SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

Final Draft Staff Report 

Proposed Amended Rule 1156 – Further Reductions of Particulate 

Emissions from Cement Manufacturing Facilities 

March February 2009 

Deputy Executive Officer 

Planning, Rule Development and Area Sources 

Elaine Chang, DrPH 

Assistant Deputy Executive Officer 

Planning, Rule Development and Area Sources 

Laki Tisopulos, Ph.D., P.E. 

Director of Strategic Initiatives 

Planning, Rule Development and Area Sources 

Jill Whynot 

AUTHOR: 

Tuyet-Le Pham - Air Quality Specialist 

TECHNICAL ASSISTANCE: 

Rudy Eden – Senior Enforcement Manager 

Philip Fine, Ph.D. – Atmospheric Measurements Manager 

Greg Hunter, Ph.D. – Air Quality Specialist 

REVIEWED BY: 

Barbara Baird – District Counsel 

Ruby Fernandez – Deputy District Counsel I 

Tracy A. Goss, P.E. - Program Supervisor 
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

GOVERNING BOARD 

Chairman: WILLIAM A. BURKE, Ed.D. 

Speaker of the Assembly Appointee 

Vice Chairman: S. ROY WILSON, Ed.D. 

Supervisor, Fourth District 

Riverside County Representative 

MEMBERS:

MICHAEL D. ANTONOVICH 

Supervisor, Fifth District 

Los Angeles County Representative 

MICHAEL A. CACCIOTTI 

Councilmember, City of South Pasadena 

Cities Representative, Los Angeles County, Eastern Region 

BILL CAMPBELL 

Supervisor, Third District 

Orange County Representative 

JANE W. CARNEY 

Senate Rules Committee Appointee 

JOSIE GONZALES 

Supervisor, Fifth District 

San Bernardino County Representative 

RONALD O. LOVERIDGE 

Mayor, City of Riverside 

Cities Representative, Riverside County 

JOSEPH K. LYOU, Ph.D. 

Governor's Appointee 

JAN PERRY 

Councilmember, 9th District

City of Los Angeles Representative 

MIGUEL PULIDO 

Mayor, City of Santa Ana 

Cities Representative, Orange County 

TONIA REYES URANGA 

Councilmember, City of Long Beach 

Cities Representative, Los Angeles County, Western Region 

DENNIS YATES 

Mayor, City of Chino 

Cities of San Bernardino County Representative 

EXECUTIVE OFFICER:

BARRY R. WALLERSTEIN, D.Env. 
Table of Contents 

i MarchFebruary 2009 

TABLE OF CONTENTS 

Executive Summary...............................................................................................1 

Portland Cement Manufacturing Process...........................................................6 

Regulatory Background ........................................................................................8 

Public Process.......................................................................................................10 

Air Quality Standards.........................................................................................10 

Health Effects from Fine Particulate Matter ....................................................11 

Health Effects from Hexavalent Chromium ....................................................11 

Purpose and Applicability...................................................................................12

Legal Authority ....................................................................................................12 

Affected Industry .................................................................................................12 

Summary of Proposed Rule ................................................................................13 

Emissions and Emission Reductions..................................................................20

Costs and Cost-Effectiveness .............................................................................20 

California Environmental Quality Act ..............................................................22 

Socioeconomic Assessment..................................................................................23 

Draft Findings .....................................................................................................23 

Alternative Control Measures ...........................................................................23 

Comparative Analysis .........................................................................................24 

Conclusion ...........................................................................................................24 

References ............................................................................................................24 

List of Figures 

Figure 1 - Cement Plants and Air Monitoring Station ............................................1 

Figure 2 - Hexavalent Chromium in Western Riverside 

 and San Bernadino County ................................................................................2 

Figure 3 - Hexavalent Chromium Sampling Locations in Western Riverside 

 and San Bernadino County ................................................................................9 

Figure 4 - All MATES III Fixed-Site Data Excluding Rubidoux .........................16 

List of Tables 

Table 1 - Particulate Matter Concentrations .........................................................11 

Table 2 - Lognormal Statistical Results.................................................................17 
Table of Contents 

ii MarchFebruary 2009 

Table 3 – Estimated Costs .....................................................................................21 

Appendices 

Appendix A – Response to Comments for the Public Review Period 

 Ending December 12, 2008 

Appendix B – Response to Comments for the Public Review Period 

 Ending July 20, 2008 

Appendix C - Comparison of PR1156 and Other Requirements for 

 Cement Manufacturing 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 1 MarchFebruary 2009 

EXECUTIVE SUMMARY 

Rule 1156 - Further Reductions of Particulate Emissions from Cement Manufacturing 

Facilities was adopted by the AQMD Governing Board in November 2005. Rule 1156 

requires cement manufacturing facilities to comply with specific requirements applicable to 

various operations, as well as materials handling and transport at the facilities. 

Elevated ambient air concentrations of the carcinogen hexavalent chromium as fine 

particulate matter in Rubidoux were discovered through sampling efforts of the Multiple Air 

Toxics Emissions Study (MATES III). Extensive additional sampling and modeling traced 

these emissions to loading, unloading, and transferring of clinker material stored in the open 

at TXI Riverside Cement (TXI) located in Riverside. Clinker material is a product from the 

kiln pyro-processing and is used as feedstock to make cement. TXI is one of the two 

facilities in the AQMD’s jurisdiction subject to Rule 1156; the other being California 

Portland Cement Company (CPCC) located in Colton (Figure 1). Figure 1 also shows the 

location of the Western Riverside Air Monitoring Station and arrows indicating prevailing 

wind directions. 

Western 

Riverside Air 

Monitoring 

Station

TXI 

Riverside 

Cement

California 

Portland

Cement

prevailing wind

Figure 1 - Cement Plants and Air Monitoring Station 

Currently, TXI no longer stores or handles clinker material in the open. As a result of a 

settlement agreement with the AQMD, as of August 2008, TXI has removed all clinker piles 

from the open storage areas, and is not allowed to have open storage and handling of clinker 

material in the future. Further, any clinker handling or storage will occur in an enclosed 

setting, controlling all emissions from clinker material processing to the extent feasible. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 2 MarchFebruary 2009 

In addition, TXI also shut down its white cement kilns and finish mills with an unknown 

restart date, although these actions were due to the economic climate and not part of the 

settlement agreement or any other AQMD enforcement actions. At cement manufacturing 

facilities, although dust from clinker material handling has been identified as the main 

contributor to ambient hexavalent chromium levels, kilns and finish mills at these facilities 

can influence the formation and emissions of hexavalent chromium. 

Since implementation of the settlement agreement, the 24-hour hexavalent chromium 

concentrations measured in the vicinity of TXI and at the Rubidoux monitoring station as 

part of the AQMD’s on-going air quality monitoring effort depict an overall downward trend. 

However, some recent measurements revealed elevated ambient concentrations of hexavalent 

chromium (Figure 2). Review of the data indicates this to be, at least in part, a seasonal 

effect due to low ambient air mixing height and Santa Ana wind conditions. Staff has been 

conducting further investigation. Site 7 is roughly located between the two cement plants. 

0

1

2

3

4

5

6

7

5-Feb-08

6-Mar-08

5-Apr-08

5-May-08

4-Jun-08

4-Jul-08

3-Aug-08

2-Sep-08

2-Oct-08

1-Nov-08

Date of Sample

Cr6 (ng/m3)

TXI

Rubidoux

Cal Portland

Site 7

TXI Removal of all open 

clinker piles – 7/23/08

Figure 2 – Hexavalent Chromium in Western Riverside and San Bernardino County

In addition to hexavalent chromium, other toxics such as lead, arsenic, cadmium, and cobalt 

may also be contained within the clinker material; however, hexavalent chromium is the 

primary toxic of concern based on AQMD staff’s analysis of raw materials, and ambient as 

well as fall-out samples collected. Chromium is a component of the primary raw material of 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 3 MarchFebruary 2009 

the cement manufacturing process, limestone, and as discussed later, is converted to 

hexavalent chromium in the pyro-processing stage. 

To further reduce particulates and to address the issue of hexavalent chromium as fine 

particulate matter from cement manufacturing facilities, AQMD staff released its initial 

proposed amendments to Rule 1156 and conducted a public workshop on July 2, 2008. That 

proposal called for total enclosure of all clinker storage and handling, regardless of size. 

However, during the public comment period, staff received comments citing intense financial 

hardship, including potential facility shut down relative to the high cost of the enclosure 

proposal. 

 

With the intent to ensure reductions of particulates from cement manufacturing facilities, and 

to limit exposure to PM10 and hexavalent chromium while addressing the issue of financial 

hardship, AQMD staff revised the proposal and held a subsequent Public Consultation 

meeting on November 20, 2008 and a Town Hall meeting on December 3, 2008. 

Following the second public review and comment period, staff made additional 

modifications to the proposal. The current Proposed Amended Rule (PAR) 1156 would 

require total enclosure of clinker storage and handling conducted within 1,000 feet from, and 

inside, a facility’s property line. For clinker storage and handling activities that occur more 

than 1,000 feet from, and inside, a facility’s property line, PAR 1156 would allow the use of 

alternatives, such as a three-sided barrier covered with a roof and wind fence for active, barntype storage; tarp and barrier/wind fence for other active piles; and tarp for inactive piles. 

The proposal would also require ambient monitoring to measure hexavalent chromium at the 

property fence line. Any hexavalent chromium concentration from either a 30-day or a 90-

day rolling average that is based on a one-in-three-day or one-in-six-day sampling, 

respectively, in exceedance of 0.7 nanograms per cubic meter (ng/m3

), excluding background 

level, if valid would trigger total enclosure within 24 months from date of exceedance, or an 

incremental enclosure over a four-year period, for all clinker storage and handling. 

For any exceedance of the PM10 level as specified in Rule 403 – Fugitive Dust, the proposal 

would require actions to reduce clinker dust, as well as application of dust suppressant on all 

openly stored non-clinker material, unpaved roads, and unpaved areas within the facility. 

The proposal would also require a continuous PM10 ambient monitoring network if this 

PM10 level is violated three times within a 36-month period. 

The present value of control costs of PAR 1156 would be $2.6 to $3.6 million, and the costeffectiveness would be $9,000 to $12,000 per ton of PM10 reduced, providing that ambient 

air monitoring for PM10 is not needed. Including PM10 monitoring, the control cost would 

be $3.69 to $4.9 million, and the cost-effectiveness would be $13,000 to $17,000 per ton of 

PM10 reduced. If total enclosure is required, these costs would be substantially higher ($9.5 

to $12 million to over $20 million). The latter cost figures in the aforementioned ranges are 

CPCC estimates.
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 4 MarchFebruary 2009 

PAR 1156 contains five main elements, as summarized below: 

Material Storage 

In the current adopted Rule 1156, operators of a cement manufacturing facility are required 

to enclose their open storage of clinker if the storage piles exceed 4 acres or 80,000 

tons/month throughput. To minimize particulate emissions from storage piles that are not 

fully enclosed, the rule requires the use of chemical dust suppression, tarps, or barriers/wind 

fences. 

Given the finding of AQMD’s recent monitoring efforts regarding hexavalent chromium and 

public complaints about fine particulates, the current proposed amendment would require 

total enclosure of clinker storage and handling conducted within 1,000 feet from, and inside, 

a facility’s property line, no later than six months from date of rule adoption, and allow the 

use of the following in the meantime: (1) chemical dust suppressants; (2) a three-sided 

barrier/wind fence with or without a roof; or (3) tarp. 

For the storage and handling of clinker piles located more than 1,000-feet from, and inside, a 

facility’s property line, PAR 1156 would allow the use of: (1) a three-sided barrier covered 

with a roof and wind fence for active, barn-type storage; (2) tarp and barrier/wind fence for 

other active piles; and (3) tarp for inactive piles. 

Given the settlement agreement with TXI, these requirements would affect primarily CPCC 

and any new operations in the future. Since CPCC does not store and handle clinker 

materials in the open area within 1,000 feet from its property line, it is expected that CPCC 

would comply with the latter option. 

Ambient Monitoring

The proposed amendments include hexavalent chromium monitoring, PM monitoring if 

repeated violations occur, and wind monitoring. AQMD staff has been working with CPCC 

and extended an invitation to TXI, to help answer technical questions to ensure that this 

process proceeds smoothly. 

PAR 1156 would require 24-hour ambient air monitoring for hexavalent chromium once 

every third day. Any confirmed 30-day rolling average hexavalent chromium concentration 

in exceedance of 0.7 nanograms per cubic meter (ng/m3

), excluding background level, would 

trigger a total enclosure within 24 months from date of exceedance, or an incremental 

enclosure over a four-year period, for all clinker storage and handling. 0.70 ng/m3 represents 

100-in-1-million cancer risk based on a 70-year exposure. 

