Draft

Technical Background Document

on Control of Fugitive Dust at Cement

Manufacturing Facilities

March 20, 1998
Draft: March 20, 1998 ii

Table of Contents

Chapter 1: Introduction ................................................. . 1-1

1.1 Background and Approach ...................................... . 1-1

1.2 Summary of Proposed Standards ................................. . 1-1

1.3 Organization of this Document ................................... . 1-2

Chapter 2: Reasons for Agency Concern .................................... . 2-1

2.1 Waste Characteristics .......................................... . 2-1

2.1.1 Physical Characteristics ................................... . 2-2

2.1.2 Chemical Characteristics .................................. . 2-2

2.2 Plant Settings ................................................ . 2-3

2.2.1 Physical Setting ......................................... . 2-3

2.2.2 Climatological Factors ................................... . 2-4

2.3 Management Practices ......................................... . 2-4

2.3.1 Recycling ............................................. . 2-8

2.3.2 Temporary Storage, Transport, and Disposal ................. , 2-9

2.3.3 Beneficial Use ......................................... . 2-10

2.4 Documented Air Damages ..................................... . 2-11

2.4.1 Holnam, Inc., Ada, Oklahoma ............................. . 2-11

2.4.2 Keystone Portland Cement, Bath, Pennsylvania ................ . 2-11

2.4.3 Lone Star Industries, Pryor, Oklahoma ...................... . 2-11

2.5 On-site Observations ......................................... . 2-11

2.5.1 Public Concerns (Comments on the Report to Congress) ......... . 2-11

2.5.2 EPA Site Visits ........................................ . 2-12

2.6 Population Effects from Exposure to Airborne CKD .................. . 2-15

Chapter 3: Identification and Evaluation of Options for Technical Design Standard .... . 3-1

3.1 Emissions Estimation .......................................... . 3-1

3.1.1 Description of CKD Handling Processes at the Sample Facilities .... . 3-1

3.1.3 Uncontrolled Emissions Estimates ........................... . 3-9

3.2 Fugitive Dust Control Techniques for Temporary Storage, Transport, and Disposal

.......................................................... . 3-9

3.2.1 Description of Dust Generation and Handling .................. . 3-9

3.2.3 Management of Transport of CKD from Plant to Landfill ........ . 3-11

3.2.4 Management of CKDLF Units ............................ . 3-12

3.3 Control Efficiencies for Fugitive Dust Control Technologies ............ . 3-14

3.3.1 Pelletization .......................................... . 3-15
Draft: March 20, 1998 iii

3.3.2 Water Addition for Storage Piles/Landfills ................... . 3-16

3.3.3 Water Addition for Roadways ............................. . 3-17

3.3.4 Soil (Loam) Cover for Storage Piles ........................ . 3-18

3.3.5 Latex Binder Addition for Storage Piles ..................... . 3-19

3.3.6 Enclose Temporary Storage Pile ........................... . 3-20

3.3.7 Cover Truck/Clean Truck and Cover ....................... . 3-20

3.3.8 Rolling of Conditioned CKD .............................. . 3-20

3.3.9 Wet Compaction ....................................... . 3-22

Chapter 4: Proposed Standards ........................................... . 4-1

4.1 Performance Standard ......................................... . 4-1

4.2 Technical Standards That Meet the Performance Standard .............. . 4-2

4.2.1 Conditioning ........................................... . 4-2

4.2.2 Covers ............................................... . 4-3

4.2.3 Wetting ............................................... . 4-3

4.2.4 Temporary Storage ...................................... . 4-3

4.3 Application of the Technology-Based Standard to Model Plants .......... . 4-3

Chapter 5: Implementation ............................................... . 5-1

5.1 Implementation of Fugitive Dust Control Technologies ................. . 5-1

5.1.1 Control of Fugitive Dust Emissions from Tanks, Containers, or Buildings

..................................................... . 5-1

5.1.2 Control of Fugitive Dust Emissions from Transport of CKD Via Trucks

..................................................... . 5-1

5.1.3 Control of Fugitive Dust Emissions at CKDLF Units ............. . 5-2

5.2 Reporting and Recordkeeping .................................... . 5-3
Draft: March 20, 1998 1-1

Chapter 1: Introduction

1.1 Background and Approach

In its Regulatory Determination on cement kiln dust (CKD) published in 1995 (60 FR 7366), EPA

concluded that additional control of CKD is warranted in order to protect the public from human

health risks and to prevent environmental damage resulting from current methods of managing

and disposing the waste. Among the environmental concerns posed by the waste and these

management and disposal methods, the Agency identified potential risks to human health from

inhalation of particulate material (pm). In response, EPA conducted a number of analyses to

identify and evaluate options for the control of fugitive emissions from the management and

disposal of the CKD waste. These analyses included researching and evaluating several

technologies for controlling fugitive dust emissions and analyzing the possible reductions in

fugitive dust emissions that might be achieved through implementing the technologies.

The objective of these analyses was to develop tailored technical standards that not only are

protective of human health and the environment but also are sufficiently flexible to allow facility

owners and operators to tailor their management approach to site specific conditions. To develop

the proposed standards, EPA evaluated the results of risk modeling and damages resulting from

documented cases of releases of toxic constituents, and conducted an emissions reduction analysis

to evaluate the effectiveness of a suite of fugitive dust control technologies. Based on the results

of these analyses, EPA developed and is proposing a performance standard, technology-based

standards, and backup tailored Subtitle C standards to minimize the impact of CKD management

and disposal practices on ambient air quality at, and surrounding, cement manufacturing facilities.

1.2 Summary of Proposed Standards

EPA is proposing a performance of standard that requires covering or otherwise managing CKD

to control fugitive dust. The proposed standards will apply to new and existing cement kiln dust

landfills, except units closed prior to the effective date of the rule. To meet the standard, the

owner/operator would cover or otherwise manage CKD in a manner to control wind dispersal.

To meet the performance standard, EPA also is proposing technology-based design standards for

three key points in the CKD management and disposal handling train. These points are: (1) the

point of temporary storage of CKD at the facility after it is removed from a dust collection device

prior to sale or final disposal; (2) trucks that transport of the CKD to the disposal site; and (3)

disposal of the CKD in an on-site landfill or monofill. EPA is proposing the following

technnology standards for these emission points:

1. Temporary storage at the facility: enclosure (e.g., in a tank, building, or container);

2. Transport of CKD from the plant to the landfill or monofill: covered trucks; and
Draft: March 20, 1998 1-2

3. Landfill disposal: conditioned CKD covered by a barrier that prevents erosion.

1.3 Organization of this Document

This Technical Background Document (TBD) summarizes the basis for EPA’s proposed

performance standards and technology-based standards for controlling fugitive emissions of CKD. 

Chapter 2 provides an overview of the reasons for the Agency’s concern regarding fugitive dust,

including the physical and chemical characteristics of CKD; the physical/climatological settings at

cement facilities; and current CKD management practices. This chapter also discusses EPA’s

reasons for developing fugitive dust control standards, including descriptions of documented air

damages, estimates of population effects from exposure to airborne CKD, and on-site

observations. Chapter 3 describes the technology options for controlling CKD air emissions that

EPA examined and the estimated effectiveness of each option. Chapter 4 identifies the proposed

standards for controlling fugitive dust. Chapter 5 discusses issues related to implementation of

the proposed standards and provides estimates of emissions following application of the proposed

technology-based standards at two example facilities.
Draft: March 20, 1998 2-1

Chapter 2: Reasons for Agency Concern

In the Report to Congress on Cement Kiln Dust (EPA 1993) and the subsequent Notice of Data

Availability (NODA) (EPA 1994) and Regulatory Determination (60 FR 7366), EPA presented

data showing that CKD contains certain Appendix VIII metals (40 CFR Part 261 “Hazardous

Constituents”) and low concentrations of dioxin and dibenzofuran. In the Report to Congress,

EPA documented evidence of damage to ground water, surface water, and air and identified

potential risks to human to human health and the environment from on-site management of CKD. 

The results of the direct inhalation exposure modeling conducted for the Report to Congress,

which modeled the intake of toxic metals, dioxins, and radionuclides, predicted only low or

negligible risk potential from on-site management of CKD via direct inhalation of air containing

particulate CKD. However, additional analyses reported in the NODA showed found evidence of

possible risk to human health due to the fine particulate nature of inhaled dust. Furthermore, in a

follow-up study conducted in 1997 of the population effects due to exposure to airborne

particulate matter released from CKD management activities, EPA estimated that up to 2,400

individuals living within 500 meters (m) of the facility boundary of 108 cement facilities may be

exposed to airborne particulate matter concentrations in excess of the National Ambient Air

Quality Standards for particulate matter (USEPA, 1997).

This chapter provides an overview of the reasons for the Agency’s concern regarding fugitive

dust, including the physical and chemical characteristics of CKD; the physical/climatological

settings at cement facilities; and current CKD management practices. This chapter also discusses

EPA’s reasons for developing fugitive dust control standards, including descriptions of

documented air damages and on-site observations. Estimates of population effects from exposure

to airborne CKD are provided in the Technical Background Document: Population Risks from

Indirect Exposure Pathways, and Population Effects from Exposure to Airborne Particles from

Cement Kiln Dust Waste in the docket for this rule (USEPA, 1997).

2.1 Waste Characteristics

Cement plants produce a considerable quantity of particulate matter as a result of the continuous

feeding of raw materials into the cool end of the cement kiln, processing, and the rapid

countercurrent flow of combustion gases over the raw feed. Particles that become entrained in

combustion gases and are removed from the kiln by exhaust gases are known as CKD. This

material is comprised of unchanged raw materials, dehydrated clay, decarbonated (calcined)

limestone, ash from fuel, and newly formed minerals produced by the chemical transformation of

raw materials during the cement manufacturing process. The physical and chemical properties

and toxicity of CKD are described below.
Draft: March 20, 1998 2-2

2.1.1 Physical Characteristics

Fresh CKD is a fine, dry alkaline dust that readily absorbs water. CKD particle sizes generally

vary by kiln process type (see Exhibit 2-1) and range from 0-5 micrometers (Fm) (approximately

clay size) to greater than 50 Fm (silt size) (EPA 1993). 

Exhibit 2-1

Particle Size Distribution of CKD by Process Type

Particle Size Unspecified Wet Kilns Long Dry Dry Kilns with

(Fm) Process Type (weight Kilns (weight Precalciner a

(weight percent) percent) (weight

percent) percent)

b

b b

0-5 5 26 45 6

5-10 10 19 45 11

10-20 30 20 5 15

20-30 17 9 1 23

30-40 13 8 1 18

40-50 7 1 0 9

>50 18 17 3 18

Median No Data 9.3 3.0 22.2

Particle Size

Kohlhaas, B., et al., 1983. Cement Engineer’s Handbook. Bauverlag GMBH, Wiesbaden and Berlin. p. 635. a

The number of samples used to develop data was not specified.

Todres, H., A. Mishulocich, and J. Ahmed, 1992. CKD Management: Permeability. Research and b

Development Bulletin RD103T, Portland Cement Association, Skokie, Illinois, p. 2.

2.1.2 Chemical Characteristics

The primary bulk constituents in CKD (those found in quantities greater than 0.05 percent by

weight) are silicates, calcium oxide, carbonates, potassium oxide, sulfates, chlorides, various

metal oxides, and sodium oxide. EPA data also suggest that variability in raw feed, fuels, process

types and product specifications may influence CKD chemical characteristics (EPA 1993). 

CKD contains certain metals listed in 40 CFR 261 Appendix VIII (“Hazardous Constituents”). 

Exhibit 2-2 presents the range of total concentration levels for a number of metals identified in

CKD. 
Draft: March 20, 1998 2-3

Volatile and semi-volatile organic compounds are generally not found in CKD. However,

generally low concentrations of 2,3,7,8-substituted dioxin (0.5 to 20 parts per trillion [ppt]), and

2,3,7,8-substituted dibenzofuran (non-detected to 470 ppt) have been detected (60 FR 7366).

Exhibit 2-2

Trace Metal Concentrations in CKD [mg/kg (parts per million), total basis] a

Analyte No. of Samples Mean Minimum Maximum

Antimony 52 11.5 0.99 102

Arsenic 60 14.1 0.26 80.7

Barium 59 181 0.43 900

Beryllium 53 1.03 0.1 6.2

Cadmium 61 9.7 0.005 44.9

Chromium 61 31.2 3.9 105

Lead 63 287 3.1 2620 b

Mercury 57 0.33 0.003 2.9

Nickel 45 19.9 3 66

Selenium 52 12.2 0.1 103

Silver 56 5.9 0.25 40.7

Thallium 57 33.5 0.44 450

(From 60 FR 7366)

 Metals data sources include 1992 PCA, EPA sampling data, and public comments on the RTC. a

 The median value for lead is 113 mg/kg. b

2.2 Plant Settings

This section describes the physical settings in which CKD is managed and the climatological

factors that influence the emission of fugitive dust.

2.2.1 Physical Setting

As described in greater detail in Section 2.3.2 of this document, CKD is typically disposed in

large, unlined piles in a retired portion of the limestone quarry co-located with the cement plant. 

These quarries can be as large as a square mile in area and typically have little or no wind barriers
These data are contained in the risk factors data base provided in Attachment 1-1 of the Technical 1

Background Document for the Notice of Data Availability on Cement Kiln Dust, Human Health and Environmental

Risk Assessment, in Support of the Regulatory Determination on Cement Kiln Dust,August, 1994.

