1

Response to EPA Request for Additional Information Regarding Certain Aggregate Operations

• Chandler Aggregates (ID 108046)

Chandler Aggregates operated an aggregate processing system consisting of numerous 

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

products in Corona, California. The PM10 credit calculations for this facility were based on 

the emissions reported in their AER 2003-2004 and AER 2004-2005. This facility reported 

PM emissions for their aggregate processing system in their AERs using a PM emission factor 

of 11.8727 lbs/1,000 tons of throughput. 

To determine if a surplus adjustment is necessary for this aggregate processing system, the 

AQMD must determine if the PM emission factor of 11.8727 lbs/1,000 tons of throughput

used by this facility in their AERs is at BARCT level. To make such a determination, a systemwide controlled emission factor using all available emission factors published by AQMD and 

EPA must be first developed for this aggregate processing system. In June 2007, the AQMD 

published a document providing PM emission factors for specific process equipment at 

Asphalt, Cement, Concrete and Aggregate Product Plants (Attachment 1). The emission 

factors in this document were derived from EPA AP-42 emission factors as well as the 

emission data obtained from the last amendment to AQMD Rule 1157 in 2006 (all 

references and assumptions of the emission factors are listed in the last column of the table 

in this document). Each of these emission factors can be used to report PM emissions for a 

specific process equipment. These emission factors can also be used to develop a systemwide emission factor for a specific process system consisting of multiple process equipment 

based on the number and types of equipment that are included in such a system.

The AQMD has used the equipment description information in the permit application file

and the controlled PM emission factors published in AQMD’s June 2007 document to 

develop a system-wide controlled emission factor for this aggregate processing system. 

The system-wide controlled PM emission factor for this aggregate process system is 

calculated to be 12.5237 lbs/1,000 ton of throughput, higher than the PM emission factor of 

11.8727 lbs/1,000 tons of throughput used by this facility in their AERs. As a result, surplus 

adjustment is not necessary for this aggregate processing system. The detailed analysis and 

calculations to develop the system-wide controlled emission factor are included in the 

attached document (Attachment 2). 

• Oldcastle Westile, Inc. (ID 121816)

Oldcastle Westile, Inc. used to produce concrete roof tiles and the equipment used at this 

facility included cement slurry system (A/N 365063) and sand handling systems (A/Ns 

365058 and 397235) in Corona California. The cement slurry system was used to produce a 

colored slurry with water, cement and ferrous oxide pigments. The sand handling systems 

were used to convey and screen washed sand, as well as to move cement from the cement 

silo to the mixers. This was done with a number of cement conveyors that at some points, 

share service with sand and aggregate and are collectively called “sand conveying” (even 

though they also may convey dry cement into the mixers). There was no separate permit 

for conveying of cement into the mixers. Therefore, the sand handling systems also 

represents the cement contribution of that conveying. The PM10 credit calculations for this 
2

facility were based on the emissions reported in their AER for 2005-2006 and AER for 2006-

2007. However, the annual emission reporting methodology for AER 2005-2006 was

different than the annual emission reporting methodology for AER 2006-2007. Prior to 

2006-2007, the AQMD would allow the asphalt, cement, concrete and aggregate product 

plants to use their own emission factors developed based on the number of transfer points 

and types of equipment used at each plant. In June 2007, the AQMD published a document 

providing PM emission factors for specific process equipment at Asphalt, Cement, Concrete 

and Aggregate Product Plants (Attachment 1). The emission factors in this document were 

derived from EPA AP-42 emission factors as well as the emission data obtained from the last 

amendment to AQMD Rule 1157 in 2006 (all references and assumptions of the emission 

factors are listed in the last column of the table in this document). Each of these emission 

factors can be used to report PM emissions for a specific process equipment. These 

emission factors can also be used to develop a system-wide emission factor for a specific 

process system consisting of multiple process equipment based on the number and types of 

equipment that are included in such a system.

Further, in order to determine what, if any, surplus adjustments are necessary for the 

reported emissions, one needs to evaluate the applicability of Rule 1157 to the operations 

at this facility. Rule 1157 only applies to aggregate and related operations and aggregate 

operations are defined as operations that produce sand, gravel, crushed stone and/or 

quarried rocks and related operations are defined as operations that use sand, gravel, 

cement, crushed stone, and/or quarried rocks in their products, or crush miscellaneous 

base, and inert landfills that handle construction/demolition debris. However, in order to 

be conservative, we can assume that Rule 1157 also applies to this facility which was 

engaged in production of concrete roof tiles. Therefore, in order to calculate the surplus 

adjusted credits for this facility, it is most appropriate to use the actual throughputs for AERs 

2005-2006 and 2006-2007 along with controlled emission factors based on the AQMD’s June 

2007 guidelines, as well as the number and types of equipment used at this facility to 

establish system-wide controlled emission factors and use these emission factors to 

calculate the surplus adjusted credits.

