Department of Health and Human Services

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

IC 9527

INFORMATION CIRCULAR/2012
Information Circular 9527 

National Survey of the Mining Population 

Part I: Employees 

Linda Jansen McWilliams, Patricia J. Lenart, Jamie L. Lancaster, John R. Zeiner, Jr.

DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health 

Office of Mine Safety and Health Research 

Pittsburgh, PA • Spokane, WA 

June 2012 
ii 

 

This document is in the public domain and may be freely 

copied or reprinted.

Disclaimer 

Mention of any company or product does not constitute endorsement by the 

National Institute for Occupational Safety and Health (NIOSH). In addition, citations to Web 

sites external to NIOSH do not constitute NIOSH endorsement of the sponsoring organizations 

or their programs or products. Furthermore, NIOSH is not responsible for the content of these 

Web sites. All Web addresses referenced in this document were accessible as of the publication 

date. 

Ordering Information 

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contact NIOSH at 

Telephone: 1–800–CDC–INFO (1–800–232–4636) 

TTY: 1–888–232–6348 

e-mail: cdcinfo@cdc.gov 

or visit the NIOSH Web site at www.cdc.gov/niosh. 

For a monthly update on news at NIOSH, subscribe to NIOSH eNews by visiting 

www.cdc.gov/niosh/eNews. 

DHHS (NIOSH) Publication No. 2012–152 

June 2012 

SAFER • HEALTHIER • PEOPLETM
SECTION CONTENTS

Employee Statistics for All Mines

Employee Statistics for Coal Mines

Employee Statistics for Metal Mines

Employee Statistics for Nonmetal Mines

Employee Statistics for Stone Mines

Employee Statistics for Sand and Gravel Mines
 
v 

Contents 

Abstract ........................................................................................................................... 1 

Introduction ..................................................................................................................... 2 

Background and Overview .............................................................................................. 2 

Survey Materials ............................................................................................................. 3 

The Paper Questionnaire ........................................................................................ 3 

The Internet Questionnaire ...................................................................................... 4 

Sample Design and Selection ......................................................................................... 4 

Definition of the Target Population .......................................................................... 4 

Construction of the Sampling Frame ....................................................................... 5 

Stratification Guidelines ........................................................................................... 5 

Sampling Plans ............................................................................................................. 15

Data Collection .............................................................................................................. 19 

Survey Packet ....................................................................................................... 19 

Survey Promotion .................................................................................................. 20 

Follow-up Contacts ............................................................................................... 21 

Data Imputation and Statistical Weighting Procedures.................................................. 21 

Data Imputation ..................................................................................................... 21 

Data Weighting, Estimation, and Variance Estimation .......................................... 22 

Lessons Learned ........................................................................................................... 22 

Survey Results .............................................................................................................. 23 

Employee Job Titles ...................................................................................................... 27 

Statistical Analysis......................................................................................................... 28 

Employee Statistics for All Mines .................................................................................. 29 

Employee Statistics for Coal Mines ............................................................................... 55 

Employee Statistics for Metal Mines.............................................................................. 73 

Employee Statistics for Nonmetal Mines ....................................................................... 91 

Employee Statistics for Stone Mines ........................................................................... 111 

Employee Statistics for Sand and Gravel Mines ......................................................... 131 

Acknowledgements ..................................................................................................... 149 

References .................................................................................................................. 151 

Appendices ................................................................................................................. 153 

Appendix A. Questionnaire Booklet ............................................................................. 155 
vi 

Appendix B. Questions and Answers Brochure ........................................................... 179 

Appendix C. MSHA Form 7000-2: Quarterly Mine Employment and Coal Production 

Report .................................................................................................................... 183

Appendix D. Standard Industrial Classifications (SIC) for Active Mines in 2007 ......... 187 

Appendix E. Stratification and Sample Size Guidelines .............................................. 191 

Appendix F. Sample Size Allocation Using MSHA Data from the Second Quarter of 

2002 ....................................................................................................................... 197 

Appendix G. Critical Items from the Questionnaire ..................................................... 209 

Appendix H. Job Titles as Submitted by Survey Respondents .................................... 215 

Appendix I. Glossary ................................................................................................... 243 
vii 

Figures 

Figure 1. Map of Active Coal Mining Operations for 2007. ............................................. 7 

Figure 2. Map of Active Metal Mining Operations for 2007. ............................................ 8 

Figure 3. Map of Active Nonmetal Mining Operations for 2007. ..................................... 9 

Figure 4. Map of Active Stone Mining Operations for 2007. ......................................... 10 

Figure 5. Map of Active Sand and Gravel Mining Operations for 2007. ........................ 11 

Figure 6. Density Map for Mine Operator Employees for 2007. ................................... 12 

Figure 7. Density Map for Underground Mine Operator Employees for 2007. .............. 13 

Figure 8. Density Map for Surface Mine Operator Employees for 2007. ...................... 14 

Figure 9. Weighted Response Rates by Sector and Mine Type. .................................. 26 

Figure 10. Education Level of Employees at All Mines. ................................................ 35 

Figure 11. Race of Employees at All Mines. ................................................................. 36 

Figure 12. Primary Work Location of Employees at All Mines. ..................................... 37 

Figure 13. Occupational Categories of Employees at All Mines. .................................. 53 

Figure 14. Education Level of Employees at Coal Mines. ............................................ 61 

Figure 15. Race of Employees at Coal Mines. ............................................................. 62 

Figure 16. Primary Work Location of Employees at Coal Mines. ................................. 63 

Figure 17. Occupational Categories of Employees at Coal Mines. .............................. 72 

Figure 18. Education Level of Employees at Metal Mines. ........................................... 79 

Figure 19. Race of Employees at Metal Mines. ............................................................ 80 

Figure 20. Primary Work Location of Employees at Metal Mines. ................................ 81 

Figure 21. Occupational Categories of Employees at Metal Mines. ............................. 89 

Figure 22. Education Level of Employees at Nonmetal Mines. .................................... 97 

Figure 23. Race of Employees at Nonmetal Mines. ..................................................... 98 

Figure 24. Primary Work Location of Employees at Nonmetal Mines........................... 99 

Figure 25. Occupational Categories of Employees at Nonmetal Mines...................... 109 

Figure 26. Education Level of Employees at Stone Mines. ........................................ 117 

Figure 27. Race of Employees at Stone Mines. ......................................................... 118 

Figure 28. Primary Work Location of Employees at Stone Mines. ............................. 119 

Figure 29. Occupational Categories of Employees at Stone Mines. .......................... 129 

Figure 30. Education Level of Employees at Sand and Gravel Mines. ....................... 137 

Figure 31. Race of Employees at Sand and Gravel Mines. ........................................ 138 

Figure 32. Primary Work Location of Employees at Sand and Gravel Mines. ............ 139 

Figure 33. Occupational Categories of Employees at Sand and Gravel Mines. ......... 147 
viii 

Tables 

Table 1. Sample Allocation for Underground Coal Mines ............................................. 16 

Table 2. Sample Allocation for Surface Coal Mines ..................................................... 16 

Table 3. Sample Allocation for Underground Metal Mines ........................................... 16 

Table 4. Sample Allocation for Surface Metal Mines .................................................... 17 

Table 5. Sample Allocation for Underground Nonmetal Mines ..................................... 17 

Table 6. Sample Allocation for Surface Nonmetal Mines ............................................. 17 

Table 7. Sample Allocation for Underground Stone Mines ........................................... 18 

Table 8. Sample Allocation for Surface Stone Mines ................................................... 18 

Table 9. Sample Allocation for Sand and Gravel Mines ............................................... 18 

Table 10. Number of Mines in the Final Sample by Sector, Type, and Reporting 

Week ..................................................................................................................... 20 

Table 11. Summary of Final Results for All Sampled Mines ......................................... 24 

Table 12. Number of Completed Surveys by Mode ...................................................... 24 

Table 13. Summary of Ineligible Mines by Sector ........................................................ 25 

Table 14. Summary of Refusal by Mine Sector and Type of Refusal ........................... 25 

Table 15. National Estimates of Mines and Mine Employees in Spring/Summer 

2008 ......................................................................................................................... 27 

Table 16. Demographic Characteristics of Employees at All Mines ............................. 33 

Table 17. Occupational Characteristics of Employees at All Mines .............................. 34 

Table 18. Estimated Number of Administration/Professional Employees at All Mines . 38 

Table 19. Estimated Number of Maintenance Employees at All Mines ........................ 43 

Table 20. Number of Miscellaneous Employees at All Mines ....................................... 44 

Table 21. Estimated Number of Production Employees at All Mines ........................... 45 

Table 22. Estimated Number of Service and Utility Employees at All Mines ................ 50 

Table 23. Demographic Characteristics of Employees at Coal Mines .......................... 59 

Table 24. Occupational Characteristics of Employees at Coal Mines .......................... 60 

Table 25. Estimated Number of Administration/Professional Employees at Coal 

Mines ....................................................................................................................... 64 

Table 26. Estimated Number of Maintenance Employees at Coal Mines ..................... 67 

Table 27. Number of Miscellaneous Employees at Coal Mines ................................... 68 

Table 28. Estimated Number of Production Employees at Coal Mines ........................ 68 
ix 

Table 29. Estimated Number of Service and Utility Employees at Coal Mines ............. 70 

Table 30. Demographic Characteristics of Employees at Metal Mines ......................... 77 

Table 31. Occupational Characteristics of Employees at Metal Mines ......................... 78 

Table 32. Estimated Number of Administration/Professional Employees at Metal 

Mines ....................................................................................................................... 82 

Table 33. Estimated Number of Maintenance Employees at Metal Mines ................... 85 

Table 34. Number of Miscellaneous Employees at Metal Mines .................................. 86 

Table 35. Estimated Number of Production Employees at Metal Mines ....................... 86 

Table 36. Estimated Number of Service and Utility Employees at Metal Mines ........... 88 

Table 37. Demographic Characteristics of Employees at Nonmetal Mines .................. 95 

Table 38. Occupational Characteristics of Employees at Nonmetal Mines .................. 96 

Table 39. Estimated Number of Administration/Professional Employees at 

Nonmetal Mines ..................................................................................................... 100 

Table 40. Estimated Number of Maintenance Employees at Nonmetal Mines ........... 103 

Table 41. Number of Miscellaneous Employees at Nonmetal Mines ......................... 104 

Table 42. Estimated Number of Production Employees at Nonmetal Mines .............. 104 

Table 43. Estimated Number of Service and Utility Employees at Nonmetal Mines ... 107 

Table 44. Demographic Characteristics of Employees at Stone Mines ...................... 115 

Table 45. Occupational Characteristics of Employees at Stone Mines ...................... 116 

Table 46. Estimated Number of Administration/Professional Employees at Stone 

Mines ..................................................................................................................... 120

Table 47. Estimated Number of Maintenance Employees at Stone Mines ................. 123 

Table 48. Number of Miscellaneous Employees at Stone Mines ............................... 124 

Table 49. Estimated Number of Production Employees at Stone Mines .................... 124 

Table 50. Estimated Number of Service and Utility Employees at Stone Mines ......... 127 

Table 51. Demographic Characteristics of Employees at Sand and Gravel Mines .... 135 

Table 52. Occupational Characteristics of Employees at Sand and Gravel Mines ..... 136 

Table 53. Estimated Number of Administration/Professional Employees at Sand 

and Gravel Mines ................................................................................................... 140 

Table 54. Estimated Number of Maintenance Employees at Sand and Gravel 

Mines ..................................................................................................................... 142

Table 55. Number of Miscellaneous Employees at Sand and Gravel Mines .............. 143 

Table 56. Estimated Number of Production Employees at Sand and Gravel Mines ... 143 
x 

Table 57. Estimated Number of Service and Utility Employees at Sand and Gravel 

Mines ..................................................................................................................... 145

Table E-1. Half-Length of 95% Confidence Intervals in Percentage Points for 

Various Percentages Being Estimated for Domains of Various Sizes with 

Various Design Effects ........................................................................................... 196 

Table F-1. Sample Allocation for Underground Coal Mines ........................................ 199 

Table F-2. Sample Allocation for Surface Coal Mines ................................................. 200 

Table F-3. Sample Allocation for Underground Metal Mines ....................................... 201 

Table F-4. Sample Allocation for Surface Metal Mines ................................................ 202 

Table F-5. Sample Allocation for Underground Nonmetal Mines ................................ 203 

Table F-6. Sample Allocation for Surface Nonmetal Mines ......................................... 204 

Table F-7. Sample Allocation for Underground Stone Mines ...................................... 205 

Table F-8. Sample Allocation for Surface Stone Mines ............................................... 206 

Table F-9. Sample Allocation for Sand and Gravel Mines ........................................... 207 

 
xi 

Acronyms and Abbreviations 

CI Confidence Interval 

DEFF Design Effect 

DSU Data suppressed 

FPC Finite population corrected 

FTE Full-time Equivalent 

IC Information Circular 

LCL Lower Confidence Limit 

MIPS Mining Industry Population Survey 

MSHA Mine Safety and Health Administration 

NA Not applicable 

NIOSH National Institute for Occupational Safety and Health 

OMB Office of Management and Budget 

OMSHR Office of Mine Safety and Health Research 

SIC Standard Industrial Classification 

UCL Upper Confidence Limit 

Definition of Terms 

Confidence Interval: An interval that gives an estimated range of values 

which is likely to include an unknown population 

parameter, the estimated range being calculated 

from a given set of sample data 

Jackknife Repeated 

Replication: 

A commonly used resampling approach to variance 

estimation 

Lower Confidence Limit: The lower bound of a confidence interval 

National Estimate: A weighted statistical calculation which uses the 

results from a probability sample survey to estimate 

a national number 

Survey Count: The actual number of responses obtained from the 

National Survey of the Mining Population 

Upper Confidence Limit: The upper bound of a confidence interval 

National Survey of the Mining Population 

Part I: Employees 

Linda Jansen McWilliams, Patricia J. Lenart, Jamie L. Lancaster, John R. Zeiner, Jr. 

Office of Mine Safety and Health Research 

National Institute for Occupational Safety and Health 

 Abstract 

The National Institute for Occupational Safety and Health (NIOSH) conducted the first 

comprehensive survey of the U.S. mining population in more than 20 years. The National 

Survey of the Mining Population captured the current profile of the U.S. mining workforce. Data 

collection began in March 2008 and continued through August 2008. Randomly selected mining 

operations in all of the major mining sectors (i.e., coal, metal, nonmetal, stone, and sand and 

gravel) received the survey and had the option of completing a paper or web-based 

questionnaire. A total of 737 mining operations returned completed questionnaires and reported 

data for 9,008 employees. 

Two sets of data were collected in this national survey. There were questions about the 

mining operation, including employee training, work schedules, the use of independent 

contractor employees, and mine communication and safety systems. The employee questions 

included demographic and occupational questions about individual employees. The survey 

sample data were weighted in order to provide national estimates of mine and employee 

characteristics. 

This Information Circular (IC) is published in two parts—“Part I: Employees” presents the 

employee-level data and “Part II: Mines” presents the mine-level data. Both parts of this IC 

include an overview of the survey background, development of the survey materials, sample 

design and sample selection, data collection and processing, statistical weighting, and lessons 

learned. The survey data are summarized for the overall U.S. mining industry and the five major 

mining sectors. The information gathered from the survey respondents is being published only 

as summarized data so that no single mining operation or employee can be identified. 
2 

Introduction 

Surveillance of occupational injuries, illnesses, and exposures has been an integral part of 

the work of the National Institute for Occupational Safety and Health (NIOSH) since its creation 

by the Occupational Safety and Health Act in 1970. Surveillance activities at the Office of Mine 

Safety and Health Research (OMSHR) are focused on the nation’s mining workforce. These 

surveillance activities make extensive use of data from a number of different national databases. 

The most frequently used databases are those maintained by the Mine Safety and Health 

Administration (MSHA). Included are databases of reported employment, 

accidents/injuries/illnesses, hazardous exposures, coal production, mine inspections, violations 

and citations, etc. Two of the most commonly used databases are the mine operator and 

contractor address/employment file and the file listing reports of accidents, injuries, and 

illnesses. 

Analysis of data from the existing MSHA employment and accident/injury/illness 

databases has been able to meet some, but not all, of the OMSHR surveillance needs. For 

example, to identify subpopulations in each major mining sector or type of mining operation at 

risk of adverse health and safety outcomes, OMSHR needs the capability to calculate age-, 

gender-, and occupation-specific rates of injuries, fatalities, and disease. Additionally, due to the 

reduced reporting requirements for independent contractors, OMSHR cannot determine the 

number of contractor employees working separately in metal, nonmetal, stone, or sand and 

gravel operations. The National Survey of the Mining Population was designed to collect mineand employee-level information to address these and other data gaps. 

Background and Overview 

The last national survey targeting the mining workforce, the Mining Industry Population 

Survey (MIPS), was conducted in 1986 by the U.S. Bureau of Mines (USBM) in the U.S. 