Draft: March 20, 1998 2-4

at their edges. Consequently, CKD managed within a quarry may be exposed to prevailing winds,

increasing the potential for fugitive emissions.

2.2.2 Climatological Factors

The climatological factors that most readily influence fugitive dust emissions are wind speed and

rainfall. In general, the potential for fugitive emissions is expected to be greater in locations that

are subject to frequent gusts of wind or sustained winds. Fugitive emissions are less likely to

occur during precipitation events, primarily due to the tendency of CKD to readily absorb water

and form an externally weathered crust, due to absorption of moisture and subsequent

cementation of dust particles on the surface of the pile. Precipitation also serves to remove

suspended particles from the air.

As a means of characterizing the potential for fugitive emissions at cement plants, EPA reviewed

annual mean wind speed and annual average precipitation data that were compiled for the

Agency’s human health and environmental risk assessment prepared in support of the regulatory

determination on CKD (EPA 1994). EPA compiled climatic and meteorologic data for the 61

cement plants that were known in 1990 to generate net CKD (i.e., CKD that is either disposed or

used beneficially off-site), the study year for the Portland Cement Association’s (PCA) first

survey of the industry (PCA 1992).1

Annual mean wind speed and annual average precipitation for each of the 61 cement plants are

provided in Exhibit 2-3. The exhibit also includes selected descriptive statistics for both

parameters, including the mean, median, mode, standard deviation, minimum, and maximum

values. The exhibit shows that the median annual mean wind speed for the 58 facilities for which

data were available is about 4 m/s (9 miles per hour (mph)); annual mean wind speeds range from

2.6 to 5.8 m/s (5.9 to 13 mph). The median annual average precipitation for the 57 facilities for

which data were available is 88.3 centimeters per year (cm/yr) (34.8 inches per year (in/yr));

annual average precipitation for these facilities ranges from 12.5 to 157 cm/yr (4.9 to 61.9 in/yr).

2.3 Management Practices

This section describes CKD waste management practices currently used by the cement industry. 

Usually 98 to 100 percent of all particulate matter generated during cement production is

captured by air pollution control devices before exiting the kiln system (EPA 1993). This gross

CKD may be recycled, treated and reused, taken off-site for beneficial use, or disposed of in

waste management units (WMUs) (Figure 2-1).
Draft: March 20, 1998 2-5

Exhibit 2-3

Annual Mean Wind Speed and Annual Average Precipitation for 61 Cement Plants

Company Name City ST Annual Mean Annual Average

Wind Speed Precipitation

(m/s) (mi/hr) (cm/yr) (in/yr)

Ash Grove Cement Co. - Chanute Chanute KS 4.31 9.65 87.8 34.6

Ash Grove Cement Co. - Foreman Foreman AR 3.53 7.91 125.5 49.4

Ash Grove Cement Co. - Inkom Inkom ID 4.51 10.1 29 11.4

Ash Grove Cement Co. - Louisville Louisville NE 3.67 8.22 73.8 29.1

Ash Grove Cement Co. - Montana City Montana City MT 3.69 8.27 33.1 13

Blue Circle Inc. - Ravena Ravena NY 4.19 9.39 88.3 34.8

Calif. Portland Cement - Mojave Mojave CA 3.89 8.71 12.5 4.9

Capitol Aggregates, Inc. San Antonio TX 3.71 8.31 74.5 29.3

Continental Cement Co., Inc. Hannibal MO 4.67 10.46 80.8 31.8

Dacotah Cement Rapid City SD 5.18 11.6 47.9 18.9

Essroc Materials - Bessemer Bessemer PA 4.22 9.45 89 35

Essroc Materials - Logansport Logansport IN 4.3 9.63 101 39.8

Essroc Materials - Speed Speed IN 3.82 8.56 107.8 42.4

Giant Cement Company Harleyville SC 3.83 8.58 115 45.3

Heartland Cement Company Independence KS 4.31 9.65 87.8 34.6

Holnam Inc. - Ada Ada OK 4.49 10.06 88.4 34.8

Holnam Inc. - Artesia Artesia MS 2.63 5.89 136.2 53.6

Holnam Inc. - Clarksville Clarksville MO 4.67 10.46 80.8 31.8

Holnam Inc. - Devil's Slide Plant Morgan UT 3.66 8.2 34.9 13.7

Holnam Inc. - Dundee Dundee MI 4.8 10.75 74.8 29.4

Holnam Inc. - Fort Collins Laporte CO 5.81 13.01 74.9 29.5

Holnam Inc. - Holly Hill Holly Hill SC 3.83 8.58 115 45.3

Holnam Inc. - Midlothian Midlothian TX NA NA NA NA

Holnam Inc. - Portland Plant Florence CO 4.15 9.3 31 12.2

Holnam Inc. - Seattle Seattle WA 3.31 7.41 90.9 35.8

Holnam Inc. - Tijeras Tijeras NM 4 8.96 NA NA

Independent Cement Corp. - Catskill Catskill NY 3.15 7.06 92.3 36.3

Independent Cement Corp. - Hagerstown Hagerstown MD 3.4 7.62 86.5 34.1

Kaiser Cement Corp. Permanente CA NA NA NA NA

Keystone Cement Company Bath PA NA NA NA NA

Kosmos Cement Co. - Pittsburgh Pittsburgh PA 3.98 8.92 91.8 36.1

Lafarge Corporation - Alpena Alpena MI 4.01 8.98 73.4 28.9

Lafarge Corporation - Balcones New Braunfels TX 3.71 8.31 71.6 28.2

Lafarge Corporation - Davenport Buffalo IA 4.52 10.12 86.1 33.9

Lafarge Corporation - Fredonia Fredonia KS 4.31 9.65 87.8 34.6

Lafarge Corporation - Joppa Grand Chain IL 3.63 8.13 157.2 61.9

Lafarge Corporation - Paulding Paulding OH 4.23 9.48 79.4 31.3

Lafarge Corporation - Sugar Creek Sugar Creek MO 4.54 10.17 90.7 35.7
Company Name City ST Annual Mean Annual Average

Wind Speed Precipitation

(m/s) (mi/hr) (cm/yr) (in/yr)

Draft: March 20, 1998 2-6

Lehigh Portland Cement Co. - Cementon Cementon NY 3.15 7.06 92.3 36.3

Lehigh Portland Cement Co. - Mason City Mason City IA 5.12 11.47 74.4 29.3

Lehigh Portland Cement Co. - Mitchell Mitchell IN 3.82 8.56 107.8 42.4

Lehigh Portland Cement Co. - Union Bridge Union Bridge MD 4.02 9 99 39

Lone Star Industries - Cape Girardeau Cape Girardeau MO 3.65 8.18 109 42.9

Lone Star Industries - Greencastle Greencastle IN 4.3 9.63 101 39.8

Lone Star Industries - Nazareth Nazareth PA 4.03 9.03 97.8 38.5

Lone Star Industries - Oglesby Oglesby IL 4.29 9.61 87.6 34.5

Medusa Cement Company - Charlevoix Charlevoix MI 3.88 8.69 75.8 29.8

Medusa Cement Company - Demopolis Demopolis AL 2.95 6.61 126.3 49.7

Medusa Cement Company - Wampum Wampum PA 3.98 8.92 89 35

National Cement Co. of California - Lebec Lebec CA 3.09 6.92 47.5 18.7

Rinker Portland Cement Corp. Miami FL 4.58 10.26 139.1 54.8

River Cement Company Festus MO 3.65 8.18 109 42.9

Roanoke Cement Company Cloverdale VA 3.35 7.5 101.7 40

Signal Mountain Cement Company Chattanooga TN 2.84 6.36 135.8 53.5

Southdown - Fairborn Fairborn OH 4 8.96 93.9 37

Southdown - Knoxville Knoxville TN 2.84 6.36 135.8 53.5

Southdown - Lyons Lyons CO 4.15 9.3 31 12.2

Southdown - Odessa Odessa TX 4.86 10.89 35.4 13.9

Southdown - Victorville Victorville CA 3.68 8.24 38.7 15.2

Tarmac Florida (Fl. Cement Plant) Medley FL 4.58 10.26 139.1 54.8

Texas Industries - Midlothian Midlothian TX 3.71 8.31 71.6 28.2

Mean 3.99 8.93 86.6 34.1

Median 3.99 8.94 88.3 34.8

Mode 4.31 9.65 87.8 34.6

Standard Deviation 0.61 1.37 31.5 12.4

Minimum 2.63 5.89 12.5 4.9

Maximum 5.81 13.01 157.2 61.9

Count 58 58 57 57

In 1995, the cement industry consisted of 110 plants operated by 46 companies (PCA 1996),

slightly differing from the 111 plants operated by 46 companies in 1992 (EPA 1995). The five

largest clinker producing states are California, Texas, Pennsylvania, Michigan, and Missouri.
GROSS CKD

(Collected at Air Pollution Control

Devices)

RECYCLED CKD

(Returned to Kiln)

NET CKD

(Removed from Kiln)

TREATED AND

RETURNED TO

KILN

SOLD OR GIVEN

FOR BENEFICIAL

USE

DISPOSED IN

WMU

Figure 2-1. Flow Chart of Gross CKD Management Practices.

(Adapted from EPA, 1993a)

Draft: March 20, 1998 2-7

Large amounts of high Btu fuels, primarily coal and other fossil fuels, are used during the cement

manufacturing process to maintain adequate temperatures within kilns. Currently, 18 cement

plants use a mixture of fuels that including RCRA hazardous wastes (EPA 1998).

The Portland Cement Association estimated that 11.7 million metric tons of gross CKD (that is,

CKD that is collected by air-pollution control devices) were generated in 1995 (1995 PCA CKD

Survey) . This is a decrease from the 12.7 million metric tons of gross CKD generated in 1990. 

Wide variations exist between kilns in the amount of net CKD that is generated (i.e., CKD that is
Draft: March 20, 1998 2-8

either disposed or used beneficially off-site). Several cement plants are able to recycle all of their

gross CKD back into the kiln (i.e., no net CKD produced). In 1995, the industry recycled 7.8

million metric tons of all CKD generated. EPA reported in the RTC that there is a correlation

between plants that burn hazardous waste and the volume of dust that is actually disposed. Kilns

that burn hazardous waste remove from the kiln system an average of 75 to 104 percent more

dust per ton of clinker than kilns that do not burn hazardous waste (60 FR 7366).

2.3.1 Recycling

Most facility operators recycle CKD to some degree. Based on data from a 1995 PCA survey

(representing usable data from 106 facilities), 71 facilities (67 percent) recycled some of their

gross CKD, and 24 facilities were able to recycle all of their gross CKD (PCA 1997). In 1995,

two-thirds of the gross CKD that was generated by the cement industry - 7.8 million metric tons -

were recycled directly back into the kiln or raw feed system. If a cement plant achieves 100

percent recycling, alternative CKD management practices, such as disposal, are deemed

unnecessary. However, direct recycling generally results in a gradual increase in the alkali and

metals content of generated dust that may damage cement kiln linings, produce inferior cement,

and increase particle emissions from the kiln stack. Depending on the quality of the raw materials

used, increased concentrations of chloride and sulfur in cement may produce structurally-defective

concrete. Some CKD removal from the kiln system as waste is therefore usually necessary (EPA

1993).

Several cost-effective treatment technologies are available or are being developed to treat CKD

with high concentrations of alkalies and/or other undesirable constituents before re-entry to the

kiln system. At some cement plants, dust reuse is preceded by pelletizing (several plants), mixing

with water to leach out alkali salts (used at two plants), or processing through a recovery

scrubber (the flue gas desulfurization process) to remove soluble alkalies, chlorides, and sulfates

(used at one plant). Pelletizing gives CKD the strength to withstand firing upon re-entry into the

kiln system without resuspending large quantities of particulate matter or changing the chemical

characteristics of clinker. The leaching process increases the amount of recyclable CKD but

generates wastewater that must be treated for high pH values and high concentrations of

dissolved and suspended solids. However, no wastewater discharge is associated with this

procedure. At one facility, a modified version of this leaching and return process reportedly

results in 100 percent recycling of CKD (EPA 1993).

In addition, the Agency has received some evidence, in comments from cement companies on the

Report to Congress, that raw material substitution may be a highly effective means of increasing

CKD recycling rates. This may be done by controlling the input of contaminants (in raw materials

and fuels) to the kiln system, thereby reducing or eliminating the need to purge the kiln system of

contaminants (60 FR 7366, February 7, 1995; document no. CKDP-0002 in the RCRA docket F98-CKDP-FFFFF).
Loading Transport

(Road/Trucks)

Unloading Interim

Storage Pile

Move into

Monofill/Final

Placement

Monofill

Interim Maintenance

Storage

Draft: March 20, 1998 2-9

Figure 2-2: Typical CKD transport and disposal sequence. Arrows show common points of

fugitive emission of dust.

2.3.2 Temporary Storage, Transport, and Disposal

CKD that is removed from the kiln and not intended to be sold for beneficial use or treated and

returned to the kiln is typically disposed on-site. This section focuses on the temporary storage of

wasted CKD after it is collected from the air pollution control device and its subsequent transport

to the final point of disposal.

CKD is usually removed from air pollution control devices (APCs) and transported to a

temporary location near the device by some means of mechanical conveyance, such as a conveyer

belt, screw conveyor, or pneumatic conveyor. After being removed from these APCs, CKD is

usually held in silos or short-term piles on the ground near the point of removal before it is

conveyed to the disposal area. (See Figure 2-2.) This temporary delay in the management and

disposal train, referred to in this document as “interim storage at the facility,” varies from hours to

days depending on the operating level of the facility. Facilities that convey CKD to the disposal

areas in trucks (which include the majority of the industry) attempt to maximize the volume of the

load carried on each trip, resulting in the need to stockpile dust at the facility in periods of

decreased production. Some facilities, in lieu of truck transport, transport CKD to the disposal

area via pneumatic conveyors.