 

The operator(s) would be able to conduct less frequent sampling (once every six days) if 

there is no hexavalent chromium exceedance during the first twelve (12) continuous months 

of monitoring. Under this schedule, any confirmed 90-day rolling average hexavalent 

chromium concentration in exceedance of 0.70 ng/m3, excluding background, would also 

trigger the aforementioned enclosure requirement and a reversion back to the once-in-threeday sampling schedule. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 5 MarchFebruary 2009 

In the event of a hexavalent chromium exceedance when there is no openly stored clinker 

material, the AQMD will conduct necessary studies to identify the source(s) and pursue 

further corrective actions. 

Any exceedance of PM10 upwind/downwind level of 50 microgram per cubic meter (μg/m3

) 

as specified in Rule 403 – Fugitive Dust, would require the operator(s) to take steps to reduce 

clinker dust emissions, as well as apply dust suppressant on their openly stored non-clinker 

materials, unpaved roads, and unpaved areas. If the aforementioned PM10 level is exceeded 

three or more times within a 36-month period, PAR 1156 would require amended compliance 

monitoring plan and on-site continuous, real-time ambient air monitoring for PM10 within 

six months from the date of amended plan approval or one year from the date of the third 

approved notice of violation, whichever occurs first. 

Compliance Monitoring Plan 

PAR 1156 would require a compliance monitoring plan for the monitoring, sampling, and 

analysis of hexavalent chromium, and fees pursuant to Rule 306 no later than three months 

from date of rule adoption. The plan will be approved or disapproved by the AQMD within 

60 days from the plan submittal date. The operator(s) must resubmit an approvable plan 

within 30 days from date of plan disapproval; failure to do so is a violation of the rule. The 

approved plan can be updated as additional site-specific data becomes available. 

In the event where continuous, real time ambient monitoring for PM10 is required as a result 

of three violations of Rule 403, the operator(s) must amend their compliance monitoring plan 

to include appropriate plan elements relative to PM10 monitoring. 

Wind Monitoring

PAR 1156 would require the operator(s) to install equipment and conduct hourly wind 

monitoring according to an AQMD-approved-protocol no later than six months from date of 

rule adoption. In addition, the proposed amendment would also call for a halt to all clinker 

handling activities in the open for two hours if instantaneous wind speeds exceed 25 miles 

per hour (mph) at any given time. During this two-hour period, the operator(s) would be 

exempt from the 100-feet visible dust plume limit, providing that the open handling of 

clinker material is ceased, dust controls as required by the AQMD are applied, and unpaved 

roads within the facility are stabilized in advance of any high wind occurrence as currently 

required elsewhere in the rule or other rules. If instantaneous wind speeds exceeding 25 mph 

subsequently occur, a new two-hour period would begin. 

Exemptions:

During days in which high wind events occur, cement manufacturing operator(s) can be 

exempt from the hexavalent chromium and PM10 averaging provisions in the proposal, 

provided that all handling of clinker materials in the open is ceased and dust controls are 

applied. However, in the event the Executive Officer determines there is a significant 

hexavalent chromium dust re-entrainment potential, the operator(s) would be required to 

implement an approved Mitigation Monitoring Plan to minimize exposure to the surrounding 

areas. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 6 MarchFebruary 2009 

Cement manufacturing operator(s) are also exempt from the wind fence requirement during 

periodic maintenance of the clinker crane or storage barn, provided that clinker crane is not 

operated. 

Currently, operator(s) of a cement manufacturing facility can be exempt from storage piles 

requirement of enclosure or three-sided barrier, or from using the AQMD Rule 403 test 

methods for the demonstration of a pile’s surface stabilization if the materials contained in 

90% of the pile’s volume are larger than 1⁄2 inch. Under the proposal, this would change to a 

mass basis and would exclude clinker material. Therefore, operator(s) who have open piles 

containing only materials other than clinker would be exempt from the above mentioned 

requirements if the materials contained in 90% of the pile’s mass are larger than 1⁄2 inch. The 

mass basis would make testing and enforcement easier. 

Other

An amendment is also proposed to the definition of Cement Manufacturing Facility to clarify 

that even though TXI is not currently manufacturing cement products, they are subject to the 

monitoring requirements (wind, hexavalent chromium, and PM10, as applicable) of the 

proposal. 

In addition, the proposed amended rule also contains other minor amendments and 

clarifications to better demonstrate the rule’s intent and to respond to US EPA comments on 

other elements of the rule. 

PORTLAND CEMENT MANUFACTURING PROCESS 

There are two Portland cement manufacturing facilities in the Basin, California Portland 

Cement Company (CPCC) and TXI Riverside Cement Company (TXI). CPCC manufactures 

gray cement, and TXI manufactures white cement and produces gray cement from clinker 

delivered to the facility from outside the Basin. The production of Portland cement is a four 

step process which includes: 

 

1) Raw materials acquisition; 

2) Preparation of raw materials into raw mix; 

3) Pyroprocessing of raw mix to make clinker; and 

4) Grinding and milling of clinker into cement. 

 

Raw Materials Acquisition

Raw materials for manufacturing cement include calcium, silica, alumina and iron. Calcium 

is the element of highest concentration, and iron is raw material for gray cement but not used 

for white cement. These raw materials are obtained from minerals such as limestone for 

calcium; sand for silica; shale and clay for alumina and silica. CPCC obtains limestone from 

the quarry located on site. Other raw materials are delivered to CPCC by truck or rail car. 

All raw materials are delivered to TXI by truck or rail car. 

 

Preparation of Raw Materials into Raw Mix

Preparing the raw mix includes crushing, milling, blending and storage. Primary, secondary 

and tertiary crushers are used to crush the raw materials until they are about 3⁄4 inch or 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 7 MarchFebruary 2009 

smaller in size. Raw materials are then conveyed to rock storage silos. Belt conveyors are 

typically used for this transport. From the rock storage silos, the raw materials are conveyed 

to roller mills or ball mills where they are blended and pulverized into a very fine powder. 

Pneumatic conveyors are typically used to transport the fine raw mix to homogenizing silos 

where they are again thoroughly blended and stored until it is fed to the kilns. 

Pyroprocessing of Raw Mix 

Pyroprocessing is the chemical and physical process of transforming the fine raw mix into 

clinker. Pyroprocessing occurs in a rotary kiln and includes three steps: 

 

― Evaporating free water and dehydrating to form oxides of silicon, aluminum, and iron. 

This process occurs in a drying and preheating zone of the rotary kiln at temperatures of 

about 212 oF – 800 oF; 

 

― Calcining of calcium carbonates (CaCO3) to form calcium oxides (CaO) and carbon 

dioxide (CO2). This process occurs in the calcining zone of the rotary kiln at 

temperatures of about 1,100 oF – 1,800 oF; and 

 

― Chemical reacting, melting and restructuring of materials occur between calcium oxides 

(CaO), silica, alumina and iron to form clinker, which is a solid material ranging in size 

from 1 – 2 inch diameter. Clinker contains four major compounds tricalcium silicate 

(~50% by weight), dicalcium silicate (~25% by weight), tricalcium aluminate (~10% by 

weight) and tetracalcium aluminoferrite (~10% by weight). The process of forming 

clinker occurs in the “burning” zone of the rotary kiln at temperatures of about 2,200 oF 

– 2,700 oF. 

 

The pyroprocessing process at CPCC and TXI is called a “long dry process” consisting 

solely of a simple long rotary kiln. CPCC operates two rotary kilns in parallel; each is about 

18 ft in diameter and 500 ft in length. TXI has two rotary kilns in parallel; each is about 12 ft 

in diameter and 200 ft in length. The kilns are slightly inclined and rotate on its longitudinal 

axis. Raw materials are fed into the upper end of the kiln while fuels are burned in the lower 

end. As the kiln rotates, the raw materials move slowly from the upper end to the lower end, 

and the combustion gases move in counter-current direction. The residence time of raw 

materials in a gray cement kiln is about 2 – 3 hours, whereas for white cement, it is about 8 

hours. The hot clinker, which exits at about 2,000 o

F from the kiln, is quickly cooled in the 

clinker cooler and is conveyed to storage. 

Clinker is water reactive and must be stored such that it is protected from moisture. If 

clinker gets wet, it will hydrate and set into concrete. Heat used in the kiln is supplied 

through the combustion of different fuels such as coal, coke, oil, natural gas, and tires. The 

combustion gases are vented to baghouse where dusts are collected. Dust is returned to the 

process or recycled if they meet certain criteria, or is discarded to landfills. 

 

Grinding and Milling Clinker into Cement 

Grinding and milling clinker into cement is the last step of the manufacturing process. Up to 

5% of gypsum is added to the clinker during grinding to control the setting time of cement. 

Other specialty chemicals are also added at this stage. After grinding and milling into fine 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 8 MarchFebruary 2009 

powder, the cement is pneumatically conveyed to the product silos. The product is either 

sold in bulk or is bagged. 

REGULATORY BACKGROUND 

Rule 1156 - Further Reductions of Particulate Emissions from Cement Manufacturing 

Facilities was adopted by the AQMD’s Governing Board in November 2005. The rule 

implemented the 2003 Air Quality Management Plan (AQMP) Control Measure BCM-08 – 

Further Emission Reductions from Aggregate and Cement Manufacturing Operations. Rule 

1156 requires cement manufacturing facilities to comply with specific requirements 

applicable to various operations, as well as materials handling and transport at the facilities. 

Rule 1156 was approved by EPA into the SIP in March 2008. 

As AQMD staff completed their data analysis for MATES III, they observed clear, 

unexpected elevated levels of hexavalent chromium, a potent, known carcinogen, at the 

Rubidoux monitoring station in Western Riverside County, over two miles to the southwest 

of TXI. The AQMD’s rigorous regulatory and enforcement program should have resulted in 

a decrease of ambient hexavalent chromium concentration. 

AQMD staff thoroughly investigated the potential sources of the elevated hexavalent 

chromium level. Staff has conducted air, material, and soil sampling, permit reviews, areawide surveys and surveillance, and air quality modeling. After five months of rigorous 

research and sampling, results indicated that TXI was the primary source of the elevated 

hexavalent chromium concentrations in the area. Specifically, the handling and transport of 

clinker material, a product from the kiln pyro-processing, which is used as feedstock to make 

cement, has been determined to be the primary source of hexavalent chromium emissions. In 

addition to hexavalent chromium, other toxics such as lead, arsenic, cadmium, cobalt may 

also be contained within the clinker material; however, hexavalent chromium is the primary 

toxic of concern based on AQMD staff’s analysis of raw materials (e.g., limestone), as well 

as ambient and fall-out samples collected. 

 

As a result of a settlement agreement with the AQMD after issuance of numerous Notices of 

Violation, TXI has removed all clinker piles from the open storage areas (as of August 2008), 

and is not allowed to have open storage and handling of clinker materials in the future. 

Further, any clinker handling or storage will occur in an enclosed setting, controlling all 

emissions from clinker material processing to the extent feasible. In addition, TXI also shut 

down its white cement kilns and finish mills with an unknown restart date, although these 

actions were due to the economic climate and not part of the settlement agreement or any 

other AQMD enforcement actions. At cement manufacturing facilities, although dust from 

clinker material handling has been identified as the main contributor to ambient hexavalent 

chromium levels, kilns and finish mills at these facilities can influence the formation and 

emissions of hexavalent chromium. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 9 MarchFebruary 2009 

 

Figure 3 – Hexavalent Chromium Sampling Locations in Western Riverside and San 

Bernadino County 

Since implementation of the settlement agreement, the 24-hour hexavalent chromium 

concentrations measured in the vicinity of TXI and at the Rubidoux monitoring station depict 

an overall downward trend (see Figure 2), except for some recent incidents where elevated 

ambient concentrations of hexavalent chromium were detected. As a result, staff is 

continuing its monitoring efforts. In addition to the seasonal trend of hexavalent chromium 

as PM10 dust emissions, staff believes there is a potential contribution to the elevated 

ambient levels by cement plants in the vicinity of the monitoring sites. 

 

To address the issues of hexavalent chromium as fine particulate, and to reduce health risks 

to the surrounding community while preserving the original intent of previously adopted 

Rule 1156, staff released its initial proposed amendment to Rule 1156 and conducted a public 

workshop on July 2, 2008. That proposal called for total enclosure of all clinker storage and 

handling, regardless of size. However, during the public comment period, staff received 

comments citing intense financial hardship, including potential facility shut down relative to 

the enclosure proposal. 