To perform the surplus adjustment, the AQMD has used the equipment description 

information in the permit application files and the controlled emission factors in AQMD’s 

June 2007 document to develop the system-wide controlled emission factors for the cement 

slurry system and sand handling system at this facility. The system-wide controlled PM 

emission factor is calculated to be 0.0456 lb/ton of throughput for cement slurry system and 

0.0127 lb/ton of throughput for the sand handling system. The detailed analysis and 

calculations to develop these system-wide controlled emission factors are included in the 

attached document (Attachment 3). Based on the throughput data reported in the AER 

2005-2006 and AER 2006-2007, the total surplus adjusted PM10 emission credits for this 

facility is 1,510 lbs/year (Please refer to Attachment 4 for detailed calculations). Therefore, 

the surplus adjustments using the system-wide controlled emission factors and throughput 

data reported in AER 2005-2006 and AER 2006-2007 would reduce the total PM10 credits 

for this facility from the previously reported 2,108 lbs/year to 1,510 lbs/year (a reduction of 

598 lbs/year).

Please note that the proposed surplus adjustments for equipment at this facility are 

previously based on a system-wide controlled emission factor of 0.0446 lb/ton for cement 
3

slurry system resulting in a total surplus adjustment amount of 615 lbs/year. I have further 

reviewed the calculations for surplus adjustments again and found that the correct systemwide controlled emission factor for cement slurry system should be 0.0456 lb/ton instead of 

0.0446 lb/ton. Using the correct emission factor of 0.0456 lb/ton, I have re-calculated the 

total surplus adjustment amount for this facility to be 598 lbs/year instead of 615 lbs/year. 

As a result, the total surplus adjustment amount for this facility is distributed to all three 

pieces of equipment as follows:

Equipment Description Application

No.

PM10 Credits

before Adjust 

(lbs/year)

Surplus 

Amount 

(lbs/year)

PM10 Credits

after Adjust

(lbs/year)

Cement Slurry System 365063 146 146 0

Sand Conveying 365058 981 226 755

Sand Conveying 397235 981 226 755

Total: 2,108 598 1,510

• Elsinore Ready-Mix (010873)

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 in Lake 

Elsinore, California. This facility reported PM emissions for the concrete batch plant and 

aggregate handling systems in their AERs using an emission factor of 10 lbs/1,000 tons of 

throughput and 2 lbs/1,000 tons of throughput, respectively.

The AQMD published a document entitled “Particulate Matter Emission Factors for 

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

2007 (Attachment 1). This document provides emission factors for specific process 

equipment at Asphalt, Cement, Concrete and Aggregate Product Plants. The emission 

factors in this document were derived from EPA AP-42 emission factors as well as the 

emission data obtained from the last amendment to AQMD Rule 1157 in 2006 (all 

references and assumptions of the emission factors are listed in the last column of the table 

in this document). Each of these emission factors can be used to report PM emissions for a 

specific process equipment. These emission factors can also be used to develop a systemwide emission factor for a specific process system consisting of multiple process equipment 

based on the number and types of equipment that are included in such a system.

For the purpose of surplus adjustment, the AQMD is certain that the PM emission factor of 2 

lbs/1000 tons used this facility’s AERs meets, and is actually far below, the BARCT 

requirement for an aggregate handling system consisting of numerous hoppers, feeders, 

crushers, screens, and conveyors. The primary sources of PM emissions from the aggregate 

handling system at this facility were the jaw crusher, cone crusher, and screens. All of the 

materials processed at this facility pass through at least the jaw crusher and two screens. As 

indicated on page 7 of Attachment 2, the combined controlled emission factor for the jaw 

crusher and two screens alone is already 4.71 lbs/1000 ton (0.31 lb/1000 ton for the jaw 

crusher and 2.2 lb/1000 ton for each screen). The combined controlled emission factor for 

the entire aggregate crushing and screening system is expected to be significantly higher 
4

since additional PM emissions are generated when the materials are processed through a 

cone crusher, the remaining screens, and other transfer points (conveyors). As a result, the 

PM emission factor of 2 lbs/1000 ton used by Elsinore Ready-Mix in their AER not only 

meets the BARCT requirement, but is at least 2.5 times lower than the BARCT emission 

factor representing emissions from this operation. As a result, no further surplus 

adjustment of PM10 credits is necessary for this aggregate handling system

To determine if a surplus adjustment is necessary for the concrete batch plant at this facility, 

the AQMD has used the equipment description information in the permit application files 

and the controlled emission factors in AQMD’s June 2007 document to develop a systemwide controlled emission factor for the concrete batch plant. The system-wide controlled 

PM emission factor for this concrete batch plant is calculated to be 9.68 lbs/1,000 ton of 

throughput. The detailed analysis and calculations to develop these system-wide controlled 

emission factors are included in the attached document (Attachment 5). Based on the 

throughput of 515,860 tons/year reported by this facility in their AER 2000-2001, the surplus 

adjusted PM10 credits for this concrete batch plant is calculated to be 1,248 lbs/year (please 

refer to Attachment 6 for detailed calculations). Therefore, the surplus adjustment using 

the system-wide controlled emission factor and throughput data reported in AER 2000-2001

would reduce the total PM10 credits for this concrete batch plant from the previously 

reported 1,290 lbs/year to 1,248 lbs/year (a reduction of 42 lbs/year).