Department of the Interior. The mining industry has experienced many changes since the MIPS 

was conducted, and its data are too outdated to be considered useful for surveillance on the 

current mining workforce. In addition, the MIPS did not include any information on independent 

contractor employees. Therefore, the National Institute for Occupational Safety and Health, 

Office of Mine Safety and Health Research conducted this survey to provide updated 

demographic and occupational information on the mining workforce. The National Survey of 

the Mining Population collected information from each of the five major mining sectors (coal, 

metal, nonmetal, stone, and sand and gravel). The survey’s main objectives were to: 

 Collect basic information about mining operations. 

 Establish the demographic and occupational characteristics of mine operator 

employees. 

 Estimate the number of independent contractor employees used by mining operations. 

Data collection began in March 2008 and continued through August 2008. A survey 

packet was mailed to each sampled mining operation. Respondents were given the option of 

completing a paper questionnaire or using a web questionnaire. Two sets of data were collected 
3 

in this survey. The mine questions included items about the mining operations, communication 

and safety systems, and the mine’s use of independent contractor employees. The employee 

questions included demographic and occupational questions about individual employees. The 

survey’s employee-level data will be used by OMSHR to determine the accident rates for various 

demographic and occupational categories as well as provide information that will be used to 

improve the safety and health of miners. 

This Information Circular (IC) is published in two parts—“Part I: Employees” presents 

the employee-level data and “Part II: Mines” presents the mine-level data. The employee and 

mine data are summarized for the overall U.S. mining industry and the major mining sectors. In 

addition, the data in the Mines IC is stratified by underground and surface for the coal, metal, 

nonmetal, and stone sectors. The information gathered from the survey respondents is being 

published only as summarized data so that no single mining operation or employee can be 

identified. The intent of this IC is to present the methodology used to design and conduct the 

survey and to provide up-to-date information about U.S. mining operations and their employees. 

Survey Materials 

A survey packet was developed which contained a cover letter, a questionnaire booklet 

with employee sampling instructions (Appendix A), directions for accessing the Internet version 

of the questionnaire, a Questions and Answers (Q&A) brochure (Appendix B), and a stamped, 

self-addressed return envelope. 

The Paper Questionnaire 

Each survey paper questionnaire booklet was personalized with a box at the top of page 1 

which included: the mine ID number, the mine name, the reporting week (date), and a “submitby” date. The Questionnaire Overview section presented general instructions and guidelines for 

completing the survey. The survey consisted of five parts as summarized below: 

 Mine Questions—This first part of the questionnaire included sections on: Training; 

Other Languages; Work Schedules for Production Workers, Production Support 

Workers, and Preparation Plant/Mill Workers; Shift Work for these same three types 

of workers; Independent Contractor Employees; and Safety, Communication, and 

Rescue Measures. 

 Employee Selection Instructions—This page contained step-by-step instructions for 

selecting the sample of employees to be included in the Employee Questions. 

Personalized mine information was preprinted at the top of this page, including: the 

mine ID number, the mine name, the reporting week (date), the range of the estimated 

number of employees working at the mine, a “start-with” number and a “take-every” 

number for selecting employees from the mine’s employee roster. 

 Instructions for Employee Questions—This two-page section of the questionnaire 

provided item-by-item explanations for the Employee Questions. 
4 

 Employee Questions—These items were formatted as a fold-out answer form. The 

sections included: Regular Job Title, Mining Experience, Number of Hours Worked 

During the Reporting Week, Primary Work Location, Gender, Race, Ethnicity, Birth 

Year, and Education Level. Two pages of the form were included, with the first page 

containing lines for reporting up to 15 employees and the second page containing 

lines for reporting up to 14 additional employees, or a maximum of 29 sampled 

employees. 

 Final Questions and Comments—This two-page section of the questionnaire 

included: questions for reporting unusual events or circumstances at the mine during 

the designated reporting week; the date the questionnaire was completed; the name, 

title and telephone number of the company representative who should be contacted 

regarding questionnaire completion; space for entering comments or explanations 

related to specific responses; and mailing instructions. 

The Internet Questionnaire 

Beginning in October 2004, a pilot study was conducted to evaluate the recruitment 

materials, questionnaire, and survey procedures developed for the nationwide survey of the 

mining population. This study allowed OMSHR to explore the feasibility of developing a webbased version of the questionnaire. The pilot study debriefing interview contained several 

questions to determine whether the mine had access to the Internet and how convenient this 

would be for completion of the questionnaire. The majority of respondents indicated that an 

Internet connection was available at their mine and more than 50 percent reported preferring an 

electronic response option. Thus, for the National Survey of the Mining Population, a web-based 

survey was made available. The survey contractor developed the web survey, including 

programming of the administrative interface, Section 508 compliance, data validation, quality 

assurance, and programming of the critical questions. 

Sample Design and Selection 

Definition of the Target Population 

The target population for a survey is the entire set of population units about which the 

survey data are to be used to make inferences. Establishment surveys such as the National 

Survey of the Mining Population must delineate the level of the business organization that 

constitutes the units of the target population. Because hazards vary across mines, the target 

population for this survey was defined in terms of the individual mining operation. 

The target population of mines consisted of active mines in current production. The 

survey was further restricted to operations that were covered under Title 30 of the U.S. Code, 

specifically mines whose mineral output was sold or used in commerce. The target population of 

employees was restricted to those mine employees for whom the mine operator must report hours 

worked using the MSHA Form 7000-2: Quarterly Mine Employment and Coal Production 
5 

Report (Appendix C). This includes all direct employees working at the mine, but not contract 

employees brought in periodically or regularly to perform work at the mine. 

There is an important temporal aspect to these definitions for mines and for mine operator 

employees. Over time, some mines will go in and out of operation. Similarly, employees join 

the mining labor force and leave the labor force over time. Accordingly, the National Survey of 

the Mining Population focused on mines in operation during a particular calendar quarter and the 

current employees of those mines. 

Construction of the Sampling Frame

The sampling frame for a survey is the list or mechanism used to enumerate target 

population members for sample selection purposes. Individual sampling frames for each of the 

five major mining sectors (see Figures 1–5) were constructed using the 2007 second quarter data 

released by the Mine Safety and Health Administration, so that the sampling frames would be in 

sync with the actual time period when data collection would begin (the second quarter of 2008). 

To ensure that any startup or intermittent mining operations would not be missed, all mines 

reporting zero employment hours were included in these frames. Any mines with a status of 

abandoned or abandoned/sealed were excluded from the sampling frames. The Standard 

Industrial Classification (SIC) for the active coal, metal, nonmetal, stone, and sand and gravel 

mines used in the sampling frames is presented in Appendix D. 

Stratification Guidelines 

For the National Survey of the Mining Population, mine-level and employee-level 

analyses were planned, which required adequate sample sizes of mines and of employees. 

Because multiple employees were to be sampled from each responding mine, sample size 

requirements for mine-level analyses tended to drive the total number of mines that needed to be 

sampled. The sample size for employees was determined by the number of sampled mines 

responding and the average number of employees sampled per mine. 

The competing needs of mine-level analysis versus employee-level analysis required the 

use of a compromise design that supported the objectives of both types of analyses. For minelevel analyses, the best design was one that selected mines with equal probability, while for 

employee-level analyses the best design was one that selected mines with probability 

proportional to the number of employees. The compromise design met both needs by stratifying 

by the number of employees and then sampling mines with equal probability within strata. Strata 

associated with large mines (in terms of employment) were given greater selection probabilities 

than small mines, which would facilitate employee-level analyses by making the employee 

selection probabilities less variable across mines. 

Mine size was an important domain for study at the mine level as well as at the employee 

level. For example, mines might be more likely to vary in their training procedures based upon 

employee size. Small mines may be more likely to use trainers from outside the organization, 

while large mines may be more likely to rely on in-house trainers. Hence, stratifying by the 

number of employees when sampling mines served an analytic purpose, as well as facilitated the 

over sampling of large mines needed for employee-level analyses (see Figure 6). 
6 

From an analysis standpoint, it was also desirable to control for underground versus 

surface mines when sampling mines and employees (see Figures 7 and 8). Underground coal 

mines, in particular, have higher injury and fatality rates than surface mines. There is substantial 

diversity in the incidence of injuries and fatalities at underground mines versus surface mines 

across all mining sectors. Nearly one-third of coal and metal mines are underground. Less than 

ten percent of nonmetal and stone mines are underground and sand and gravel mines are surface 

only. Stratification by underground mines versus surface mines allows for the control over 

sample sizes needed for effective comparisons of underground mines to surface mines. A more 

in-depth discussion of the stratum size formation and sample size guidelines used in this survey 

can be found in Appendix E.
7 

Figure 1. Map of Active Coal Mining Operations for 2007. 
8 

Figure 2. Map of Active Metal Mining Operations for 2007.
9 

Figure 3. Map of Active Nonmetal Mining Operations for 2007.
10 

Figure 4. Map of Active Stone Mining Operations for 2007.
11 

Figure 5. Map of Active Sand and Gravel Mining Operations for 2007.
12 

Figure 6. Density Map for Mine Operator Employees for 2007.
13 

Figure 7. Density Map for Underground Mine Operator Employees for 2007.
14 

Figure 8. Density Map for Surface Mine Operator Employees for 2007.
15 

Sampling Plans 

The original sampling plans were finalized in 2004 after a pretest with eight mining 

operations. These plans were developed using MSHA data from the second quarter of 2002. 

The number of actual employees was used to develop these designs rather than the number of 

full-time equivalent (FTE) employees, because the mine operator would be sampling based upon 

counts of actual employees, not FTEs. Mines were classified as surface or underground based 

upon MSHA subunit codes. Mines reporting any employment at underground work locations 

were classified as underground mining operations. 

Because there would actually be two surveys, one for mines and one for employees, the 

sampling allocation needed to be balanced. An approach that Cochran [1977] suggested was 

used where the size strata were defined so that they were equal in terms of the square root of the 

size measure (in this case, the number of employees). The square root was used as a 

compromise between the needs of mine-level estimation where equal selection probabilities were 

best (size = 1) and employee-level estimation was best (size = number of employees). Detailed 

sample size allocation tables based on 2002 data for coal, metal, nonmetal, stone, and sand and 

gravel mines can be found in Appendix F. 

Following the Office of Management and Budget (OMB) approval to conduct the 

national survey, the final sampling allocations were updated using 2007 second quarter MSHA 

data. Nine sampling frames were constructed based on the mining sector and mine type 

(underground or surface). The sampling was conducted using the SurveySelect procedure in the 

SAS statistical software package (SAS Institute Inc., Cary, NC). Systematic random sampling 

within the employee size strata was used together with controlled sorting by the state where the 

mine was located. The latter was done to ensure that the sample of mines was geographically 

representative. All metal mines and all underground nonmetal mines were selected with 

certainty from every stratum. The final survey sample of mines consisted of 331 underground 

coal, 385 surface coal, 74 underground metal, 159 surface metal, 39 underground nonmetal, 286 

surface nonmetal, 96 underground stone, 498 surface stone, and 453 sand and gravel, for a total 

of 2,321 mining operations. Tables 1–9 present the sample allocations by mining sector and mine 

type. 
16 

Table 1. Sample Allocation for Underground Coal Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–9 146 25.4% 331 0.8% 56

10–25 118 20.5% 1,972 4.8% 68

26–50 117 20.3% 4,460 10.8% 67

51–75 58 10.1% 3,622 8.8% 35

76–100 32 5.6% 2,790 6.8% 22

101–250 61 10.6% 9,267 22.5% 49

251+ 43 7.5% 18,750 45.5% 34

Total 575 100% 41,192 100% 331

Table 2. Sample Allocation for Surface Coal Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–9 725 51.8% 2,147 5.7% 101

10–25 302 21.6% 4,945 13.1% 84

26–50 209 14.9% 7,305 19.4% 75

51–75 65 4.6% 4,057 10.8% 36

76–100 30 2.1% 2,612 6.9% 20

101–250 44 3.1% 7,235 19.2% 44

251+ 25 1.8% 9,407 24.9% 25

Total 1,400 100% 37,708 100% 385

Table 3. Sample Allocation for Underground Metal Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–9 26 35.1% 137 1.8% 26

10–25 8 10.8% 134 1.8% 8

26–50 9 12.2% 327 4.3% 9

51–75 7 9.5% 443 5.8% 7

76–100 2 2.7% 168 2.2% 2

101–250 13 17.6% 2,312 30.4% 13

251+ 9 12.2% 4,077 53.7% 9

Total 74 100% 7,598 100% 74
17 

Table 4. Sample Allocation for Surface Metal Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–9 60 37.7% 217 0.9% 60

10–25 21 13.2% 325 1.3% 21

26–50 13 8.2% 454 1.9% 13

51–75 4 2.5% 239 1.0% 4

76–100 3 1.9% 254 1.0% 3

101–250 26 16.4% 4,518 18.7% 26

251+ 32 20.1% 18,204 75.2% 32

Total 159 100% 24,211 100% 159

Table 5. Sample Allocation for Underground Nonmetal Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–9 7 17.9% 30 0.6% 7

10–25 5 12.8% 95 1.9% 5

26–50 6 15.4% 258 5.2% 6

51–75 4 10.3% 257 5.2% 4

76–100 2 5.1% 170 3.5% 2

101–250 11 28.2% 1,980 40.3% 11

251+ 4 10.3% 2,125 43.2% 4

Total 39 100% 4,915 100% 39

Table 6. Sample Allocation for Surface Nonmetal Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–9 339 53.6% 1,305 7.5% 92

10–25 128 20.2% 1,990 11.4% 65

26–50 81 12.8% 3,052 17.6% 46

51–75 32 5.1% 2,026 11.7% 32

76–100 19 3.0% 1,689 9.7% 17

101–250 25 3.9% 3,805 21.9% 25

251+ 9 1.4% 3,520 20.2% 9

Total 633 100% 17,387 100% 286
18 

Table 7. Sample Allocation for Underground Stone Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–9 15 14.0% 78 2.0% 14

10–25 42 39.3% 733 18.8% 32

26–50 30 28.0% 1,030 26.4% 30

51–75 13 12.1% 812 20.8% 13

76–100 2 1.9% 174 4.5% 2

101–250 4 3.7% 511 13.1% 4

251+ 1 0.9% 560 14.4% 1

Total 107 100% 3,898 100% 96

Table 8. Sample Allocation for Surface Stone Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–9 2,034 49.6% 9,039 11.9% 116

10–25 1,345 32.8% 21,224 28.0% 114

26–50 426 10.4% 15,002 19.8% 95

51–75 107 2.6% 6,537 8.6% 51

76–100 56 1.4% 4,903 6.5% 36

101–250 128 3.1% 18,294 24.1% 83

251+ 3 0.1% 911 1.2% 3

Total 4,099 100% 75,910 100% 498

Table 9. Sample Allocation for Sand and Gravel Mines 

Stratum

Number of 

Mines

Percentage of 

Total Mines

Number of 

Employees

Percentage of 

Total 

Employees

Sample 

Mines

1–3 2,846 44.3% 5,555 13.0% 119

4–6 1,615 25.1% 7,761 18.2% 80

7–9 729 11.3% 5,682 13.3% 37

10–25 1,010 15.7% 14,629 34.4% 110

26–50 190 3.0% 6,411 15.1% 70

51–75 27 0.4% 1,632 3.8% 27

76–100 8 0.1% 684 1.6% 8

101–250 2 0.0% 219 0.5% 2

251+ 0 0.0% 0 0.0% 0

Total 6,427 100% 42,573 100% 453
19 

Data Collection 

Survey Packet 

The survey packet mailed to each sampled mining operation contained the following 

materials: 

 A cover letter from NIOSH that introduced the study to the selected mines and 

stressed the importance of the study to the safety and health of miners. The letter was 

personalized and addressed to the best respondent identified through initial contacts 

with the mine. 

 A Questions and Answers brochure that answered frequently asked questions. 

 A copy of the paper questionnaire. 

 Personalized directions for accessing the Internet questionnaire. 

 A postage-paid return envelope for returning the hard-copy questionnaire. 

The mine respondents were given the option of completing either the paper questionnaire 

booklet or the web-based survey questionnaire. The Questions and Answers brochure explained 

that both surveys asked the same questions. To minimize the employee-level questionnaire 

burden, mines with 30 or more employees were asked to provide data for only a sample of the 

total employees working during the specific reporting week. Mines with less than 30 employees 

were asked to report for all of them. 

For mines with 30 or more employees working in the reference week, the mine 

respondent was asked to select the sample of employees by following sampling instructions 

included in the survey questionnaire. The sampling instructions were designed to select from 15 

to 25 employees per mine, with employee counts from the frame used to determine the sampling 

rate. The employees were selected using systematic sampling with custom-generated “startwith” and “take-every” numbers included on the instructions page of the questionnaire. The 

“take-every” number was determined by dividing the number of employees the mine reported to 

MSHA by 30 and then rounding down. A random number table was consulted to get a random 

number between 1 and the “take-every” number which would be the “start-with” number. The 

“start-with” number constituted the first selection made from the list, prepared by the mine, of 

employees working during the reference week. The “take-every” number needed to be added 

repeatedly to the “start-with” number to determine the remaining selections. The variable 

number of employees selected per mine resulted from the need to use an integer as the “takeevery” number to simplify the mathematics for the respondent. 