With the intent to ensure reductions of particulates from cement manufacturing facilities, and 

to limit exposure to PM10 and hexavalent chromium while addressing the issue of financial 

hardship, AQMD staff has revised its initial proposal. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 10 MarchFebruary 2009 

PUBLIC PROCESS

Staff released the initial proposed amendment to Rule 1156 for the Public Workshop held on 

July 2, 2008 in the community near the two cement manufacturing facilities. Approximately 

1,000 notices were mailed, including to attendees of the two Town Hall meetings held in the 

area regarding the ambient air monitoring efforts that were begun due to the MATES III 

findings. Comments received reflecting public support for the rule amendments, and 

concerns from industry regarding the total enclosure requirement were considered by staff. 

Staff has been working closely with the cement manufacturing industry on key technical 

elements of the rule amendment proposal, such as additional controls on clinker material 

handling and monitoring issues, as well as technical and financial constraints. Staff also 

contacted representatives from various dome manufacturing companies, as well as tarp and 

wind fence manufacturers/distributors, to gather information regarding costs and feasibility. 

Staff released a revised amendment proposal and held a November 20, 2008 public 

consultation meeting. Staff also organized a Town Hall meeting on December 3, 2008 to 

provide the communities near TXI and CPCC with an update regarding cement plant issues, 

including ambient monitoring, and to introduce a summary of the revised proposed 

amendments to Rule 1156. Staff worked with industry on their various concerns, such as 

rule applicability, compliance monitoring plan development, monitoring systems as well as 

guidelines and/or protocols, and laboratory certification process for hexavalent chromium 

analysis. Staff also addressed all public comments received by November 20, 2008 during 

the rule amendment process in this Staff Report (see appendices A and B). 

In addition, the AQMD Governing Board will have a community “meet and greet” scheduled 

for March 5th, prior to the scheduled March 6, 2009 Public Hearing. Readers may refer to 

www.aqmd.gov/calendar/calev.html for information regarding these meetings. 

AIR QUALITY STANDARDS 

The District monitors ambient air quality for criteria pollutants (ozone, carbon monoxide, 

particulate matter, NO2, lead, SO2, and sulfate) at 32 locations within the District. The 

following table presents a summary of the federal National Ambient Air Quality Standards 

(NAAQS) and State of California air quality standards for particulate matter. These air 

quality standards are set to protect public health. The Basin is not in attainment with the 24-

hour or annual average NAAQS for PM2.5. The Basin is also not in attainment with State 

annual average air quality standards for PM2.5. 

Table 1 shows the air quality standards and the annual average air quality data for Rubidoux. 

This illustrates the magnitude of the particulate matter air quality in the area near these two 

cement manufacturing facilities. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 11 MarchFebruary 2009 

Table 1 

Particulate Matter Concentrations (μg/m3) 

Jurisdiction PM10 PM2.5 

Annual 24-Hour Annual 24-Hour 

Annual Average Ambient 

Concentrations at 

Rubidoux (Riverside 

County, 2007) 

54.7 -- 19.1 -- 

Federal Standards -- 150 15 35 

California Standards 20 50 12 -- 

HEALTH EFFECTS FROM FINE PARTICULATE MATTER 

The following is an excerpt from Chapter 2, Air Quality and Health Effects, from the 2007 

Air Quality Management Plan: 

A consistent correlation between elevated ambient fine particulate matter (PM10 and 

PM2.5) levels and an increase in mortality rates, respiratory infections, number and 

severity of asthma attacks and the number of hospital admissions has been observed in 

different parts of the United States and various areas around the world. In recent years, 

studies have reported an association between long-term exposure to air pollution 

dominated by fine particles (PM2.5) and increased mortality, reduction in life-span, and 

an increased mortality from lung cancer. 

Daily fluctuations in fine particulate matter concentration levels have also been related to 

hospital admissions for acute respiratory conditions, to school and kindergarten absences, 

to a decrease in respiratory function in normal children and to increased medication use in 

children and adults with asthma. Recent studies show lung function growth in children is 

reduced with long-term exposure to particulate matter. The elderly, people with preexisting respiratory and/or cardiovascular disease, and children appear to be more 

susceptible to the effects of PM10 and PM2.5. 

HEALTH EFFECTS FROM HEXAVALENT CHROMIUM 

Hexavalent chromium compounds are used in many industries, mainly in chrome plating, and 

chromate and chromate pigment productions. Hexavalent chromium can also be emitted 

from cement manufacturing facilities. Studies indicate that exposure to hexavalent 

chromium could result in the following: 

• Lung cancer; 

• Irritation and damage to the skin, eyes, nose, throat, and lung, if exposed to high 

concentrations; 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 12 MarchFebruary 2009 

• Asthma symptoms; or 

• Allergic skin reaction such as a red, itchy rash. 

Hexavalent chromium compounds are classified as Toxic Air Contaminants by the CARB. 

The California EPA’s (CalEPA) Office of Environment Health Hazard Assessment has 

established a cancer risk potency factor from breathing in hexavalent chromium. Hexavalent 

chromium is a potent, known carcinogen. This potency factor can be used to assess cancer 

risk over a lifetime exposure. 

Based on monitoring data, the cancer risk associated with hexavalent chromium from TXI is 

estimated at 300 to 500 in a million, which is similar to the risk found next to a busy freeway, 

a rail yard, or a large chrome plating facility. In addition to the requirements in the 

settlement agreement, TXI was required to conduct a facility-wide health risk assessment 

under the Air Toxics Hotspot Information and Assessment Act, AB 2588. That assessment 

has been received and is undergoing staff review. 

PURPOSE AND APPLICABILITY 

The proposed amendments are designed to ensure further reductions of particulate matter 

emissions from cement manufacturing facilities, in order to aid in progress towards 

attainment of the federal and state standards, and health protection from the emissions of fine 

particulates (including hexavalent chromium). 

PAR 1156 would strengthen the requirements for clinker storage and handling at cement 

manufacturing facilities, and would require ambient monitoring for hexavalent chromium in 

addition to wind monitoring. PM10 monitoring would be required in the event of recurring 

Rule 403 violations of the upwind/downwind fugitive dust limit (50 μg/m3). 

LEGAL AUTHORITY 

The AQMD obtains authority to adopt, amend, or repeal rules and regulations which control 

air pollution from Health and Safety Code Sections 39002, 40000, 40001, and 40440. 

AFFECTED INDUSTRY 

There are two existing facilities subject to PAR 1156: CPCC located in Colton (southwestern San Bernardino County), and TXI located in Riverside (north-western Riverside 

County). Rule amendments would make existing requirements more stringent and add 

ambient and wind monitoring requirements. Since TXI no longer stores and handles clinker 

material in the open, it would only be subject to the monitoring requirements (i.e., hexavalent 

chromium and wind monitoring, and PM10 monitoring as applicable). CPCC currently does 

not store and handle clinker material within 1,000 ft from, and inside, its property line, hence 

CPCC would likely elect to comply with the alternative requirements in subparagraph 

(d)(5)(C), in addition to being subject to the monitoring provisions. 

SUMMARY OF PROPOSED RULE 

PAR 1156 is summarized below. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 13 MarchFebruary 2009 

Subdivision (d) – Requirements 

Material Storage 

Current proposed amendments to Rule 1156 would require total enclosure of clinker storage 

and handling conducted within 1,000 feet from, and inside, a facility’s property line, no later 

than six months from date of rule adoption. Prior to the completion and operation of the 

enclosure, PAR 1156 would allow use one of the following: (1) chemical dust suppressants; 

(2) a three-sided barrier/wind fence with or without a roof, in addition to maintaining the 

pile’s surface stabilization; or (3) tarp. 

For the storage and handling of clinker piles located more than 1,000-feet from, and inside, a 

facility’s property line, PAR 1156 would allow use of: (1) a three-sided barrier covered with 

a roof and wind fence of a maximum 20% porosity for active, barn-type storage; (2) tarp and 

extended wind fence with at least 5-foot freeboard for active piles that are immediately 

adjacent to the above mentioned covered barrier; and (3) tarp and barrier/wind fence with at 

least a 5-foot freeboard and extended at least 20 feet beyond the active portion of a pile for 

other active piles. The 1,000 foot level is selected because most fugitive dust emissions 

deposit within 1,000 feet from the source. 

The removable wind fence for vehicle access at the barn-type storage can be removed only 

during minor or routine maintenance activities, the creation or reclamation of outside storage 

piles, the importation of clinker from outside the facility, and reclamation of plant clean-up 

materials, provided that appropriate records required in the proposal are kept. The 

removable opening shall be less than 50% of the total surface area of the wind fence and the 

amount of time shall be minimized to the extent feasible. 

For inactive clinker storage, PAR 1156 would alternatively allow tarping only, provided that 

records of inactive status are maintained. Inactive clinker piles are piles of clinker materials 

that have not been disturbed, removed, and/or added to as a result of loading, unloading, 

and/or transferring activities for a minimum of 30 consecutive days. 

 

Language in subparagraph (d)(2)(B) has been revised to clarify that during all conveying 

activities, the enclosed transfer points and enclosed conveying systems must be vented to a 

permitted and operated air pollution control device that meet the required standards. 

Hexavalent Chromium Ambient Monitoring 

PAR 1156 would require the operator(s), no later than six months from compliance plan 

approval or March 1, 2010, whichever occurs first, to conduct 24-hour ambient air 

monitoring for hexavalent chromium once every third day according to the EPA 1-in-3-day 

sampling calendar. The sample may be collected on the following business day if the 

collection occurs on a weekend or a facility-observed national and/or state holiday. The 30-

day rolling average hexavalent chromium concentration at each monitoring station shall not 

exceed 0.70 ng/m3

, excluding background level of 0.16 ng/m3. This background inherently 

includes trip blanks of 0.08 to 0.10 ng/m3

. 

Any 30-day rolling average hexavalent chromium concentration in exceedance of 0.70 

ng/m3

, excluding background level of 0.16 ng/m3, if deemed valid by examining wind 

monitoring data, would trigger a total enclosure within 24 months from date of exceedance, 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 14 MarchFebruary 2009 

or an incremental enclosure requirement over a four year period, for all clinker storage and 

handling. If an incremental enclosure is chosen, 25% of the facility’s five-year annual 

average clinker material stored, by weight, must be enclosed no later than 12 months from 

date of exceedance, and an incremental 25% per subsequent year until all material is 

enclosed. It is important to note that hexavalent chromium monitoring according to this 

schedule shall be maintained, and that control measures such as chemical dust suppressants, 

wind fences/barriers, or tarps shall be used until the completion and operation of the 

enclosure. 

The operator(s) would be able to conduct 24-hour hexavalent chromium sampling once every 

six days if there is no exceedance of the 0.70 ng/m3

 level, excluding background of 0.16 

ng/m3

, during the first twelve (12) continuous months of monitoring. While on the less 

frequent compliance schedule, a 90-day rolling average would be used. The operator(s) may 

continue this less frequent monitoring schedule if there is no exceedance of the 0.70 ng/m3

level. Otherwise, the operator(s) shall incrementally enclose their open clinker storage and 

handling at 25% per year until completion pursuant to the schedule explained earlier, or 

totally enclose those operations/activities within 24 months of exceedance, and immediately 

revert back to the previous once-in-three-days monitoring schedule while maintaining control 

measures until completion and operation of the enclosure. 

In the event of a hexavalent chromium exceedance when there is no openly stored clinker 

material, the AQMD will conduct necessary studies to identify the source(s) and take 

necessary mitigative actions. 

Derivation of Hexavalent Chromium Level 

Following is a summary of why the 0.7 ng/m3 level is proposed and how it was derived: 

The 0.70 ng/m3 represents a concentration level at the receptor, that if exposed continuously 

for 70 years would pose a 100-in-1-million cancer risk. Staff selected 100-in-1-million as 

the cancer risk level in PAR 1156 for the nearest sensitive receptor as it is the significant risk 

level under Rule 1402 – Control of Toxic Air Contaminants from Existing Sources. 

The 0.7 ng/m3

 level was based on analysis of the nearest receptors to the two cement 

manufacturing facilities as described below. This value has a greater than 99% statistical 

confidence level in that there would be a significantly less than 1% chance that the risk due 

to hexavalent chromium would come from a source other than a cement manufacturing 

facility. 

 

In deriving this level, staff first identified an emission point, which is the finish mills area at 

TXI and open clinker storage area in front of the clinker barn at CPCC; then, staff conducted 

a model with site-specific information to the nearest receptors. Staff evaluated the decay in 

concentrations for TXI and CPCC, using SCREEN3, an USEPA dispersion model. Staff 

selected the 0.7 ng/m3

 to represent a 100-in-1-million cancer risk at fence line to be 

protective of the nearest receptors. Sensitivity modeling demonstrated that source type 

(volume vs. area source of which clinker material storage and handling could be considered) 

has little effect on the rate at which the concentrations decrease downwind. Therefore, to 

ensure public health protection, staff proposes to establish a fence-line hexavalent chromium 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 15 MarchFebruary 2009 

level of 0.7 ng/m3. This level represents exposure due to the facility and excludes 

background levels. 