• Whitewater Rock and Supply (005004)

Whitewater Rock and Supply operated two aggregate crushing systems (A/Ns 03115 E and 

120515) to produce various sizes of aggregate products in Whitewater, California. The 

PM10 credit calculations for this facility were based on the emissions reported in their AER 

for 2006-2007. The PM emissions reported in this facility’s AER 2006-2007 for their 

aggregate crushing systems, each consist of numerous hoppers, feeders, crushers, screens, 

and conveyors, were based on the emission factors published in a document entitled 

“Particulate Matter Emission Factors for Processes/Equipment at Asphalt, Cement, 

Concrete, and Aggregate Product Plants” published by the AQMD in June 2007 (Attachment 

1). This document provides emission factors for specific process equipment at Asphalt, 

Cement, Concrete and Aggregate Product Plants. The emission factors in this document 

were derived from EPA AP-42 emission factors as well as the emission data obtained from

the last amendment to AQMD Rule 1157 in 2006 (all references and assumptions of the 

emission factors are listed in the last column of the table in this document). The total PM10 

credits for these two aggregate crushing systems were originally calculated to be 4,837 

lbs/year using the total PM emissions reported in AER 2006-2007. The PM10 credits for 

each system were then calculated using the ratio of individual system process rate to the 

total process rate of two systems. The AQMD reviewed the permit application files for 

these two systems and obtained the individual process rate for each system (25 tons/hr for 

system under A/N 03115E and 35 tons/hr for system under A/N 120515). Based on these 

process rates, the PM10 credits for each system were calculated as follows:

A/N 03115E – 4,837 lbs/year x [25/(25 + 35)] = 2,015 lbs/year

A/N 120515 – 4,837 lbs/year x [35/(25 + 35)] = 2,821 lbs/year
5

The AQMD has reviewed this facility’s AER 2006-2007 and found that this facility used 

uncontrolled emission factors to report the PM emissions from all process equipment in 

these two aggregate crushing systems. As a result, surplus adjustment of PM10 credits is 

necessary for the aggregate crushing systems. To determine the amount of necessary 

surplus adjustment, the AQMD has repeated all emission calculations in this facility’s AER 

2006-2007 using the AER throughput data and the controlled PM10 emission factors in EPA 

AP-42, Table 11.19.2-2 for all process equipment in these two systems. As indicated in the 

attached spreadsheet (Attachment 7), the total surplus adjusted PM10 credits for these two 

systems are calculated to be 163 lbs/day. Based on the same individual process rate for 

each system, the surplus adjusted PM10 credits for each system are calculated as follows:

A/N 03115E – 163 lbs/year x [25/(25 + 35)] = 68 lbs/year

A/N 120515 – 163 lbs/year x [35/(25 + 35)] = 95 lbs/year

For the purpose of surplus adjustment, the PM10 credits before surplus adjustment, surplus 

adjustment amount, and PM10 credits after surplus adjustment for each of these two 

aggregate crushing systems are summarized as follows:

Equipment Description Application 

No.

PM10 Credits

before Adjust 

(lbs/year)

Surplus 

Amount 

(lbs/year)

PM10 Credits

after Adjust 

(lbs/year)

Aggregate Crushing System 03115E 2,015 1,947 68

Aggregate Crushing System 120515 2,821 2,726 95

Total: 4,836 4,673 163
 1 

Particulate Matter (PM) Emission Factors 

For Processes/Equipment at 

Asphalt, Cement, Concrete, and Aggregate Product Plants 

June 2007 

This document provides emission factors for estimating total suspended particulate matter (PM) 

emissions (not PM10) for individual emission source at aggregate (sand and gravel), brick and tile, hot 

mix asphalt, cement, and concrete batch plants. These factors are also applicable to emission sources 

other than processes identified in recently adopted Rules 1156 and 1157. 

The factors and equations are extracted from the US EPA AP-42 document. Some of the complex 

equations are simplified with either default settings or assumptions that are applicable to the conditions 

and operations existing in the South Coast Air Basin as shown in the Reference column of the attached 

table. 

Facility is encouraged to apply specific parameters that are applicable to its operations to calculate 

emissions from the equipment/processes including the results from approved source tests. Supporting 

documents must be submitted with the Annual Emission Report to show the use of such parameters or 

source test results in calculating annual emissions. 

In the absence of specific parameters and/or source tests, facility can calculate its annual emissions using 

the factors provided in the attached table and the following equation. 

E = TP × EF

Where: E = Emission (tons/year) 

 TP = Annual Throughput 

 EF = Emission Factor 

The unit for TP in this equation must be consistent with the unit of EF. For example, if EF is in pound 

per ton of material transferred (lb/ton), then TP must be tons of transferred material. For unique emission 

sources, additional data must be used in determining the factor (EF or TP) before it can be used in 

emission calculation as discussed in the following notes: 

Note 1: For mining/quarrying, emission factor is expressed in pound per blast (lb/blast) and is 

calculated as: 

1.5 EF = 0.000014 × A

Where: A = Total horizontal blasted area in squared foot (ft2), provided that the blast 

depth is less than 70 ft. 