Transport of CKD from the plant to the landfill area may begin immediately after dust is removed

from the APC, or it may start at the interim storage area. Transport may proceed from either of

these two locations directly to the landfill, or it may end at a temporary storage area near the

landfill. As with the need to temporarily store dust after removing it from APCs, the timing of

these procedures depends upon the operating level of the facility.

In most cement manufacturing facilities, at least a part, if not all, of the route traveled by CKD

haul trucks is unpaved. The length of this route varies among facilities, typically ranging from less

than a mile to three miles, round trip. To reduce dust emissions from the haul road’s surface,

many (but not all) facilities employ some means and frequency of road wetting to suppress dust. 
Draft: March 20, 1998 2-10

Similarly, some facilities cover their haul trucks to reduce CKD emissions from the truck beds

during the trip to the disposal area.

At the disposal area, CKD is commonly dumped in a series of temporary storage piles at the edge

of the final disposal area. Temporary storage near the landfill is necessary when operating levels

are such that a bulldozer cannot be operated full-time at the disposal area. This temporary delay

in disposal is referred to in this document as “temporary storage near the landfill” and, as with

interim storage at the facility, varies from hours to days depending on the operating level of the

facility. For final disposal of the dust, the most common management practice is bulldozing the

temporary storage piles into an unlined, retired portion of the limestone quarry associated with the

cement plant. CKD is also often dumped in large unlined piles at other on-site locations. CKD

fugitive emissions are typically generated by wind erosion and dispersal of these open or exposed

piles.

According to the 1991 PCA survey (representing usable data from 79 plants and 145 kilns), in

1990, land-disposed CKD averaged 33,000 metric tons per plant, and land-disposed CKD from

the entire cement manufacturing industry was estimated to be 3.3 million metric tons (PCA 1991). 

Typically, WMUs are on-site, non-engineered, unlined and uncovered landfills and piles located in

abandoned quarries, retired portions of operating quarries, or nearby ravines. Some active piles

are also managed underwater or adjacent to surface water and/or agricultural lands (60 FR 7366). 

From the 1991 PCA survey (EPA 1993), in 1990, 52 percent of active WMUs were landfills, 43

percent were piles, and less than one percent were ponds. The average pile was 15 meters (15 m)

(49.2 ft) thick or 1 m (3.3 ft) thicker than the average landfill. Maximum reported thicknesses for

landfills and waste piles were 56.4 m (185 ft) and 34.6 m (113.5 ft) respectively. However, the

average basal area for landfills (7.9 hectares (19.5 acres)) was approximately twice that of piles

(3.6 hectares (8.9 acres)). Landfills may therefore cover significantly larger land areas than piles. 

In contrast, the average basal area of ponds was less than one hectare.

Non-CKD waste materials such as furnace brick, concrete debris, and tires may be co-disposed

with CKD in WMUs. Responses to the 1991 PCA survey reveal that in 1990 of 66 WMUs, 23

percent co-disposed non-CKD material amounting to one percent of the material disposed in these

units.

Approximately half of the facilities use some form of dust suppression/control such as wetting,

compacting, or covering the CKD pile or landfill. About 30 to 40 percent of the facilities

compact CKD in their active CKDLFs (EPA 1993).

2.3.3 Beneficial Use

CKD may be sold or given away for off-site applications. Beneficial uses of waste CKD include

the stabilization of municipal sewage sludges, waste oil sludges, and contaminated soils; the

neutralization of acid mine drainage; the addition to agricultural lands as a fertilizer and/or liming

agent, and inclusion in Portland cement as a materials additive. In 1995, about six percent of the
Draft: March 20, 1998 2-11

CKD generated (658,000 metric tons) was use off-site in beneficial applications (PCA, 1997). 

Mostly, CKD was used as waste stabilizer, liming agent, and materials additive.

2.4 Documented Air Damages

In the Report to Congress on Cement Kiln Dust several cases referencing emissions of cement

kiln dust (CKD) were noted. Three cases involving violations of air quality regulations regarding

fugitive emissions are included here. (It is important to note that these violations are not

examples of stack emissions but of fugitive dust violations.)

2.4.1 Holnam, Inc., Ada, Oklahoma

The Oklahoma State Department of Health issued a Notice of Violation on July 23, 1991 to

Holnam, Inc of Ada, Oklahoma for excessive particulate emissions from kiln dust storage area

blowing off of the plant’s property.

2.4.2 Keystone Portland Cement, Bath, Pennsylvania

Between May 22, 1979 and February 1, 1980 the Pennsylvania Department of Environmental

Resources notified Keystone Portland Cement of Bath, Pennsylvania of various dust emissions

violations, including fugitive particulate emissions caused by area air contamination sources. A

Notice of Violation (NOV) and Consent Order was issued August 27, 1980.

2.4.3 Lone Star Industries, Pryor, Oklahoma

Lone Star Industries of Pryor, OK was issued a Notice of Violation on October 3, 1990. The

Oklahoma State Department of Health found a sizable accumulation of baghouse waste dust on

the property outside of the building. This accumulation of dust was in violation of the Oklahoma

air pollution control regulation governing fugitive dust.

2.5 On-site Observations

In addition to documented cases of violations of air quality regulations for fugitive dust emissions,

EPA also has received reports (in some cases including photographs) of and observed examples of

particulate emissions of CKD from quarries, haul roads, and dust handling equipment. These

observations are summarized below.

2.5.1 Public Concerns (Comments on the Report to Congress)

In response to its Report to Congress on Cement Kiln Dust, EPA received a number of comments

from citizen groups and individuals regarding fugitive CKD emissions in areas adjacent to cement

plants (EPA 1994). For example, a citizens’ group in Texas commented that residents of

Midlothian have observed, measured, and documented clouds of fugitive dust emissions,
Draft: March 20, 1998 2-12

containing CKD, coming from pits at several area cement plants adjacent to residential and

agricultural areas. A second Texas group cited a letter from the American Lung Association that

states that “[t]here have been extensive problems at Lafarge [in New Braunfels and now owned

by Texas Industries] of fugitive emissions from the handling, conveyance and disposal of CKD

leading to community air pollution problems and enforcement actions.” Some commenters

expressed concern over inadequate dust control measures; one stated that fallout from quarrydumps containing CKD can be significant for adjacent landowners in the absence of buffers

between the dumps and residential, agricultural, and recreational land use areas. Another

commenter suggested that all dust piles must be kept covered to prevent fugitive emissions, and

one commenter expressed concern about those who handle CKD during the application to

agricultural fields.

2.5.2 EPA Site Visits

Since beginning its study of the cement industry and CKD in 1991, EPA has visited more than 25

cement plants across the country. During several of these visits, the Agency has observed

examples of fugitive dust emissions at disposal sites, along roads from trucks used to transport

dust from the kiln to the final point of disposal, and outside of air pollution control devices

(baghouses, electrostatic precipitators).

2.5.2.1 1992 and 1993 CKD Sampling and Analysis Program

EPA conducted a CKD and cement clinker sampling and analysis program in 1992 and 1993 as

part of its data collection efforts for the Report to Congress. Over the two-year period, EPA

visited 20 cement plants. In addition to clinker, EPA sampled CKD at the point of generation

(“as generated” samples) as well as at the point of on-site disposal (“as managed” samples). In

several cases, the Agency observed emissions of fugitive dust from CKD waste piles while

collecting the “as managed” samples. These observations are documented in trip reports (EPA,

1992) that are available in the RCRA docket on the Report to Congress (Docket No. F-94-

RCKA-FFFFF) and are summarized below.

• Essroc Materials, Speed, IN, March 16, 1992: EPA observed fugitive dust being

swept from CKD piles during sampling; wind speed was estimated to be

approximately 10 miles per hour (mph).

• Holnam, Inc., Clarksville, MO, April, 2, 1992: EPA observed large amounts of

fugitive dust at the CKD disposal area during sampling. The Agency determined

that the source of the dust was primarily the sifting operations near the pug mill

and not emissions from the waste pile itself.

• Ash Grove Cement, Chanute, KS, April 3, 1992: Before beginning sampling at the

facility’s CKD monofill, EPA observed considerable fugitive dust emissions from a

truck depositing CKD on the monofill. Facility representatives attributed the
Draft: March 20, 1998 2-13

emissions to the loss of water pressure in the truck’s dustless unloader. During

sampling, fugitive dust from the sampled piles often obscured visibility; the

sampling team estimated wind speeds at more than 20 mph.

• Independent Cement, Catskill, NY, April 6, 1992: EPA observed that some CKD

would blow away when the surface of the CKD disposal pile was broken in order

to collect unweathered dust samples.

• Dixie Cement, Knoxville, TN, April 9, 1992: EPA observed frequent dust

emissions from the tops of piles in the CKD disposal area during sampling.

• Texas Industries, Midlothian, TX, April 10, 1992: While preparing equipment rinse

blanks in the back of the sampling truck, EPA observed some fugitive dust in

ambient air outside the truck. Wind speed was estimated to range between 10 and

20 mph.

2.5.2.2 Lafarge Corporation, Alpena, Michigan Site Video

Lafarge’s Alpena, Michigan plant is the nation’s largest cement manufacturing facility. Its five

kilns have combined annual and daily clinker capacities of 1.92 million metric tons and 5,922

metric tons, respectively, as reported in 1994 (PCA 1995). EPA visited the plant in May, 1996 to

update and augment its knowledge of CKD management practices. In addition, a local citizens’

group provided the Agency with several video tapes of fugitive dust emissions from the site.

EPA visited the Lafarge facility to examine CKD disposal areas and practices at the plant. In

addition, EPA sought to learn about facility operations, CKD generation and management

practices, design of future CKD disposal areas, environmental monitoring practices (and, as

available, results), and compliance with relevant federal and state laws (e.g., permit conditions). 

As part of the May 1996 site visit, EPA recorded CKD management practices on video tape. 

The following observations were made based on the video-taped (Tape #1) management practices

as part of the May 96 site visit:

Loading: Tape # 1 shows wet pelletized CKD being loaded into a dump truck. It

is evident that steam is being generated from the CKD in the truck. This is

possibly a result of hydration reactions within the CKD or as a result of potentially

elevated temperatures of the pelletized CKD compared to air temperatures. 

Although this material appears to be all steam, these are less than ideal conditions

for observations because the steam could hide some fine particle emissions.

Transport: Tape # 1 shows the same conditions occur during transport, although

the emissions appear to be steam, some particulate emissions could be occurring. 

Some dust is evident from the truck tires as the trucks transport the pile to the

disposal area.
Draft: March 20, 1998 2-14

The following observations are based on independent video footage, which consisted of three

tapes (#'s 6, 11 and 12):

Loading: Tapes 6, 11 and 12 show a conveyor that carries the CKD directly to

the disposal storage area. Here the release of CKD high above the ground leads to

a lot of dispersion of the dust. At times, when the wind conditions are just right,

the dispersion is so widespread that the entire conveyor system disappears from

sight.

Transport: Tape #'s 6, 11 and 12 show the plumes of dust from both the

uncovered truck-bed as well as the truck tires, as the trucks transport the pile to

the disposal area. However, it is also observed that when the transport route was

wetted sufficiently by a sprinkler, such fugitive emissions reduced dramatically

from the tires and no emissions are evident when haul roads are sufficiently wetted.

Wet CKD also reduced emissions from the truck-bed. This can be seen from both

tapes 6 and 12.

Unloading: Just like the loading process, unloading releases tremendous amounts

of dust into the atmosphere, especially under the right wind conditions. This is

further aided by the high rate of dumping from the truck-beds themselves. Massive

vertical dust clouds rising approximately 100 feet in the air result from the rapid

dumping of CKD. In the disposal quarry shown in tapes 6, 11 and 12, dumping is

carried out from the top of a huge CKD pile (formed by repeated bulldozing) into

a valley. The CKD is blown around not only by the wind blowing along, or across

the valley, but also by the downward momentum of the dumped CKD mass along

the steep pile slopes.

Placement/compaction at the landfill: Both the bulldozing of the CKD into the

landfill and the temporary storage piles at the disposal site are huge sources of

fugitive dust emissions. This is captured very vividly in two dust "eruptions"

(Tapes 6 and 11) on the pile slopes (or CKD dunes), due to sudden gusts of wind

in the quarry. This is a chain event, triggering further agitation of dust in the path

of the dust cloud. The right wind conditions can quickly spread this dust over a

huge area as can be seen in Tapes 6 and 11.

Water: Other problems include the dust depositing and transporting CKD

contaminants onto runs, and culverts (adjacent to the quarry) emptying into lake

Huron. The stream/culvert water is varied in color, murky at most times, with a

lot of scum, or oil on the surface at times (Tapes 6 and 12). This contaminated

runoff discharges directly into the lake. This can have a detrimental effect on

aquatic life in the lake - for instance, the commentator shows a dead fish with

badly burnt tissue that was found floating on the lake, close to the runoff . 