Hexavalent Chromium Background 

Staff believes the proper background deduction should be based on the two-year sampling 

effort (from 2004 to 2006) of the most current multiple air toxics study (MATES III) in 

which the Basin-wide average level of hexavalent chromium, excluding readings from 

Rubidoux, is 0.16 ng/m3

. 

The 0.16 ng/m3 level was derived from the 30-day rolling average ambient air concentrations 

of hexavalent chromium from the monitoring stations across the Basin (excluding the 

Rubidoux station) as depicted in Figure 4. Rubidoux station was excluded from the 

derivation as its hexavalent chromium readings are likely influenced by the cement 

manufacturing facilities. 

MATES III samples were collected and analyzed on a one-in three-day basis, and thirty-day 

rolling averages were calculated on a site-by-site basis. A minimum requirement of 7 days 

of valid data (70%) was used to produce valid 30-day averages. Data from nine of the ten 

fixed-sites in MATES III were combined in the analysis. There are no known stationary 

sources of hexavalent chromium in the immediate vicinity of the two cement manufacturing 

facilities. Therefore, the data represent a robust data set of typical basin-wide background 

hexavalent chromium levels, as well as the expected variability in those levels. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 16 MarchFebruary 2009 

0

50

100

150

200

250

300

350

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

30-Day Rolling Average Cr6+ Concentrations

Frequency of Occurance

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Frequency

Cumulative %

Figure 4 - All MATES III Fixed-Site Data Excluding Rubidoux 

(Nine Sites, 2004-2006) 

 

Statistical Analysis 

A greater than 99% statistical confidence level means a significantly less than 1% chance 

that the risk due to hexavalent chromium would come from a source other than a cement 

manufacturing facility. 

The methodology for this statistical analysis follows: 

The data used for the statistical analysis were based on the two-year sampling effort of 

MATES III, excluding readings from the Rubidoux station. The data used to measure the 

background levels of hexavalent chromium in the basin are a 30-day moving average of the 

levels recorded at each of nine MATES III monitoring stations. Each 30-day average is 

recorded as a single data point and taken to be an accurate reflection of the background 

emission level over that 30-day period. This analysis of MATES III data generated a sample 

size of approximately 2,300 measurements towards background level. The minimum 

background level in the sample is 0.027 ng/m3

 and the maximum level is 0.62 ng/m3. The 

data approximate a lognormal density function, which is the starting point for the 

calculations that followed. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 17 MarchFebruary 2009 

The estimates in Table 2, below, were calculated using the described methodology: The 

emissions data were transformed using the log function, the resulting transformed data were 

used to calculate the sample mean and sample standard deviation, the mean and standard 

deviation were used to calculate the Z-score for the specific log-transformed level level, and 

the resulting Z-score was used to calculate the probability (P-value) that a level greater than 

the level level would be observed. 

Table 2 

Lognormal Statistical Results 

Level 

(ng/m3

) 

Log 

(Level) 

Zscore P-value

0.40 -0.916 1.945 0.026 

0.50 -0.693 2.360 0.009 

0.60 -0.511 2.699 0.004 

0.70 -0.357 2.985 0.001 

0.80 -0.223 3.234 0.0006 

0.90 -0.105 3.453 0.0003 

Interpreting the results of the statistical analysis from Table 2, the likelihood that a rolling 

average would exceed 0.7 ng/m3 and come from a source other than the cement plant would 

be one-tenth of one percent. 

PM10 Monitoring 

Any exceedance of PM10 upwind/downwind level of 50 μg/m3 as measured by specified 

sampling requirements in Rule 403 – Fugitive Dust, would require the operator(s) to take 

steps to reduce clinker dust emissions, as well as apply dust suppressant on their openly 

stored non-clinker materials, unpaved roads, and unpaved areas. 

 

If the aforementioned PM10 level is violated three or more times within a 36-month period, 

PAR 1156 would require an amended compliance monitoring plan, and on-site continuous, 

real-time ambient air monitoring for PM10 within six months from the date of amended plan 

approval or one year from the date of the third approved notice of violation, whichever 

occurs first. 

 

Compliance Monitoring Plan 

PAR 1156 would require the operator(s) to submit a compliance monitoring plan for the 

monitoring and sampling analysis of hexavalent chromium and wind monitoring, and pay 

fees pursuant to Rule 306 no later than three months from date of rule adoption. The plan 

will be approved or disapproved by the AQMD within 60 days from the plan submittal date. 

The operator is responsible to resubmit an approvable plan within 30 days from date of plan 

disapproval; otherwise, the operator is deemed in violation of the rule. Hexavalent 

chromium monitoring would be required no later than six months from compliance plan 

approval or March 1, 2010, whichever occurs first. Wind monitoring is required six months 

from date of adoption. 

 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 18 MarchFebruary 2009 

In addition to any relevant data and information required by the AQMD, at a minimum, the 

plan shall contain the following: 

• Siting and monitoring protocols that comply with EPA’s and CARB’s guidance and/or 

protocols for measurement of hexavalent chromium, wind direction, and wind speed. 

PAR 1156 would require a minimum set of three fence-line monitors for hexavalent 

chromium: one upwind and one downwind of the facility under the common prevailing 

wind directions, and one subject to approval by the AQMD to ensure maximum 

effectiveness of the monitoring to the most potentially affected receptor, such as nearest 

residential or business receptors relative to clinker storage areas or potential hexavalent 

chromium emitting sources. 

• Breakdown provisions which include: (1) a policy for breakdown notification for 

monitors to the AQMD within 24 hours of its occurrence; (2) a repair schedule; and (3) 

an action plan with detailed measures to be taken by the operator(s) to ensure there will 

be at least 70% data capture at each site by each monitoring system. In the event the 

breakdown occurs on a Friday, holiday, or weekend, such breakdown should be 

reported on the following business day. 

• Operator’s consent allowing the AQMD to conduct any co-located and audit sampling 

at any time. The operator(s) of a cement manufacturing facility are also required to 

allow District staff unlimited access to the facility’s monitoring sites at any time, and 

provide District staff with sufficient power so that co-located PM10 and/or hexavalent 

chromium monitors can be set-up and sampling and/or auditing can be conducted as 

necessary. 

• Sampling analysis protocols that comply with EPA and/or CARB’s appropriate 

guidance and/or protocols for hexavalent chromium. PAR 1156 would require that all 

samples are analyzed at an AQMD-approved laboratory, which can be audited any 

time. If there is no approved laboratory, the AQMD may grant approval of the testing 

procedures currently used by the laboratory on a case-by-case basis, based on 

appropriate AQMD protocols and procedures. If such an approval does not occur, the 

AQMD will provide the sample analysis for hexavalent chromium.

• Other relevant data and information required by the AQMD. 

The operator may file for a Compliance Monitoring Plan amendment in the future relative to 

monitor siting or other elements of the plan as more site-specific data becomes available. 

 

In the event where continuous, real time ambient monitoring for PM10 is required as a result 

of three violations of Rule 403 upwind/downwind limit, the operator(s) must amend their 

Compliance Monitoring Plan to include appropriate plan elements relative to PM10 

monitoring. The amendment must be filed within 90 days of the date of the third approved 

notice of violation. The monitoring equipment must be installed and operated within 6 

months from the date of plan approval, or one year from the date of the third approved notice 

of violation, whichever occurs first. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 19 MarchFebruary 2009 

Wind Monitoring 

Wind monitoring is required six months from date of adoption. PAR 1156 would require the 

operator(s) to install equipment and conduct hourly wind monitoring according to an AQMD 

approved protocol no later than six months from date of rule adoption. In addition, the 

proposed amendment would also call for a two-hour halt to all clinker handling activities in 

the open if instantaneous wind speeds exceed 25 miles per hour (mph). If instantaneous 

wind speeds subsequently exceed 25 mph, a new two-hour period shall begin. During the 

aforementioned two-hour period, the facility would be exempt from the 100-feet visible dust 

plume limit, provided that the open handling of clinker material is ceased, dust controls as 

required by the AQMD are applied, and unpaved roads within the facility are stabilized. 

Subdivision (h) - Exemptions 

Operators who have open piles containing materials other than clinker would be exempt from 

the requirement of enclosure or three-sided barrier, or from using the AQMD Rule 403 test 

methods for the demonstration of pile’s surface stabilization, if the materials contained in 

90% of the piles’ mass (instead of volume) are larger than 1⁄2 inch (paragraph (h)(1)). 

Applicability of this exemption must be determined through the measurement of any 

composite sample of at least 10 pounds taken at a minimum depth of 12 inches below the pile 

surface, from various locations on the pile, but not from within 12 inches from the base of the 

pile, to ensure adequate sampling. This change is being proposed to better provide guidance 

on sampling and to improve the effectiveness of the exemption. 

In high wind days, cement manufacturing operator(s) can be exempt from the hexavalent 

chromium and PM10 averaging provisions in the proposal, provided that all handling of 

clinker materials in the open is ceased and dust controls are applied. As a result, the 

operator(s) can exclude hexavalent chromium and PM10 ambient air concentrations detected 

during high wind days from their 30-day or 90-day rolling average. Appropriate records 

required by PAR 1156 must be kept. However, in the event the Executive Officer determines 

there is a significant hexavalent chromium dust re-entrainment potential, the operator(s) 

would be required to implement a Mitigation Monitoring Plan that is approved by the District 

to minimize exposure to the surrounding areas and to ensure implementation of all applicable 

dust controls (e.g., piles, road, and soil stabilization pursuant to Rule 403). If it is 

determined that a significant hexavalent chromium dust re-entrainment exists, the Executive 

Officer will conduct a management review prior to requiring a plan submittal. Such a 

determination will be, in part, based on wind data, and ambient as well as soil samples. 

Cement manufacturing operator(s) can be exempt from the wind fence requirement during 

periodic maintenance of the clinker crane or storage barn, provided that clinker crane is not 

operated except for post maintenance equipment testing. 

Other 

Relative to this provision, an amendment is also proposed to the definition of Cement 

Manufacturing Facility to clarify that even though TXI is not currently manufacturing 

cement products, they are not immune from the monitoring requirements (wind, hexavalent 

chromium, and PM10, as applicable) of the proposal. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 20 MarchFebruary 2009 

In addition, the proposed amended rule also contains other minor amendments and 

clarifications to better demonstrate the rule’s intent and to respond to USEPA comments on 

other elements of the rule. 

EMISSIONS AND EMISSION REDUCTIONS 

Since TXI no longer stores and handles clinker material in the open, the emissions inventory 

and reduction estimated herein are only for CPCC. 

According to staff estimates, emissions from clinker storage and handling activities are 0.08 

tpd for PM10 and 0.16 tpd for PM. This emissions inventory is consistent with CPCC’s 

estimates. The majority of existing emissions are from the storage and handling of clinker 

material. The current control for these activities is a 3-sided barrier with a roof at 75% 

control efficiency (CE). Low emissions come from wind erosion and traffic around the piles 

because most of these emissions are controlled with chemical dust suppressants (at 80% CE) 

and tarping (at 60% CE). 

 

Based on the current proposed amendment for clinker material storage and handling, and the 

assumptions that the existing barn enclosed with wind fencing would achieve an 85% CE and 

that wind fencing in addition to tarping would result in an 80% CE, staff has estimated 

reductions of 0.04 tpd for PM10 and 0.09 tpd for PM. If total enclosure is required due to 

monitoring violations, the reductions would be 0.07 tpd for PM10 and 0.16 tpd for PM. 

COSTS AND COST-EFFECTIVENESS 

The present value of control cost for PAR 1156 as originally proposed in July 2008, which 

included total enclosure of all clinker storage and handling, was estimated to be between $9.5 

to $12 million. This cost included the cost of domes at $38/ft2 to $46/ft2, the annual 

operating and maintenance (O/M) costs, and the savings from not applying chemical dust 

suppressant and tarp required by current Rule 1156. The estimated cost-effectiveness based 

on Discounted Cash Flow method for the total enclosure would be $8,000 to $10,000 per ton 

of PM reduced and $18,000 to $22,000 per ton of PM10 reduced, assuming a 20-year 

equipment life. CPCC estimated that it would cost approximately $21 to $24 million to 

comply with the proposed amendments introduced in July 2008 that required total enclosure. 

The proposal at this time did not include a monitoring component, which was added when 

the proposal was revised and as discussed below. 