In this case, the throughput (TP) is number of blast per year. 
2

Note 2: For road emissions (E) caused by vehicle traffic, the throughput is expressed in annual 

vehicle miles traveled (VMT) as follows: 





 



  ×



 



 ×













 = = ×

5,280ft

1Mile

Year

# Days

Day

# Truck Trips TP VMT Road Length 

Where: Road Length = One-way distance in feet (ft) of paved or unpaved road within 

the facility, used by haul trucks and non-haul trucks. 

# Truck Trips = the number of roundtrips the vehicle made. 

Definitions: 

Haul Road: an unpaved road used by haul trucks to carry materials from the quarry to the 

unloading/processing area within the facility. 

 Non-Haul Road: unpaved and/or paved road used by non-haul trucks to carry materials from 

one location to another location within the facility, usually between the facility’s entrance/exit 

to loading/unloading/processing areas. 

Note 3: For PM emissions (E) at each conveyor transfer point, the emission factor (lb/ton of material 

transferred) can be determined using the following equation: 

1.4

1.3

2

5 EF k 0.0032





 









 





= × ×

M

U

Where: k = Particle Size Multiplier (dimensionless) 

 U = Average Wind Speed (mile per hour) 

 M. = Average Moisture Content (%) 

Note 4: In addition to PM emissions, VOC emissions are also expected from asphalt product during 

loading out and silo filling operations. Emission factor (lb/ton of product loaded) is expressed 

in as follows: 

ASPHALT LOAD-OUT

( ) (( 0.0251 ( 460 )) 20 .43 ) EF PM 0.000181 0.00141 - V × + − = + T

e

( ) (( 0.0251 ( 460 )) 20 .43 ) EF VOC 0.0172 - V × + − = T

e

SILO FILLING

( ) (( 0.0251 ( 460 )) 20 .43 ) EF PM 0.000332 0.00105 - V × + − = + T

e

( ) (( 0.0251 ( 460 )) 20 .43 ) EF VOC 0.0504 - V × + − = T

e

Where: V = Asphalt Volatility (in negative %); (Example -2.5%) 

 T = Asphalt Product Mix Temperature (degree F) 
Emission Factor References

 Operation/Emission Sources Unit And 

UNCONTROLLED CONTROLLED Assumptions

3

ROAD EMISSIONS FROM VEHICLE TRAFFIC• PAVED ROAD 

b W

3

a

2

sL k VMT E   ×   × × =

Where:  E = PM emissions  TP = VMT = annual vehicle mile traveled  (see Note 2) 

b W

3

a

2

sL k EF   ×   × =

 k = particle size multiplier  a, b = constants  sL = road surface silt loading (g/m2) 

 W = average weight (tons) of the vehicle 

Aggregate / Crushed Material Plants EF = 11.65 EF = 2.33Hot Mix Asphalt Plants EF = 14.73 EF = 2.95Concrete BatchingEF = 4.91 EF = 0.98Cement/Other Plants EF = 4.19 EF = 0.84

lb/VMT lb/VMT lb/VMT 

lb/VMT 

Chapter 13.2.1, Equation 1 Assumptions: k = 0.082, a = 0.65, b = 1.5 Aggregate / Crushed Material  sL = 53 g/m2 *Hot Mix Asphalt  sL = 76 g/m2 *Cement / Concrete / Others  sL = 11 g/m2 *Control Efficiency = 80% W Loaded = 30 tons W Unloaded = 5 tons 

W Unloaded for concrete Batching = 12 tons 

* Per agreement between the District & Industry 
Emission Factor References

 Operation/Emission Sources Unit And 

UNCONTROLLED CONTROLLED Assumptions

4

• UNPAVED ROAD 

b W

3

a S

12

k VMT E   ×   × × =

Where:  E = PM emissions  TP = VMT = annual vehicle mile traveled  (see Note 2) 

b W

3

a S

12

k EF   ×   × =

 k = particle size multiplier  a, b = constants  S = surface material silt content (%)  W = average weight (tons) of the vehicle 

Aggregate Plants  HAUL VEHICLE EF = 16.36 EF = 3.27

 NON-HAUL VEHICLE EF = 8.79 EF = 1.76Other Plant  HAUL VEHICLE EF = 14.66 EF = 2.93

 NON-HAUL VEHICLE EF = 5.26 EF =1.05

lb/VMT lb/VMT lb/VMT lb/VMT 

Assumptions: k = 4.9, a = 0.7, b = 0.45 HAUL  W Loaded = 120 tons  W Unloaded = 45 tons 

 S Aggregate = 8.3%  S Others = 7.1% NON-HAUL  W Loaded = 30 tons 

 W Unloaded = 5 tons 

 S Aggregate = 10%  S Others = 4.8 % Control Efficiency = 80%

OPEN STORAGE PILETP = annual tonnage of stored material = amount of material loaded into, or out of, the pile 

EF = 0.33 EF = 0.0165 lb/ton Chapter 11.19.1, Final Report, 

Table 4-1 Control Efficiency = 95%
Emission Factor References

 Operation/Emission Sources Unit And 

UNCONTROLLED CONTROLLED Assumptions

5

MINING/QUARRYING• DRILLING  TP = number of hole drilled • BLASTING (see Note 1)

 TP = number of blast

EF = 1.3 EF = 0.000014 (A) 1.5

lb/hole 

lb/blast 

Chapter 11.9, Table 11.9-4 Chapter 11.9, Table 11.9-1 

LOADING / UNLOADING• CONVEYOR TRANSFER POINT 

4. 1

3. 1

52

0032 . 0 k EF

 

  × × = U

M

k= Particle size multiplier M = Material moisture content U = Mean wind speed For a system of multiple transfer points, this EF must be multiplied by the number of transfer points (where materials drop from one point to another). Refer to Rule 1157 definition for more detail. Also see Note 3.