Effects on humans: According to the commentator, the smell is carried into

nearby towns when the wind changes direction. Dust can be seen from the town

located at least a mile from the plant (Tapes 6 ad 12).
Draft: March 20, 1998 2-15

The commentator makes the following observations: The dust itself is very irritating to

the throat and causes coughing. The sometimes very turbulent conditions combine with

the dry disposal storage piles and produce near zero visibility. Sometimes, dust storm-like

conditions are produced due to large disturbances. Homes located close to the site ( a

mile or so away), receive a daily coat of fine dust on car wind-shields and home windowpanes that are reported to have to be cleaned daily (Tape 12). Although some of this dust

is likely to come from stack emissions, transfer of fugitive CKD across property lines in

visible quantities is evident. 

2.6 Population Effects from Exposure to Airborne CKD

Following the Regulatory Determination, EPA calculated population risks for individuals living in

the vicinity of cement manufacturing plants that manage CKD onsite. The assessment included

population risks from indirect, or foodchain, exposure pathways and population effects from

exposure to airborne particles. A detailed description of the population risk assessment is

provided in the Technical Background Document: Population Risks from Indirect Exposure

Pathways, and Population Effects from Exposure to Airborne Particles from Cement Kiln Dust

Waste in the docket for this rule (EPA 1997).
Draft: March 20, 1998 3-1

Chapter 3: Identification and Evaluation of Options for Technical Design Standard

This chapter examines air emissions of CKD from waste management activities, techniques for

controlling such emissions, and the effectivenss of these control techniques. To estimate air

emissions of CKD and the emission reductions that may be realized by applying selected control

technologies, EPA evaluated the technologies as they would be applied at two cement

manufacturing facilities, Facility A and Facility B. The Agency chose these facilities because they

are considered to be (1) a representative drier climate, potentially high-emissions facility (Facility

A) and (2) a representative wetter climate, potentially low-emissions facility (Facility B), based on

a review of previous modeling results of airborne particulate concentrations (EPA 1994). Exhibit

3-1 presents the input data parameters assumed for each facility. (These parameter values are

consistent with the values used for these facilities in the Agency’s risk analysis of particulate

matter.) The facilities dispose different amounts of CKD, with Facility A disposing 67,438 tons

of CKD and Facility B disposing 907 tons of CKD in 1990 (PCA Survey 1991).

3.1 Emissions Estimation

3.1.1 Description of CKD Handling Processes at the Sample Facilities

At Facility A, CKD from the electrostatic precipitator is collected in a storage tank that is

essentially closed. From the tank, the CKD is pelletized with water during the transfer process

before being loaded into a transport truck. The truck then transports the CKD to the disposal

site, where it is placed in temporary piles. Periodically, the temporary piles are leveled by

bulldozing. Since two of the control options under consideration for this analysis are pelletization

and addition of water to storage piles, EPA assumed dry, unpelletized CKD for estimating

baseline emissions for Facility A’s CKD handling train in order to examine the emission reductions

achievable through water addition and pelletization for a facility of this size.

At Facility B, CKD is first stored in an temporary storage pile located near the facility. The CKD

is then periodically loaded into trucks using a front-end loader; no wetting occurs in this process. 

After loading, the trucks transport the CKD to the final pile. There is no temporary storage at the

disposal site.
Draft: March 20, 1998 3-2

Exhibit 3-1

Input Data Used to Estimate Emissions from CKD Handling Train

Parameter Comments

Site

Facility B Facility A

Exposed area of landfill (m ) 10,219 8,733 2 Site-specific, based on facility responses to the PCA

Cement Kiln Dust Survey (1991) and best engineering

judgement and observations made during EPA’s site

visit in 1992

Percent of landfill area disturbed each 20 30 Site-specific, based on best engineering judgement

time CKD is dumped (%) and observations made during EPA’s site visit in 1992

Moisture content of CKD in handling 0.25 0.25 Selected as the smallest value possible (closest to

train (%) zero) within the range of validity for the emissions

equation

Number of days with > 0.01' of rain 115 79 From closest meteorological station

Mean wind speed (m/s) 4.58 4.31 From closest meteorological station

Fastest mile (m/s) 22.2 26 From “Extreme Wind Speed at 129 Stations in the

Contiguous United States”(values used for previous

exposure modeling)

Threshold friction velocity (m/s) 0.25 0.25 Estimated based on graphical relationship of threshold

friction velocity to CKD size distribution mode

(Gillette, 1980)

Silt content of unpaved road surface (%) 20 20 Default assumption (no site-specific data provided)

near upper end of range reported in literature for

industrial sites (Cowherd et al., 1985)

Silt content of CKD (%) 90 90 Estimated based on weight fraction of CKD less than

75 μm (obtained from literature)

Mean weight of vehicle (tons) 52 52 Gross weight of a 25-ton capacity truck

Mean number of wheels 10 10 Best engineering judgement and field observations

Length of road in miles (one way) 0.25 0.6 Site-specific, based on facility maps and site visits

Number of vehicle round trips/day 0.2 16 Calculated based on daily disposal rate (see below)

Vehicle miles traveled (VMT)/day 0.1 19.2 Calculated based on length of road and number of

round trips/day

Mean vehicle speed (mph) 20 20 Best engineering judgement based on site

observations

Number of working days/year 340 339 PCA Cement Kiln Dust Survey (1991)

Annual CKD disposal rate (tons) 907 67,438 PCA Cement Kiln Dust Survey (1991)

Daily CKD disposal rate (tons/operating 2.7 198.9 Calculated from annual disposal rate and number of

day) working days/year
Draft: March 20, 1998 3-3

3.1.2 Description of Methodology

EPA estimated emissions using methods and equations from its Compilation of Air Pollutant

Emission Factors, Volume I: Stationary Point and Area Sources, Fifth Edition (commonly

referred to as AP-42); much of the following discussion is extracted from this document. The 

methods presented in AP-42 for estimating fugitive dust emissions are principally compiled from

Control of Open Fugitive Dust Sources by Cowherd et. al. (1988), which was used as a 

supplemental reference. AP-42 contains the emission estimation methods and equations 

recommended for use by EPA’s Office of Air Quality Planning and Standards. EPA believes that

it provides the best approach available, short of conducting new field studies to measure

emissions.

As noted in AP-42, significant atmospheric dust arises from the mechanical disturbance of

granular material exposed to the air. Dust generated from these open sources is termed "fugitive"

because it could not reasonably pass through a stack, chimney, vent or other functionally

equivalent opening. As previously described, common sources of fugitive dust include wind

erosion from CKD piles, CKD handling (e.g., loading and unloading), unpaved road travel, and

bulldozing of CKD. For these sources, the dust-generation process is caused by two basic

physical phenomena:

4. Entrainment of dust particles by the action of turbulent air currents, such as wind erosion

of an exposed surface; and

5. Pulverization and abrasion of surface materials by application of mechanical force through

implements (wheels, blades, etc.), as usually occurs during CKD handling.

3.1.2.1 Estimating Emissions from Wind Erosion

EPA estimated emissions from wind erosion of exposed surfaces using the procedures outlined in

AP-42, Section 13.2.5, for the temporary storage piles and the area of the landfill disturbed during

each loadout of CKD. These procedures are based on the following assumptions:

1. The uncovered surface of the dust pile or landfill is characterized by a finite availability of

erodible material, referred to as the erosion potential;

2. Particulate emission rates tend to decay rapidly (i.e., with a half life of a few minutes)

during an erosion event; and

3. Emissions can be related to the erosion potential of the surface.

A single gust of wind can quickly deplete a substantial portion of the erosion potential, and the

erosion potential will not be restored until the surface is subsequently disturbed. 

Erosion potential is calculated based on the fastest wind speed during the period between

disturbances and the threshold friction velocity of the material. (The friction velocity is the

measure of wind shear stress on the erodible surface; the friction velocity must exceed the
Draft: March 20, 1998 3-4

threshold friction velocity of the material for wind erosion to occur.) Since the erosion potential

of a surface is restored each time the surface is disturbed, emissions for a specified time period are

also dependent on the number of disturbances occurring within that period. Any natural crusting

of the surface, such as that which has been observed in the field for weathered CKD, binds the

erodible material and thus reduces the erosion potential. Exhibit 3-2 lists the AP-42 variables and

equations that EPA used to estimate erosion potential for storage piles and disposal sites at the

two facilities. It is important to note that the equations presented in AP-42 for estimating wind

erosion represent intermittent events, rather than steady-state emissions. The Agency used the

“fastest mile” data from “Extreme Wind Speed at 129 Stations in the Contiguous United States”

to calculate emissions for this analysis. This wind speed represents the mean annual fastest mile. 

(Analysis of historical meteorological data to determine mean daily fastest mile values for each

facility and the subsequent use of these values to estimate emissions were beyond the scope of this

effort.) Consequently, EPA calculated the emission estimates prepared for this analysis by

assuming that the mean annual fastest mile occurs between every disturbance (i.e., as frequently as

once per day) instead of once per year, and thus may overstate actual emission rates.

Threshold friction velocity data for CKD were not available from literature or site-specific data. 

It is likely that additional field studies and/or wind tunnel measurements would be required to

adequately quantify this parameter, as previous work in the field has not focused on collecting

physical data needed to characterize air emissions of CKD. Absent such data for CKD, EPA

estimated the threshold friction velocity based on a graphical relationship developed by Gillette et.

al. (1980) between threshold friction velocity and the size of the aggregate distribution mode (see

Figure 3-1). Because CKD is predominantly less than 75 micrometers (μm) in diameter (see

Exhibit 2-1), the threshold friction velocity for the smallest distribution mode included on the

graph (0.1 mm or 100 μm) was selected. Since the behavior of the function outside of the

reported data range was unknown, the Agency made no attempt to extrapolate the threshold

friction velocity for a smaller size distribution mode. The resulting threshold friction velocity,

0.25 meters per second (m/s), is approximately half of the value reported in AP-42 for fine coal

dust on a concrete pad (0.54 m/s). The actual threshold friction velocity of dry CKD may be

smaller than the assumed value due to the extremely fine particle size of CKD. However, the

natural tendency of CKD to crust when exposed to moisture will tend to increase the threshold

friction velocity for weathered surfaces by an unknown amount.
u

%

10 u

%

10 ' u

% 1n (10/0.005)

1n (z/0.005)

(us)

(ur)

u

%

s u

%

s ' u

%

10

(us)

(ur)

u

( '

(0.4 u

%

s

)

25

1n(0.5)

' 0.10 u

%

s

u

( ' 0.053 u

%

10

u

(

t

P ' 58 (u

( & u

(

t

)

2 % 25 (u( & u

(

t

)

P ' 0 for u

( u

(

t

EF ' k j

N

i'1

P1

Draft: March 20, 1998 3-5

Exhibit 3-2

Variables and Equations Used to Estimate Emissions from Wind Erosion

Variable Description Method of Determination/Calculation

u Fastest mile value (m/s) at an anemometer Obtained from meteorological data +

height of z meters

Fastest mile value (m/s) converted to a

referenced height of 10 meters

Ratio of surface wind speed (us) to approach Determined from AP-42 Figure 13.2.5-2 based on

wind speed (ur) pile geometry and wind flow direction

Surface wind speed (m/s) corresponding to

the fastest mile

u which significantly penetrate the surface *

Equivalent friction velocity (m/s) for piles

wind layer (height-to-base ratio exceeding

0.2) (used to estimate erosion from storage

piles)

u* relatively flat piles or exposed areas with

Equivalent friction velocity for large,

little penetration into the surface wind area

(used to estimate erosion from landfill)

Threshold friction velocity (m/s) the aggregate size distribution, from graphical

Obtained from field measurements of the mode of

relationship by Gillette (see Figure 1), or from

reported values in AP-42 for selected materials

P Erosion potential (g/m )

2

N Number of disturbances/year Site-specific

k Particle size multiplier (dimensionless)

k = 1.0 for PM30

 = 0.5 for PM10

 = 0.2 for PM2.5

EF Emission factor (g/m -yr) 2

Note: These are standard methods employed in AP-42.
10 

100 

1000 

Threshold Friction Velocity (cm/sec)

0.1 1 10 100 

Aggregate Size Distribution Mode (mm)

Draft: March 20, 1998 3-6

Figure 3-1: Gillette relationship of threshold friction velocity to size distribution mode (source:

Control of Open Fugitive Dust Sources, EPA, 1988).

To estimated emission rates, EPA assumed storage piles to be conical in shape and equal in

volume to one truck load (assumed to be 10 cubic yards [yd ]), with a height equal to two-thirds 3

the base diameter. Due to the geometry of a conical storage pile, EPA divided the surface area of

the pile into four separate regimes, each characterized by a different ratio of surface wind speed to

approach wind speed. The Agency estimated the erosion potential for each subarea of the pile

separately and summed over all subareas to yield the total erosion potential for the pile. This

procedure, which is standard practice in fugitive dust modeling, is described in Section 13.2.5 of

AP-42. In addition, due to the relatively small quantity of CKD produced by Facility B (2.3

yd /day), the Agency assumed that the temporary storage pile accumulates over a period of five 3

days (i.e., until approximately one full truck load has accumulated) prior to removal of the pile

and transport to the landfill.

3.1.2.2 Estimating Emissions from CKD Handling

EPA estimated dust emissions from several distinct handling activities, including loading of CKD

onto storage piles and loadout of CKD to trucks and from trucks to the landfill. The Agency

estimated these emissions using the following empirical relationship from AP-42 (Section 13.2.4,

Aggregate Handling and Storage Piles):
E ' 0.0032k

U

5

1.3

M

2

1.4

E ' 0.59k

s

12

S

30

W

3

0.7 w

4

0.5

365 & p

365

 AP-42 assigns an “excellent” quality rating to emission factors when they are based on test data developed with a sound 2

methodology from many randomly chosen facilities and the source category population is sufficiently specific to minimize variability. 