Based on the current proposed amendments to Rule 1156, which allows alternative control 

options for clinker material storage and handling located at more than 1,000 feet from the 

property line, staff has estimated the present value of control cost of PAR 1156 to be $2.6 

million, and the cost-effectiveness to be $9,000 per ton of PM10 reduced, providing that 

ambient air monitoring for PM10 is not needed. Including PM10 monitoring, the control 

cost would be $3.69 million, and the cost-effectiveness would be $13,000 per ton of PM10 

reduced. The control costs account for the discounted present value capital costs assuming a 

20-year life equipment, O/M costs, and the savings from not using dusts suppressants to 

reduce traffic emissions around the clinker piles. The capital cost includes: (1) wind fence at 

$15/ft2

; (2) tarp at $0.12/ ft2; (3) continuous monitoring system for PM10 at $23,000 each, if 

required; (4) multi-chamber hexavalent chromium monitoring system at $21,000 each; and 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 21 MarchFebruary 2009 

(5) wind monitoring systems at $10,000 each. The O/M costs include: (1) hexavalent 

chromium analysis at $100 per sample; (2) O/M costs for the clinker barn due to wind 

fencing, assuming that the O/M costs are 5% of the wind fence costs; and (3) O/M costs for 

the monitoring systems, including sample collection. The monitoring O/M costs range from 

$82,000 (if PM10 monitoring is not needed) to $164,000 (if PM10 monitoring is required). 

In addition to the aforementioned costs, monitoring plan submittal and review costs pursuant 

to Rule 306 - Plan Fees - includes a minimum of approximately $500 plus additional cost for 

staff time, if needed to evaluate the plan. 

CPCC provided information that estimates the control costs to be $3.6 million and the 

resulting cost-effectiveness would be approximately $12,000 per ton of PM10 reduced, 

providing that ambient air monitoring for PM10 is not needed. Including PM10 monitoring, 

CPCC estimated control costs to be upwards of $4.9 million, and the cost-effectiveness to be 

$17,000 per ton of PM10 reduced. 

The following table summarizes the estimated capital and O/M costs of each major rule 

provision that one or both of the facilities are expected to follow. These costs are compared 

to data/information provided by the primarily affected facility (CPCC). 

Table 3 

Estimated Costs 

Staff Estimated Costs 

($) 

Industry Estimated 

Costs ($) 

Alternative Control Options (More 

than 1,000 feet from property line) 

Wind fences & tarps 

548,000 1,049,000 

Hexavalent chromium monitors 

(three for each facility) 126,000 --- 

PM10 monitors (three for each 

facility and if applicable) 138,000 --- 

Wind monitors (for both facilities) 20,000 --- 

Dust suppressants (as savings) 10,000 --- 

Hexavalent chromium analysis (for 

both facilities at $100/sample) 24,000 24,000 

O/M costs at clinker barn 4,000 15,000 

O/M costs for PM10 and 

hexavalent chromium monitors (for 

both facilities and if applicable) 

84,000 (without PM10) 

and 164,000 (with PM10) --- 

Plan fees (for both facilities) 1,000 1,000 

CALIFORNIA ENVIRONMENTAL QUALITY ACT 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 22 MarchFebruary 2009 

In accordance with the California Environmental Quality Act (CEQA), the South Coast Air 

Quality Management District (SCAQMD) is the Lead Agency for PAR 1156 pursuant to its 

certified regulatory program (SCAQMD Rule 110). A Final Environmental Assessment 

(EA) (SCAQMD No. 050307JK, dated October 13, 2005) was previously prepared pursuant 

to CEQA, which identified “air quality” as the only environmental topic that might be 

adversely affected by the current rule. Since the currently proposed project would be within 

the scope of what was analyzed in the previous Final EA that was circulated for public 

review and comment and subsequently certified, SCAQMD will rely on that previously 

certified Final EA for the currently proposed project pursuant to CEQA Guidelines §15153, 

because the circumstances of the projects are essentially the same. Greenhouse gases and 

PM2.5 analyses were not prepared as part of the Final EA, but were evaluated and found not 

to be significant in an Initial Study (IS) prepared for the proposed project (CEQA Guidelines 

§15153(c)). Since the circumstances of the currently proposed project are essentially the 

same as those analyses in the October 13, 2005 Final EA, and the greenhouse gases and 

PM2.5 impacts were concluded to be less than significant, no additional reasonable 

alternatives or mitigations are required. A Notice to Rely on the October 13, 2005 Final EA 

was circulated pursuant to CEQA Guidelines §15087 and the October 13, 2005 Final EA was 

made available for public review and comment on the environmental analysis for a 45-day 

period from July 15, 2008 to August 28, 2008 and no comments were received. A single 

comment was received on the IS asking for clarification on the PM2.5 analysis. The 

comment and response to comment is included as an appendix to the IS. 

Two comment letters were received from CPCC on PAR 1156. In these letters, the CPCC 

representative stated that the CEQA analysis of PAR 1156 should have included an analysis 

of the closure of cement manufacturing operation and its conversion to a storage and transfer 

facility for cement manufactured at other facilities. However, PAR 1156 is designed to 

control PM emissions from cement manufacturing facilities, not to permanently stop cement 

manufacturing operations at any affected facility. Modifications have been made to PAR 

1156 to address CPCC’s concerns. In addition, a socioeconomic analysis has been prepared 

that concludes that the cost of PAR 1156 requirements is reasonable. Since, PAR 1156 is not 

intended or designed to stop cement manufacturing operations, the alternative to permanently 

stop cement manufacturing operations was not analyzed. 

Staff has reviewed the modifications made to PAR 1156 since the circulation of the Notice to 

Rely and the October 13, 2005 Final EA for public review and concluded that they would 

not generate environmental impacts that would exceed those evaluated in the October 13, 

2005 Final EA. The proposed project in the October 13, 2005 Final EA included the 

construction of three-sided enclosures, wind fences and the use of tarping. The proposed 

project assumed that one full enclosure would be constructed at both the TXI and CPCC 

sites. No clinker enclosures would be required at TXI, since TXI no longer stores clinker per 

a memorandum of understanding with SCAQMD. 

The adverse impacts from the construction of one full enclosure at each facility would be the 

same as two full enclosures at a single affected facility. Since no more than two full 

enclosures at CPCC would be expected because of PAR 1156, the proposed full enclosure 

requirements would have adverse environmental effects similar to the proposed project 

evaluated in the October 13, 2005 Final EA. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 23 MarchFebruary 2009 

Since no comments were received that changed any conclusions from the October 13, 2005 

Final EA or the IS prepared for PAR 1156, SCAQMD staff will continue to rely on the 

October 13, 2005 Final EA as the CEQA document for the proposed project. 

SOCIOECONOMIC ASSESSMENT 

Staff has conducted a socioeconomic assessment on the final proposal for public review, 

which was made available 30 days prior to the public hearing. 

DRAFT FINDINGS 

Health and Safety Code Section 40727 requires the AQMD to adopt written findings of 

necessity, authority, clarity, consistency, non-duplication and reference. 

Necessity

A need exists to amend Rule 1156 to ensure that fugitive dust and hexavalent chromium 

emissions from the storage and handling of clinker and non-clinker materials are minimized. 

Authority 

The AQMD Governing Board obtains its authority to adopt, amend, or repeal rules and 

regulations from California Health & Safety Code Sections 39002, 40000, 40001, 40702, and 

40725 through 40728, and 41700, inclusive. 

Clarity 

The proposed amended rule has been written or displayed so that its meaning can be easily 

understood by persons directly affected by it. 

Consistency 

The proposed amended rule is in harmony with and not in conflict with or contrary to, 

existing statutes, court decisions or state or federal regulations. 

Non-Duplication 

The proposed amended rule does not impose the same requirements as any state or federal 

regulations. The amendment is necessary and proper to execute the powers and duties 

granted to, and imposed upon, AQMD. 

Reference 

By adopting the proposed amended rule, the AQMD Governing Board will be implementing, 

interpreting, and making specific the provisions of the California Health & Safety Code 

Sections 40000 (authority over non-vehicular sources), 40001 (rules to achieve ambient air 

quality standards), and 41700 (public nuisance). 

ALTERNATIVE CONTROL MEASURES 

Health and Safety Code Section 40440.5, subsection (c)(3) requires an analysis of alternative 

control measures. Staff conducted such an analysis for public review. Staff did not pursue 

their original proposal (July 2008) of total enclosure due to comments of severe economic 

hardship. The revised proposals herein were developed. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District 24 MarchFebruary 2009 

COMPARATIVE ANALYSIS 

Health and Safety Code §§40727.2 requires a written analysis comparing a proposed rule or 

amendment with existing federal, State and District regulations. Health and Safety Code 

§§40727.2, subsection (c) and (d) further require the analysis to review averaging provisions, 

operating parameters, work practice requirements, and monitoring, reporting and 

recordkeeping requirements associated with existing applicable rules and proposed 

regulations. A comparative analysis for the adoption of Rule 1156 in 2005 was conducted 

and is included in Appendix C. The comparative analysis contains italicized text to reflect 

the current staff proposal. 

CONCLUSION 

The current proposed amendments would reduce particulate as well as hexavalent chromium 

fugitive dust emissions generated from the storage and handling of clinker material. 

PAR 1156 would achieve reductions of 0.04 tpd for PM10 and 0.09 tpd for PM at a cost 

estimated to be in the range of $2.56 to $3.56 million, providing that ambient air monitoring 

for PM10 is not needed. Including PM10 monitoring, the cost would be $2.73.9 to $3.74.9

million. Without PM10 monitoring, the cost-effectiveness would be $8,5009,000 to 12,000 

per ton of PM10 reduced. If PM10 monitoring is triggered, the cost-effectiveness would be 

$913,000 to 1713,000 per ton of PM10 reduced. 

PAR 1156 would increase public health protection through additional fugitive dust control 

measures and ambient monitoring efforts. 

REFERENCES 

 AQMD, 2005. Final Staff Report on Proposed Rule 1156 - Further Reductions of Particulate 

Emissions from Cement Manufacturing Facilities. November 2005. 

AQMD, 2005. Final Environmental Assessment, Proposed Rule 1156 - Further Reductions 

of Particulate Emissions from Cement Manufacturing Facilities. SCAQMD No. 050307JK, 

dated October 13, 2005. 

AQMD, 2008. Attachment 1 from Dr. Barry W. Wallerstein’s letter to the public dated May 

6, 2008. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-1 MarchFebruary 2009 

APPENDIX A 

RESPONSE TO COMMENTS 

Response to Comment for the Public Review Period Ending December 12, 2008 

___________________________________________________________________________ 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-2 MarchFebruary 2009 

The following are comments and responses on the revised amendment to Rule 1156 that was 

released for public review in November 2008 and for which a Public Consultation meeting was 

held on November 20, 1008. The public review and comment period ended on December 12, 

2008. These responses are relative to the current proposal. Comments from US EPA and CARB 

are included below. (Note: at the end of each comment, in parenthesis, is the originator of the 

comment). 

Agency Comments 

Comment #1: We support the District’s efforts to reduce exposure to particulate matter and 

hexavalent chromium from cement manufacturing facilities. We encourage 

the District to speak with other California agencies (e.g., the Monterey Bay 

Unified APCD) that are also trying to address hexavalent chromium emissions 

from similar sources. We do not currently believe there are any approvability 

issues with the rule. (US EPA) 

Response #1: Staff appreciates the support of U.S. EPA, Region IX. Staff has been engaged 

with other air districts regarding regulatory efforts at cement manufacturing 

plants under their jurisdiction. The collaboration has been helpful. 

Comment #2: For haul roads, clause (d)(7)(A)(i) requires that chemical dust suppressants be 

applied twice a year, that signs be posted at the two ends stating that haul 

trucks use these roads unless traveling to maintenance areas, and that a speed 

limit of 35 mph or less be enforced. For other unpaved roadways and areas, 

clause (d)(7)(A)(ii) requires that chemical dust suppressants be applied twice 

a year or that a gravel pad be applied, and that a speed limit of 15 mph or less 

be enforced. However, haul roads do not seem to be defined in Rule 1156. 

Please insert a definition for haul road in order to ensure that the requirements 

in (d)(7)(A)(i) and (d)(7)(A)(ii) are enforceable. (US EPA) 

Response #2: A clarification has been added in clause (d)(7)(A)(ii), consistent with the 

definition in Rule 1157, for moving material from the quarry to different 

locations within the facility. Staff will consider a specific definition in a 

future amendment. 