Aggregate/Crushed Miscellaneous Base/ Asphalt Plants EF = 0.00234 EF = 0.00012Concrete Batching and Others  SAND: EF = 0.0021 EF = 0.00011 AGGREGATE: EF = 0.0069 EF = 0.00035

lb/ton lb/ton lb/ton 

Chapter 13.2.4, Equation 1(b) Assumptions:  k = 0.74  U = 6.3 mph  M = 2.5% Control Efficiency = 95% 
Emission Factor References

 Operation/Emission Sources Unit And 

UNCONTROLLED CONTROLLED Assumptions

6

• WEIGHT HOPPER / SURGE BIN • SILOS  Cement Cement Supplements (Fly Ash) • CONCRETE TRUCK MIX 

LOADING 

• CONCRETE CENTRAL MIX 

LOADING 

• ASPHALT PRODUCTS LOAD OUT

(see Note 4) 

• ASPHALT SILO FILLING  (see Note 4) 

EF = 0.0051 EF = 0.00026EF = 0.72 EF = 0.00099EF = 3.14 EF = 0.0089EF = 0.995 EF = 0.0568EF = 0.544 EF = 0.0173 PM: EF = 0.00052

VOC: EF = 0.0042

 PM: EF = 0.00059

VOC: EF = 0.0122

lb/ton lb/ton lb/ton lb/ton lb/ton lb/ton lb/ton lb/ton lb/ton 

Chapter 11.12, Table 11.12-2 Control Efficiency = 95% Chapter 11.12, Table 11.12-2Control Efficiency = 99% Chapter 11.12, Table 11.12-2Chapter 11.12, Table 11.12-2Chapter 11.1, Table 11.1-14V=-0.5, T=325 oF Chapter 11.1, Table 11.1-14V=-0.5, T=325 oF 
Emission Factor References

 Operation/Emission Sources Unit And 

UNCONTROLLED CONTROLLED Assumptions

7

CRUSHING• PRIMARY CRUSHER • TERTIARY CRUSHER • FINE CRUSHER 

EF = 0.014* EF = 0.00031EF = 0.055* EF = 0.0012

EF = 0.136* EF = 0.003* Based on using controlled EF & control efficiency of 97.8% 

lb/ton lb/ton lb/ton 

Chapter 11.6, Table 11.6-4 Control Efficiency = 97.8% Chapter 11.19.2, Table 11.19.2-2 Control Efficiency = 97.8% Chapter 11.19.2, Table 11.19.2-2 Control Efficiency = 97.8%

SCREENING

• COARSE • FINE • SAND 

EF = 0.056* EF = 0.0022

EF = 0.092* EF = 0.0036EF = 0.21* EF = 0.0083* Based on using controlled EF & control efficiency of 96.1%

lb/ton lb/ton lb/ton 

Chapter 11.19.2, Table 11.19.2-2 Control Efficiency = 96.1% Chapter 11.19.2, Table 11.19.2-2 Control Efficiency = 96.1% Chapter 11.19.1, Final Report, Table 4-3 Control Efficiency = 96.1%
Emission Factor References

 Operation/Emission Sources Unit And 

UNCONTROLLED CONTROLLED Assumptions

8

MILLING

• GENERAL • CEMENT 

Raw Mill 

 Finish Grinding Mill 

EF = 0.62* EF = 0.0062EF = 1.2* EF = 0.012EF = 0.8* EF = 0.008* Based on using controlled EF & control efficiency of 99%

lb/ton lb/ton lb/ton 

Chapter 11.3, Table 11.3-1 Control Efficiency = 99%

Chapter 11.6, Table 11.6-4 Control Efficiency = 99%

OTHER PROCESS/EQUIPMENT• MATERIAL DRYER  SAND and GRAVEL  BATCH MIX ASPHALT  DRUM MIX ASPHALT  BRICK MANUFACTURING • KILNS  BRICK  CEMENT  CLINKER COOLER 

EF = 2.0 EF = 0.039

EF = 32 EF = 0.042EF = 28 EF = 0.033EF = 0.187 EF = 0.96 EF = 109* EF = 1.09

EF = 14.7* EF = 0.147

* Based on using controlled EF & control efficiency of 99%

lb/ton lb/ton lb/ton lb/ton lb/ton lb/ton lb/ton 

Chapter 11.19.1, Table 11.19.1-1 Chapter 11.1, Table 11.1-1 Chapter 11.1, Table 11.1-3 Chapter 11.3., Table 11.3-1 Chapter 11.3., Table 11.3-1 Chapter 11.6, Table 11.6-2 Control Efficiency = 99%
Chandler Aggregates (ID 108046)