The MSHA employment data printed on the mine’s questionnaire may not have been 

current for the data collection period. This limitation was handled by instructing the mine 

respondents to call in when their mine employment for the reference week was 20 percent 

greater or 20 percent less than the employment projected from the MSHA data. The survey 

contractor would then provide alternative “start-with” and “take-every” numbers to these mine 

respondents, after determining that the respondents were reporting for the correct mine. 

Each sampled mining operation was randomly assigned a reporting week, balanced by 

mine type and sector. The reporting week was a seven-day period that the mine respondent was 

asked to reference when answering some items in the questionnaire. The reporting week was 
20 

described in the questionnaire as the mine’s payroll week, which included the date that was 

preprinted on the first page of the questionnaire. Over the course of the survey, there were a total 

of 12 reporting weeks. On average, 193 mines were assigned to each reporting week (see Table 

10). 

Table 10. Number of Mines in the Final Sample by Sector, Type, and Reporting Week 

Week

Total 

Mines Coal Metal Nonmetal Stone

Sand 

and 

Gravel Surface Underground

1 193 59 20 27 50 37 147 46

2 193 60 19 27 49 38 148 45

3 194 60 19 28 50 37 148 46

4 193 60 19 27 49 38 148 45

5 194 60 19 27 50 38 149 45

6 194 60 19 27 50 38 149 45

7 193 59 20 27 49 38 149 44

8 194 60 20 27 50 37 148 46

9 193 60 19 27 49 38 148 45

10 193 59 20 27 49 38 149 44

11 193 59 20 27 49 38 149 44

12 194 60 19 27 50 38 149 45

Total 2,321 716 233 325 594 453 1,781 540

Survey Promotion 

Several initiatives were implemented before the start of data collection to promote the 

survey and to maximize response rates. OMSHR undertook considerable efforts to publicize the 

survey. At the start of data collection in March 2008, the National Mining Association offered to 

prepare and publish an article about the survey in its newsletter. Throughout the data collection 

period, OMSHR continued to pursue additional publicity efforts, promoting the survey both 

within NIOSH and to the mining community. A sand and gravel industry newsletter included an 

article about the survey. A notice about the survey was also published in the May 2008 issue of 

CoalUSA magazine. 

Prior to the mailing of the survey packet, initial telephone calls were made to the contacts 

identified for each selected mine. In some cases the same contact individuals were found to be 

associated with multiple mines; for example, nine contacts were affiliated with mining 

companies that each had seven or more mines in the sample. A special effort was made by 

OMSHR to contact these individuals and inform them of the selection of multiple mining 

operations, determine the most appropriate addressee/recipient of the survey packet, and 

encourage participation in the survey. Throughout the data collection period, OMSHR continued 

to assist the survey contractor in both initiating and receiving calls with mine contacts and in 

responding to e-mails from the sampled mining operations. 
21 

Follow-up Contacts 

Once the survey packet had been sent to the contact person at the mine, the data 

collection schedule provided for a three-week waiting period, to allow the contact the 

opportunity to complete the survey. After the waiting period, follow-up reminder calls were 

made to those mines that did not return their questionnaires or complete the web surveys by the 

“please submit” date printed on the survey. The main functions of the follow-up calls were to: 

 Ensure that the survey materials had been received and that the materials were 

delivered to the appropriate person. 

 Answer any questions regarding completing the survey. 

 Serve as a reminder to complete the survey. 

The most difficult challenge of follow-up was simply reaching the contacts. To deal with 

this issue, various approaches and initiatives were implemented. Because e-mail addresses were 

often available for mine contacts, an e-mail initiative was developed whereby an e-mail reminder 

was sent to anyone who had: (1) started, but did not complete a web survey; (2) not yet opened a 

web survey; (3) not returned a questionnaire; or (4) not made contact during the follow-up calls. 

This resulted in some immediate responses to the e-mails, along with many calls to the toll-free 

study telephone line and directly to OMSHR, often from contact persons who had a question on 

how to complete the survey. There were also a number of out-of-office replies that were useful in 

determining when another follow-up attempt could be made. 

In addition, OMSHR also prepared a follow-up letter, cosigned by the study project 

director and the director of the NIOSH Office of Mine Safety and Health Research, with space at 

the bottom for the web survey login information and mine-specific password. This letter was 

mailed to contacts at more than 1,000 mining operations. As a result, OMSHR received some 

additional completed questionnaires. However, a large number of letters were returned as 

undeliverable. 

Data Imputation and Statistical Weighting Procedures 

A questionnaire was considered completed if it was missing no more than two of the 52 

critical items listed in Appendix G. Returned questionnaires with more than two missing critical 

items were considered partially complete and, when possible, data imputation was used to 

complete these missing items. 

Data Imputation 

Imputation is the process of replacing missing data with legitimate values derived 

through logical deduction, regression models, or other probabilistic means. For the National 

Survey of the Mining Population, an attempt was made to impute missing data for the questions 

in the Training; Prep Plant/Mill Workers (found in the Work Schedules and Shift Work 

sections); Independent Contractor Employees; Safety, Communication, and Rescue Measures; 

and Employee Length of Service sections of the questionnaire. The Prep Plant/Mill Workers 

questions were imputed via information retrieved from the MSHA data on mines not having a 
22 

preparation plant. In these cases, the relevant questionnaire items were set equal to zero or to the 

“not applicable” response. The questions in the Training; Independent Contractor Employees; 

and Safety, Communication and Rescue Measures sections were imputed via logical deduction, 

that is, when one or more responses were affirmative within the section and no negative 

responses were recorded, all missing items were set to the negative response. The Employee 

Length of Service section was completed via a regression model that predicted one or more 

missing items for the Total Years in this Job Title, Total Years at this Mine, and Total Years in 

Mining questions from those of the three that were reported. 

Data Weighting, Estimation, and Variance Estimation 

Sample survey data are weighted in order to provide unbiased or nearly unbiased 

estimates. The weights take into account variable probabilities of selection as well as 

compensate for bias introduced by differences between respondents and nonrespondents. For the 

National Survey of the Mining Population, weights were calculated in two steps. First, a base 

weight was calculated as the reciprocal of a given mine’s probability of selection. These 

probabilities varied by major mining sector (coal, metal, nonmetal, stone, and sand and gravel), 

mine type (underground or surface), and mine size (number of employees). Second, a 

nonresponse adjusted weight was calculated as the product of the base weight and a nonresponse 

adjustment factor. The nonresponse adjustment factor was calculated as the ratio of the sum of 

weights for all eligible mines within a primary stratum (sector by mine type) to the sum of the 

weights for all responding mines. 

Survey sampling implies some imprecision in the estimates and this imprecision is 

measured as variance and standard errors. For this survey, the Jackknife Repeated Replication 

(JRR) method was used to support variance estimation. One hundred replicate weights were 

created for each record in the dataset, with every replicate weight repeating the two steps 

described previously. Each replicate weight was used to derive a replicate estimate, and the 

variance in the replicate estimates (across the 100 replicates) could then be used to estimate the 

variance and standard error of each survey estimate. 

Lessons Learned 

The following lessons learned are based on project staff observations (by both OMSHR 

and the survey contractor) and the feedback obtained from the survey respondents. Also 

presented are any additional methods that could have been implemented to potentially increase 

the response rate or the efficiency of the study management. 

 The questionnaire, with its foldout employee section and sample selection approach, 

appeared to be a barrier to completion. It is possible that the perceived level of effort for 

completing the survey prevented some mines from participating. 

 Comments regarding ease of use of the survey were similar for both paper and web-based 

respondents. Partial responses on both versions of the questionnaire often stopped at the 

beginning of the employee section. This may have occurred when the mine contact 

realized that he/she could not complete the full questionnaire without retrieving 

information from other people in the mine organization, or from records not conveniently 
23 

located, or that other staff may have been unable or unwilling to complete the 

questionnaire. 

 There was no incentive provided for completion of the survey, other than to assist 

OMSHR. 

 Most refusal information related to time/burden issues. Some contacts refused after 

learning that they were assigned to complete questionnaires for multiple mines in their 

organization. Health and safety contacts often said that the survey content focused too 

little on health and safety issues and too much on human resource questions. 

 The e-mail follow-up reminders and OMSHR follow-up letter were helpful initiatives, 

but may have been more effective had they been initiated at an earlier time in the data 

collection process. 

 Even though multiple contact attempts and various response modes were used in this 

survey, conducting a nonresponse survey could have helped to ascertain whether the 

population of nonresponders differed measurably from the participants. It also could 

have been very useful in understanding and characterizing barriers to participation. 

 Some suggestions for future surveys are the following: 

o Conducting the survey to focus on one major mining sector at a time in order to 

improve performance. 

o Reducing the length of the questionnaire, in response to complaints from mines 

that did not have the staff or the time to complete it. 

o Involving large mining companies in early reviews of the survey to obtain their 

input on questions they might find objectionable and their feedback on how to 

best administer the survey. 

Survey Results 

Overall, 954 completed or partial surveys were returned from the sampled mining 

operations. The outcomes of data collection for each of the sampled mines are summarized in 

Table 11. The 651 “critical items complete” and 86 “final missing critical items” questionnaires 

were the 737 survey responses that were used for the estimates presented in this IC. The mode 

of completion by the respondents is shown in Table 12. 

 
24 

Table 11. Summary of Final Results for All Sampled Mines 

Result Code Description Total

Critical items complete * 651

Final missing critical items * 86

Partial response 217

Final refusal—explicit refusal by corporate management 56

Final refusal, other reason—explicit refusal by local mine management 77

Final refusal, records unavailable—explicit refusal by local mine management 5

Final refusal, staff time—explicit refusal by local mine management 85

Ineligible mine 85

Ineligible, no contact 32

Initialized, no response 1,020

Hard-copy questionnaire received, but blank 7

Total 2,321

 *Comprised final survey dataset 

Table 12. Number of Completed Surveys by Mode 

Mode Count Percentage

Web questionnaire 360 49%

Paper questionnaire 377 51%

Total 737 100%

Based on the review of the results of all contact attempts, 117 mines were determined to 

be ineligible. A summary of the ineligible mines by sector is presented in Table 13. Some of the 

reasons for ineligibility were: 

 Mine has been closed. 

 No contact was ever made with anyone at the mine. 

 Mine is nonproducing. 

 Construction work on the mine has not yet begun. 

 Mine is shutting down and moving out equipment. 

 Mine was just an exploration mine and was never in a producing status. 

 Mine contracts out all of its mining operations. 
25 

Table 13. Summary of Ineligible Mines by Sector 

Mine Sector

Ineligible

Mine

Ineligible

No Contact Total

Coal 53 14 67

Metal 10 7 17

Nonmetal 9 4 13

Stone 7 3 10

Sand and Gravel 6 4 10

Total 85 32 117

Refusals to participate in the survey were received from 223 mines. The major reasons for 

refusal are shown in Table 14. 

Table 14. Summary of Refusal by Mine Sector and Type of Refusal 

Reason for Refusal Coal Metal Nonmetal Stone

Sand 

and 

Gravel Total

Corporate refusal 20 1 11 16 8 56

General refusal 18 7 13 23 16 77

Records unavailable 1 3 0 0 1 5

Staff time 27 8 12 16 22 85

Total 66 19 36 55 47 223

The overall weighted response rate for the survey was 36.7 percent, with the lowest response 

rate for coal mines (25.8 percent) and the highest for nonmetal mines (48.8 percent). 

Underground mines responded at 30.1 percent compared to surface mines at 37.1 percent. The 

response rate data are presented in Figure 9. 

The weighted response rates were calculated as the ratio of the sum of the weights of 

responding mines divided by the sum of the weights for all eligible sampled mines. The 

denominator included all nonresponding mines that were known to be eligible along with a 

percentage, p, of the weight corresponding to mines which did not respond but for whom it was 

not possible to determine whether in fact they were eligible. The percentage, p, was computed as 

the ratio of the weights of known eligible nonrespondents, plus respondents, plus ineligible 

mines. The ratios were computed separately for each nonresponse adjustment cell, which was 

defined by sector, mine type, and mine size. 
Figure 9. Weighted Response Rates by Sector and Mine Type. 

36.7%

36.2%

39.7%

48.8%

34.9%

25.8%

37.1%

36.2%

39.9%

48.3%

37.7%

25.3%

30.1%

33.9%

55.5%

29.8%

27.2%

0% 10% 20% 30% 40% 50% 60%

All Mining Sectors

Sand and Gravel

Stone

Nonmetal

Metal

Coal

Weighted Response Rate, Percent

Sector MiningUnderground Surface

Overall

26 
27 

Based on the data collected in this survey, Table 15 represents national estimates of the 

number of mines and the mine operator employees (with associated 95 percent confidence 

intervals) by sector during a typical week in the spring/summer of 2008. There were an 

estimated 231,549 employees working in 12,321 mines. Of these employees, 53,326 worked in 

668 underground mines and the remaining 178,222 worked in 11,654 surface mines. 

Table 15. National Estimates of Mines and Mine Employees in Spring/Summer 2008 

Mine Sector

Number of 

Mines* 95% CI

Number of 

Employees* 95% CI

Coal, underground 454 (411, 498) 38,290 (31,088, 45,492)

Coal, surface 1,053 (925, 1,181) 31,717 (23,810, 39,625)

Metal, underground 71 (62, 79) 8,653 (2,419, 14,887)

Metal, surface 130 (113, 147) 30,430 (9,332, 51,528)

Nonmetal, underground 38 (29, 47) 3,424 (1,919, 4,928)

Nonmetal, surface 577 (506, 647) 15,925 (10,668, 21,182)

Stone, underground 105 (92, 118) 2,959 (2,491, 3,427)

Stone, surface 3,852 (3,600, 4,104) 68,006 (62,641, 73,372)

Sand and Gravel 6,042 (4,774, 7,309) 32,144 (26,275, 38,013)

Total 12,321 (11,003, 13,640) 231,549 (204,685, 258,413)

*Data do not sum to total due to independent rounding. 

Employee Job Titles 

The information for the mine operator employee job titles was collected using an openended format in which the survey respondent was asked to “write in” the job title for each of 

his/her sampled employees. A detailed listing of the job titles supplied by the respondents can be 

found in Appendix H. This approach allowed flexibility and lessened burden by not constraining 

the respondent to determine the most appropriate fit from a list of predefined job-title categories. 

Initially, the Mine Safety and Health Administration (MSHA) Part 50 Data User’s 

Handbook [MSHA 2007] was used to code the job titles supplied by the survey respondents. In 

some cases, slang terms or the name of a piece of mining equipment were provided as the 

employee’s job title. To handle these situations, job codes were assigned by researching the 

equipment, mine type or commodity, and consulting A Dictionary of Mining, Mineral, and 

Related Terms [Thrush 1968] and The Dictionary of Mining and Mineral Terms [Infomine Inc. 

2010]. Mining program researchers who were former mine employees also assisted by 

reviewing the “difficult-to-code” job titles and defining the occupation. In some instances, 

where logical, multiple job titles were combined under a single occupation code. For example, a 

“Belt Worker” and “Belt Man” were assigned the same code. 

Once the job titles were coded, they were grouped into occupational categories. The four 

major categories are Administration/Professional, Maintenance, Production, and Service and 
28 

Utility. When a reported job title did not fit within any of these four categories, it was put into a 

Miscellaneous category. Within the four major occupational categories, there are subunits with 

up to four levels. Each of these subunits is further divided based on the type of work performed. 

National estimates of the number of workers have been computed for each major category 

(excluding Miscellaneous where only survey counts are reported) and the first three subunit 

levels. 