Comment #3: In addition to meeting other requirements, clause (d)(7)(A)(ii) allows sources 

to comply by applying a “gravel pad containing 1-inch or larger washed 

gravel to a depth of six inches.” We recommend including the additional 

requirements for gravel pads that can be found in subparagraph (d)(1)(E) of 

District Rule 1157 for a geotextile lining underneath the washed gravel and 

for the gravel pad to be flushed with water or completely replaced as 

necessary to comply with the track out level set forth in Rule 403. (US EPA) 

Additionally, subparagraph (d)(8)(B) states that “If necessary to comply with 

the opacity limits in paragraph (d)(1), the operator shall install a rumble grate, 

truck washer, or wheel washer; and ensure that all trucks go through the 

rumble grate, truck washer, or wheel washer such that the entire 

circumference of each wheel or truck is cleaned before leaving the facility.” 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-3 MarchFebruary 2009 

In addition to having opacity limits that sources must comply with, District 

Rule 1157 requires that facilities install and utilize a rumble grate, truck 

washer, or wheel washer. Moreover, subparagraphs (d)(8)(C) and (d)(8)(D) 

of Rule 1157 have more specific requirements, including where rumble grates 

and wheel washers should be located, and for a sign to be posted near the 

rumble grate, wheel washer, or truck washer to designate the speed limit to be 

5 mph for using such control equipment. We recommend inserting similar 

requirements into subparagraph (d)(8)(B) of 1156 in order to further 

strengthen the rule. (US EPA) 

Response #3: Given the requirement that a minimum of 0.25 mile of internal roads must be 

paved pursuant to subparagraph (d)(8)(A) at both cement manufacturing 

facilities prior to accessing any public roadway, staff does not believe the 

additional requirements are necessary at this time. Staff will, however, 

consider these additional requirements in a future amendments to Rule 1156. 

In addition, were the language to be added, it would likely constitute new 

information that was not taken into consideration and through the public 

review process. 

Comment #4: Section (h)(4) exempts the operator from the use of chemical dust suppressants 

in clause (d)(7)(A)(ii) where a road is used less than a monthly average of 

twice a day by a designated vehicle at a speed limit less than 15 miles per 

hour. Please add corresponding recordkeeping requirements to the rule to 

ensure that this provision is enforceable. (US EPA) 

Response #4: The recordkeeping requirement has been added to subparagraph (f)(2)(J). 

Comment #5: Subparagraph (d)(5)(c)(ii) allows for clinker to be stored outside a three-sided 

barrier if there are space limitations inside the structure caused by 

“operational constraints”. This latter term is not defined in the rule, nor is any 

further clarification of this term provided in the rule. We suggest that this 

issue be addressed at least for the benefit of enforcement staff and affected 

facility operators in an advisory notice if not defined in the rule. (CARB) 

Response #5: As the key element of this subparagraph for requiring wind fencing and tarps 

on clinker material stored outside of the three-sided relative is due to “space 

limitations”, the clarifier of “caused by operational constraints” is not 

necessary in the rule. It has been deleted, although for clarification purposes 

it remains in the staff report descriptive text regarding the explanation of the 

proposed added rule language. That is, the excess clinker due to production 

may require storage of clinker outside of the structure. 

Comment #6: Subparagraph (d)(5)(c)(iii) requires one side of the three-sided enclosure to 

face the prevailing wind. An operator may be able to interpret this to allow 

for the open side to face the wind, which is contrary to the intent of this 

design. We recommend the District rewrite the section to require that the 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-4 MarchFebruary 2009 

open side not face the prevailing wind direction to eliminate this erroneous 

interpretation. (CARB) 

Response #6: Clarifying language has been added to the rule to state that one side “of the 

wind fence” shall face the prevailing wind direction. 

Comments on Proposed Amended Rule Language 

Comment #7: The rule applicability should be revised to exclude the aggregate operations 

and equipment subject to 40 CFR Part 60 Subpart OOO, and include only 

operations and equipment subject to 40 CFR Part 63 Subpart LLL and 40 CFR 

Part 60 Subpart F. As a result, amended rule 1156 should only apply to 

equipment/operations starting from the surge bin immediately prior to the raw 

milling. (CPCC) 

Response #7: An amendment to the rule is unnecessary. To clarify, however, Rule 1156 

begins at CPCC upon the transfer of materials into the blending silos, which 

are either proportioned into the feed bin for the raw mills, or directly to the 

finish mills. As stated in exemption paragraph (h)(6), “With the exception of 

primary crushing, open material storage piles, and covers and existing 

enclosures for conveying systems...”, the provisions of this rule shall not 

apply to equipment or operations that are subject to Rule 1157 or Rule 1158. 

Therefore, with consideration of those exemptions, Rule 1156 begins at the 

blending silos and its associated control devices, and thereafter in the cement 

manufacturing process. 

 

Comment #8: Staff cost estimates are low. Facility’s new cost data will be submitted. 

(CPCC) 

Response #8: Staff is confident that their estimates are reasonable since they are based on 

current cost information provided by manufacturers and distributors; however, 

staff has also included the facility provided cost data in their analysis. 

Therefore, the cost and cost-effectiveness associated with this rule are 

represented as a range. 

Comment #9: Amended Rule 1156 should allow for the removal of the wind fence from the 

clinker barn to accommodate the equipment maintenance. (CPCC) 

Response #9: The rule language has been modified to allow such maintenance activities. 

 

Comment #10: The deadline to submit the Compliance Monitoring Plan should be revised to 6 

months instead of 2 months from date of adoption. (CPCC) 

Response #10: Staff is committed to working with both facilities to help facilitate preparation 

of the compliance monitoring plan. Staff revised the plan submittal deadline 

to 3 months from date of rule adoption, and extended installation of the 

monitoring network to 6 months from compliance plan approval or 

03/01/2010, which ever occurs first. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-5 MarchFebruary 2009 

Comment #11: CPCC opposes the proposal that they will be subject to an interim plan 

if their submitted compliance plan is rejected and an approvable plan is not 

resubmitted. (CPCC) 

Response #11: Staff revised the rule language so that a violation would occur if an 

approvable plan is not resubmitted within 30 days from plan disapproval. 

Comment #12: Breakdown provisions should be revised to allow facilities 72 hours from 

discovery (instead of “24 hours of its occurrence”) to report a breakdown of 

the ambient monitoring equipment. (CPCC) 

Response #12: Staff revised the rule language so that if a breakdown occurs on a Friday, over 

a weekend, or on a facility-observed national and/or state holiday, the 

breakdown may be reported on the following business day. 

Comment #13: CPCC raised concerns regarding AQMD lab certification process and the 

availability of an AQMD-approved lab for hexavalent chromium analysis. 

(CPCC) 

Response #13: Staff is working with the facility to identify acceptable laboratory and is 

confident that the certification process will be completed well in advance of 

the rule compliance date. If that does not occur, the AQMD lab can provide 

that service.

Comment #14: Trip blanks should be subtracted from hexavalent chromium sampling and 

analysis, and background concentrations should be deducted from 

upwind/downwind concentration levels. (CPCC) 

 

Response #14: The proposed rule language has been revised to reflect the 0.70 ng/m3 level, 

excluding background. Since trip blanks are inherently included in the 

background, subtracting trip blanks would be double counting. The 

background for the purposes of Rule 1156 will be 0.16 ng/m3

 hexavalent 

chromium, based on the 2-year MATES III monitoring efforts. As described 

in the staff report, this data is from 9 fixed sites, excluding Rubidoux, and is 

comprised of approximately 2,300 data points evaluated on a 30-day average 

as in the proposed rule amendment. 

Comment #15: If monitoring shows hexavalent chromium levels above the rule level, a toxic 

reduction plan should be implemented instead of enclosure, particularly in the 

event hexavalent chromiumis not from clinker. (CPCC) 

Response #15: A toxic risk reduction plan would take a long time to develop, review, 

approve, and be implemented. Since extensive sampling indicates that clinker 

dust contributes to ambient hexavalent chromium concentrations, enclosure 

would be an appropriate control strategy in the event the hexavalent 

chromium level established in the rule is exceeded. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-6 MarchFebruary 2009 

 

Comment #16: The requirement of incremental enclosure (in the events of hexavalent 

chromium exceedance) is not feasible or cost-effective, and total enclosure 

would result in facility shut down. (CPCC) 

Response #16: The facility must take all necessary preventive steps and at a minimum, those 

established in the rule, to ensure that the hexavalent chromium level is not 

exceeded and the public is not exposed to undue risk. Staff added an 

alternative so that facility may select total enclosure within 24-months or 

incremental enclosure over 4 years.

Comment #17: PM10 monitoring is not justified and should only be required in the event of 

recurrent Notices of Violation on a 12-month rolling average. (CPCC) 

Response #17: PAR 1156 has been revised to require such monitoring in the event of three 

verified violations of the Rule 403 upwind/downwind ambient air 

concentration level (50 μg/m3) over a 36-month period. Upon the third 

verified violation, the facility would have 90 days to file for a modification to 

their Compliance Monitoring Plan. The monitoring equipment would be 

required to be installed and operated within 6 months from the date of plan 

approval or one year from the date of the third approved notice of violation, 

whichever occurs first. 

Comment #18: The method of PM10 measurement and PM10 upwind/downwind 

concentration levels should be based upon the results of the AQMD’s ongoing study. (CPCC) 

Response #18: The method of PM10 measurement is consistent with EPA and CARB’s 

guidance, including use of continuous and real-time monitors. As mentioned 

in the response to the previous comment, PAR 1156 has been modified. 

Comment #19: A sunset date should be included in PAR 1156 in the events that no 

hexavalent chromium exceedance of the level specified in the proposed rule 

occurs in a 3-year period. (CPCC) 

Response #19: It is important to continue hexavalent chromium monitoring to ensure 

continued public health protection. PAR 1156 contains a provision to reduce 

the 1-in-3-day monitoring to 1-in-6-day monitoring schedule if there is no 

single exceedance of the 0.70 ng/m3 level at any station (excluding 

background and based on a 30-day rolling average) during the first 24 months 

of monitoring, which was revised to the first 12 continuous months of 

monitoring in the most recent revised rule proposal. Nevertheless, a 

resolution commitment will be has been drafted directing staff to report 

annually to the Stationary Source Committee regarding all monitoring 

activities, including a reevaluation of the need for continued hexavalent 

chromium monitoring in the fifth year report. Additionally, staff will provide 

biannual reports to the full Board.
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-7 MarchFebruary 2009 

Comment #20: The sampling schedule for hexavalent chromium should be changed to twice 

per week to reduce the need for personnel on weekends and holidays. Our 

facility has minimal operation on weekends or holidays. (CPCC) 

Response #20: The one-in-three day sampling schedule is consistent with EPA sampling 

schedules and helps cover all days of the week, on a rotating schedule to 

characterize emissions more thoroughly. The amended rule language has 

been modified to reflect that the monitoring schedule may change to 1-in-6 

days in the event no exceedance of the 0.70 ng/m3 level occur within the first 

twelve (12) continuous months. Also, sample collection that would have 

occurred on a weekend or a facility observed-and/or state holiday may take 

place the following business day. Studies have shown that sample collection 

one to three days after the 24-hour monitoring period would not result in any 

additional sample loss. 

 

Comment #21: Wind monitoring provisions should be revised to allow for the resumption of 

clinker handling in the open after 2 hours of a high winds event greater than 

25 mph (instead of 24 hours). (CPCC) 

Response #21: Staff has revised rule language to require a two-hour operation halt during a 

high wind event. If another wind gust greater than 25 mph occurs subsequent 

to the initiation of the first 2-hour halt, a new 2-hour period would begin. 

Comment #22: Facilities should be exempt from visible emission standards in the event of 

high winds greater than 25 mph (similar to Rule 403) when clinker handling 

in the open is ceased. (CPCC) 

Response #22: Staff has revised the rule language so that the facility would be exempt from 

the requirement of 100-feet visible dust plume limit, provided that the open 

handling of clinker material is ceased, so long as dust controls are applied, 

and unpaved roads within the facility are stabilized prior to the time of the 

high wind occurrence as required by this and other AQMD rules. 

Comments on the Revised Preliminary Draft Staff Report 

Comment #23: There is no justification that hexavalent chromium monitoring is needed and 

evidence suggests that with the TXI settlement agreement, the concentration 

levels have dropped to background levels. (CPCC) 

Response #23: The ongoing monitoring program around the two cement manufacturing 

facilities has demonstrated, even recently, that the ambient levels have on 

occasion exceeded 1 ng/m3

. Evaluation of wind data indicates that the reentrainment of hexavalent chromium laden dust is originating from one of the 

two facilities. Therefore, due diligence to evaluate the source of the emissions 

and continued monitoring is warranted. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-8 MarchFebruary 2009 

Comment #24: There is no discussion as to why a 24-hour sampling period at a frequency of 

1 in three days is appropriate or relevant. Why is such data better than once a 

week or once a month? (CPCC) 

Response #24: The reader is referred to the response to Comment #20. In addition, the 

hexavalent chromium sampling timeframe and frequency is not only 

consistent with EPA sampling protocols, it has been used extensively by the 

District, such as in conjunction with the ambient monitoring efforts of 

MATES III. The frequency and schedule of monitoring will provide 

information that is reflective of fluctuations in operating parameters and 

conditions in and around the area. If 12 months of data is collected and the 

30-day average of fence line monitoring is not exceeded, a one in six day 

schedule would be required. 