An “above average” rating is assigned when the test data are from a “reasonable number” of facilities, such that no specific bias is

evident but it is not clear if the data are from a random sample.

Draft: March 20, 1998 3-7

where

E = emission factor (lb/ton);

k = particle size multiplier (dimensionless);

U = mean wind speed (mph); and

M = moisture content of material (%).

The particle size multiplier, k, varies with aerodynamic particle size range; the values given for k

for this equation in AP-42 are 0.74 for PM , 0.35 for PM , and 0.11 for PM . Note that values 30 10 2.5

for k are usually determined from field studies, and that recommended k values for different

equations and empirical correlations will differ (e.g., the k value for the wind erosion calculations

differ from these k values). Further, EPA notes that the silt content is outside the range of the

source conditions used to develop the above equation. As a result, AP-42 recommends that the

quality rating of the emissions estimates be reduced from “excellent” to “above average.”2

EPA applied this equation each time the CKD was handled. For Facility B, EPA assumed three

handling operations for a given quantity of CKD: (1) loading onto the temporary storage pile at

the facility; (2) loading from the temporary storage pile into the truck for transport to the landfill;

and (3) loadout from the truck into the landfill. Because Facility A does not have a temporary

storage pile at the facility (CKD is transferred from an enclosed storage tank directly to the

truck), the Agency assumed only the latter two handling operations.

3.1.2.3 Estimating Emissions from Unpaved Road Travel

EPA estimated emissions from unpaved road travel for trucks transporting CKD to the disposal

site and returning to the facility using the following equation from Section 13.2.2 of AP-42:
EPM30

' 5.7

(s)

1.2

(M)

1.3

EPM10' 0.75 (s)

1.5

(M)

1.4

EPM2.5

' 0.105 EPM30

EPM30

EPM10

EPM2.5

s

M

Draft: March 20, 1998 3-8

where

E = emission factor (lb/VMT);

k = particle size multiplier; equals 1.0 for PM , 0.36 for PM , and 0.095 for 30 10

PM (dimensionless); 2.5 

s = silt content of road surface material (%);

S = mean vehicle speed (mph);

W = mean vehicle weight (tons);

w = mean number of wheels; and

p = number of days per year with at least 0.01 inches of precipitation.

The resulting emission factor was then multiplied by the vehicle miles traveled (VMT) to estimate

emissions. The Agency estimated vehicle miles traveled for each facility based on the road

distance between the facility and the disposal site, and the number of trips per day required to

dispose of the amount of CKD generated daily, assuming a truck capacity of 10 yd of CKD. Due 3

to the relatively small amount of CKD generated at Facility B (2.7 yd /day), EPA assumed one 3

trip every five days for this facility.

3.1.2.4 Estimating Emissions from Bulldozing

The Agency estimated emission factors from bulldozing of the temporary CKD storage piles at

Facility A using the following equations for bulldozing of overburden from Table 11.9-2 of AP42:

where

= emission factor (lb/ton) for PM ; 30

= emission factor (lb/ton) for PM ; 10

= emission factor (lb/ton) for PM ; 2.5

= silt content of material (%); and

= moisture content of material (%).

EPA estimated the silt content of CKD to be 90 percent, based on the weight fraction of particles

less than 75 μm (from Dust “G” from the article “Cement Kiln Dust Management: Permeability,”

Todres et al., Portland Cement Association, 1992). Since the CKD is allowed to weather prior to
Draft: March 20, 1998 3-9

bulldozing, EPA assumed that the moisture content increased from 0.25 percent (dry CKD from

the kiln) to 1 percent in the temporary storage piles prior to bulldozing. The emission factors

were then multiplied by the annual and daily CKD disposal rates to estimate total emissions.

3.1.3 Uncontrolled Emissions Estimates

Using the methods and equations described in Section 3.1.2, EPA developed uncontrolled annual

and average working day emission rates for the two facilities; these are presented in Exhibit 3-3.

3.2 Fugitive Dust Control Techniques for Temporary Storage, Transport, and Disposal

This section describes the techniques EPA considered and evaluated for controlling fugitive dust

at each of the points in the CKD management process.

3.2.1 Description of Dust Generation and Handling

There are several points in the CKD management process at which fugitive dust controls can be

applied. While not every facility manages dust in exactly the same manner, a typical management

sequence may include: 

Temporary storage at the facility, 

Transport of CKD from the plant to the landfill area, and 

Disposal activities at the landfill.

Each of the technologies considered for meeting the performance design standard for controlling

fugitive dust emissions at these points is discussed in more detail below.

3.2.2 Management at Temporary Storage Point at the Plant

Technologies considered for controlling fugitive dust emissions at the temporary storage point at

the facility include enclosures, covers, pelletization of the dust, and adding water to the surface of

the pile.
Draft: March 20, 1998 3-10

Exhibit 3-3

Uncontrolled Emission Estimates

Facility B Facility A

PM30 PM10 PM2.5 PM30 PM10 PM2.5

Emissions (lb/year)

Temporary Storage at facility 771 386 154 NA NA NA

Aggregate Handling 301 142 45 13,783 6,519 2,049

Transport - unpaved road 1,531 689 182 335,345 150,905 39,822

Transport - entrainment from truck 124 62 25 12,747 6,373 2,549

Temporary Piles at Disposal Site NA NA NA 14,569 7,284 2,914

Bulldoze Temporary Storage Piles NA NA NA 85,074,685 43,177,700 8,932,842

Disposal Site - Disturbed Area 24,767 12,383 4,953 22,0943 110,472 44,189

Total 27,494 13,662 5,359 85,672,071 43,459,254 9,024,365

Emissions (lb/average working day)

Temporary Storage at facility 2.3 1.1 0.5 NA. NA NA

Aggregate Handling 0.9 0.4 0.1 40.7 19.2 6.0

Transport - unpaved road 4.5 2.0 0.5 989.2 445.1 1,17.5

Transport - entrainment from truck 0.4 0.2 0.1 37.6 18.8 7.5

Temporary Piles at Disposal Site NA NA NA 43.0 21.5 8.6

Bulldoze Temporary Storage Piles NA NA NA 250,957.8 127,367.8 26,350.6

Disposal Site - Disturbed Area 72.8 36.4 14.6 651.7 325.9 130.3

Total 81 40 16 252,720 128,198 26,621

Percent of Total Emissions

Temporary Storage at facility 2.81 2.82 2.88 NA NA NA

Aggregate Handling 1.09 1.04 0.83 0.02 0.02 0.02

Transport - unpaved road 5.57 5.04 3.39 0.39 0.35 0.44

Transport - entrainment from truck 0.45 0.45 0.46 0.01 0.01 0.03

Temporary Piles at Disposal Site NA NA NA 0.02 0.02 0.03

Bulldoze Temporary Storage Piles NA NA NA 99.30 99.35 98.99

Disposal Site - Disturbed Area 90.08 90.64 92.43 0.26 0.25 0.49

Total 100.00 100.00 100.00 100.00 100.00 100.00

NA = not applicable (the source does not exist at that facility).

3.2.2.1 Enclosures

Enclosures include silos as well as warehouse-type structures and dome-shaped buildings such as

those used by transportation agencies to store road chemicals (e.g., salt and sand). These

buildings do not have to conform to full RCRA Subtitle C containment standards, but should have

a roof, floor, and walls. These structures reduce emissions by removing the CKD from the

environment, thus eliminating exposure to wind and subsequent dispersal.

3.2.2.2 Covers on Piles

Examples of covers on temporary storage piles include adding a layer of soil (loam) to the top of

the pile or spraying a latex binder on the top of the pile. Adding a layer of soil over the top of the

pile will reduce emissions, because the soil is less erodible; that is, the soil is more likely to clump
Draft: March 20, 1998 3-11

together and less likely to be blown away. The latex binder reduces emissions in a similar manner,

by causing the CKD to form a crust, thereby reducing the erodibility of the CKD.

3.2.2.3 Pelletization

Pelletization is a control technology that might first be applied at an temporary storage point;

however, it is likely to help reduce emissions during transport and at temporary storage piles as

well. Pelletization is currently used both to aid in recycling CKD and to prepare CKD for

disposal (EPA 1993). CKD is formed into small spherical pellets by passing it through paired

rollers with recessed surfaces. These pellets have much more cohesion than loose CKD, and are

therefore less susceptible to wind erosion. (Pellets can also be formed by rolling CKD in a drum

or inclined disk with water; however, pellets made this way are more likely to break up.) 

Depending on the strength of the pellets, pelletization may even reduce emissions at the landfill, if

the pellets are strong enough to maintain their cohesive properties. Drying and excessive

mechanical damage to pellets can reduce or eliminate the effectiveness of this technique in

controlling fugitive emissions.

3.2.2.4 Water Addition

Water addition may be used to suppress fugitive dust emissions at temporary storage piles. 

Application of water to piles of CKD promotes formation of a crust that will decrease emission of

dust (by increasing the threshold frictional velocity; see discussion in section 3.1.2.1 above) from

the temporary storage pile. For this technology, a facility is assumed to apply water to the pile

using a hose and nozzle. Application rates vary depending upon climatological factors, especially

rainfall, relative humidity, evaporation rate, and wind speeds at the temporary pile.

3.2.3 Management of Transport of CKD from Plant to Landfill

Appropriate techniques for controlling fugitive dust along the haul road from the plant to the

disposal area include adding water to the road surface, covering the dust in the bed of the truck,

and/or cleaning the bed of the truck after dust is unloaded at the disposal area. These techniques

are summarized below.

3.2.3.1 Water Addition to Unpaved Road Surface

Applying water to unpaved roads is known to be effective in mitigating fugitive dust emission at

industrial and construction sites. At most cement manufacturing facilities, at least a part of the

route traveled by CKD haul trucks is unpaved. These unpaved roads also are used by trucks

transporting raw materials to the cement plant. Regular water addition to unpaved roads

suppresses dust emission and prevents the carryout of fugitive CKD by the truck traffic. 

(“Carryout” refers to the dispersion of dust on paved and unpaved roads caused by vehicular

traffic.) The control efficiency of water addition to unpaved roads depends upon the following

key variables: (1) traffic volume; (2) climatological conditions (especially rainfall, humidity, wind
Draft: March 20, 1998 3-12

sprred, evaporation); (3) application rates for water; and (4) elapsed time between water

applications.

3.2.3.2 Pelletization and Water Addition to Trucked CKD

Addition of water to CKD prior to transport in trucks will reduce fugitive emissions. The amount

of water added to CKD will vary between sites and climatic areas of the country. Addition of

greater than about 50 percent water to CKD results in producing a slurry. Slurries will generally

be piped (rather than trucked) to the disposal site. Pelletization involves addition of about 10

percent water to CKD. Wet compaction is generally described as wetter than pelletized CKD, but

not as wet as a slurry. Wet compaction is assumed to require about 30 percent water addition. 

This type of wetting of CKD prior to transport may be as effective for control at some facilities as

covering of trucks carrying dry CKD. 

3.2.3.3 Covers on Trucks

To prevent air entrainment and spillage during hauling, CKD must be transported in trucks with

adequate freeboard and cover. (“Freeboard” is the distance between the top of material stored in

a truck bed and the rim of the bed’s walls.) Typically, these covers are tarps or screening material

that is extended over the truck’s bed and secured. At least one state (Michigan) has defined

“completely covering open-bodied trucks” as a requirement of fugitive dust emission control

programs. The construction industry is required to follow the practice of covering dump trucks in

some cases (e.g., when hauling hotmix asphalt, construction debris, etc.). Several manufacturers

supply roll-on tarp systems for covering bulk materials transported by trucks. Alternatively, tarps

can be tied down manually after the truck has been loaded.

3.2.3.4 Cleaning of Trucks and Covers After Each Load

In addition to transporting CKD in trucks with covers, the trucks themselves may be cleaned after

unloading CKD at the disposal area. Cleaning these trucks can help reduce air emissions on the

return trip and prevents the buildup of excessive dust in and on the trucks over time. 

Operationally, this involves vacuuming all surfaces of the truck that were in contact with the CKD

being hauled and, as an added measure, replacing the truck cover with a cleaned one after each

hauling trip.

3.2.4 Management of CKDLF Units

Techniques for controlling dust emissions from a CKD landfill unit (CKDLF) include (1) wetting

and pelletizing the dust before disposal, (2) wet compaction of CKD, and (3) adding water, soil,

or a chemical covering such as latex to the pile.
Draft: March 20, 1998 3-13

3.2.4.1 Pelletization

As described above, pelletization is a material management method in which finely divided

particulate material is compressed through paired rollers with recessed surfaces so that the

particles cling together and form small, spherical pellets. In the current context, pelletization also

can be accomplished by rolling CKD in a drum or inclined disk with water; however, pellets made

this way are more likely to break up. A typical pelletization system will consist of a pelletizer,

which includes a feed hopper, a chute feeding the roller pair, a roller pair, and a chute to convey

the pellets away from the roller.

3.2.4.2 Wet Compaction/Conditioning

The process of wet compaction involves adding water to the CKD prior to load-out to get a

clotted material with a wet consistency. Although wet compaction management scenarios may

vary by facility, the material will generally be similar to or wetter than pelletized CKD and drier

than a slurry. The moisture content for wet compaction is assumed to be between 10 and 50 per

cent. This wet material is then transferred to the landfill and dumped. The method of transport is

assumed to be in a truck similar to pelletized CKD. At the disposal site, the wet CKD is

compacted into layers by the use of either rollers or other heavy equipment driving over the

material.