Statistical Analysis 

The statistical analysis of the data from the National Survey of the Mining Population 

was conducted using the SAS statistical software package. The SAS SURVEYFREQ and 

SURVEYMEANS procedures were used to create the weighted summary statistics that are 

reported in the IC. These procedures properly analyze data from complex sample surveys by 

taking the sample design into account. The variance estimation method used with these data was 

the Jackknife Repeated Replication (JRR). At this time, the subpopulation analysis for JRR is 

not available in SAS 9.2. In order to provide national estimates for the coal, metal, nonmetal, 

stone, and sand and gravel mining sectors, a SAS macro, using a reweighting method, proposed 

by Wang and Waldron [2010] was adopted for these subpopulation analyses. In their paper, 

Wang and Waldron compared the results of a subgroup analysis using their macro with PROC 

SURVEYMEANS and found these results were almost identical to those obtained when using 

the standard subpopulation analysis procedure in both the Stata 10.0 (StataCorp LP) and 

SUDAAN 10 (RTI International) statistical analysis software packages. In order to provide a 

measure of precision, a 95 percent confidence interval (CI) has been calculated for all survey 

estimates reported in this IC. Data were suppressed, and no national estimates were computed 

when the unweighted survey count was fewer than five responses (i.e., the number of responses 

was too small to be able to produce a reliable estimate) [NCHS 2002, 2004]. Due to independent 

rounding, the percentages shown in the individual bar charts may not sum to exactly 100 percent. 
29 

 

Employee Statistics for 

All Mines 
30 
31 

Summary of Employee Statistics for All Mines 

The demographic and occupational characteristics of employees in the U.S. mining 

industry are presented in Tables 16 and 17 and Figures 10–12. The weighted estimate for gender 

indicates that the workforce is composed predominately of male employees (92.5 percent). The 

major racial category is White (93.6 percent) followed by Black or African American (4.3 

percent). Twelve percent of these employees have an ethnicity of Hispanic or Latino. Sixty-five 

percent are high school graduates, with another 24.1 percent having an education level beyond 

high school. A review of the weighted estimates indicates that the average worker is 43.3 years 

of age and has worked in mining for 12.9 years, 9.0 years at the current mine, and 7.1 years in 

his/her job title. The number of hours worked per week averages 45.4 with the “Surface Mine: 

Strip, Open Pit or Quarry” being the primary work location for the majority, or 34.1 percent of 

miners. An additional 23.0 percent of employees work in “Mill Operations, Preparation Plants, 

or Breakers,” and another 18.3 percent are employed in the “Underground Mine: Underground” 

work location. 

 Tables 18, 19, 21, 22, and Figure 13 present the national estimates of the number of 

workers by four major occupational categories. (No estimates were calculated for Table 20: 

“Miscellaneous.”) An estimated 62,646 (27.2 percent) mine workers are employed in the 

“Administration/Professional” category; 35,276 (15.3 percent) in the “Maintenance” category; 

90,495 (39.4 percent) in the “Production” category; and 41,851 (18.2 percent) in the “Service 

and Utility” category. 

 
32 
33 

Table 16. Demographic Characteristics of Employees at All Mines 

Demographic Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Gender:

Male 8,414 211,471 188,671 234,270 92.5 91.1 93.9Female 577 17,213 12,403 22,024 7.5 6.1 8.9

Age (years) 8,673 43.3 42.4 44.1Highest level of education:

Less than 9th grade 222 4,996 3,062 6,930 2.4 1.5 3.39th–12th grade (no diploma) 800 18,600 15,299 21,902 8.8 7.3 10.3HS Graduate or Equivalent (GED) 5,452 136,599 121,769 151,429 64.7 61.3 68.1Some College, Associate Degree, or 

Technical School

1,392 39,326 30,655 47,996 18.6 15.9 21.3

Bachelor's Degree or beyond 452 11,516 9,017 14,014 5.5 4.5 6.4

Ethnicity:

Hispanic or Latino 927 26,622 17,120 36,123 12.1 8.9 15.4Non-Hispanic or Non-Latino 7,766 192,839 172,663 213,016 87.9 84.6 91.1

Race:

American Indian or Alaska Native 119 4,050 1,851 6,249 2.0 0.9 3.0Asian 9 183 56 311 0.1 0.0 0.2Black or African American 397 8,893 6,419 11,367 4.3 3.2 5.4Native Hawaiian or Other Pacific Islander 14 634 140 1,127 0.3 0.1 0.5White 7,717 194,016 174,955 213,077 93.6 92.1 95.0
34 

Table 17. Occupational Characteristics of Employees at All Mines 

Occupational Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Hours worked (per week) 8,363 45.4 44.6 46.2Experience:

Experience in this Job Title (years) 8,641 7.1 6.4 7.8Experience at this Mine (years) 8,773 9.0 8.3 9.6Total Mining Experience (years) 8,539 12.9 12.1 13.7

Primary Work Location:

Underground Mine: Underground 1,585 42,191 34,049 50,333 18.3 15.0 21.6Underground Mine: Surface Shops or 

Yards

287 4,884 3,461 6,307 2.1 1.5 2.7

Surface Mine: Strip, Open Pit, or Quarry 2,722 78,493 58,106 98,879 34.1 28.4 39.7Surface Mine: Auger, Culm Bank, or 

Refuse Pile (Coal Mine Only)

78 3,581 267 6,896 1.6 0.1 3.0

Surface Mine: Dredge 185 4,491 2,551 6,430 1.9 1.1 2.8Surface Mine: Other Surface Mining 

(Metal/Nonmetal Only)

922 21,492 14,757 28,227 9.3 6.4 12.3

Independent Shops or Yards 64 1,304 205 2,404 0.6 0.1 1.0Mill Operations, Preparation Plants, or 

Breakers

2,251 53,052 45,563 60,541 23.0 19.2 26.9

Office 889 20,835 16,764 24,906 9.0 7.8 10.3
35 

Figure 10. Education Level of Employees at All Mines. 

5.5%

18.6%

64.7%

8.8%

2.4%

0 20 40 60 80 100 120 140 160

Bachelor's Degree or beyond

Some College, Associate Degree, or Technical School

HS Graduate or Equivalent (GED)

9th‐12th grade (no diploma)

Lessthan 9th grade

National Estimate (Thousands)
36 

Figure 11. Race of Employees at All Mines. 

93.6%

0.3%

4.3%

0.1%

2.0%

0 50 100 150 200 250

White

Native Hawaiian or Other Pacific Islander

Black or African American

Asian

American Indian or Alaska Native

National Estimate (Thousands)
37 

Figure 12. Primary Work Location of Employees at All Mines. 

9.0%

23.0%

0.6%

9.3%

1.6%

1.9%

34.1%

2.1%

18.3%

0 10 20 30 40 50 60 70 80 90

Office

Mill Operations, Preparation Plants, or Breakers

Independent Shops or Yards

Surface Mine: Other Surface Mining (Metal / Nonmetal Only)

Surface Mine: Dredge

Surface Mine: Auger, Culm Bank, or Refuse Pile (Coal Mine Only)

Surface Mine: Strip, Open Pit, or Quarry

Underground Mine: Surface Shops or Yards

Underground Mine: Underground

National Estimate (Thousands)
38 

Table 18. Estimated Number of Administration/Professional Employees at All Mines 

Occupation by Category 

Survey 

Count 

National 

Estimate 95% LCL 95% UCL 

ADMINISTRATION/PROFESSIONAL 2,453 62,646 54,584 70,708

Office Staff 408 10,181 8,304 12,057 

Administrative Staff 225 5,493 4,299 6,687 

Administration 

Administrative Assistant

Clerk 

Coal Distribution Coordinator 

Communications 

Customer Service 

Human Resources 

Information Technology

Mine Clerk 

Office Clerk 

Office Staff 

Plant Clerk 

Receptionist 

Secretary 

Systems Analyst 

Technical Coordinator 

 

Business 136 3,510 2,257 4,762 

Accounting 

Bookkeeper

Buyer

Cost Coordinator

Payroll

Procurement

Purchasing

Sales

Shipping

Terminal Operator

 

Security 14 346 119 573 

Guard 

Security 

 

Supplies 31 818 404 1,232 

Supply Clerk 

Warehouse

Warehouse Technician

Warehouseman

 

Union Representative 2 DSU DSU DSU 

 

Professional 334 10,304 7,332 13,276 

Engineer 61 1,722 860 2,584 

Director of Engineering 

Engineer 

(Electrical/Mining/Ventilation)

 

Engineer, not otherwise specified 

Environmental Engineer

Plant Engineer 
Table 18. Estimated Number of Administration/Professional Employees at All Mines 

(continued) 

39 

Occupation by Category 

Survey 

Count 

National 

Estimate 95% LCL 95% UCL 

Process Engineer 

Production Engineer

Project Engineer

 

Non-engineer 90 3,408 1,568 5,249 

Chemist 

Control Person/Analyst

Environmental

Environmental Specialist

Geologist

Metallurgist

Operating Engineer

Operations

Operations Specialist

Physical Tester

Planner 

Production Scheduler 

Reliability Engineer 

Surveyor 

Utility Engineer 

 

Technician 183 5,174 3,148 7,199 

Coal Sampler 

Electrical Technician

Electronic Technician

Engineering Technician

Fuel Operator/Technician

Lab Technician

Laboratory Technician/Refiner

Materials Technician

Mechanic Technician

Mill Technician

Mine Technician

Plant Technician

Process Control 

Operator/Technician

 

Production Technician 

Quarry Technician 

Sampler/Lab Technician

Technician 

Utility Technician

 

Safety 51 1,425 854 1,996 

Inspector 

Safety

Safety Director

Safety Manager

Safety Supervisor

 

 
Table 18. Estimated Number of Administration/Professional Employees at All Mines 

(continued) 

40 

Occupation by Category 

Survey 

Count 

National 

Estimate 95% LCL 95% UCL 

Supervisory 1,660 40,736 35,454 46,018 

Executive 71 1,365 1,005 1,726 

CEO 

General Manager

Mine Owner

President

Vice President

 

Foreman 626 15,807 12,870 18,744 

Assistant Superintendent 

Belt Foreman (underground) 

Electrical Foreman (underground)

Foreman 

Foreman/Manager

Foreman/Shift Boss

Labor Foreman

Lead Man

Maintenance Foreman

Maintenance Lead Man

Mill Foreman

Mine Foreman

Outby Foreman

Pit Foreman

Plant Foreman

Preparation Plant Foreman

Production Foreman

Section Foreman

Section Foreman/Boss

Shift Foreman

Shop Foreman 

Superintendent 

Track Foreman 

Underground Foreman

 

Manager 339 8,224 6,266 10,182 

Area Manager 

Assistant Manager

Assistant Mine Foreman/Assistant 

Mine Manager

Concentrator Manager 

Customer Service Manager

Distribution Manager

Dredge Manager

Dry Plant Manager

Engineer/Operations Manager

Engineering Manager

Environmental Manager

Equipment Maintenance Manager

Equipment Manager

Facility Manager

Financial Manager

Human Resources Manager
Table 18. Estimated Number of Administration/Professional Employees at All Mines 

(continued) 

41 

Occupation by Category 

Survey 

Count 

National 

Estimate 95% LCL 95% UCL 

Lab Manager 

Maintenance Manager 

Management 

Manager

Mill Manager

Mine Foreman/Mine Manager

Mine Manager

Office Manager

Operations Manager

Plant Manager

Plant Superintendent

Process Manager 

Production Manager 

Project Manager

Purchasing Manager

Quality Control Manager

Quarry Manager

Raw Material Manager

Regulatory Manager

Sales Manager

Scale Office Manager

Shift Manager

Shipping Manager

Shop Manager

Storeroom Manager

Technical Services Manager

 

Supervisor 624 15,340 13,052 17,627 

Assistant Mine Supervisor 

Assistant Supervisor 

Auger Crew Supervisor

Backhoe Supervisor

Bagging/Baghouse Supervisor

Belt Coordinator

Blasting Supervisor

Clay Operator

Concentrator Supervisor

Control Room Supervisor

Crusher Supervisor

Dozer Supervisor

Electrical Supervisor

Engineering Supervisor

Equipment Supervisor

Gold House Supervisor

Lab Supervisor

Leaching Supervisor

Loader Supervisor

Loadhouse Supervisor

Maintenance Supervisor

Mechanic Supervisor

Mine Operations

Mine Operator
Table 18. Estimated Number of Administration/Professional Employees at All Mines 

(continued) 

42 

Occupation by Category 

Survey 

Count 

National 

Estimate 95% LCL 95% UCL 

Mine Supervisor 

Mobile Equipment Supervisor 

Pit Operator 

Pit Supervisor

Plant Operator

Plant Supervisor

Prep Plant Operator

Process Supervisor

Production Supervisor

Quality Assurance Supervisor

Quarry Operator

Quarry Supervisor

Shift Supervisor

Shipping Supervisor

Supervisor

Tailings Supervisor

Transportation Supervisor

Warehouse Supervisor

Wash Plant Supervisor

Abbreviation: DSU, data suppressed. 
43 

Table 19. Estimated Number of Maintenance Employees at All Mines 

Occupation by Category 

Survey

Count

National

Estimate 95% LCL 95% UCL

MAINTENANCE 1,311 35,276 29,913 40,639

Specialty 272 8,234 6,445 10,022

Electrician 190 6,291 4,592 7,990

Diagnostic Electrician

Electrician

Electrician/Wireman

Electrician Trainee

Maintenance Electrician

Master Electrician

Trainer Electrician

Welder 82 1,942 1,312 2,572

Certified Welder

Maintenance Welder

Repair/Welder

Welder

Welder (nonshop)

Welder/Fabricator

Welder/Mechanic

Support 1,039 27,043 22,718 31,367

Maintenance 392 8,873 7,065 10,682

Continuous Miner Maintenance

Crusher Maintenance

Dragline Oiler

Electrical Maintenance

Equipment Maintenance

Fixed Maintenance

Greaser/Oiler

Liquid Fuel Handler

Maintenance

Maintenance Clerk

Maintenance Coordinator

Maintenance Planner

Maintenance Technician

Mechanic Clerk

Mechanical Maintenance

Mill Maintenance

Millwright

Mobile Maintenance

Pipefitter

Plant Maintenance

Production/Process Maintenance

Road Maintenance

Skilled Maintenance

Truck Maintenance

Underground Belt Maintenance

Underground Maintenance
Table 19. Estimated Number of Maintenance Employees at All Mines (continued) 

44 

Occupation by Category 

Survey

Count

National

Estimate 95% LCL 95% UCL

Mechanic 556 14,368 11,607 17,129

Aggregate Mechanic

Automotive Mechanic

Belt Mechanic

Diagnostic Mechanic

Diesel Mechanic

Equipment Mechanic

Heavy Equipment Mechanic

Maintenance Mechanic

Master Mechanic

Mechanic

Mechanic/Electrician

Mechanic/Welder

Mechanic Helper

Mechanic Trainee

Mobile Equipment Mechanic

Mobile Maintenance Mechanic

Mobile Mechanic

Plant Mechanic

Prep Plant Mechanic

Shop Mechanic

Underground Belt Mechanic

Wrens Mechanic

Repairman 91 3,801 739 6,864

Automotive Repairman

Crusher Repairman

Electronic/Electrical Repairman

Heavy Duty Repairman

Instrument Repairman

Maintenance Repairman

Mechanical Repairman

Plant Repairman

Repairman

Skilled Repairman

Tailings Repairman

Underground Belt Repairman

Underground Repairman

Table 20. Number of Miscellaneous Employees at All Mines 

Occupation by Category 

Survey 

Count 

MISCELLANEOUS 35 

Trainee 19

 

Unknown 16 
45 

Table 21. Estimated Number of Production Employees at All Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

PRODUCTION 3,571 90,495 76,183 104,807

Equipment Operator 1,860 49,707 40,495 58,920

Dragline Operator 24 677 275 1,079

Equipment Operator 944 23,373 19,276 27,469

Backhoe Operator

Bobcat Operator

Bulldozer Operator

Crane Operator

Dredge Operator

End Dump Driver

End Dump Driver/Operator

Equipment Operator

Forklift Operator

Front End Loader

Front End Loader Operator

Grader Operator

Gravity Mag Operator

Heavy Equipment Operator

Highlift Operator

Hopper Operator

Large Shovel/Backhoe/Load 

Operator

Machine Operator

Mobile Bridge Operator

Mobile Equipment Operator 

Mucking Machine Operator

Paver Operator

Payloader Operator

Raise Borer Operator

Road Grader Operator

Rock Duster

Rotary Bucket Excavator Operator

Rotary Dump Operator

Scaler (mechanical)

Scraper Operator

Stationary Equipment Operator

Stripping Operator

Tower Operator

Track Hoe

Tractor Operator

Tractor Operator/Motorman

Hoist 36 430 93 766

Hoist Engineer

Hoist Operator

Hoistman

Skip Tender/Cager/Station 

Attendant
Table 21. Estimated Number of Production Employees at All Mines (continued) 

46 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Material Mover 704 18,923 14,005 23,841

Dump Truck Driver

Haul Truck Operator

Haul Truck Operator/Driver

Hauler/Haul Unit Operator

Hauler Operator

Off Road Truck Driver

Ore Truck Driver/Operator

Pit Truck Driver

Quarry Truck Driver

Refuse Truck Driver/Backfill Truck 

Driver

Rock Truck Driver

Rubber Tire Operator

Scoop Car Operator

Scoop Loader

Scoop Tram Operator

Shuttle Car Operator

Stock Truck/Stock Pile Driver

Truck Driver

Underground Coal Hauler

Underground Haulage Operator

Water Truck Operator

Mining Machines 106 4,056 2,635 5,477

Continuous Miner Helper

Continuous Miner Operator

Face Operator

Head Operator

Jacksetter

Longwall Operator

Shearer Operator 

Undercutter Operator

Operator/Driver 29 740 300 1,179

Dump Operator

Motorman

Motorman/Locomotive Operator

Operator/Driver

Transportation

Shovel Operator 17 1,510 0 3,434

Extraction Labor 212 5,229 2,590 7,868

Coal Miner

Heading Prep

Mine Production

Mine Spec

Mine Support

Miner

Miner Support

Production Miner 
Table 21. Estimated Number of Production Employees at All Mines (continued) 