Comment #25: There needs to be more discussion as to the derivation of the hexavalent 

chromium level of 0.7 ng/ m3

 and how it was determined that this level was 

appropriate. Specifically, what authority does the District have to set such a 

standard and what levels of safety were built into its development? Further, 

who reviewed this standard and how does it relate to the state standard of 200 

ng/m3, and how does it relate to the industrial occupational standard of 

OSHA? This standard appears arbitrary and has not gone through a formal 

peer review process and the District does not have the authority to establish an 

ambient standard. (CPCC) 

Response #25: The reader is referred to the additional write-up and information provided in 

the Staff report as to the derivation and appropriateness of the 0.7 ng/m3 level. 

The District does indeed have authority granted to it to derive and utilize such 

rule-based standard for local purposes to protect the public from undue risk. 

In the derivation, safe guards were used in that the level was derived in the 

absence of background and would account only for emissions from the facility 

contributing to such a concentration. In addition, the risk factors used are 

consistent with those established by the state Office of Environmental Health 

Hazard Assessment (OEHHA) and adopted by the Scientific Review Panel. 

The standards referenced by the commenter are workplace standards and not 

directly related to 0.7 ng/m3 level, as it is a public health exposure level over a 

70-year lifetime, not a short-term exposure level. 

Comment #26: How is to be determined that the hexavalent chromium concentrations are 

coming from the facilities, particularly if there is no recognition of 

background. The levels could be coming from other sources, such as a 

railway or freeway. Making the facility responsible for background 

concentrations and tying additional control measures to a standard is arbitrary 

and illegal. (CPCC) 

Response #26: The proposal has been modified to reflect that the monitoring level excludes 

background and is discussed in detail in the staff report. If there were an 

exceedance, staff would conduct an evaluation using meteorological data to 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-9 MarchFebruary 2009 

firmly establish if a facility was the source of the emissions resulting in the 

elevated concentrations. Only upon that determination would the facility be 

required to pursue enclosure of clinker material storage and handling. 

Comment #27: The consequence of exceeding the hexavalent chromium level is too high, that 

is to spend millions of dollars for enclosures when the District’s monitoring 

data demonstrates that the problem has been solved. (CPCC) 

Response #27: The modifications made to the proposed rule amendment allow sufficient 

alternatives that would not require enclosures unless all of the clinker material 

handling occurred within 1,000 feet of, and inside, the facility property line. 

Staff fully expects that both facilities will be able to demonstrate compliance 

with the newly established rule requirements using the alternative provisions, 

and does not expect that enclosure would be required up front for rule 

compliance. As discussed earlier recent monitoring data demonstrates the 

continued need for ongoing hexavalent chromium monitoring. 

Comment #28: The staff report states that if the hexavalent chromium level is exceeded and 

no openly stored clinker material exists, then the District would conduct a 

study and implement mitigation measures. This is not in the rule and assumes 

clinker to be the only source, which is not the case. (CPCC) 

Response #28: The commenter is correct that the source of hexavalent chromium monitored, 

although believed to primarily be from clinker material handling, may not 

specifically be from clinker material handling. It may come from unpaved 

roads or re-entrained fugitive dust from accumulated material. Case in point 

is the TXI facility, which no longer by settlement agreement, openly handles 

clinker material. Therefore, were the monitor(s) at that facility’s fence line to 

detect elevated hexavalent chromium levels exceeding the 0.7 ng/m3

, a study 

would be required to derive the source of the emissions and take mitigative 

action. This is explained in more detail in the staff report. 

Comment #29: There is no justification as to why PM10 monitoring is needed. It is neither 

practical nor workable. (CPCC) 

Response #29: The rule has been modified to only require PM10 monitoring if the District 

finds that on at least three occasions the facility violates the 

upwind/downwind level level of 50 μg/ m3 established in Rule 403. The 

reader is referred to the response to Comment #17. 

Comment #30: The efficacy of continuous ambient PM10 monitors has not been 

demonstrated and there is no basis for using this as a compliance tool. 

(CPCC) 

Response #30: The use of such continuous monitors for measuring PM10 has been occurring 

for years and they are a key tool used by air districts to demonstrate 

compliance with the federal ambient air standards and justify its status of 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-10 MarchFebruary 2009 

attainment status. Protocols for the use of these continually operating devices 

have been developed and are being used by EPA, CARB, as well as numerous 

air districts throughout the state. 

Comment #31: Continuous ambient monitors are not allowed under Rule 403 for evaluating 

upwind/downwind concentrations and should not be designated for use 

relative to the Rule 403 level of 50 μg/m3. (CPCC) 

Response #31: The use of continuous PM10 monitors are indeed allowed under Rule 403 

criteria; however, in evaluating the upwind/downwind concentration 

differentials, the District has historically used high-volume samplers. The 

Rule 403 methodology is currently under review and changes to the rule or 

procedures may be made in the future. 

Comment #32: It is not fair to require hexavalent chromium monitoring from cement 

manufacturing facilities and not of other higher polluting facilities, such as 

plating facilities. (CPCC) 

Response #32: As specific industries have been identified that pose significant risks to the 

surrounding the community, it is not atypical to require specific ambient 

monitoring. For example, District Rule 1420 applicable to lead emitting 

sources. Monitoring is required under that rule, including submission of a 

compliance plan. In addition, other rules exist to specifically control air 

toxics from those sources (i.e., plating operations). 

Comment #33: A statement by Dr. John Morgan, Professor of Epidemiology, and 

Biostatistics, School of Public Health, Loma Linda University that there are 

no cancer clusters or increases in cancer detected in the areas around the 

plants have not been taken into account. This review of significant historic 

data should be considered as both plants have been around for years and one 

would think that if there were any cancer cases, these would have manifested 

themselves by now. (CPCC) 

Response #33: It is very difficult to correlate cancer incidence with specific facilities. Given 

the monitored levels from the MATES III study and the recent localized 

monitoring efforts in the areas around the cement manufacturing facilities, 

future and continued exposures must be considered. From a public health 

standpoint, it is prudent to move forward to ensure these exposures are limited 

to the extent feasible and future risks are avoided, even if the facilities 

shutdown. 

Comment #34: The definition of cement manufacturing within the rule would preclude TXI 

from being subject to the new rule requirements, as they do not manufacture 

cement anymore. Based on their current operations, they are only a cement 

transfer facility, subject to other requirements. (CPCC) 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-11 MarchFebruary 2009 

Response #34: The definition has been modified in the current rule amendment proposal to 

clarify that the monitoring requirements of the rule are intended to apply to 

both facilities. Specifically, any facility manufacturing cement prior to 

November 2005 is subject to the requirements of Rule 1156. In addition, even 

though the facility has currently ceased such cement manufacturing 

operations, they retain their permits for such processes and the potential to 

emit, therefore, remains. 

Comment #35: The costs associated with monitoring are not sufficient and need to be 

updated, such as filter sample analysis, construction of monitoring sites, 

maintenance, and personnel costs. (CPCC) 

Response #35: These costs have been updated and the reader is referred to the discussion of 

compliance costs and cost-effectiveness in the staff report. 

Comment #36: Clarification is needed as to how monitoring data is to be submitted. (CPCC) 

Response #36: The proposed amended rule language has been modified to reflect that the 

data be submitted electronically on a monthly basis. Staff will work with the 

facility operators. 

Comment #37: Relative to monitoring and quantification of emissions, why is PM2.5 not also 

measured? (Public) 

Response #37: The hexavalent chromium measured is a component of the total fugitive from 

the cement manufacturing operations. Fugitive dust is typically measured in 

terms of PM10, which is inclusive of the PM2.5 fraction. So, it is included 

relative to evaluating the hexavalent chromium contribution in the larger sized 

material. 

Comment #38: A socioeconomic impact report should be completed as required by the state 

Health and Safety Code and include an analysis of impacts to the cement 

plants and the surrounding communities, including lost revenues to local 

governments and closure of at least one plant (e.g., CPCC). (CPCC) 

Response #38: A socioeconomic analysis has been prepared for the proposed amendments. 

Comment #39: The CEQA document should evaluate the possibility of plant shutdowns as a 

result of the amendments. The previous EA was written specifically to avoid 

imposing control measures that could shut down clinker manufacturing. As a 

result of the closure, the EA should address the potential increase in air toxics 

associated with rail, ship, or truck import of cement materials. (CPCC) 

Response #39: Staff has evaluated the currently proposed amendments to Rule 1156 and 

determined that potential impacts from the proposed project are within the 

scope of the analysis contained in the 2005 Final EA for Rule 1156. 

Consequently, SCAQMD is relying on the 2005 Final EA as the CEQA 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District A-12 MarchFebruary 2009 

document for proposed amended Rule 1156 pursuant to CEQA Guidelines 

§15153 because impacts from the currently proposed amendments are 

essentially the same as impacts analyzed in the 2005 Final EA, in particular 

the analysis of Alternative C – Full Enclosures. Pursuant to §15153(b)(2), 

staff notified the public that the SCAQMD would be relying on the 2005 Final 

EA for Rule 1156 as the CEQA document for the currently propose 

amendments and would accept comments regarding potential impacts from 

the currently proposed amendments. 

In the 2005 Final EA it is clearly stated that the Governing Board may adopt 

all, or portions of any of the project alternatives, including Alternative C. No 

comment letters were submitted on the 2005 Draft EA for Rule 1156. 

Consequently, the issue of affected facilities shutting down as a result of 

implementing Rule 1156 or any of the project alternatives was not raised at 

that time. 

With regard to recently received comments about the possibility of affected 

facilities shutting down, as noted in response #34, the Socioeconomic Impact 

Analysis prepared for the currently proposed amendments to Rule 1156 did 

not indicate that the proposed amendments would result in the closure of any 

affected facilities. Further, subsequent to the start of the CEQA comment 

period, proposed amended Rule 1156 was modified based on comments 

received to provide more flexibility in complying with the proposed 

amendments by allowing alternative compliance options to total clinker 

storage requirements. Based on these conclusions, staff did not evaluate 

facility closures and any associated impacts from facility closures because this 

is not a “reasonably foreseeable” effect of the currently proposed 

amendments. 

Information regarding the CEQA analysis is included in the Staff Report for 

proposed amended Rule 1156. 

Comment #40: The focus of these efforts really comes down to protection of public health, 

which needs to remain in the forefront. Staff’s efforts are supported. What 

are the penalties for non-compliance with the new rule provisions? (Public) 

Response #40: Penalties for non-compliance are administered on a case-by-case basis as 

required in the California Health and Safety Code. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District B-1 MarchFebruary 2009 

APPENDIX B 

RESPONSE TO COMMENTS 

Response to Comments for the Public Review Period Ending July 20, 2008 

___________________________________________________________________________ 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District B-2 MarchFebruary 2009 

Response to Comments 

The following are comments and responses on the initial proposed amendment to Rule 1156 that 

was released for public review June 2008 and for which the public workshop was held on July 2, 

2008. The public review and comment period ended in July 20, 2008. These responses are 

relative to the revised staff proposal that was released to the public for review in November 

2008. 

Comment # 1: California Portland Cement Company (CPCC) is the only facility that would 

be significantly, unfairly, and unnecessarily impacted by the proposed 

amended rule (PAR) 1156, although none of the AQMD’s studies identify 

levels of concern of hexavalent chromium in the vicinity of CPCC in Colton. 

TXI has been identified as the source of the elevated hexavalent chromium 

and has received associated violations for PM. (CPCC) 

 

Response # 1: On the average, hexavalent chromium content in samples taken adjacent and 

downwind of CPCC in spring 2008 are lower than TXI (0.35 ng/m3

 and 1.58 

ng/m3, respectively), and hexavalent chromium content of CPCC clinker is 

about 20% lower than TXI. However, in 9 ambient samples taken between 

2/12/08 and 4/3/08, the 24-hour hexavalent chromium concentrations 

measured near the facilities were close to or exceeded 1 ng/m3. Similar 

hexavalent chromium concentrations occurred again in July and September 

2008. 

Hexavalent chromium is a potent, known human carcinogen. PAR 1156 will 

ensure reductions of particulate emissions from cement manufacturing 

facilities and limit exposure to PM10, as well as hexavalent chromium. To 

address the issue of financial hardship raised by CPCC, AQMD staff has 

significantly revised their proposal. 