System-Wide Controlled Emission Factor for Aggregate Processing System

350 ton/hr max

532011 YEAR 1 actual PW, tons

301 YEAR 1 operating days

257239 YEAR 2 actual PW, tons

198 YEAR 2 operating days

Emission Factors from PM Emission Factors for Processes/Equipment at Asphalt, Cement, Concrete, and Aggregate Plants, June 2007

EF PM lbs/ton 

(uncontrolled)

EF PM lbs/ton 

(controlled)

Transfer 0.00234 0.00012

Jaw (primary) 0.014 0.00031

Cone (tertiary) 0.055 0.0012

Screen (coarse) 0.056 0.0022

Screen (fine) 0.092 0.0036

Screen (sand) 0.21 0.0083

Uncont Cont

3 transfer point 350.0 1.00 0.00234 0.00012 0.00702 0.0003600

1 screen (coarse) 350.0 1.00 0.05600 0.00220 0.05600 0.0022000

3 transfer point 262.5 0.75 0.00234 0.00012 0.00527 0.0002700

1 screen (coarse) 262.5 0.75 0.05600 0.00220 0.04200 0.0016500

1 transfer point 220.0 0.63 0.00234 0.00012 0.00147 0.0000754

2 transfer point 192.5 0.55 0.00234 0.00012 0.00257 0.0001320

1 screen (sand) 192.5 0.55 0.21000 0.00830 0.11550 0.0045650

6 transfer point 140.0 0.40 0.00234 0.00012 0.00562 0.0002880

1 screen (coarse) 140.0 0.40 0.05600 0.00220 0.02240 0.0008800

5 transfer point 87.5 0.25 0.00234 0.00012 0.00293 0.0001500

10 transfer point 70.0 0.20 0.00234 0.00012 0.00468 0.0002400

2 transfer point 52.5 0.15 0.00234 0.00012 0.00070 0.0000360

6 transfer point 50.0 0.14 0.00234 0.00012 0.00201 0.0001029

6 transfer point 40.0 0.11 0.00234 0.00012 0.00160 0.0000823

2 screen (fine) 40.0 0.11 0.09200 0.00360 0.02103 0.0008229

2 jaw (primary) 87.5 0.25 0.01400 0.00031 0.00700 0.0001550

2 cone (tertiary) 40.0 0.11 0.05500 0.00120 0.01257 0.0002743

1 cone (tertiary) 70.0 0.20 0.05500 0.00120 0.01100 0.0002400

0.32136 0.0125237

321.36 12.5237

*The process weight (PW) distribution for this aggregate processing system was included in a process flow

diagram on A/N 167658. The fraction of the maximum PW for each processing equipment/transfer point was 

calculated using the PW distribution specified on the flow diagram.

Facility Wide Factor, lbs/ton

Facility Wide Factor, lbs/Mton

Facility-Wide EF, 

lbs/ton # of Transfer 

Pts at PW Description PW, max*

PW, 

fraction of 

max PW

EF, lbs/ton 

(uncont)

EF, 

lbs/ton 

(cont)
1

Oldcastle Westile, Inc. (ID 121816)

Calculations for System-Wide Controlled Emission Factors

Cement Slurry System

The cement slurry system was used to produce a colored slurry with water, cement, and ferrous 

oxide pigments. Based on the engineering evaluation, dated July 3, 1979, cement from a silo is 

fed by an enclosed screw conveyor into a cement weigh hopper. The cement is gravity 

discharged into a mixing machine with measured quantities of water and ferrous oxide 

pigments. The mixture is agitated to form a colored slurry which is used is used to provide a 

finished colored surface to concrete roof tiles. The cement screw conveyor and cement weigh 

hopper are completely enclosed. Feeding of the cement into the mixer may cause some 

fugitive dust emissions, but water added to the mixer minimizes these emissions. A flexible 

feed duct from the weigh hopper to the mixer vents emissions generated by transfer of cement 

from the screw conveyor to the weigh hopper to the mixer, where the emissions are minimized 

by water added to the mixer. Use of 95% control efficiency for the use of water is acceptable 

for emissions generated by these two transfer points. Calculations of the system-wide 

controlled emission factor may be found in Attachment 1.

Sand Handling System

The sand handling system was used to convey and screen washed sand. Based on the 

engineering evaluation, dated January 26, 1995, the moisture content of the sand ranged from 

7 - 11%. The sand was considered “wet” and Achieved in Practice as BACT. Also according to 

the evaluation, the system was comprised of nine transfer points, for which emissions were 

estimated using conveyor transfer points emission factors and an emission factor for sand 

screening. All transfer points for this system are identified in the accompanying calculations for 

the system-wide controlled emission factor (Attachment 2). The use of controlled emission 

factors is appropriate since the sand is wet (7 – 11%) and was considered AIP BACT.
2

Attachment 1 (Cement Slurry System)

The cement slurry system consists of three transfer points:

1. Cement silo loading

2. Transfer from screw conveyor to cement hopper

3. Transfer from hopper to slurry mixer

Emission factors are published in AP-42, Chapter 11 as well as the District’s AER Guidelines

entitled “Particulate Matter (PM) Emission Factors For Processes/Equipment at Asphalt, 

Cement, Concrete, and Aggregate Product Plants, June 2007”.