47 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Material Preparation 304 6,178 4,598 7,758

Additives 14 271 9 532

Additive Press Operator

Additives Utility

Calcine Operator

Thickener Operator

Crusher 122 2,891 1,732 4,050

Blunging Operator

Breaker Operator

Crusher Attendant

Crusher Helper

Crusher Operator/Pan Feeder 

Operator

Crusher Plant Operator

Hammer Mill Operator

Jaw Operator

Mill Crusher Operator

Rock Breaker Operator

Screenhouse Crusher

Cutter 70 1,194 286 2,102

Cutting Machine Operator

Sawyer

Splitter

Stone Cutter

Trimmer

Mill 98 1,822 1,101 2,543

Dry Mill Operator

Limestone Prep Operator

Mill Hand/Helper

Mill Operator (ball/pebble/rod)

Mill Production Worker

Milling Machine Operator

Mill Man

Roller Mill Operator

Roller Operator

Process 186 5,769 2,649 8,890

Belt Vulcanizer 9 464 0 1,197

Dry Processing 42 763 362 1,164

Dry Plant/Process Operator

Dryer Operator

Fluid Bed Dryer Operator

Kiln Operator

Other 32 825 300 1,351

Fabricator

Process Attendant

Process Operator
Table 21. Estimated Number of Production Employees at All Mines (continued) 

48 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Separation 83 3,244 275 6,212

Centrifuge Utility

Digestion Operator

Extruder Operator

Filter Evaporation Operator

Filter Operator

Flotation Plant Operator

Flotation/Concentrator Operator

Froth Cell Operator

Grinder Operator

Leach Utility

Leaching Operations Worker

Mix Chemist

Mix Operator

Pan Operator

Pelletizing Operations Worker

Pug Operator/Mixer Tender

Rotex Operator

Screen Plant Labor

Screen Plant Operator

Slurry Operator

Tailings Operator

Wash Process 12 410 105 715

Wash Operator

Washer Operator

Wet Processing 8 63 7 120

Wet Plant Attendant

Wet Plant Operator

Support 1,009 23,611 19,052 28,170

Drill Operator 101 1,684 1,179 2,189

Auger Operator

Coal Drill Operator

Drill Helper/Chuck Tender

Drill Operator

Highwall Drill Operator

Rotary Electric/Hydraulic Drill 

Operator

Electronics 4 DSU DSU DSU

Console Operator

Power Systems

Robot Operator

Explosives 82 1,524 864 2,183

Blaster

Driller/Blaster

Explosives/Powder Man

Shooter

Shot Firer
Table 21. Estimated Number of Production Employees at All Mines (continued) 

49 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Other 579 14,279 9,944 18,614

Control Room

Controller

Control Man

Dispatcher

Operator, not otherwise specified

Panel Operator

Port Operator

Production Operator

Rak Handler

Scaler (hand)

Top Operator

Underground Operator

Underground Plant Operator

Quality Control 75 1,609 1,090 2,128

Quality Control

Quality Control/Quality Assurance

Roof Bolter 168 4,321 3,073 5,569

Roof Bolter

Roof Control Operator

Abbreviation: DSU, data suppressed. 
50 

Table 22. Estimated Number of Service and Utility Employees at All Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

SERVICE and UTILITY 1,638 41,851 36,921 46,781

General Labor 817 21,603 17,514 25,692

Cleaners 10 212 68 356

Cleanup Man

Dry Attendant

Janitor

Steamer

Tank Car Washer

Tower Cleaner

Construction 35 1,064 394 1,734

Cement Man/Concrete Worker

Construction

Curb Cutter

Ground Control/Timberman

Packer

Screed Person

Shaft Miner/Shaft Repairer 

Laborer 490 13,000 9,958 16,042

Cook

Ground Hand

Ground Man

Inside Laborer

Laborer

Miller

Outby Laborer

Outside Laborer

Plant Helper

Plant Man

Production Support

Production Worker

Quarry Worker

Root Picker

Shop Man

Stick Picker

Surface Support

Track Man

Material Handling 145 2,867 1,880 3,853

Bagger/Bagging Operations 

Worker

Crude Pile Operator

Material Handler

Mudpicker

Palletizer

Reclaim Operator

Rolling Stock Crew

Silo Operator

Stacker

Storage Operator
Table 22. Estimated Number of Service and Utility Employees at All Mines (continued) 

51 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Storeroom

Sweeper Operator

Yard Laborer

Yard Man

Tradesman 33 1,928 0 3,966

Apprentice/Journeyman

Boiler Operator

Boilermaker

Carpenter/Plumber/Painter

Craftsman

Machinist

Trades Person

Weighman 104 2,532 1,869 3,195

Scale Clerk/Operator

Weighman

Weighmaster

Support Labor 821 20,249 17,248 23,249

Barge Operations 28 442 120 763

Barge Attendant/Boat Operator

Boat Pilot

Deck Hand

Dock Hand

Dock Worker

Conveyor Operator 56 1,557 771 2,343

Belt Cleaner/Conveyor Man

Belt Man/Conveyor Man

Distribution 35 564 106 1,021

Packaging Operations Worker

Packhouse

Examiner 34 1,006 408 1,605

Fire Boss

Mine Examiner

Underground Belt Examiner 

Loading 462 11,020 9,083 12,958

Bin Attendant

Bin Puller/Truck Loader

Bulk Loader

Chute Puller

Load Haul Dump—Complete Cycle

Loader Operator

Loading

Loadman

Loadout Operator

Operator/Loader

Pit Loader Operator

Plant Loader Operator
Table 22. Estimated Number of Service and Utility Employees at All Mines (continued) 

52 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Production Loader

Quarry Loader Operator

Rail Loader Operator

Shipping Loader

Stock Loader/Piler

Tipple Operator

Underground Loader

Yard Loader Operator

Pumper 10 467 0 982

Gravel Pumper

Pumper

Supplies 15 214 87 341

Parts

Parts Runner

Supply Hauler

Supply Man

Supply Man/Nipper

Utility 177 4,853 3,328 6,377

Crusher Utility

E.O. Utility

Equipment Utility

Lampman 

Mill Utility

Operator Utility

Outside Utility

Pit Utility Person

Plant Utility

Production Utility

Quarry Utility

Utility Beltline

Utility Belts

Utility Bolter

Utility Lubricator

Utility Man

Utility Scaler

Wet Utility

Ventilation 4 DSU DSU DSU

Brattice Man

Ventilation Man

Abbreviation: DSU, data suppressed. 
53 

Figure 13. Occupational Categories of Employees at All Mines. 

8.8%

9.4%

10.3%

2.7%

2.5%

2.3%

21.6%

11.7%

3.6%

17.7%

0.6%

4.4%

4.5%

0 10 20 30 40 50 60

Support Labor

General Labor

Process

Support

Material Preparation

Extraction Labor

Equipment Operator

Support

Specialty

Supervisory

Safety

Professional

Office Staff

and Service

Production Maintenance Utility

Administration/

Professional

National Estimate (Thousands)
54 

 
55 

 

Employee Statistics for 

Coal Mines 
56 

 
57 

Summary of Employee Statistics for Coal Mines 

The demographic and occupational characteristics of employees in the U.S. coal mining 

industry are presented in Tables 23 and 24 and Figures 14–16. The weighted estimate for gender 

indicates that the workforce is composed predominately of male employees (96.2 percent). The 

majority of coal mine employees are White (96.4 percent) followed by American Indian or 

Alaska Native (2.5 percent). Only 1.9 percent of these employees have an ethnicity of Hispanic 

or Latino. Seventy-seven percent are high school graduates, with another 16.8 percent having an 

education level beyond high school. A review of the weighted estimates indicates that the 

average coal mine worker is 43.8 years of age and has worked in mining for 16.0 years, with 8.2 

years at the current mine, and 7.8 years in his/her job title. The national estimate for the average 

number of hours worked per week is 47.3. The primary work location for an estimated 46.8 

percent of coal mine employees is “Underground Mine: Underground.” An additional 24.0 

percent of these employees work at a “Surface Mine: Strip, Open Pit, or Quarry,” while another 

15.3 percent are employed in the “Mill Operations, Preparation Plants, or Breakers” work 

location. 

Tables 25, 26, 28, 29, and Figure 17 present the national estimates of the number of coal 

mine workers by four major occupational categories. (No estimates were calculated for Table 

27: “Miscellaneous.”) An estimated 16,048 (23.2 percent) are employed in the 

“Administration/Professional” category; 12,000 (17.3 percent) in the “Maintenance” category; 

29,562 (42.7 percent) in the “Production” category; and 11,791 (17.0 percent) in the “Service 

and Utility” category. 

 
58 
59 

Table 23. Demographic Characteristics of Employees at Coal Mines 

Demographic Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Gender:

Male 2,260 65,374 54,760 75,989 96.2 94.7 97.7Female 66 2,559 1,406 3,713 3.8 2.3 5.3

Age (years) 2,255 43.8 42.5 45.1Highest level of education:

Less than 9th grade 14 182 66 299 0.3 0.1 0.59th–12th grade (no diploma) 149 3,839 2,040 5,638 6.2 3.5 8.9HS Graduate or Equivalent (GED) 1,644 47,548 38,760 56,336 76.7 72.4 80.9Some College, Associate Degree, or 

Technical School

273 8,698 6,097 11,300 14.0 10.7 17.4

Bachelor's Degree or beyond 56 1,742 973 2,512 2.8 1.7 3.9

Ethnicity:

Hispanic or Latino 37 1,222 430 2,015 1.9 0.7 3.0Non-Hispanic or Non-Latino 2,224 64,548 53,859 75,237 98.1 97.0 99.3

Race:

American Indian or Alaska Native 37 1,635 0 3,434 2.5 0.0 5.2Asian 0 NA NA NA NA NA NABlack or African American 26 774 189 1,358 1.2 0.3 2.1Native Hawaiian or Other Pacific Islander 0 NA NA NA NA NA NAWhite 2,209 62,528 51,932 73,125 96.4 93.5 99.3

Abbreviation: NA, not applicable. 
60 

Table 24. Occupational Characteristics of Employees at Coal Mines 

Occupational Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Hours worked (per week) 2,131 47.3 45.9 48.7Experience:

Experience in this Job Title (years) 2,209 7.8 6.9 8.7Experience at this Mine (years) 2,294 8.2 6.6 9.8Total Mining Experience (years) 2,166 16.0 14.3 17.7

Primary Work Location:

Underground Mine: Underground 1,021 32,358 26,196 38,519 46.8 40.5 53.1Underground Mine: Surface Shops or 

Yards

82 2,477 1,447 3,508 3.6 2.0 5.1

Surface Mine: Strip, Open Pit, or Quarry 613 16,620 11,106 22,135 24.0 17.5 30.6Surface Mine: Auger, Culm Bank, or 

Refuse Pile (Coal Mine Only)

78 3,581 267 6,896 5.2 0.6 9.8

Independent Shops or Yards 19 462 0 1,344 0.7 0.0 1.9Mill Operations, Preparation Plants, or 

Breakers

407 10,565 6,984 14,147 15.3 10.8 19.7

Office 107 3,103 1,956 4,249 4.5 3.0 6.0
61 

Figure 14. Education Level of Employees at Coal Mines. 

2.8%

14.0%

76.7%

6.2%

0.3%

0 5 10 15 20 25 30 35 40 45 50

Bachelor's Degree or beyond

Some College, Associate Degree, or Technical School

HS Graduate or Equivalent(GED)

9th‐12th grade (no diploma)

Lessthan 9th grade

National Estimate (Thousands)
62 

Figure 15. Race of Employees at Coal Mines. 

96.4%

1.2%

2.5%

0 10 20 30 40 50 60 70

White

Black or African American

American Indian or Alaska Native

National Estimate (Thousands)
63 

Figure 16. Primary Work Location of Employees at Coal Mines. 

4.5%

15.3%

0.7%

5.2%

24.0%

3.6%

46.8%

0 5 10 15 20 25 30 35

Office

Mill Operations, Preparation Plants, or Breakers

Independent Shops or Yards

Surface Mine: Auger, Culm Bank, or Refuse Pile (Coal Mine Only)

Surface Mine: Strip, Open Pit, or Quarry

Underground Mine: Surface Shops or Yards

Underground Mine: Underground

National Estimate (Thousands)
64 

Table 25. Estimated Number of Administration/Professional Employees at Coal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

ADMINISTRATION/PROFESSIONAL 523 16,048 12,552 19,544

Office Staff 69 2,120 1,395 2,846

Administrative Staff 43 1,323 730 1,916

Administration

Administrative Assistant

Clerk

Coal Distribution Coordinator

Human Resources

Mine Clerk

Office Staff

Secretary

Technical Coordinator

Business 16 479 254 704

Accounting 

Purchasing 

Sales 

Shipping

Security 2 DSU DSU DSU

Supplies 8 254 49 459

Supply Clerk

Warehouse Technician

Warehouseman

Professional 59 2,214 683 3,746

Engineer 10 303 42 564

Engineer 

(Electrical/Mining/Ventilation)

Engineer, not otherwise specified

Non-engineer 7 176 7 344

Environmental 

Professional, not otherwise 

specified 

Surveyor 

Technician 42 1,736 178 3,293

Coal Sampler

Electronic Technician 

Engineering Technician

Fuel Operator/Technician 

Lab Technician

Plant Technician

Technician
Table 25. Estimated Number of Administration/Professional Employees at Coal Mines 

(continued) 

65 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Safety 12 464 143 785

Safety

Safety Director

Safety Supervisor

Supervisory 383 11,249 8,753 13,745

Executive 3 DSU DSU DSU

CEO

Mine Owner

Foreman 208 5,346 4,296 6,397

Assistant Superintendent 

Belt Foreman (underground)

Electrical Foreman (underground)

Foreman

Foreman/Manager

Labor Foreman

Lead Man

Maintenance Foreman

Outby Foreman

Pit Foreman

Preparation Plant Foreman 

Section Foreman

Section Foreman/Boss

Shift Foreman

Superintendent 

Track Foreman

Underground Foreman

Manager 76 3,187 1,456 4,918

Assistant Manager

Assistant Mine Foreman/Assistant 

Mine Manager

Engineer/Operations Manager

Maintenance Manager 

Management

Manager

Mine Foreman/Mine Manager

Office Manager

Plant Manager

Plant Superintendent
Table 25. Estimated Number of Administration/Professional Employees at Coal Mines 

(continued) 

66 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Supervisor 96 2,657 1,677 3,636

Assistant Supervisor

Auger Crew Supervisor

Belt Coordinator

Electrical Supervisor

Engineering Supervisor

Maintenance Supervisor

Mine Operator

Mine Supervisor

Pit Operator

Pit Supervisor

Plant Operator

Plant Supervisor

Prep Plant Operator

Production Supervisor

Supervisor

Warehouse Supervisor

Abbreviation: DSU, data suppressed. 
67 

Table 26. Estimated Number of Maintenance Employees at Coal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

MAINTENANCE 370 12,000 8,929 15,071

Specialty 118 3,719 2,569 4,869

Electrician 98 3,137 2,073 4,202

Electrician

Electrician Trainee

Maintenance Electrician

Master Electrician

Trainer Electrician

Welder 20 582 205 959

Welder

Welder (nonshop)

Welder/Fabricator

Welder/Mechanic

Support 252 8,281 5,764 10,798

Maintenance 51 1,550 763 2,337

Continuous Miner Maintenance

Dragline Oiler

Greaser/Oiler 

Maintenance

Maintenance Technician

Mechanic Clerk

Pipefitter

Underground Belt Maintenance

Underground Maintenance

Mechanic 184 6,334 4,071 8,597

Belt Mechanic

Diesel Mechanic

Mechanic

Mechanic/Electrician

Mechanic Helper

Mechanic Trainee

Mobile Equipment Mechanic

Plant Mechanic

Prep Plant Mechanic

Shop Mechanic

Underground Belt Mechanic

Repairman 17 397 76 717

Automotive Repairman

Repairman

Underground Belt Repairman

Underground Repairman
68 

Table 27. Number of Miscellaneous Employees at Coal Mines 

Occupation by Category 

Survey 

Count 

MISCELLANEOUS 15

Trainee 14

 

Unknown 1 

Table 28. Estimated Number of Production Employees at Coal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

