District Rule 219 – Equipment Not Requiring a 

Written Permit Pursuant to Regulation II. The Federal government or local air agency 

may bring an enforcement action against a source operating without a permit. Citizens 

may also bring such actions because Rule 203 is included in the SIP. For these reasons, 

when a source shuts down and surrenders its permit to the District, its emissions 

reductions are permanent and enforceable. The source would be required to apply for a 

new permit, and provide new offsets, in order to operate again.
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III.EPA ACTION

The December 29, 2010, TSD provided a discussion of the five offset integrity criteria and 

how the emission reductions met each of these criteria. EPA continues to rely on the 

evaluation provided in our earlier TSD, but has supplemented certain subsections in this 

TSD. 

As discussed above, the CAA requires that NSR offsets be actual emission reductions which 

are quantifiable, surplus, permanent, and enforceable. EPA has reviewed each of the OFVs 

and associated documents demonstrating the PM10 and SOx offsets listed in Attachment A 

and submitted as part of this source-specific SIP revision comply with the integrity criteria. 

EPA has determined that more than 118,120 lbs of PM10 offsets and 13,928 lbs of SOx offsets 

in the AB 1318 Tracking System meet the necessary criteria, in that they are real, 

quantifiable, surplus, permanent and enforceable. Therefore, this source-specific SIP revision 

is approvable into the SIP and the offsets listed in Attachment A and included in the AB 

1318 Tracking System are federally enforceable. 

This source-specific SIP revision complies with the EPA review criteria as discussed above

and in our TSD dated December 29, 2010; therefore EPA is proposing full approval of the 

SIP revision because it complies with all relevant CAA requirements and is consistent with 

EPA’s regulations for NSR. 

ATTACHMENTS

A. Verified PM10 and SOx Offset Summaries

B. Additional information provided by South Coast AQMD, via email, dated August 8, 

2012, regarding Rule 1157 adjustments.

C. Letter from Barry R. Wallerstein to Malcolm C. Weiss, Subject: Rule 1157 – PM10 

Emission Reductions from Aggregate and Related Operations, dated December 15, 2006. 

D. SC AQMD Particulate Matter (PM) Emission Factors Guidance For 

Processes/Equipment at Asphalt, Cement, Concrete, and Aggregate Product Plants, June 

2007.