1. Cement silo loading = 0.00099 lbs/ton PM controlled by filter, AP-42 Table 11.12-2 and 

Page 6 of the District’s AER Guidelines

2. Transfer to hopper = 0.0016 lbs/1000 lbs PM controlled by fabric filter, AP-42 Table 

11.26-1. This factor is for ground talc storage bin loading, which is comparable to 

cement hopper loading.

a. EF = 0.0016 lbs/1000 lbs = 0.0032 lbs/ton controlled

b. EF uncontrolled = (0.0032 lbs/ton)/(0.01) = 0.32 lbs/ton

c. EF controlled with water @ 95% = (0.32 lbs/ton)(1 – 0.95) = 0.016 lbs/ton PM

3. Transfer to mixer = 0.572 lbs/ton PM uncontrolled, AP-42 Table 11.12-2 for mixer 

loading

a. EF controlled with water @ 95% = (0.572 lbs/ton)(1 – 0.95) = 0.0286 lbs/ton PM

4. System-Wide Controlled Emission Factor = 0.00099 lb/ton + 0.016 lbs/ton + 0.0286 

lbs/ton = 0.0456 lbs/ton PM
3

Attachment 2 (Sand Handling System)

The sand handling system consists of nine transfer points:

1. Belt to reversing belt

2. Belt to silo

3. Silo

4. Belt to screen

5. Screen

6. Screen to belt

7. Belt to belt

8. Belt to hopper

9. Hopper

Emission factors are published in the District’s AER Guidelines entitled “Particulate Matter (PM)

Emission Factors For Processes/Equipment at Asphalt, Cement, Concrete, and Aggregate 

Product Plants, June 2007”.

Conveyor transfer points (Page 5 of the District’s AER Guidelines)

Except for the screen, emissions from each transfer point can be represented by the conveyor 

transfer point formula. This factor is considered controlled due to moisture content of sand.

EF = k ( 0.0032) (U/5)1.3/(M/2)1.4

where,

k = particle size = 0.74 for < 30 μm

U = wind speed = 6.3 mph (default from AER)

M = moisture content = 7% minimum from engineering evaluation

EF = (0.74)(0.0032)(6.3/5)1.3/(7/2)1.4 = 0.00055 lbs/ton PM

Sand screen (Page 7 of the District’s AER Guidelines)

EF = 0.0083 lbs/ton PM, controlled, from AER 2007 guidance

System-Wide Controlled Emission Factor

EF = 8 * conveyor transfer point + sand screen = (8)*0.00055 + 0.0083 = 0.0127 lbs/ton PM
Oldcastle Westile Inc. (ID 121816)

Surplus Adjustment for PM10 Credits Based on System-Wide Controlled Emission Factors

Throuhput 

(tons/year)

PM 

Emission 

(lbs/year)

Througput 

(tons/year)

PM 

Emissions 

(lbs/year)

365063 Cement Slurry System 0.0456 32,032 1,461 37,634 1,716 1,588 794

365058/397235 Sand Handling System 0.0127 120,598 1,532 104,873 1,332 1,432 716

Total: 3,020 1,510 2,108 598

AER 2006-2007 AER 2005-2006 Average 

PM 

(lbs/year)

Average 

PM10 

(lbs/year)

Appl No Equipment

Emission 

Factor 

(lbs/ton)

PM10 

Credits in 

SIP Revision 

(lbs/year)

Surplus 

Adjustment 

Amount 

(lbs/year)
Elsinore Ready Mix (ID 010873)

System-Wide Controlled PM Emission Factor for Concrete Batch Plant

Operating Schedule 8 hr/day 1 cubic yard of concrete: 3293 0.818 lbs, aggregate/sand

6 day/week 564 0.140 lbs, cement/supplement

52 week/yr 167 0.042 lbs, water

180 cu yd/hr 4024 lbs/cu yd

4024 lbs/cu yd

362.16 ton/hr concrete

2897.28 ton/day concrete

Emission Factors from PM Emission Factors for Processes/Equipment at Asphalt, Cement, Concrete, and Aggregate Products Plants, June 2007