This compacted wet material is reported to bind and form a fairly solid material. This solid

material is reported to be similar to a low-grade cement and will remain in a fairly solid form until

mechanically disturbed. Although some flaking or scaling may occur that may produce fugitive

dust from undisturbed compacted CKD, when subjected to mechanical action the dry material is

easily crushed and once again prone to substantial fugitive emissions. For this reason, wet

compaction must be part of an overall management practice that includes covering and protection

from mechanical disturbance once it is dry. The emissions from wet compacted CKD once it is

covered are assumed to be zero.

3.2.4.3 Water Addition

Adding water to CKD at the landfill is used to suppress dust emissions following placement in a

disposal unit. Water addition controls dust emissions by causing the fine particles of dust to

agglomerate and bind to the aggregate surface, preventing them from becoming suspended in air. 

The degree of agglomeration depends on the amount of material covered and on the ability of the

liquid to wet small particles.

For this control technique, a facility is assumed to pump available on-site water to the landfill via

piping, and spray the water over the disturbed portion of the landfill each day CKD is placed in

the landfill. In reality, the frequency of application will depend on climatological factors such as

humidity, evaporation rate, wind speed, and rainfall. Also, water addition cannot be used when

temperatures fall below freezing. More effective wetting can be achieved by reducing the
Draft: March 20, 1998 3-14

diameter of the water droplets and increasing their number through appropriate selection of

pumps and nozzles used for the water spraying system. Surfactants also may be used with water

sprays to improve the wetting of materials.

3.2.4.4 Chemical Addition

Chemical addition to CKD at the landfill is used to suppress dust emissions following placement in

a disposal unit. Chemical addition controls dust emissions by causing the fine particles of dust to

agglomerate and bind to the aggregate surface, preventing them from becoming suspended in air. 

The degree of agglomeration depends on the amount of material covered and on the ability of the

liquid to wet small particles. For this control technique, a facility would mix the chemical binder

(e.g., latex) with water, and spray the solution over the landfill.

3.2.4.5 Covering Conditioned CKD Lifts

Conditioned CKD forms a solid material similar to a low-grade cement. As mentioned in the

discussion of wet compaction, this material has the potential to be a source of fugitive emissions if

not properly managed. Drying, scaling and mechanical disturbance can combine to break

conditioned CKD down to produce fine particles that can once again become airborne fugitive

dusts. This can be prevented by covering the conditioned CKD with materials (e.g., latex

additives, soil) of sufficient strength, thickness, chemical and physical properties to prevent

contact with the conditioned CKD. Appropriate selection of cover materials should be done on a

site specific basis. 

3.3 Control Efficiencies for Fugitive Dust Control Technologies

This section describes the estimation of control efficiencies for the fugitive dust control

technologies considered. The primary sources of information and equations used as a basis for

estimating the efficiency of each control are described in detail below.

In conducting research on CKD and the cement manufacturing industry for the past several years,

especially in support of the Report to Congress, EPA conducted extensive literature searches on

CKD and potential fugitive dust control options. Since these initial searches were conducted,

subsequent literature searches and interviews with experts reveal that little new material has been

published on fugitive dust emissions and controls, particularly regarding fugitive CKD at the

disposal area. Cowherd (and Muleski and Kinsey) at Midwest Research Institute (MRI) are the

primary authors of most of the available fugitive dust control technology information. Even

recent publications on fugitive dust tend to focus on manufacturing processes, rather than bulk

material handling and disposal operations. Even with the recent proposal of the new PM2.5

National Ambient Air Quality Standards (NAAQS), new data regarding control technologies are

limited because EPA’s focus for the NAAQS revision has been on the health effects of PM2.5 and

not the potential control requirements, anticipated level of reductions, and the associated costs. 

Consequently, for this proposal, EPA based most of its analysis related to CKD on the MRI
Draft: March 20, 1998 3-15

documents and other literature for which MRI provided input; the Agency supplemented this

information with phone calls to control technology vendors and state regulators (for a few

technologies) and other documents discussing fugitive dust in general. For many of the

technologies, EPA relied upon its knowledge of cement facility operations and air emissions,

especially fugitive dust and the associated control technologies, to develop control efficiencies

using their best engineering and professional judgement.

3.3.1 Pelletization

EPA estimated the control efficiency for pelletization by considering two factors:

1. The change in the threshold friction velocity due to the increase in effective

particle size; and

2. The increase in moisture content due to the addition of water during the

pelletization process.

In the article “Pelletizing Waste Cement Kiln Dust for More Efficient Recycling”, Sell and

Fischbach (1978) examined two sizes of oval pellets which were prepared with commercial

pelletizing equipment: 1/4” x 3/8” x 1⁄2”, and 5/8” x 1⁄2” x 1”. Throughout the literature review

summarized above, the Agency found no other or more current information on the size of pellets

from commercial pelletizers. This review includes conversations with pelletizer vendors.

In order to estimate the impact of threshold friction velocity, EPA converted the smallest

dimension listed in the article to millimeters, giving an approximate pellet diameter of 6.35 mm. 

The Agency then used the graphical relationship developed by Gillette et. al. (refer to Figure 3-1)

to estimate a threshold friction velocity of approximately 1.3 m/s for an aggregate size distribution

mode of 6 mm. EPA substituted this value for the CKD threshold friction velocity in the wind

erosion calculations for temporary storage piles, resulting in a 92 percent reduction in emissions

due to pelletizing (assuming minimal breakage of pellets).

For estimating reduced emissions from pelletization at the disturbed areas of the landfill, EPA

performed a similar calculation. For the disturbed areas, however, the Agency assumed

considerable pellet breakage due to driving over the material with the CKD haul trucks. EPA

simulated the effects of breakage by assuming a reduced size distribution mode of 1 mm,

corresponding to a threshold friction velocity of approximately 0.65 m/s. The resulting control

efficiencies for pelletization at the landfill were 50 percent for Facility A and 57 percent for

Facility B, accounting for the fraction of the surface area that is disturbed during dumping

operations and the frequency of disturbance. The higher control efficiency estimated for Facility

B results from the greater amount of time assumed between disturbances for this facility.

For handling and bulldozing of pelletized material, EPA assumed a moisture content of 10 percent

for pelletized CKD in order to estimate the reduction in emissions. This value represents the
Ec

' Eu

(Mu)

2

(Mc)

2

CE ' 75(M&1) for 1 M 2

CE ' 62%6.7M for 2 M 5

Draft: March 20, 1998 3-16

lower end of the range reported by personnel at a sample of facilities that use pelletizers

(interviewed over the phone or in person during site visits) and, thus, actual control efficiencies

would likely be greater than evaluated efficiencies assuming minimal breakage of pellets. The

resulting control efficiencies were 95 percent for PM and PM , and 96 percent for PM . 30 2.5 10

3.3.2 Water Addition for Storage Piles/Landfills

Wind erosion emissions are known to be strongly correlated with the inverse square of the

moisture content, so EPA used the following relationship from Control of Open Fugitive Dust

Sources (Cowherd et al., 1988) to relate controlled and uncontrolled emissions with controlled

and uncontrolled moisture content:

where

E = controlled emission rate; c

E = uncontrolled emission rate; u

Mc = controlled moisture content (%); and

M = uncontrolled moisture content (%). u

Accordingly, for a given control efficiency, EPA calculated the ratio of uncontrolled moisture

content to controlled moisture content as shown in Exhibit 3-4. Note that doubling the moisture

content resulted in a 75 percent reduction in emissions. This corresponds well with the control

efficiencies predicted by another relationship presented in Control of Open Fugitive Dust Sources

(Cowherd et al., 1988) for watering of unpaved road surfaces, in which the instantaneous control

efficiency was related to the ratio of controlled to uncontrolled surface moisture content

according to the following bilinear relationship:

where

CE = control efficiency (%), and

M = ratio of controlled to uncontrolled moisture content (equal to M /M ). c u
CE ' 100 &

0.8 pdt

i

Draft: March 20, 1998 3-17

Exhibit 3-4

Estimated Moisture Content Ratios for

Various Control Efficiencies

CE Mc

/Mu CE Mc/Mu

10% 1.05 70% 1.83

20% 1.12 75% 2.00

30% 1.20 80% 2.24

40% 1.29 85% 2.58

50% 1.41 90% 3.16

60% 1.58 95% 4.47

65% 1.69 99% 10.00

M = controlled moisture content (%) c

M = uncontrolled moisture content (%) u

CE = control efficiency

This relationship predicts that between one and two

times the average uncontrolled moisture content (a small

increase in moisture content) yields a large increase in

control efficiency. Beyond this point, control efficiency

increases more slowly with moisture content.

For any particular situation, the required water

application rate will be dictated by the desired control

efficiency. Based on the above, a 75 percent reduction

in emissions appears readily achievable. For this

analysis, EPA assumed a low-end control efficiency of

55 percent corresponding to a 50 percent increase in

moisture content and a high-end control efficiency of 75

percent corresponding to a doubling of moisture content

because these appeared achievable. Higher control efficiencies (e.g., 90 percent) should also be

achievable, but would require doubling of the moisture content.

3.3.3 Water Addition for Roadways

EPA estimated the control efficiency for water addition to unpaved roads using the following

relationship from the Air Pollution Engineering

Manual (Buonicore and Davis, 1992):

where

CE = average control efficiency (%);

p = potential average hourly daytime evaporation rate (mm/hr);

d = average hourly daytime traffic rate (hr ); -1

i = application intensity (liters per square meter [L/m ]); and 2

t = time between applications (hr).

The Agency estimated the potential average hourly daytime evaporation rate in mm/hr, which

varies from site to site, by multiplying the mean annual Class A Pan Evaporation (in inches) by

0.0049 for annual conditions and by 0.0065 for summer conditions. The mean annual Class A

Pan Evaporation for various areas of the US can be read from the isopleth diagram presented as

Figure 4 of Chapter 4 of the Air Pollution Engineering Manual. The resulting potential average

hourly daytime evaporation rates for the locations of Facilities A and B are shown in Exhibit 3-5.
Draft: March 20, 1998 3-18

Exhibit 3-5

Parameters Needed to Estimate Control Efficiency for Unpaved Road Watering

Class A Pan

Evaporation (inches)†

Potential Average Hourly

Daytime Evaporation Rate

(mm/hr)

Hourly Vehicular

Traffic Rate (hr ) Annual -1 ‡ Summer

Facility A 70 0.34 0.46 4.08

Facility B 65 0.32 0.42 0.05

Generally, the target control efficiency for dust suppression from unpaved roads is used to

determine the amount and frequency of water application required. Control efficiencies can fall

from approximately 95 percent for total suspended particulates (TSP) (with higher efficiencies for

finer particles) shortly after application to approximately 50 percent within five hours of

application for unpaved roads with heavy traffic.

As an example, Exhibit 3-6 presents estimated average control efficiencies for annual and summer

conditions for Facility A. At an application rate of 1 L/m , the average control efficiency for 2

watering every 24 hours is 73 percent for annual conditions and 64 percent for summer

conditions.

For Facility B, the extremely low hourly vehicular traffic rate (i.e., only one round-trip every five

days) would result in control efficiencies of 99 percent or higher even at low application rates,

assuming that the road would be watered at some point during the day prior to each trip. For this

analysis, EPA assumed a control efficiency of 70 percent for Facility A, and 99 percent for Facility

B, because the Agency believes that these control efficiencies are readily achievable. For

example, the assumed control efficiency for Facilty A fall between the mean annual and the

summer conditions control efficiencies for daily watering at reasonable application rates. The

Agency also believes that higher efficiencies would also be achievable with increases in the

frequency or amount of water application.