The current proposed amendment would require total enclosure of clinker 

storage and handling conducted within 1,000 feet from, and inside, a facility’s 

property line. For clinker storage and handling activities that occur more than 

1,000 feet from, and inside, a facility’s property line, PAR 1156 would allow 

the use of alternatives, such as a three-sided barrier covered with a roof and 

wind fence for active, barn-type storage; tarp and barrier/wind fence for other 

active piles; and tarp for inactive piles. The proposal would also require 

ambient monitoring to measure hexavalent chromium at fence-lines and 

includes corrective actions should the monitoring indicate elevated levels of 

hexavalent chromium. PM10 monitoring is no longer required unless 

upwind/downwind level of 50 microgram per cubic meter (μg/m3

) as specified 

in Rule 403 – Fugitive Dust, is violated three or more times within a 36-month 

period. The revised proposal will significantly reduce costs to CPCC 

compared to the initial proposal, while still reducing particulate emissions and 

being public health protective. 

 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District B-3 MarchFebruary 2009 

Comment # 2: CPCC proposes language that “the rule does not apply to operations and 

materials handling and transporting that are regulated by Rules 1157 and 

1158” and that facilities subject to Rules 1156, 1157, and 1158 shall be 

consistent with the definition of affected facilities as defined in 40 CFR Part 

63 and Part 60. (CPCC) 

Response # 2: Rule 1156 was specifically developed to reduce particulate emissions from 

cement manufacturing facilities. Since Rule 1156 only focuses on equipment 

and operations that are typical for cement manufacturing facilities, it is not 

necessary to exclude other types of industries from the rule. 

Comment # 3: CPCC suggests the deletion of “equal to” in the opacity limits set forth in 

(d)(1)(A) and (d)(1)(B) because the added language actually makes the 

requirements more stringent instead of clarifying them. (CPCC) 

Response # 3: Staff has revised the language to maintain the opacity levels in previously 

adopted Rule 1156. 

 

Comment # 4: CPCC suggests the added terms “on-road” before “trucks” and “commercial” 

before “modes of material transportation” in (d)(2)(A) for clarification 

purposes. (CPCC) 

Response # 4: During the initial Rule 1156 development process, staff worked closely with 

the cement manufacturing facilities to develop such language, which is very 

specific to the facility’s activities and operations; therefore, the language will 

not be revised. 

Comment # 5: CPCC suggests that clinker storage piles located within 1,000 ft inside of the 

fence line of a cement manufacturing facility be enclosed, and that the 

alternatives, such as tarping, 3-way barrier, wind fence, or stabilizing can be 

applied to clinker storage piles located 1,000 ft or more from the fence line. 

(CPCC) 

Response # 5: After further consideration, staff has revised the proposed amendment. To 

reduce PM and hexavalent chromium fugitive dust emissions from the storage 

and handling of clinker material that occur further than 1,000 feet from, and 

inside, a facility’s property line, the current proposal would allow the use of: 

(1) a three-sided barrier covered with a roof and wind fence of a maximum 

20% porosity for active, barn-type storage; (2) tarp and extended wind fence 

with at least 5-foot freeboard for active piles that are immediately adjacent to 

the above mentioned covered barrier; and (3) tarp and barrier/wind fence with 

at least 5-foot freeboard and extended at least 20 feet beyond the active 

portion of a pile for other active piles. 

For inactive clinker storage, PAR 1156 would alternatively allow tarping 

only, provided that records of inactive status are maintained. 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District B-4 MarchFebruary 2009 

The majority of emissions would be reduced at a significant cost reduction 

compared to the initial staff proposal. This will minimize adverse economic 

impacts on cement manufacturing facilities. The addition of ambient 

monitoring and required corrective actions if certain emission levels are 

exceeded will provide public health protection. 

Comment # 6: CPCC proposes a change in (d)(5)(B) from a prohibition on the open clinker 

storage piles to a set of stringent control measures that would achieve nearly 

the same dust control at a significantly reduced cost. CPCC believes that its 

existing dust control measures are sufficient to reduce health risks to the 

surrounding community, and that the proposed enclosure requirement would 

be infeasible to CPCC since it has only 20 years left of identified quarry 

reserves. In addition, CPCC also believes that the elimination of outdoor 

clinker piles would increase NOx emissions. (CPCC) 

Response # 6: Please see response to comment # 5. 

Comment # 7: CEQA and socioeconomic assessment should be conducted to analyze the 

impacts of PAR 1156. (CPCC) 

Response # 7: CEQA relies on the previous document prepared relative to the initial 

adoption of Rule 1156 in November 2005. Cost and cost-effectiveness are 

included in the staff report. Socioeconomic analysis will be available 30 days 

prior to the public hearing. 

Comment # 8: The current PAR 1156 is strongly supported. Natural Resources Defense 

Council (NRDC) and the communities also believe that further investigation 

and control of other sources of PM emissions from cement manufacturing 

facilities are needed to protect the surrounding communities. Steps should be 

taken to remediate past pollution of land and water from cement deposition. 

(NRDC) 

Response # 8: Public health protection, cost, technical feasibility, impacts on industry, and 

emission reductions have been considered and have resulted in the current 

staff proposal. The proposed wind and hexavalent chromium monitoring will 

provide additional information to ensure continued public health protection. 

Comment #9: Further reduction in both criteria and toxics pollutants, as well as greenhouse 

gases emissions, can be attained through the adoption of cleaner fuels and 

limited clinker production. (NRDC) 

Response #9: PAR 1156 will reduce PM and hexavalent chromium fugitive dust from 

cement manufacturing facilities. Other reductions through clean fuel or 

limiting clinker production are beyond the scope of this amendment. 

Comment #10: We strongly support the enclosure requirement of all clinker storage and 

handling since it will promote a healthful local environment. (Public) 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District B-5 MarchFebruary 2009 

Response #10: As noted in the response to comment #5, the initial staff proposal may have 

resulted in the early closure of one of the cement manufacturing facilities. 

CPCC, under the revised proposal would not be subject to full enclosure, 

unless hexavalent chromium monitoring levels are exceeded. Staff believes 

the revised proposal is a good balance. It will achieve the majority of the 

particulate and hexavalent chromium reductions at significantly less cost by 

adding several control techniques to reduce fugitive dust, including 

monitoring and corrective actions. 

 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District C-1 MarchFebruary 2009 

APPENDIX C 

COMPARATIVE ANALYSIS 

Comparison of PAR 1156 and Other Requirements for Cement Manufacturing 

___________________________________________________________________________ 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District C-2 

Appendix C - Comparison Between PR1156 and Other Requirements for Cement Manufact

Note: For comparison purposes, Rule 1156 proposed amendments are reflected in italics format. 

RULE 1156 AQMD RULE 1112.1 NSPS -- 40CFR PART 60 

SUBPART F 

NESHAP -- 40 CFR PART 63 

SUBPART LLL 

COMP

MONIT

APPLICABILITY Equipment/Operation: 

Kiln, clinker cooler, raw mill system, finish mill system, raw mill dryer, raw material storage, clinker storage, conveyor transfer points, bagging, bulk loading and unloading systems; and operations that generate fugitive dusts. 

Equipment/Operation: 

Cement kiln and clinker cooler for dry-process manufacturing of gray cement. 

Equipment/Operation: 

Kiln, clinker cooler, raw mill system, finish mill system, raw mill dryer, raw material storage, clinker storage, conveyor transfer points, bagging and bulk loading and unloading systems • Equipment constructed 

or modified after 7/17/1971. 

Facility is a major source or area source of air toxics; Equipment/Operation: 

Kiln, clinker cooler, raw mill system, finish mill system, raw mill dryer, raw material storage, clinker storage, conveyor transfer points, bagging and bulk loading and unloading systems • Existing equipment or 

equipment constructed or reconstructed after 9/11/1998. 

Equipm• is su

(e.g40 Crule

• uses • 3) h

that the tpy 

COMPLIANCE DATE By December 2006. Facility Emissions

Reduce 2003 baseline emissions by 50% by 2006. Clinker Material Storage

Enclosure or alternatives: 6 months from date of adoption Monitoring Requirements

Wind: 6 months from date 

of adoption. 

Cr+6: 6 months from date 

On and after February 1986. 

On or after completion of the initial performance test. 

• For existing equipment: 

6/14/2002 

• For new or modified 

equipment: Upon startup 

If the Ticompletplan is dfor the Tpart of thsignifica
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District C-3 

RULE 1156 AQMD RULE 1112.1 NSPS -- 40CFR PART 60 

SUBPART F 

NESHAP -- 40 CFR PART 63 

SUBPART LLL 

COMP

MONIT

plan approval or 3/1/10, whichever occurs earlier. 

PM10 (if applicable): 

6 months from date plan or 12 months from date of third confirmed violation, whichever occurs first. 

PERFORMANCE STANDARDS All Equipment

Opacity ≤ 10% Kilns and Clinker Coolers

PM10 ≤ 0.05 lb/ton clinker All Baghouses

Outlet concentration ≤

0.005 grain/dscf ; or 99.5% capture efficiency and 99.5% collecting efficiency Other Equipment

• Opacity ≤ 10% process 

equipment via method 9 

• Opacity < 20% open 

piles & roadways via method 9B 

• Visible emissions not to 

exceed 100 ft. plume in any direction 

Other Requirements

• Enclosed storage piles, 

crushers, screens, mills, conveying systems, and other equipment. 

Kilns and Clinker Coolers 

Combined

• PM ≤ 0.4 lb/ton feed 

when kiln feed rates <75 ton/hr 

• PM ≤ 30 lb/hr when 

kiln feed rates >75 ton/hr 

Kilns

• PM ≤ 0.3 lb/ton feed dry 

basis 

• Opacity ≤ 20% Clinker Coolers

• PM ≤ 0.1 lb/ton feed dry 

basis 

• Opacity ≤ 10% Other Equipment

Opacity ≤ 10% 

Kilns:• PM ≤ 0.3 lb/ton feed dry 

basis 

• Opacity ≤ 20% Clinker Coolers

• PM ≤ 0.3 lb/ton feed dry 

basis 

• Opacity ≤ 10% Other Equipment

Opacity ≤ 10% Other Requirements

THC < 50 ppmvd as propane corrected to 7% oxygen D/F <8.7 x 10-11 grain/dscf 

corrected to 7% oxygen 

Not specstandard
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District C-4 

RULE 1156 AQMD RULE 1112.1 NSPS -- 40CFR PART 60 

SUBPART F 

NESHAP -- 40 CFR PART 63 

SUBPART LLL 

COMP

MONIT

• Pave roads, use 

chemical dust suppressants, limit vehicle speed, street sweeping, and facility cleanup. 

• Enclose clinker 

material storage and handling; alternatively, tarp/wind fence if >1,000 feet from property line.

Monitoring

• Wind gusts >25 mph: 

shutdown of material handling.

• Cr+6 30-day or 90-day 

rolling average, as applicable, shall not exceed 0.7 ng/m3. 

• PM10 monitoring, if 

applicable, shall require dust control activities if 3 NOVs for upwind/downwind concentration exceeding 50 μg/m3.

MONITORING, RECORDKEEPING AND REPORTING REQUIREMENTS • Annual source testing 

for kilns and clinker coolers 

• Source test at least 10 

equipment vented to baghouses which are in the top 20% PM10 

Not specify. • Continuous opacity 

monitoring for kilns and clinker coolers and any bypass 

• Record visible emissions 

at least three 6-minute 

• Initial performance test is 

required to determine compliance with the emission limitation and to establish the operating limits 

• Performance test is required 

A CAM V permi• Des

mon

• Des• Des

for 
FinalDraft Staff Report for Proposed Amended Rule 1156 

South Coast Air Quality Management District C-5 

RULE 1156 AQMD RULE 1112.1 NSPS -- 40CFR PART 60 

SUBPART F 

NESHAP -- 40 CFR PART 63 

SUBPART LLL 

COMP

MONIT

emitters at the facility. 

• Monitor operating 

parameters of baghouses such as flue gas flow rates and pressure drop across filters. 

• Keep all records to 

demonstrate compliance for at least 5 years. 

• Report annual 

emissions for all process equipment, open storage piles and vehicle traffic. 

• Source Test Methods: 

AQMD Method 5.1, 5.2, 5.3 or EPA Method 5 modified; or EPA Method 201A and 202 for PM10. 

• Submit compliance plan 

3-months from date of adoption.

• Keep records relative to 

monitoring and use of exemptions.

• Report monitoring data 

monthly.

periods each day, and records maintained for 2 years. 

• Record daily production 

rates and kiln feed rates 

• Initial performance test 

is required to be conducted. 

• Excess emissions must 

be reported semi –annually. 

• Malfunctions must be 

reported. 

• Semiannual report of 

excess emissions and malfunctions 

• Source Test Methods: 

EPA Method 5 for PM and Method 9 for opacity. 

every 30 months – 5years 

• Source Test Methods: EPA 

Method 5 for PM and Method 9 for opacity. 

• Pro

of thmon

• Pro

nec

• Pro

plan

A Title V 

• Inc

app

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recand 

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