uncont cont

Weigh hopper/surge bin loading 0.0051 0.00026 lbs/ton of aggregate/sand

Conveyor transfer point 0.0069 0.00035 lbs/ton of aggregate/sand

Concrete truck mix loading 0.995 0.0568 lbs/ton of cement/supplement

PM Emissions from Permit Unit

Emission Point PW, tph EF uncont, 

lbs/ton

EF cont, 

lbs/ton R1, lbs/hr R2, lbs/hr R1, lbs/day R2, lbs/day

Receiving hopper loading 296.37 0.0069 0.00035 2.045 0.104 16.36 0.83

Hoppers to belt conveyors 296.37 0.0069 0.00035 2.045 0.104 16.36 0.83

Conveyors to surge bin 296.37 0.0069 0.00035 2.045 0.104 16.36 0.83

Surge bin to agg weigh hopper 296.37 0.0069 0.00035 2.045 0.104 16.36 0.83

Weigh hopper (agg) to belt conveyor 296.37 0.0069 0.00035 2.045 0.104 16.36 0.83

Belt conveyor to loadout 296.37 0.0069 0.00035 2.045 0.104 16.36 0.83

Weigh hopper (cement) to loadout* 50.76 0.995 0.0568 50.506 2.883 404.05 23.07

Total 62.776 3.506 502.21 28.0444

Facility Wide Factor - does not include emissions from cement/flyash silo loading

Total daily emissions, lbs 28.04

Total daily throughput, tons 2897.28

PM Emissions, lbs/ton 0.009680

PM Emissions, lbs/Mton 9.680
Elsinnore Ready-Mix (ID 010873)

Surplus Adjustment Calculations for Concrete Batch Plant

PM10 Credits for Shutdown of Concrete Batch Plant Listed on Offset Source Calculation/Verification Form

AER Throughput (1000 

tons/year)

PM Emission Factor 

(lbs/1000 tons)

PM Emissions 

(lbs/year)

PM10 Credits (lbs/year; 

PM10 = 50% PM)

2000-2001 515.86 10 5158.60 2579

2001-2002 0 0 0 0

Average of 2 years: 1290

PM10 Credits for Shutdown of Concrete Batch Plant After Surplus Adjustment

AER Throughput (1000 

tons/year)

PM Emission Factor 

(lbs/1000 tons)

PM Emissions 

(lbs/year)

PM10 Credits (PM10 = 

50% PM; lbs/year)

2000-2001 515.86 9.68 4993.52 2497

2001-2002 0 0 0 0

Average of 2 years: 1248

Reduction of PM10 Credits Due to Surplus Adjustment: 1290 - 1248 = 42
Whitewater Rock and Supply (ID 005004)

Calculations for Surplus Adjusted PM10 Emissions for Aggregate Crushing Systems

AER 2006-2007 

2006-2007

A/N 120515 (Permit No.: M 41985; 35 tons/hr Unit)

[35/(35+25)] *(Total PM10) in lb] 95

A/N 03115E (Permit No.: E 05327; 25 tons/hr Unit)

[25/(35+25) * (Total PM10) in lb] 68

Row Process Annual Throughput 

or Operating Hours Unit

PM10 Emission 

Factor

(lb/ton)

PM10 Emissions

(lb)

1 Material Handling/Loading/Unloading - Aggregate Plant 77,024.00 1 ton 4.60E-05 3.54

2 Aggregate Plant - Crusher 77,024.00 1 ton 5.40E-04 41.59

3 Aggregate Plant - Screener 77,024.00 1 ton 7.40E-04 57.00

4 Aggregate Plant - Conveyor/Transfer 38,512.00 1 ton 4.60E-05 1.77

5 Aggregate Plant - Conveyor/Transfer 38,512.00 1 ton 4.60E-05 1.77

6 Aggregate Plant - Conveyor/Transfer 38,512.00 1 ton 4.60E-05 1.77

7 Aggregate Plant - Conveyor/Transfer 38,512.00 1 ton 4.60E-05 1.77

8 Material Handling/Loading/Unloading - Aggregate Plant 38,512.00 1 ton 4.60E-05 1.77

9 Aggregate Plant - Conveyor/Transfer 38,512.00 1 ton 4.60E-05 1.77

10 Aggregate Plant - Screener 38,512.00 1 ton 7.40E-04 28.50

11 Aggregate Plant - Conveyor/Transfer 27,035.00 1 ton 4.60E-05 1.24

12 Aggregate Plant - Conveyor/Transfer 27,035.00 1 ton 4.60E-05 1.24

13 Aggregate Plant - Conveyor/Transfer 9,012.00 1 ton 4.60E-05 0.41

14 Aggregate Plant - Conveyor/Transfer 9,012.00 1 ton 4.60E-05 0.41

15 Aggregate Plant - Conveyor/Transfer 2,465.00 1 ton 4.60E-05 0.11

16 Aggregate Plant - Conveyor/Transfer 2,465.00 1 ton 4.60E-05 0.11

17 Aggregate Plant - Conveyor/Transfer 13,479.00 1 ton 4.60E-05 0.62

18 Aggregate Plant - Fines 13,479.00 1 ton 1.20E-03 16.17

19 Aggregate Plant - Conveyor/Transfer 13,479.00 1 ton 4.60E-05 0.62

20 Aggregate Plant - Conveyor/Transfer 13,479.00 1 ton 4.60E-05 0.62

21 Blending, mixing and packaging 580.00 1 ton 4.12E-04 0.24

22 Gasoline storage and dispensing 2.18 1,000 Gallons 0.00E+00 0.00

23 Diesel storage and dispensing 16.49 1,000 Gallons 0.00E+00 0.00

Total 163.08