3.3.4 Soil (Loam) Cover for Storage Piles

EPA found no specific information regarding potential reductions in emissions from covering

storage piles with less-erodible material such as soil. Instead, the Agency estimated a control

efficiency for this control measure by comparing the relative erodibility of loam (56

tons/acre/year) with sand (220 tons/acre/year) as reported in Control of Open Fugitive Dust

Sources (Cowherd et al., 1988). EPA chose sand as the most appropriate surrogate for uncrusted

CKD because sand was the most erodible material for which a value was provided in the

reference, and because dry, uncrusted CKD is expected to be highly erodible. The ratio of loam

erodibility to sand erodibility yielded an estimated control efficiency of 75 percent.
Draft: March 20, 1998 3-19

Exhibit 3-6

Example Control Efficiency Matrices for Watering of Unpaved Roads for Facility A (%)

Annual Conditions

Application Intensity Time Between Applications (Hours)

gal/ft L/m 2 4 6 8 12 16 20 24 2 2

0.0025 0.10 77.6 55.3 32.9 10.5 - - - -

0.005 0.20 88.8 77.6 66.5 55.3 32.9 10.5 - -

0.007 0.30 92.5 85.1 77.6 70.2 55.3 40.4 25.5 10.5

0.010 0.40 94.4 88.8 83.2 77.6 66.5 55.3 44.1 32.9

0.012 0.50 95.5 91.1 86.6 82.1 73.2 64.2 55.3 46.3

0.025 1.00 97.8 95.5 93.3 91.1 86.6 82.1 77.6 73.2

0.05 2.00 98.9 97.8 96.6 95.5 93.3 91.1 88.8 86.6

0.07 3.00 99.3 98.5 97.8 97.0 95.5 94.0 92.5 91.1

0.10 4.00 99.4 98.9 98.3 97.8 96.6 95.5 94.4 93.3

0.12 5.00 99.6 99.1 98.7 98.2 97.3 96.4 95.5 94.6

0.15 6.00 99.6 99.3 98.9 98.5 97.8 97.0 96.3 95.5

Summer Conditions

Application Intensity Time Between Applications (Hours)

gal/ft L/m 2 4 6 8 12 16 20 24 2 2

0.0025 0.10 70.3 40.7 11.0 - - - - -

0.005 0.20 85.2 70.3 55.5 40.7 11.0 - - -

0.007 0.30 90.1 80.2 70.3 60.4 40.7 20.9 1.1 -

0.010 0.40 92.6 85.2 77.8 70.3 55.5 40.7 25.8 11.0

0.012 0.50 94.1 88.1 82.2 76.3 64.4 52.5 40.7 28.8

0.025 1.00 97.0 94.1 91.1 88.1 82.2 76.3 70.3 64.4

0.05 2.00 98.5 97.0 95.6 94.1 91.1 88.1 85.2 82.2

0.07 3.00 99.0 98.0 97.0 96.0 94.1 92.1 90.1 88.1

0.10 4.00 99.3 98.5 97.8 97.0 95.6 94.1 92.6 91.1

0.12 5.00 99.4 98.8 98.2 97.6 96.4 95.3 94.1 92.9

0.15 6.00 99.5 99.0 98.5 98.0 97.0 96.0 95.1 94.1

3.3.5 Latex Binder Addition for Storage Piles

The Air Pollution Engineering Manual (Buonicore and Davis, 1992) cites wind tunnel studies of

a 2.8 percent solution of Dow Chemical M-167 Latex Binder in water applied at an average

intensity of 1.5 gal/yd on low-volatility coking coal. These studies show control efficiencies 2

ranging from approximately 90 percent for TSP at two days after application, dropping to

approximately 40 percent at four days after application. For Facility A, EPA assumed the

temporary storage piles located at the disposal site to be bulldozed into the landfill at the end of

each day, so the high end of control efficiency is assumed. For Facility B, the Agency assumed

the temporary storage pile at the plant to accumulate over a five-day period, with each addition to
Draft: March 20, 1998 3-20

the pile resulting in a disturbance of the entire surface. Accordingly, the Agency assumed latex

addition to Facility B’s temporary storage to occur after each disturbance of the pile.

3.3.6 Enclose Temporary Storage Pile

As stated in the Air Pollution Engineering Manual (Buonicore and Davis, 1992), enclosure of

material transfer points and storage piles can result in particulate emission reductions ranging

from 70 to essentially 100 percent control, depending on the type of enclosure (partial or full), the

type of operation, and whether or not the enclosure vent is routed to a control device such as a

baghouse. For this analysis, EPA estimated emissions for both 70 percent control efficiency

(partial enclosure) and 99 percent control efficiency (full enclosure).

3.3.7 Cover Truck/Clean Truck and Cover

EPA found no data regarding the effectiveness of these control measures. The Agency estimated

the control efficiencies for covering the truck and cleaning the truck and cover after each use at

90 percent and 95 percent, respectively based on engineering judgment and discussions with

vendors. (Note that these controls only apply to emissions resulting from wind entrainment of the

material in the truck.) Higher efficiencies may be achievable in actual practice.

3.3.8 Rolling of Conditioned CKD

To estimate the emissions due to rolling vehicles over the wet CKD to compact the material, the

unpaved road emission equation was used. The silt content was modified to reflect the moisture

content of the CKD. The silt content is an estimate of percentage of material with particle

diameters less than 75 microns. As more moisture is applied to the CKD, more particles will

become agglomerated and the silt content would decrease. 

EPA used a two step approach to modeling the emissions resulting from different moisture

content assumptions for CKD. The unpaved road model typically uses moisture content to

calculate a control efficiency that can be applied to a baseline condition to calculate emissions

reductions. In order to get comparability between the two model plants and the different moisture

contents, EPA first calculated the percent improvements resulting from three different moisture

levels. Using these control efficiencies, an emission factor was calculated using the unpaved roads

equation and solving for the silt content that produced the calculated emissions reduction

associated with the previously calculated control efficiency. It is likely that this underestimates

the emissions reductions that would actually result in wet compaction because the fine particles in

CKD would also bind chemically.

One percent moisture content was used as a baseline condition and 10%, 30%, and 50% moisture

content was modeled. Using the equation 3.3.8-1 for water addition to storage piles/landfill (see

Section 3.3.2) and the unpaved roads equation 3.3.8-3 (see Section 3.3.3), EPA developed a

relationship between moisture content and silt content. Uncontrolled emission factors were
Draft: March 20, 1998 3-21

developed (assuming 90% silt content) using the unpaved roads equations. Control efficiencies

were developed for each of the predetermined moisture contents using the water addition

equation.

CE = 100 * (1- Mu/Mc) eqn. 3.3.8-1 2 2

Where:

CE = Control Efficiency

Mu = Moisture Content of Dry CKD = 1%

Mc = Moisture Content of Wet CKD = 10%, 30%, and 50%

The unpaved roads equation was used to establish the baseline uncontrolled emissions for a

moisture content of 1 percent and a silt content of 90%. Control efficiencies were calculated

using the water addition equation and the moisture contents of 10%, 30%, and 50% for Mc while

the uncontrolled moisture content, Mu remained 1%. The control efficiencies were then applied

to the uncontrolled emissions factor to create the emissions factors for each of the three moisture

contents using equation 3.3.8-2. These three emission factors (in lb per vehicle mile traveled)

were then used to solve for the silt content from the unpaved road model equation (equation

3.3.8-3). The unpaved road model was rerun to find a silt content that was consistent with the

control efficiencies estimated for the different moisture levels.

Ec(lb/VMT) = Eu x (1 - CE)/100 eqn. 3.3.8-2

E (lb/VMT) = k x (5.9) x (s/12) x (S/30) x (W/2.7) x (w/4) x [(365-p)/365] 0.7 0.5

eqn. 3.3.8-3

Where:

E = Emission Factor of Unpaved Road Emissions

k = Particle Size Multiplier

s = Silt Content = 90% for Dry CKD

S = Mean Vehicle Speed = 4 mph

W = Mean Vehicle Weight = 75 tons

w = Mean Number of Wheels = 4

p = Days With Greater Than 0.01" Precipitation

p = 115 days for Facility B

p = 79 days for Facility A

Uncontrolled emissions of CKD due to rolling activities were calculated for both Facility A and

Facility B and are presented in Exhibit 3-7 below. Control efficiencies were then determined for

each moisture content and then controlled emissions were estimated. These emissions were then

used to back calculate a silt content from the unpaved road equation. The results are listed below. 

The emissions from wet compaction of CKD when moisture content is above 10% are quite small. 
Draft: March 20, 1998 3-22

These low emission values for wet CKD have been verified through EPA’s plant visits and

through the observation of videos of facilites using water addition to CKD as well as activities at

those facilities under uncontrolled conditions.

Exhibit 3-7

Moisture Contents and Corresponding Silt Contents

Mc CE Facility A Facility B

Moisture Control

Content Efficiency

(%) (%)

Ec * s (silt) Ec * s (silt)

(lb/VMT) (%) (lb/VMT) (%)

1(baseline) 0.00 37.9 90 33.13 90

10 99.00 0.379 0.9 0.331 0.9

30 99.89 0.0421 0.1 0.0368 0.1

50 99.96 0.0152 0.036 0.0133 0.036

*Ec = emission factor for compaction in pounds (lb) per vehicle mile traveled (VMT).

The silt content values were then used to determine emission factors for the rolling emissions

developed by the unpaved roads equation. The silt contents for wet CKD are also quite small. As

previously mentioned, it is possible that actual silt contents will be lower due to chemical reaction

in the CKD. However, emissions are so low that this impact is probably not significant. 

Total emissions from the rolling of the wet CKD were calculated using the emission factors

calculated and shown in Exhibit 3-7 and applying the vehicle miles traveled (VMT) per year to

compact the wet CKD. Total amounts of CKD deposited in the monofill by each sample facility

were used to determine the amount of VMT. Wet CKD was assumed to be deposited into the

monofill in 3 yard wide and 1 yard deep lifts and rolled over twice by a 4 wheeled tractor. The

amount of wet CKD deposited in the monofill was calculated by the size of the truck and the

number of trips made per year for each example facility.

3.3.9 Wet Compaction

The wet compaction scenario is based on CKD management activities observed by EPA at the

Lafarge facility in Alpena, Michigan. Alpena has proposed wet transfer and dumping followed by

spreading the wet CKD and compacting it by driving over the material. For most of this scenario,

the emissions would be the similar to other scenarios already presented. The higher moisture

content of wet compaction has some impact on overall emissions. Moisture contents of 10%,

30% and 50% were modeled to bracket the expected ranges of moisture content for wet

compaction. The unique step in this process is the compaction into horizontal lifts by rolling with
Draft: March 20, 1998 3-23

heavy equipment. This estimate uses a modified unpaved road scenario based on driving heavy

equipment over a surface of 100% CKD at low speeds.

To determine the overall impacts of these different approaches, EPA developed emissions

estimates for four distinct sequences:

Loading of wet CKD slurry onto trucks causing fugitive dust due to handling activities

(see Section 3.1.2.2 for an explanation of equations);

Transportation of the CKD to the disposal site causing fugitive dust through wind

entrainment from the truck, and unpaved roads (see Section 3.1.2.3 for an explanation of

equations);

Unloading of CKD from the trucks causing fugitive dust resulting from dumping (see

Section 3.1.2.2 for an explanation of equations); and

Wet compaction of the wet CKD in the disposal area causing dust emissions due to the

mechanical disturbance of the CKD (see Section 3.3.8 for an explanation of equations).

The results of these emissions modeling are summarized in Exhibit 3-8. It can be seen from these

results that emissions from CKD with a high moisture content (above 10%) are very low in all

stages of management. The majority of the emissions under the wet compaction scenarios result

from the wetted haul roads. The roads are modeled using the wetting assumptions described in

Section 3.3.3. The fact that the trucks that are driving on the roads contain wet CKD is not

assumed to have any impact on the roadway emissions.
Draft: March 20, 1998 3-24

Exhibit 3-8

Emissions from Wet Compaction Scenario (lbs/yr)

Moisture Facility B Facility A

Content

PM-30 PM-10 PM-2.5 PM-30 PM-10 PM-2.5

Enclosed

Temporary 0.00 0.00 0.00 0.00 0.00 0.00

Storage

Loading of

Conditioned

CKD

10% 1 0 0 39 19 6

30% 0 0 0 8 4 1

50% 0 0 0 4 2 1

Covered

Truck 7 4 1 677 338 135

Entrainment

Wetted

Unpaved 192 86 23 40,210 18,095 4,775

Roads

Unloading of

Conditioned

CKD

10% 1 0 0 39 19 6

30% 0 0 0 8 4 1

50% 0 0 0 4 2 1

Wet

Compaction 

Conditioned

CKD*

10% 0 0 0 10 5 1

30% 0 0 0 1 1 0

50% 0 0 0 0 0 0

Covered CKD

Lifts 0 0 0 0 0 0

Total

10% 200 90 25 40,976 18,475 4,923

30% 199 90 24 40,905 18,441 4,913

50% 199 90 24 40,895 18,437 4,912

*Note: Wet compaction assumes mechanical compression through rolling.
The proposed standards to not apply to CKD from kilns that burn hazardous waste as a fuel when the CKD is a hazardous 3

waste as defined by 40 CFR part 261. Such waste-derived characteristically hazardous CKD continues to be subject to the provisions

of 40 CFR 266.112.

Draft: March 20, 1998 4-1

Chapter 4: Proposed Standards

This chapter provides a summary of EPA’s proposed standards for controlling fugitive dust

emissions from cement kiln dust landfill (CKDLF) units. A CKDLF unit is defined as a discrete

area of land or an excavation that receives CKD waste, and that is not a land application unit,

surface impoundment, injection well, or waste pile. A CKDLF unit may receive other types of

non-hazardous industrial wastes, such as kiln brick, construction debris, mining overburden or

other commercial industrial waste. A CKDLF unit may be a new CKDLF unit, an existing

CKDLF unit or a lateral expansion of an existing unit.

EPA has proposed air protection standards for all new and existing CKD waste landfill units,

except units closed prior to the effective date of the rule and units that receive waste-derived

CKD that exhibits a characteristic of hazardous waste. Any expansion of an existing CKD 3

landfill unit, defined as any horizontal or vertical expansion of the waste boundary of an existing

landfill unit, are considered new units and must meet the requirements applicable to new units. 

Under this proposed definition, any area of any existing unit that receives waste after the effective

date of this rule is an expansion. EPA has also proposed that interim storage units, such as

containers or buildings which contain CKD destined for recycling or sale, must also comply with

the air performance standard. 

These standards could be met in one of two ways. First, a facility could obtain a determination

from an authorized State or (in unauthorized States) from the EPA Regional Administrator that a

management practice or alternative design meets the standard, providing adequate assurance that

the unit is managed to control wind dispersal of particulate matter. Second, the facility could

design units according to technology-based standards outlined below, so as to obviate the need

for such a demonstration.

The standards to control fugitive dust emissions from CKDLF units include a performance

standard (Section 4.1) and default technical standards that meet the performance standard

(Section 4.2).

4.1 Performance Standard

Under EPA’s proposal, unit design and operation must ensure that wind dispersal of particulate

material (PM) is controlled. The specific performance standard for air is that the owner or

operator of a facility must cover or otherwise manage the unit to control wind dispersal of CKD

waste. This standard would apply to solid PM that becomes airborne directly or indirectly as a

result of CKD handling procedures. The most common sources of PM at cement manufacturing
Draft: March 20, 1998 4-2

facilities to which this standard applies includes vehicular traffic on unpaved roads or on CKD

waste management units, and wind erosion from waste management units. This standard would

not apply to CKD emitted from an exhaust stack. 