PRODUCTION 1,016 29,562 23,638 35,485

Equipment Operator 626 18,710 14,430 22,990

Dragline Operator 11 369 21 718

Equipment Operator 276 7,391 5,196 9,587

Backhoe Operator

Bulldozer Operator

Crane Operator

End Dump Driver/Operator

Equipment Operator

Front End Loader

Heavy Equipment Operator

Highlift Operator

Large Shovel/Backhoe/Load 

Operator

Machine Operator

Mobile Bridge Operator 

Mobile Equipment Operator

Road Grader Operator

Rock Duster

Rotary Bucket Excavator Operator

Rotary Dump Operator

Scraper Operator

Stationary Equipment Operator

Tractor Operator/Motorman

Hoist 2 DSU DSU DSU

Hoistman

Material Mover 227 6,423 4,140 8,707

Dump Truck Driver

Haul Truck Operator

Hauler Operator

Off Road Truck Driver

Refuse Truck Driver/Backfill Truck 

Driver

Rock Truck Driver

Rubber Tire Operator

Scoop Car Operator 

Shuttle Car Operator
Table 28. Estimated Number of Production Employees at Coal Mines (continued) 

69 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Truck Driver

Underground Coal Hauler

Underground Haulage Operator

Water Truck Operator

Mining Machines 97 3,906 2,484 5,328

Continuous Miner Helper

Continuous Miner Operator

Face Operator

Jacksetter

Longwall Operator

Shearer Operator

Operator/Driver 12 354 61 647

Motorman

Motorman/Locomotive Operator

Transportation

Shovel Operator 1 DSU DSU DSU

Extraction Labor 53 1,609 256 2,963

Coal Miner

Mine Spec

Miner Support

Production Miner

Material Preparation 5 116 0 302

Crusher 4 DSU DSU DSU

Crusher Attendant 

Cutter 1 DSU DSU DSU

Cutting Machine Operator 

Process 13 334 85 584

Conveyor Operator 5 96 0 230

Belt Vulcanizer 

Separation 4 DSU DSU DSU

Flotation Plant Operator

Froth Cell Operator

Wash Process 3 DSU DSU DSU

Washer Operator 

Wet Process 1 DSU DSU DSU

Wet Plant Attendant 

Support 319 8,791 6,547 11,036

Drill Operator 25 616 245 986

Auger Operator

Coal Drill Operator

Highwall Drill Operator
Table 28. Estimated Number of Production Employees at Coal Mines (continued) 

70 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Explosives 15 638 130 1,145

Blaster

Driller/Blaster

Explosives/Powder Man

Shooter

Shot Firer

Other 126 3,349 1,777 4,920

Control Man

Dispatcher

Operator, not otherwise specified

Underground Operator

Underground Plant Operator

Quality Control 1 DSU DSU DSU

Roof Bolter 152 4,169 2,927 5,411

Abbreviation: DSU, data suppressed. 

Table 29. Estimated Number of Service and Utility Employees at Coal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

SERVICE and UTILITY 410 11,791 9,398 14,184

General Labor 163 4,863 3,101 6,625

Cleaner 3 DSU DSU DSU

Cleanup Man

Janitor

Steamer

Construction 2 DSU DSU DSU

Laborer 138 4,229 2,472 5,985

Inside Laborer

Laborer

Outby Laborer

Outside Laborer

Production Support

Production Worker

Shopman

Surface Support

Track Man

Material Handling 4 DSU DSU DSU

Rolling Stock Crew

Yard Man

Tradesman 5 102 0 248

Apprentice/Journeyman 
Table 29. Estimated Number of Service and Utility Employees at Coal Mines (continued) 

71 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Weighman 11 239 73 404

Weighman

Weighmaster

Support Labor 247 6,928 4,770 9,085

Barge Operations 12 180 0 383

Barge Attendant/Boat Operator

Boat Pilot

Deck Hand

Dock Hand

Conveyor Operator 45 1,254 511 1,996

Belt Cleaner/Conveyor Man

Belt Man/Conveyor Man

Examiner 34 1,006 408 1,605

Fire Boss

Mine Examiner

Underground Belt Examiner 

Loading 74 1,514 988 2,040

Bin Attendant

Loader Operator

Loadout Operator

Tipple Operator

Underground Loader

Pumper 9 400 0 902

Supplies 8 151 34 267

Parts Runner

Supply Man

Utility 61 2,298 1,043 3,552

Outside Utility

Utility Belts

Utility Bolter

Utility Man

Ventilation 4 DSU DSU DSU

Brattice Man

Ventilation Man

Abbreviation: DSU, data suppressed. 
72 

Figure 17. Occupational Categories of Employees at Coal Mines. 

10.0%

7.0%

12.7%

0.2%

0.5%

2.3%

27.0%

11.9%

5.4%

16.2%

0.7%

3.1%

3.2%

0 2 4 6 8 10 12 14 16 18 20

Support Labor

General Labor

Process

Support

Material Preparation

Extraction Labor

Equipment Operator

Support

Specialty

Supervisory

Safety

Professional

Office Staff

and Service

Production Maintenance Utility

Administration/

Professional

National Estimate (Thousands)
73 

 

Employee Statistics for 

Metal Mines 
74 
75 

Summary of Employee Statistics for Metal Mines 

The demographic and occupational characteristics of employees in the U.S. metal mining 

industry are presented in Tables 30 and 31 and Figures 18–20. The weighted estimate for gender 

indicates that the workforce is composed predominately of male employees (86.2 percent). The 

majority of metal mine workers are White (91.4 percent), with another 4.7 percent of the workers 

having a racial category of Black or African American. Twenty-five percent of these employees 

are Hispanic or Latino. An estimated 53.3 percent are high school graduates and 43.6 percent 

have a level of education beyond high school. A review of the weighted estimates indicates that 

the average metal miner is 41.5 years of age and has worked in mining for 10.7 years, 8.7 years 

at the current mine, and 4.7 years in his/her job title. The national estimate for the average 

number of hours worked per week is 42.7. The primary work location for an estimated 42.7 

percent of metal mine employees is a “Surface Mine: Strip, Open Pit or Quarry.” An additional 

23.9 percent of these employees work in “Mill Operations, Preparation Plants, or Breakers,” 

while another 15.8 percent are employed in the “Underground Mine: Underground” work 

location. 

Tables 32, 33, 35, 36, and Figure 21 present the national estimates of the number of 

workers by four major occupational categories. (No estimates were calculated for Table 34: 

“Miscellaneous.”) An estimated 10,652 (27.5 percent) metal mine workers are employed in the 

“Administration/Professional” category; 7,238 (18.7 percent) in the “Maintenance” category; 

17,581 (45.3 percent) in the “Production” category; and 3,339 (8.6 percent) in the “Service and 

Utility” category. 

 
76 
77 

Table 30. Demographic Characteristics of Employees at Metal Mines 

Demographic Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Gender:

Male 871 33,562 15,620 51,504 86.2 81.9 90.4Female 93 5,383 1,152 9,615 13.8 9.6 18.1

Age (years) 958 41.5 39.3 43.8Highest level of education:

Less than 9th grade 7 63 0 153 0.2 0.0 0.49th–12th grade (no diploma) 32 1,030 276 1,784 2.9 0.9 4.9HS Graduate or Equivalent (GED) 496 18,934 9,552 28,317 53.3 44.0 62.6Some College, Associate Degree, or 

Technical School

242 12,377 4,629 20,125 34.9 27.2 42.5

Bachelor's Degree or beyond 87 3,104 1,515 4,692 8.7 6.1 11.3

Ethnicity:

Hispanic or Latino 137 9,483 1,132 17,834 24.6 14.4 34.9Non-Hispanic or Non-Latino 783 29,008 14,213 43,803 75.4 65.1 85.6

Race:

American Indian or Alaska Native 17 1,073 0 2,156 3.3 1.3 5.4Asian 0 NA NA NA NA NA NABlack or African American 35 1,492 0 3,059 4.7 0.6 8.7Native Hawaiian or Other Pacific Islander 3 DSU DSU DSU DSU DSU DSUWhite 818 29,276 16,297 42,255 91.4 86.8 96.0

Abbreviations: DSU, data suppressed; NA, not applicable. 
78 

Table 31. Occupational Characteristics of Employees at Metal Mines 

Occupational Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Hours worked (per week) 922 42.7 41.4 44.0Experience:

Experience in this Job Title (years) 916 4.7 2.9 6.5Experience at this Mine (years) 928 8.7 7.3 10.0Total Mining Experience (years) 871 10.7 9.4 12.0

Primary Work Location:

Underground Mine: Underground 172 6,152 876 11,428 15.8 2.0 29.5Underground Mine: Surface Shops or 

Yards

53 1,252 327 2,177 3.2 0.6 5.8

Surface Mine: Strip, Open Pit, or Quarry 204 16,624 0 34,516 42.7 20.9 64.4Surface Mine: Dredge 1 DSU DSU DSU DSU DSU DSUSurface Mine: Other Surface Mining 

(Metal/Nonmetal Only)

127 1,876 405 3,348 4.8 0.5 9.1

Mill Operations, Preparation Plants, or 

Breakers

301 9,307 4,644 13,970 23.9 9.1 38.7

Office 106 3,751 782 6,720 9.6 6.9 12.4

Abbreviation: DSU, data suppressed. 
79 

Figure 18. Education Level of Employees at Metal Mines. 

8.7%

34.9%

53.3%

2.9%

0.2%

0 2 4 6 8 10 12 14 16 18 20

Bachelor's Degree or beyond

Some College, Associate Degree, or Technical School

HS Graduate or Equivalent(GED)

9th‐12th grade (no diploma)

Lessthan 9th grade

National Estimate (Thousands)
80 

Figure 19. Race of Employees at Metal Mines. 

91.4%

4.7%

3.3%

0 5 10 15 20 25 30 35

White

Black or African American

American Indian or Alaska Native

National Estimate (Thousands)
81 

Figure 20. Primary Work Location of Employees at Metal Mines. 

9.6%

23.9%

4.8%

42.7%

3.2%

15.8%

0 2 4 6 8 10 12 14 16 18

Office

Mill Operations, Preparation Plants, or Breakers

Surface Mine: Other Surface Mining (Metal / Nonmetal Only)

Surface Mine: Strip, Open Pit, or Quarry

Underground Mine: Surface Shops or Yards

Underground Mine: Underground

National Estimate (Thousands)
82 

Table 32. Estimated Number of Administration/Professional Employees at Metal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

ADMINISTRATION/PROFESSIONAL 308 10,652 5,754 15,550

Office Staff 49 1,889 725 3,053

Administrative Staff 24 811 241 1,381

Administration

Administrative Assistant

Clerk 

Human Resources

Office Staff

Receptionist

Secretary

Systems Analyst

Business 16 804 0 1,782

Accounting

Bookkeeper

Buyer

Cost Coordinator

Payroll

Purchasing

Shipping 

Security 5 96 0 222

Guard

Supplies 4 DSU DSU DSU

Warehouse 

Professional 85 3,368 1,260 5,475

Engineer 12 496 0 1,131

Engineer 

(Electrical/Mining/Ventilation)

Engineer, not otherwise specified

Environmental Engineer

Plant Engineer 

Non-engineer 42 2,027 342 3,712

Environmental Specialist

Geologist

Metallurgist

Operations

Operations Specialist

Planner

Professional, not otherwise 

specified 

Surveyor/Transit Man 

Utility Engineer

Technician 31 845 6 1,684

Electrical Technician 

Laboratory Technician/Refiner
Table 32. Estimated Number of Administration/Professional Employees at Metal Mines 

(continued) 

83 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Mechanic Technician 

Mill Technician

Mine Technician

Process Control 

Operator/Technician

Sampler/Lab Technician

Technician

Utility Technician 

Safety 11 303 87 519

Safety

Safety Manager

Safety Supervisor

Supervisory 163 5,092 2,545 7,640

Executive 13 120 8 232

CEO

General Manager

President

Vice President

Foreman 69 2,235 941 3,530

Assistant Superintendent 

Foreman

Foreman/Shift Boss

Lead Man

Maintenance Foreman 

Mill Foreman

Mine Foreman

Plant Foreman

Production Foreman 

Shift Foreman

Superintendent 

Manager 26 410 85 735

Area Manager

Concentrator Manager

Engineering Manager

Environmental Manager

Human Resources Manager

Manager

Mill Manager

Mine Manager

Office Manager

Plant Manager

Process Manager

Production Manager

Project Manager

Storeroom Manager
Table 32. Estimated Number of Administration/Professional Employees at Metal Mines 

(continued) 

84 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Supervisor 55 2,327 1,020 3,634

Concentrator Supervisor

Crusher Supervisor

Gold House Supervisor

Leaching Supervisor

Maintenance Supervisor

Mechanic Supervisor

Mine Operations

Mine Operator

Mine Supervisor

Plant Operator

Process Supervisor

Shift Supervisor

Supervisor

Tailings Supervisor

Transportation Supervisor

Warehouse Supervisor

Abbreviation: DSU, data suppressed. 
85 

Table 33. Estimated Number of Maintenance Employees at Metal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

MAINTENANCE 179 7,238 3,058 11,418

Specialty 28 1,585 350 2,819

Electrician 22 1,483 264 2,702

Diagnostic Electrician

Electrician/Wireman

Welder 6 102 0 252

Maintenance Welder

Welder

Support 151 5,653 2,515 8,791

Maintenance 55 1,670 677 2,664

Crusher Maintenance

Greaser/Oiler

Maintenance

Maintenance Planner

Maintenance Technician

Mill Maintenance

Millwright

Skilled Maintenance

Mechanic 84 2,088 1,325 2,851

Automotive Mechanic

Diagnostic Mechanic

Diesel Mechanic

Equipment Mechanic

Heavy Equipment Mechanic

Maintenance Mechanic

Mechanic

Mechanic/Welder

Mechanic Helper

Mobile Equipment Mechanic

Mobile Maintenance Mechanic

Plant Mechanic

Repairman 12 1,895 0 4,796

Automotive Repairman

Crusher Repairman

Electronic/Electrical Repairman

Heavy Duty Repairman

Instrument Repairman

Plant Repairman

Repairman

Tailings Repairman
86 

Table 34. Number of Miscellaneous Employees at Metal Mines 

Occupation by Category 

Survey 

Count 

MISCELLANEOUS 3 

Trainee 1

 

Unknown 2 

Table 35. Estimated Number of Production Employees at Metal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

PRODUCTION 373 17,581 5,896 29,266

Equipment Operator 113 7,185 0 14,993

Equipment Operator 53 2,280 167 4,394

Bulldozer Operator

Crane Operator

Dredge Operator

Equipment Operator

Grader Operator

Heavy Equipment Operator

Mucking Machine Operator

Raise Borer Operator

Hoist 6 93 4 182

Hoist Operator

Hoistman

Skip Tender/Cager/Station 

Attendant

Material Mover 42 3,569 0 7,682

Haul Truck Operator/Driver

Truck Driver

Mining Machines 4 DSU DSU DSU

Head Operator 

Shovel Operator 8 1,186 0 3,088

Extraction 60 2,192 119 4,265

Material Preparation 35 1,315 534 2,096

Additives 3 DSU DSU DSU

Additive Press Operator

Thickener Operator

Crusher 17 650 0 1,340

Crusher Helper

Crusher Operator/Pan Feeder 

Operator

Mill Crusher Operator
Table 35. Estimated Number of Production Employees at Metal Mines (continued) 

87 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Mill 15 594 162 1,025

Mill Operator (ball/pebble/rod)

Mill Production Worker

Process 54 3,088 78 6,098

Conveyor Operator 3 DSU DSU DSU

Belt Vulcanizer 

Other 17 366 0 753

Process Operator 

Separation 34 2,360 0 5,284

Digestion Operator

Filter Evaporation Operator

Flotation/Concentrator Operator

Grinder Operator

Leach Utility

Leaching Operations Worker

Screen Plant Operator

Tailings Operator

Support 111 3,801 503 7,099

Drill Operator 17 237 57 416

Drill Operator

Rotary Electric/Hydraulic Drill 

Operator

Electronics 1 DSU DSU DSU

Power Systems 

Explosives 9 145 10 279

Blaster

Driller/Blaster

Other 75 3,212 0 6,461

Control Room

Controller

Dispatcher

Operator, not otherwise specified

Port Operator

Production Operator

Top Operator

Quality Control 4 DSU DSU DSU

Quality Control/Quality Assurance 

Roof Bolter 5 42 0 104

Abbreviation: DSU, data suppressed. 
88 

Table 36. Estimated Number of Service and Utility Employees at Metal Mines 

Occupation by Category 

Survey

Count

National

Estimate 95% LCL 95% UCL

SERVICE and UTILITY 103 3,339 1,155 5,523

General Labor 61 2,474 367 4,580

Cleaners 1 DSU DSU DSU

Dry Attendant 

Construction 6 537 0 1,130

Cement Man/Concrete Worker

Construction

Shaft Miner/Shaft Repairer 

Laborer 30 160 14 307

Cook

Laborer

Production Worker

Material Handling 5 156 0 390

Bagger/Bagging Operations 

Worker

Material Handler

Tradesman 18 1,590 0 3,617

Apprentice/Journeyman

Boiler Operator

Boilermaker

Carpenter/Plumber/Painter

Craftsman

Trades Person

Weighman 1 DSU DSU DSU

Weighmaster 

Support Labor 42 865 253 1,478

Conveyor Operator 4 DSU DSU DSU

Belt Cleaner/Conveyor Man 

Distribution 9 48 0 140

Packaging Operations Worker 

Loading 14 186 45 326

Chute Puller

Load Haul Dump—Complete Cycle

Loader Operator

Supplies 5 39 0 78

Parts

Supply Hauler

Supply Man/Nipper

Utility 10 380 0 890

Lampman

Utility Man 

Abbreviation: DSU, data suppressed. 
89 

Figure 21. Occupational Categories of Employees at Metal Mines. 

2.2%

6.4%

9.8%

8.0%

3.4%

5.6%

18.5%

14.6%

4.1%

13.1%

0.8%

8.7%

4.9%

012345678

Support Labor

General Labor

Process

Support

Material Preparation

Extraction Labor

Equipment Operator

Support

Specialty

Supervisory

Safety

Professional

Office Staff

and Service

Production Maintenance Utility

Administration/

Professional

National Estimate (Thousands)
90 

 
91 

 

Employee Statistics for 

Nonmetal Mines 
92 
93 

Summary of Employee Statistics for Nonmetal Mines 

The demographic and occupational characteristics of employees in the U.S. nonmetal 

mining industry are presented in Tables 37 and 38 and Figures 22–24. The weighted survey 

estimate for gender indicates that the workforce is composed predominately of male employees 

(89.3 percent). The majority of nonmetal mine employees are White (85.6 percent) followed by 

Black or African American (13.6 percent). Eight percent of these employees have an ethnicity of 

Hispanic or Latino. An estimated 64.2 percent are high school graduates, with another 28.1 

percent having a level of education beyond high school. A review of the weighted estimates 

indicates that the average nonmetal mine worker is 42.0 years of age and has worked in mining 

for 12.0 years, with 10.3 years at the current mine, and 6.7 years in his/her job title. The national 

estimate for the average number of hours worked per week is 42.4. The primary work location 

for an estimated 37.0 percent of nonmetal mine employees is “Mill Operations, Preparation 

Plants, or Breakers.” An additional 24.4 percent of these employees work at a “Surface Mine: 

Other Surface Mining,” while another 13.0 percent are employed in the “Surface Mine: Strip, 

Open Pit, or Quarry” work location. 

Tables 39, 40, 42, 43, and Figure 25 present the national estimates of the number of 

nonmetal mine workers by four major occupational categories. (No estimates were calculated 

for Table 41: “Miscellaneous.”) An estimated 7,066 (36.7 percent) are employed in the 

“Administration/Professional” category; 2,836 (14.7 percent) in the “Maintenance” category; 

6,426 (33.3 percent) in the “Production” category; and 2,968 (15.4 percent) in the “Service and 

Utility” category. 
94 
95 

Table 37. Demographic Characteristics of Employees at Nonmetal Mines 

Demographic Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National

Percent 95% LCL 95% UCL

Gender:

Male 1,458 17,241 12,526 21,956 89.3 86.6 91.9Female 136 2,074 1,174 2,973 10.7 8.1 13.4

Age (years) 1,505 42.0 40.2 43.8Highest level of education:

Less than 9th grade 21 193 80 305 1.1 0.4 1.89th–12th grade (no diploma) 123 1,154 720 1,589 6.6 3.6 9.6HS Graduate or Equivalent (GED) 888 11,242 6,837 15,647 64.2 58.1 70.3Some College, Associate Degree, or 

Technical School

286 2,956 2,371 3,540 16.9 11.6 22.1

Bachelor's Degree or beyond 120 1,958 922 2,993 11.2 7.9 14.5

Ethnicity:

Hispanic or Latino 158 1,368 854 1,883 8.3 5.7 10.9Non-Hispanic or Non-Latino 1,384 15,171 12,851 17,491 91.7 89.1 94.3

Race:

American Indian or Alaska Native 12 87 24 150 0.5 0.1 0.8Asian 1 DSU DSU DSU DSU DSU DSUBlack or African American 174 2,479 1,483 3,474 13.6 8.0 19.3Native Hawaiian or Other Pacific Islander 3 DSU DSU DSU DSU DSU DSUWhite 1,262 15,567 10,412 20,721 85.6 79.8 91.4

Abbreviation: DSU, data suppressed. 
96 

Table 38. Occupational Characteristics of Employees at Nonmetal Mines 

Occupational Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Hours worked (per week) 1,489 42.4 41.6 43.3Experience:

Experience in this Job Title (years) 1,570 6.7 5.3 8.1Experience at this Mine (years) 1,581 10.3 8.9 11.7Total Mining Experience (years) 1,507 12.0 10.9 13.2

Primary Work Location:

Underground Mine: Underground 175 1,971 1,050 2,892 10.3 5.5 15.0Underground Mine: Surface Shops, Yards 31 422 94 751 2.2 0.5 3.9Surface Mine: Strip, Open Pit, or Quarry 310 2,483 1,515 3,450 13.0 6.9 19.0Surface Mine: Dredge 7 49 0 130 0.3 0.0 0.7Surface Mine: Other Surface Mining 

(Metal/Nonmetal Only)

199 4,673 0 9,870 24.4 5.2 43.6

Independent Shops or Yards 16 159 5 313 0.8 0.0 1.7Mill Operations, Preparation Plants, or 

Breakers 

632 7,088 4,880 9,296 37.0 24.0 50.0

Office 213 2,324 1,502 3,146 12.1 7.2 17.0
97 

Figure 22. Education Level of Employees at Nonmetal Mines. 

11.2%

16.9%

64.2%

6.6%

1.1%

0 2 4 6 8 10 12

Bachelor's Degree or beyond

Some College, Associate Degree, or Technical School

HS Graduate or Equivalent(GED)

9th‐12th grade (no diploma)

Lessthan 9th grade

National Estimate (Thousands)
98 

Figure 23. Race of Employees at Nonmetal Mines. 

85.6%

13.6%

0.5%

0 2 4 6 8 10 12 14 16 18

White

Black or African American

American Indian or Alaska Native

National Estimate (Thousands)
99 

Figure 24. Primary Work Location of Employees at Nonmetal Mines. 

12.1%

37.0%

0.8%

24.4%

0.3%

13.0%

2.2%

10.3%

012345678

Office

Mill Operations, Preparation Plants, or Breakers

Independent Shops or Yards

Surface Mine: Other Surface Mining (Metal / Nonmetal Only)

Surface Mine: Dredge

Surface Mine: Strip, Open Pit, or Quarry

Underground Mine: Surface Shops or Yards

Underground Mine: Underground

National Estimate (Thousands)
100 

Table 39. Estimated Number of Administration/Professional Employees at Nonmetal 

Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

ADMINISTRATION/PROFESSIONAL 499 7,066 3,597 10,536

Office Staff 108 1,504 901 2,107

Administrative Staff 46 514 292 735

Administration

Administrative Assistant

Clerk 

Customer Service

Human Resources

Office Staff

Receptionist

Secretary

Business 49 745 327 1,164

Accounting

Bookkeeper

Buyer

Payroll

Purchasing

Sales

Shipping 

Security 1 DSU DSU DSU

Guard 

Supplies 12 227 0 463

Supply Clerk

Warehouse

Professional 65 987 618 1,355

Engineer 18 297 84 509

Director of Engineering 

Engineer 

(Electrical/Mining/Ventilation) 

Engineer, not otherwise specified 

Environmental Engineer 

Plant Engineer 

Process Engineer 

Project Engineer

Non-engineer 13 309 61 557

Control Person/Analyst

Environmental Specialist

Geologist

Planner

Production Scheduler

Professional, not otherwise 

specified 

Reliability Engineer

Surveyor/Transit Man 
Table 39. Estimated Number of Administration/Professional Employees at Nonmetal 

Mines (continued) 

101 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Technician 34 381 182 581

Electrical Technician 

Process Control 

Operator/Technician

Sampler/Lab Technician 

Technician

Safety 7 147 0 314

Inspector

Safety

Supervisory 319 4,429 1,704 7,154

Executive 25 179 89 269

General Manager

Mine Owner

President

Vice President

Foreman 98 2,102 0 4,363

Foreman

Foreman/Shift Boss

Lead Man

Maintenance Foreman

Maintenance Lead Man

Mill Foreman

Mine Foreman

Pit Foreman

Plant Foreman

Production Foreman

Shift Foreman

Shop Foreman 

Superintendent 

Manager 72 737 467 1,006

Assistant Manager

Customer Service Manager

Environmental Manager

Financial Manager

Human Resources Manager

Lab Manager

Maintenance Manager 

Manager

Mill Manager

Mine Manager

Office Manager

Plant Manager

Production Manager

Project Manager

Quality Control Manager

Quarry Manager

Raw Material Manager

Sales Manager
Table 39. Estimated Number of Administration/Professional Employees at Nonmetal 

Mines (continued) 

102 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Shipping Manager

Supervisor 124 1,411 828 1,995

Assistant Mine Supervisor

Bagging/Baghouse Supervisor

Blasting Supervisor

Clay Operator

Electrical Supervisor

Lab Supervisor

Maintenance Supervisor

Mine Operations

Mine Operator

Mine Supervisor

Plant Operator

Plant Supervisor

Production Supervisor

Quality Assurance Supervisor

Quarry Supervisor

Shift Supervisor

Shipping Supervisor

Supervisor

Abbreviation: DSU, data suppressed. 

 
103 

Table 40. Estimated Number of Maintenance Employees at Nonmetal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

MAINTENANCE 202 2,836 1,781 3,890

Specialty 30 437 168 706

Electrician 25 401 136 667

Electrician/Wireman

Maintenance Electrician

Welder 5 35 0 81

Welder

Welder/Mechanic

Support 172 2,399 1,531 3,267

Maintenance 98 1,246 486 2,005

Electrical Maintenance

Greaser/Oiler

Maintenance

Maintenance Clerk

Maintenance Planner

Maintenance Technician

Mechanical Maintenance

Millwright

Plant Maintenance

Road Maintenance

Mechanic 70 1,099 554 1,644

Diesel Mechanic

Heavy Equipment Mechanic

Maintenance Mechanic

Master Mechanic

Mechanic

Mechanic Helper

Mobile Equipment Mechanic

Mobile Maintenance Mechanic

Mobile Mechanic

Plant Mechanic

Wrens Mechanic

Repairman 4 DSU DSU DSU

Automotive Repairman

Heavy Duty Repairman

Maintenance Repairman

Abbreviation: DSU, data suppressed. 
104 

Table 41. Number of Miscellaneous Employees at Nonmetal Mines 

Occupation by Category 

Survey 

Count 

MISCELLANEOUS 4 

Trainee 2

 

Unknown 2 

Table 42. Estimated Number of Production Employees at Nonmetal Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

PRODUCTION 636 6,426 5,142 7,710

Equipment Operator 221 1,892 1,308 2,477

Equipment Operator 124 1,058 603 1,512

Backhoe Operator

Bulldozer Operator

Crane Operator

Dredge Operator

Equipment Operator

Forklift Operator

Front End Loader Operator

Grader Operator

Gravity Mag Operator

Heavy Equipment Operator

Mobile Equipment Operator

Rotary Bucket Excavator Operator

Scraper Operator

Stripping Operator

Tractor Operator

Hoist 12 117 22 211

Hoist Engineer

Hoist Operator

Hoistman

Skip Tender/Cager/Station 

Attendant

Material Mover 75 548 284 812

Haul Truck Operator/Driver

Hauler/Haul Unit Operator 

Off Road Truck Driver

Ore Truck Driver/Operator

Pit Truck Driver

Rock Truck Driver

Scoop Loader

Scoop Tram Operator

Truck Driver

Water Truck Operator
Table 42. Estimated Number of Production Employees at Nonmetal Mines (continued) 

105 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Mining Machines 5 93 0 204

Continuous Miner Operator

Head Operator

Undercutter Operator

Operator/Driver 3 DSU DSU DSU

Dump Operator

Transportation

Shovel Operator 2 DSU DSU DSU

Extraction Labor 77 1,018 363 1,673

Mine Production

Mine Support

Miner

Material Preparation 106 918 544 1,293

Additives 10 121 0 286

Calcine Operator 

Crusher 30 180 83 276

Blunging Operator

Crusher Helper

Crusher Operator/Pan Feeder 

Operator

Screenhouse Crusher

Cutter 11 45 0 124

Cutting Machine Operator

Sawyer

Mill 55 572 271 873

Dry Mill Operator

Mill Hand/Helper

Mill Operator (ball/pebble/rod)

Mill Production Worker

Roller Mill Operator

Process 61 659 370 948

Conveyor Operator 1 DSU DSU DSU

Belt Vulcanizer 

Dry Processing 20 199 56 342

Dry Plant/Process Operator

Dryer Operator

Kiln Operator

Other 6 90 0 210

Fabricator

Process Attendant

Process Operator
Table 42. Estimated Number of Production Employees at Nonmetal Mines (continued) 

106 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Separation 28 337 132 541

Centrifuge Utility

Extruder Operator

Filter Operator

Flotation/Concentrator Operator

Grinder Operator

Leaching Operations Worker

Mix Operator

Pan Operator

Screen Plant Labor

Screen Plant Operator

Slurry Operator

Wet Process 6 28 0 58

Wet Plant Operator 

Support 171 1,938 988 2,889

Drill Operator 11 72 21 123

Electronics 2 DSU DSU DSU

Robot Operator 

Explosives 8 175 0 406

Blaster

Driller/Blaster

Explosives/Powder Man

Other 129 1,412 525 2,298

Control Room

Controller

Operator, not otherwise specified

Production Operator

Rak Handler

Quality Control 15 186 51 320

Quality Control/Quality Assurance 

Roof Bolter 6 61 0 124

Abbreviation: DSU, data suppressed. 
107 

Table 43. Estimated Number of Service and Utility Employees at Nonmetal Mines 

Occupation by Category 

Survey

Count

National

Estimate 95% LCL 95% UCL

SERVICE and UTILITY 254 2,968 2,236 3,699

General Labor 150 1,776 1,217 2,334

Cleaner 2 DSU DSU DSU

Janitor

Tank Car Washer

Construction 16 198 18 378

Construction

Packer

Shaft Miner/Shaft Repairer 

Laborer 51 587 256 918

Laborer

Miller

Plant Helper

Plant Man

Production Worker

Quarry Worker

Material Handling 78 928 502 1,355

Bagger/Bagging Operations 

Worker

Crude Pile Operator

Material Handler

Palletizer

Reclaim Operator

Stacker

Storage Operator

Storeroom

Yard Laborer

Tradesman 2 DSU DSU DSU

Boiler Operator 

Weighman 1 DSU DSU DSU

Scale Clerk/Operator 

Support Labor 104 1,192 742 1,641

Barge Operations 6 46 0 111

Barge Attendant/Boat Operator

Deck Hand

Conveyor Operator 1 DSU DSU DSU

Belt Cleaner/Conveyor Man 

Distribution 18 316 0 697

Packaging Operations Worker 
Table 43. Estimated Number of Service and Utility Employees at Nonmetal Mines 

(continued) 

108 

Occupation by Category 

Survey

Count

National

Estimate 95% LCL 95% UCL

Loading 49 561 344 779

Bulk Loader

Load Haul Dump—Complete Cycle

Loader Operator

Loading

Plant Loader Operator

Production Loader

Rail Loader Operator

Shipping Loader

Stock Loader/Piler

Tipple Operator

Utility 30 252 79 425

Operator Utility

Plant Utility

Quarry Utility

Utility Lubricator

Utility Man

Abbreviation: DSU, data suppressed. 

 
109 

Figure 25. Occupational Categories of Employees at Nonmetal Mines. 

6.2%

9.2%

10.0%

3.4%

4.8%

5.3%

9.8%

12.4%

2.3%

23.0%

0.8%

5.1%

7.8%

012345

Support Labor

General Labor

Process

Support

Material Preparation

Extraction Labor

Equipment Operator

Support

Specialty

Supervisory

Safety

Professional

Office Staff

and Service

Production Maintenance Utility

Administration/

Professional

National Estimate (Thousands)
110 

 
111 

 

Employee Statistics for 

Stone Mines 
112 
113 

Summary of Employee Statistics for Stone Mines 

The demographic and occupational characteristics of employees in the U.S. stone mining 

industry are presented in Tables 44 and 45 and Figures 26–28. The weighted estimate for gender 

indicates that the workforce is composed predominately of male employees (93.4 percent). The 

majority of stone mine workers are White (93.8 percent), with another 4.7 percent of the workers 

having a racial category of Black or African American. Fourteen percent of these employees are 

Hispanic or Latino. An estimated 62.0 percent are high school graduates and 20.9 percent have a 

level of education beyond high school. A review of the weighted estimates indicates that the 

average stone miner is 43.8 years of age and has worked in mining for 12.5 years, 10.3 years at 

the current mine, and 7.8 years in his/her job title. The national estimate for the average number 

of hours worked per week is 45.7. The primary work location for an estimated 36.3 percent of 

stone mine employees is a “Surface Mine: Strip, Open Pit or Quarry.” An additional 33.5 

percent of these employees work in “Mill Operations, Preparation Plants, or Breakers,” while 

another 14.4 percent are employed in the “Surface Mine: Other Surface Mining” work location. 