The Agency understands that methods for controlling fugitive dust will vary depending on factors

such as geographic location, climate, facility design, and CKD management method. Therefore,

the proposal provides owners and operators, working with State agencies, with substantial

flexibility do determine the appropriate method to control fugitive emissions based on facilityspecific conditions.

To demonstrate compliance with the performance standard for the protection of air, EPA has

proposed that owners or operators of new and existing CKD landfills employ the technologybased standards described below for controlling fugitive dust. For example, an owner or operator

may employ all of the following to demonstrate compliance with the performance standard for the

protection of air:

• emplace CKD waste in a landfill as conditioned CKD;

• cover the waste in the landfill at the end of each operating day with material

sufficient to prevent blowing dust;

• water unpaved roads with sufficient frequency to prevent blowing dust;

• use covers on trucks transporting CKD; and

• place CKD destined for temporary storage prior to recycling, sale, or disposal in

tanks, containers, or buildings.

4.2 Technical Standards That Meet the Performance Standard

4.2.1 Conditioning

For facilities complying with the technology-based standards, EPA has proposed that CKD

managed in landfills must be emplaced as conditioned CKD. Proper conditioning includes mixing

the CKD with water on a continuous or batch basis, such as pug-milling, followed by compaction. 

The material should be spread in lifts of uniform thickness and compacted to the required density

with appropriate equipment (e.g., a heavy sheeps-foot roller). The Agency believes that

compaction of moist CKD, coupled with the waste’s natural cementitious properties enables

individual waste particles to bond together, thus greatly reducing the availability of particulate

material for air dispersal, and thus, this standard is protective for fugitive dust from landfills. For

purposes of this section, conditioned CKD means cement kiln dust that has been compacted in the

field at appropriate moisture content using moderate to heavy equipment to attain 95% of the

standard Proctor maximum dry density value according to ASTM D 698 or D 1557 test methods.
 Although wetting and watering is a common fugitive dust suppression practice at CKD 4

landfills, the persistent releases of fugitive CKD reported in the Report to Congress on Cement

Kiln Dust suggest that frequent wetting alone is not sufficient to prevent blowing dust.

Draft: March 20, 1998 4-3

4.2.2 Covers

The Agency has also proposed that disposed CKD be covered with material at the end of each

operating day sufficient to prevent blowing dust. EPA believes that cover material applied at the

end of each operating day over the active face of the CKD landfill will prevent the entrainment of

CKD as fugitive dust, and is a more effective practice for dust suppression than frequent wetting

and watering . The cover must be constructed of materials that have appropriate physical and 4

chemical properties, and sufficient strength and thickness to prevent failure due to physical

contact with CKD, climactic conditions, the stress of installation, and the stress of daily operation. 

Similarly, EPA has proposed that CKD transported in trucks on or off the facility be covered to

minimize fugitive emissions of CKD. Alternative materials or actions may be approved by the

State (or, in unapproved States by the EPA Regional Administrator), as long as the facility makes

a demonstration that the alternative meets the performance standard.

4.2.3 Wetting

EPA believes that consistent wetting and watering of unpaved roads can sufficiently reduce

releases of fugitive emissions from facilities that manage CKD. As discussed above in Section 3,

fugitive dust emissions from unpaved roads can be significantly reduced by increasing the

moisture content of the dust.

4.2.4 Temporary Storage

The Agency has proposed that CKD destined for temporary storage prior to recycling, sale, or

disposal not be placed in land-based units, but in tanks, containers, or buildings. CKD would not

be a hazardous waste provided the storage that precedes sale or recycling does not entail land

placement. An acceptable building containment unit must be a man-made structure with a

foundation constructed of non-earthen materials, have walls (which may be removable), and have

a roof suitable for diverting rainwater away from the foundation. In considering these criteria for

containers and buildings, EPA is placing special emphasis upon practical considerations, such as

the need to transport materials in and out of the unit in a reasonable fashion. The Agency would

not require that these units meet full Subtitle C requirement for storage of hazardous wastes as

outlined in Part 265 Subpart J.

4.3 Application of the Technology-Based Standard to Model Plants

The technology-based standard proposes four majors areas of control, these are:

Conditioning,
Draft: March 20, 1998 4-4

Covers,

Wetting, and

Enclosure of Temporary Storage.

As this document demonstrates, there are a wide variety of control techniques and technologies

that can be successfully applied to control of CKD. The performance of most of these will vary

from site to site. The technology-based standard proposes a set of control technologies that have

the potential to provide a high level of emissions control under a variety of circumstances. The

proposed Rule allows for flexible implementation for facilities wishing to employ and demonstrate

alternative control techniques.

EPA has applied the technical standard to the two model plant scenarios and compared these

technical standards to baseline, uncontrolled emissions in order to calculate the overall emissions

reduction that can be achieved by complying with the standards. Exhibit 4-1 presents the percent

emissions reductions achieved by implementing the technology-based standards in comparison to

an uncontrolled emissions baseline.

Exhibit 4-1

Control Efficiencies Achieved by Technology-Based Standard

Moisture Facility B Facility A

Content PM-30 PM-10 PM-2.5 PM-30 PM-10 PM-2.5

Uncontrolled Emissions Estimates (lbs/yr) (from Exhibit 3-3)

na 27,494 13,662 5,359 85,672,071 43,459,254 9,024,365

Emissions Estimates (lbs/yr) for a Wet Compaction Scenario Meeting the Requirements of the

Proposed Technology-Based Standard (from Exhibit 3-8)

10% 200 90 25 40,976 18,475 4,923

30% 199 90 24 40,905 18,441 4,913

50% 199 90 24 40,895 18,437 4,912

Percent Reduction Achieved Over Uncontrolled Scenario Through Application of TechnologyBased Standard

10% 99.27% 99.34% 99.53% 99.95% 99.96% 99.95%

30% 99.28% 99.34% 99.55% 99.95% 99.96% 99.95%

50% 99.28% 99.34% 99.55% 99.95% 99.96% 99.95%
Draft: March 20, 1998 4-5

The emissions reductions in Exhibit 4-1 represent control improvements over uncontrolled

emissions. Because most facilities currently operate with some fugitive dust controls, these

estimates do not necessarily represent typical current industry practice. In addition, due to the use

of simplifying and conservative assumptions (such as the “fastest mile” values used to calculate

wind erosion), the estimates of uncontrolled conditions represent upper bound or high end

estimates. Actual percent reductions achievable at a typical facility implementing the technologybased standard might be lower than those estimated for the sample plants. However the Agency

believes this analysis demonstrates the proposed technology-based standard represents a high level

of emissions reduction that can be achieved using currently available and implementable

technologies. 
 For purposes of this section, temporary storage means interim storage of CKD designated for recycling, sale 5

or final disposal. 

Draft: March 20, 1998 5-1

Chapter 5: Implementation

5.1 Implementation of Fugitive Dust Control Technologies

As described in Chapter 4, the Agency is proposing standards to control fugitive dust emissions of

CKD at cement manufacturing facilities. Under the proposed regulations, owners or operators 

will be required to control fugitive dust emissions (1) from tanks, containers, or buildings used for

temporary storage of CKD for recycling, sale or final disposal, (2) from trucks transporting CKD,

and (3) at CKD landfills. This section describes technical considerations for implementation of

the proposed standards for control of fugitive emissions from CKD management activities.

5.1.1 Control of Fugitive Dust Emissions from Tanks, Containers, or Buildings

Under the proposed rule for CKD, the Agency is proposing standards to control fugitive

emissions from cement kiln dust waste placed in temporary storage. Temporary storage of CKD

includes CKD tanks, containers or buildings. To control fugitive emissions, the temporary

storage unit must meet the following minimum standards:5

The tank, container, or building should be an engineered structure with a

man-made floor, walls, and a roof all of which prevent water from reaching the

stored CKD and are made of non-earthen materials providing structural support.

The tank, container, or building must be free standing and not a surface

impoundment (as defined in 40 CFR 260.10), be manufactured of a material

suitable for storage of its contents, and meet appropriate specifications such as

those established by either ASTM, API, or UL standards.

In implementing these standards, owner/operators may make a demonstration to the State that

alternative measures will control wind dispersal of dust without presenting a threat to human

health and the environment. The owner or operator must place the demonstration in the operating

record and notify the State that it has been placed in the operating record.

5.1.2 Control of Fugitive Dust Emissions from Transport of CKD Via Trucks

Under the proposed rule for CKD, the Agency is proposing standards to control fugitive

emissions during the transport of CKD in trucks to a CKDLF units. In implementing the

regulations, owner/operators must cover vehicles or otherwise manage the CKD to control wind

dispersal of dust. Sources of emissions can include CKD in the truck beds, CKD on the trucks,

and CKD on roadways. While the proposed technical standard applies to cover on truck,
For purposes of this section conditioned CKD means cement kiln dust that has been compacted in the field at 6

appropriate moisture content using moderate to heavy equipment to attain 95% of the standard Proctor maximum dry

density value according to ASTM D 698 or D 1557 test methods.

Draft: March 20, 1998 5-2

owner/operators may wish to also use other good housekeeping methods such as moisture

addition to roads and periodic cleaning of trucks.

Alternative measures for dust control may be approved by the State if a demonstration is made

that the alternative controls wind dispersal of dust without presenting a threat to human health

and the environment. The owner or operator must place the demonstration in the operating record

and notify the State Director that it has been placed in the operating record.

5.1.3 Control of Fugitive Dust Emissions at CKDLF Units

The Agency is proposing standards to control fugitive emissions at CKDLF units. Under the

proposed standards, CKD disposed in all CKDLF units must be managed in a manner that does

not violate any applicable requirements developed under a State Implementation Plan (SIP)

approved or promulgated by the Administrator pursuant to section 110 of the Clean Air Act, as

amended. 

In implementing these standards, the owner or operator must dispose CKD in CKDLF units and

expansions constructed so that such CKD is:

1. Covered or otherwise managed to control wind dispersal of dust, or

2. Emplaced as conditioned CKD to control wind dispersal, and 6

3. Covered with a sufficient thickness of earthen material at the end of each operating

day, or at more frequent intervals if necessary to control blowing dust. 

If approved by the State, an owner or operator may use alternative materials and actions for

fugitive CKD control. To use an alternative material or action, owner/operators must

demonstrate to the State that the alternative controls blowing dust without presenting a threat to

human health and the environment. The owner or operator must place the demonstration in the

operating record and notify the State that it has been placed in the operating record.

The Agency has identified two CKD-based products have been identified for potential use as a

daily or intermediate cover for a CKD landfill. The Report to Congress (USEPA, 1993b)

identifies a product known as N-Viro Soil , which is a mixture of CKD and sewage sludge, and ®

notes its use as a cover at landfills. A product known as Posi-Shell , also CKD-based, has also ®

been used as a cover material at landfills. As part of the evaluation of CKD as landfill liners and
 For additional information, see Sections 6.4.5.1 and 6.4.5.2 of the Technical Background Document on 7

Ground Water Controls at CKD Landfills in today’s docket.

Draft: March 20, 1998 5-3

caps , N-Viro Soil , and Posi-Shell , were briefly evaluated based on vendor information and 7 ® ®

available information.

5.2 Reporting and Recordkeeping

In implementing the fugitive dust control provisions of the proposed rule, owner/operators have

the option of demonstrating to the State the effectiveness of alternatives to control fugitive dust

emissions during temporary storage, transport, and landfilling of waste CKD. Such a 

demonstration must be placed in the operating record of the facility and the owner/operator must

notify the State that such a demonstration has been made. Alternatives to earthen cover materials

must be approved by the State.

In addition, any deviations from the default technical standards (or demonstrated alternative

measures) must be documented in the facility’s operating record.
Draft: March 20, 1998

References

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Management Association. New York: Van Nostrand Reinhold.

Cowherd, Jr., C., et al., 1985. Rapid Assessment of Exposure to Particulate Emissions from

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Cowherd, Jr., C., et al., 1988. Control Of Open Fugitive Dust Sources, EPA 450/3-88-008, U.

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Kohlhaas, B., et al., 1983. Cement Engineer’s Handbook. Bauverlag GMBH, Wiesbaden and

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Development Bulletin RD103T, Portland Cement Association.

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of Solid Waste, Washington, D.C., December 1993.

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and Response Document on Cement Kiln Dust. Office of Solid Waste, Washington, D.C.,

August, 1994.

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of Data Availability on Cement Kiln Dust, Human Health and Environmental Risk

Assessment, in Support of the Regulatory Determination on Cement Kiln Dust. Office of

Solid Waste, Washington, D.C., August, 1994.
Draft: March 20, 1998

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Volume I: Stationary Point and Area Sources, AP-42 Fifth Edition, U.S. Environmental

Protection Agency, Research Triangle Park, NC, January 1995.

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Risks from Indirect Exposure Pathways, and Population Effects from Exposure to

Airborne Particles from Cement Kiln Dust Waste. Office of Solid Waste, Washington,

D.C., June, 1997.

U.S. Environmental Protection Agency, 1998a. Personal communication with Frank Smith,

Office of Solid Waste.

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Michigan. Tape #1: Alpena dust handling, March 1994; Tape #6: Air, Water, Dust, 6/92

to 10/93; Tape #11: Fugitive Dust Stack and Water Emissions; Tape #12: Dust and Stack

Emissions.