Tables 46, 47, 49, 50, and Figure 29 present the national estimates of the number of 

workers by four major occupational categories. (No estimates were calculated for Table 48: 

“Miscellaneous.”) An estimated 19,435 (27.5 percent) stone mine workers are employed in the 

“Administration/Professional” category; 10,563 (14.9 percent) in the “Maintenance” category; 

24,955 (35.3 percent) in the “Production” category; and 15,826 (22.3 percent) in the “Service 

and Utility” category. 

 
114 
115 

Table 44. Demographic Characteristics of Employees at Stone Mines 

Demographic Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Gender:

Male 2,545 65,950 60,931 70,970 93.4 92.3 94.4Female 173 4,666 3,802 5,530 6.6 5.6 7.7

Age (years) 2,629 43.8 42.9 44.7Highest level of education:

Less than 9th grade 111 3,094 1,630 4,558 4.7 2.5 6.99th–12th grade (no diploma) 320 8,075 6,195 9,956 12.4 9.6 15.1HS Graduate or Equivalent (GED) 1,607 40,481 35,504 45,457 62.0 56.9 67.1Some College, Associate Degree, or 

Technical School

353 10,020 7,927 12,112 15.3 12.6 18.1

Bachelor's Degree or beyond 129 3,647 2,686 4,607 5.6 4.2 6.9

Ethnicity:

Hispanic or Latino 309 9,394 6,111 12,676 13.6 9.1 18.1Non-Hispanic or Non-Latino 2,348 59,768 54,166 65,370 86.4 81.9 90.9

Race:

American Indian or Alaska Native 25 815 306 1,323 1.3 0.5 2.1Asian 4 DSU DSU DSU DSU DSU DSUBlack or African American 104 3,040 1,551 4,529 4.7 2.5 7.0Native Hawaiian or Other Pacific Islander 6 198 0 441 0.3 0.0 0.7White 2,362 60,494 55,116 65,872 93.8 91.5 96.0

Abbreviation: DSU, data suppressed. 
116 

Table 45. Occupational Characteristics of Employees at Stone Mines 

Occupational Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Hours worked (per week) 2,601 45.7 44.2 47.2Experience:

Experience in this Job Title (years) 2,596 7.8 7.2 8.3Experience at this Mine (years) 2,635 10.3 9.3 11.2Total Mining Experience (years) 2,643 12.5 11.7 13.3

Primary Work Location:

Underground Mine: Underground 217 1,710 1,305 2,115 2.4 1.8 3.0Underground Mine: Surface Shops, Yards 121 732 482 983 1.0 0.7 1.4Surface Mine: Strip, Open Pit, or Quarry 917 25,736 21,819 29,654 36.3 31.6 41.0Surface Mine: Dredge 6 248 0 584 0.4 0.0 0.8Surface Mine: Other Surface Mining 

(Metal/Nonmetal Only)

352 10,203 7,034 13,372 14.4 10.0 18.8

Independent Shops or Yards 22 530 0 1,077 0.7 0.0 1.5Mill Operations, Preparation Plants, or 

Breakers 

782 23,787 19,554 28,021 33.5 28.3 38.8

Office 301 7,957 6,438 9,475 11.2 9.3 13.1
117 

Figure 26. Education Level of Employees at Stone Mines. 

5.6%

15.3%

62.0%

12.4%

4.7%

0 5 10 15 20 25 30 35 40 45

Bachelor's Degree or beyond

Some College, Associate Degree, or Technical School

HS Graduate or Equivalent(GED)

9th‐12th grade (no diploma)

Lessthan 9th grade

National Estimate (Thousands)
118 

Figure 27. Race of Employees at Stone Mines. 

93.8%

0.3%

4.7%

1.3%

0 10 20 30 40 50 60 70

White

Native Hawaiian or Other Pacific Islander

Black or African American

American Indian or Alaska Native

National Estimate (Thousands)
119 

Figure 28. Primary Work Location of Employees at Stone Mines. 

11.2%

33.5%

0.7%

14.4%

0.4%

36.3%

1.0%

2.4%

0 5 10 15 20 25 30

Office

Mill Operations, Preparation Plants, or Breakers

Independent Shops or Yards

Surface Mine: Other Surface Mining (Metal / Nonmetal Only)

Surface Mine: Dredge

Surface Mine: Strip, Open Pit, or Quarry

Underground Mine: Surface Shops or Yards

Underground Mine: Underground

National Estimate (Thousands)
120 

Table 46. Estimated Number of Administration/Professional Employees at Stone Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

ADMINISTRATION/PROFESSIONAL 725 19,435 16,978 21,891

Office Staff 117 3,155 2,320 3,990

Administrative Staff 69 1,748 1,250 2,245

Administration

Administrative Assistant

Clerk

Communications

Customer Service

Human Resources

Information Technology

Office Clerk

Office Staff

Plant Clerk

Secretary

Business 38 1,131 609 1,653

Accounting

Bookkeeper

Buyer

Payroll

Procurement

Purchasing

Sales

Shipping

Terminal Operator

Security 3 DSU DSU DSU

Guard 

Supplies 7 158 8 308

Supply Clerk

Warehouse

Warehouse Technician 

Professional 92 3,139 1,947 4,332

Engineer 14 566 234 897

Engineer 

(Electrical/Mining/Ventilation)

Engineer, not otherwise specified 

Environmental Engineer

Plant Engineer

Process Engineer

Production Engineer

Project Engineer

Non-engineer 16 596 166 1,025

Chemist

Control Person/Analyst

Environmental Specialist

Physical Tester

Planner
Table 46. Estimated Number of Administration/Professional Employees at Stone Mines 

(continued) 

121 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Professional, not otherwise 

specified 

Reliability Engineer

Technician 62 1,978 990 2,966

Electrical Technician 

Materials Technician

Process Control 

Operator/Technician

Production Technician

Quarry Technician

Sampler/Lab Technician 

Technician

Utility Technician 

Safety 11 346 80 613

Inspector

Safety

Safety Manager

Supervisory 505 12,794 11,322 14,265

Executive 22 659 390 929

General Manager

Mine Owner

President

Vice President 

Foreman 165 4,255 3,512 4,998

Assistant Superintendent 

Foreman

Foreman/Shift Boss

Lead Man

Maintenance Foreman

Maintenance Lead Man

Mine Foreman

Pit Foreman

Plant Foreman 

Shop Foreman 

Superintendent 

Manager 105 2,406 1,880 2,933

Assistant Manager

Distribution Manager

Environmental Manager

Equipment Maintenance Manager

Equipment Manager

Facility Manager

Human Resources Manager

Maintenance Manager

Manager

Mine Manager

Office Manager
Table 46. Estimated Number of Administration/Professional Employees at Stone Mines 

(continued) 

122 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Operations Manager

Plant Manager 

Production Manager

Project Manager

Purchasing Manager

Quality Control Manager

Quarry Manager

Regulatory Manager

Sales Manager

Scale Office Manager

Technical Service Manager 

Supervisor 213 5,473 4,284 6,662

Blasting Supervisor

Control Room Supervisor

Crusher Supervisor

Electrical Supervisor

Equipment Supervisor

Lab Supervisor

Loader Supervisor

Loadhouse Supervisor

Maintenance Supervisor

Mine Operator

Mine Supervisor

Mobile Equipment Supervisor

Plant Operator

Plant Supervisor

Process Supervisor

Production Supervisor

Quality Assurance Supervisor

Quarry Operator

Quarry Supervisor

Shift Supervisor

Shipping Supervisor

Supervisor

Transportation Supervisor

Warehouse Supervisor

Wash Plant Supervisor

Abbreviation: DSU, data suppressed. 
123 

Table 47. Estimated Number of Maintenance Employees at Stone Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

MAINTENANCE 384 10,563 8,999 12,127

Specialty 79 2,219 1,533 2,904

Electrician 39 1,191 709 1,674

Electrician/Wireman

Maintenance Electrician

Welder 40 1,027 572 1,483

Maintenance Welder

Repair/Welder

Welder

Welder/Mechanic

Support 305 8,344 6,908 9,780

Maintenance 132 3,604 2,585 4,624

Electrical Maintenance

Equipment Maintenance

Fixed Maintenance

Greaser/Oiler

Liquid Fuel Handler

Maintenance

Maintenance Clerk

Maintenance Coordinator

Maintenance Planner

Maintenance Technician

Mechanical Maintenance

Millwright

Mobile Maintenance

Plant Maintenance

Mechanic 149 3,721 2,632 4,811

Heavy Equipment Mechanic

Maintenance Mechanic

Master Mechanic

Mechanic

Mechanic Helper

Mobile Equipment Mechanic

Mobile Maintenance Mechanic

Mobile Mechanic

Plant Mechanic

Repairman 24 1,019 258 1,780

Automotive Repairman

Electronic/Electrical Repairman

Instrument Repairman

Mechanical Repairman

Repairman
124 

Table 48. Number of Miscellaneous Employees at Stone Mines 

Occupation by Category 

Survey 

Count 

MISCELLANEOUS 7 

Trainee 1

 

Unknown 6 

Table 49. Estimated Number of Production Employees at Stone Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

PRODUCTION 1,040 24,955 21,960 27,951

Equipment Operator 589 14,803 12,345 17,261

Dragline Operator 4 DSU DSU DSU

Equipment Operator 297 8,113 6,018 10,208

Bobcat Operator

Bulldozer Operator

Crane Operator

Dredge Operator

End Dump Driver

Equipment Operator

Forklift Operator

Front End Loader Operator

Grader Operator

Heavy Equipment Operator

Highlift Operator

Machine Operator

Mobile Equipment Operator

Paver Operator

Payloader Operator

Rotary Bucket Excavator Operator

Scaler (mechanical)

Tower Operator

Track Hoe

Tractor Operator

Material Mover 275 6,209 4,898 7,521

Dump Operator

Haul Truck Operator/Driver

Hauler/Haul Unit Operator 

Motorman

Off Road Truck Driver

Operator/Driver

Pit Truck Driver

Quarry Truck Driver

Rock Truck Driver

Stock Truck/Stock Pile Driver

Transportation 

Truck Driver

Water Truck Operator
Table 49. Estimated Number of Production Employees at Stone Mines (continued) 

125 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Shovel Operator 3 DSU DSU DSU

Extraction Labor 22 410 0 950

Heading Prep

Miner

Material Preparation 115 2,718 1,728 3,709

Additives 1 DSU DSU DSU

Additives Utility 

Crusher 45 978 586 1,369

Breaker Operator

Crusher Operator/Pan Feeder 

Operator

Crusher Plant Operator

Hammer Mill Operator

Jaw Operator

Rock Breaker Operator

Cutter 47 1,115 215 2,015

Sawyer

Splitter

Stone Cutter

Trimmer

Mill 22 547 167 927

Limestone Prep Operator

Mill Man 

Mill Operator (ball/pebble/rod)

Milling Machine Operator

Roller Operator

Process 34 1,177 588 1,767

Dry Processing 10 373 33 713

Dryer Operator

Kiln Operator

Other 9 369 50 689

Fabricator

Process Attendant

Separation 15 435 93 776

Grinder Operator

Mix Chemist

Mix Operator

Pelletizing Operations Worker

Pug Operator/Mixer Tender

Rotex Operator

Screen Plant Operator
Table 49. Estimated Number of Production Employees at Stone Mines (continued) 

126 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Support 280 5,847 4,387 7,308

Drill Operator 46 730 442 1,019

Drill Helper/Chuck Tender

Drill Operator

Electronics 1 DSU DSU DSU

Console Operator 

Explosives 48 561 288 834

Blaster

Driller/Blaster

Explosives/Powder Man

Shooter

Other 142 3,500 2,176 4,823

Control Room

Controller

Dispatcher

Operator, not otherwise specified

Panel Operator

Production Operator

Scaler (hand)

Quality Control 38 965 638 1,292

Quality Control/Quality Assurance 

Roof Bolter 5 49 0 107

Roof Bolter

Roof Control Operator

Abbreviation: DSU, data suppressed. 
127 

Table 50. Estimated Number of Service and Utility Employees at Stone Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

SERVICE and UTILITY 565 15,826 13,213 18,439

General Labor 293 9,020 6,871 11,169

Cleaner 3 DSU DSU DSU

Janitor

Tower Cleaner

Construction 11 271 0 547

Curb Cutter

Ground Control/Timberman

Packer

Screed Person

Laborer 190 6,107 4,029 8,184

Ground Man

Laborer

Miller

Plant Man

Quarry Worker 

Material Handling 36 1,215 518 1,911

Bagger/Bagging Operations 

Worker

Material Handler

Palletizer

Silo Operator

Stacker

Storeroom

Yard Laborer

Tradesman 5 141 0 319

Apprentice/Journeyman

Machinist

Weighman 48 1,183 836 1,529

Scale Clerk/Operator

Weighmaster

Support Labor 272 6,806 5,172 8,440

Barge Operations 6 188 0 407

Barge Attendant/Boat Operator

Deck Hand

Dock Worker

Conveyor Operator 2 DSU DSU DSU

Belt Cleaner/Conveyor Man 

Distribution 7 187 0 407

Packaging Operations Worker

Packhouse
Table 50. Estimated Number of Service and Utility Employees at Stone Mines (continued) 

128 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Loading 202 4,840 3,396 6,284

Bin Puller/Truck Loader

Bulk Loader

Load Man 

Loader Operator

Loading

Loadout Operator

Pit Loader Operator

Plant Loader Operator

Production Loader

Quarry Loader Operator

Rail Loader Operator

Stock Loader/Piler

Yard Loader Operator 

Utility 55 1,561 912 2,210

Crusher Utility

E.O. Utility

Equipment Utility

Mill Utility

Pit Utility Person

Plant Utility

Production Utility

Quarry Utility

Utility Man

Utility Scaler

Abbreviation: DSU, data suppressed. 
129 

Figure 29. Occupational Categories of Employees at Stone Mines. 

9.6%

12.7%

8.3%

1.7%

3.8%

0.6%

20.9%

11.8%

3.1%

18.1%

0.5%

4.5%

4.4%

0 2 4 6 8 10 12 14 16

Support Labor

General Labor

Process

Support

Material Preparation

Extraction Labor

Equipment Operator

Support

Specialty

Supervisory

Safety

Professional

Office Staff

and Service

Production Maintenance Utility

Administration/

Professional

National Estimate (Thousands)
130 

 
131 

Employee Statistics for 

Sand and Gravel Mines 
132 

 
133 

Summary of Employee Statistics for Sand and Gravel Mines 

The demographic and occupational characteristics of employees in the U.S. sand and 

gravel mining industry are presented in Tables 51 and 52 and Figures 30–32. The weighted 

survey estimate for gender indicates that the workforce is composed predominately of male 

employees (92.1 percent). The majority of sand and gravel mine employees are White (94.1 

percent), followed by Black or African American (4.0 percent). Almost 18 percent of these 

employees have an ethnicity of Hispanic or Latino. An estimated 59.9 percent are high school 

graduates, with another 20.7 percent having a level of education beyond high school. A review 

of the weighted estimates indicates that the average sand and gravel mine worker is 44.0 years of 

age and has worked in mining for 10.3 years, with 7.4 years at the current mine, and 7.4 years in 

his/her job title. The national estimate for the average number of hours worked per week is 46.1. 

The primary work location for an estimated 53.0 percent of sand and gravel mine employees is a 

“Surface Mine: Strip, Open Pit, or Quarry.” An additional 14.8 percent of these employees work 

at a “Surface Mine: Other Surface Mining,” while another 13.0 percent are employed in the 

“Surface Mine: Dredge” work location. 

Tables 53, 54, 56, 57, and Figure 33 present the national estimates of the number of sand 

and gravel mine workers by four major occupational categories. (No estimates were calculated 

for Table 55: “Miscellaneous.”) An estimated 9,445 (29.5 percent) are employed in the 

“Administration/Professional” category; 2,640 (8.3 percent) in the “Maintenance” category; 

11,971 (37.5 percent) in the “Production” category; and 7,928 (24.7 percent) in the “Service and 

Utility” category. 

 
134 
135

Table 51. Demographic Characteristics of Employees at Sand and Gravel Mines 

Demographic Characteristic

Survey

Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Gender:

Male 1,280 29,343 24,178 34,508 92.1 90.0 94.2Female 109 2,531 1,607 3,456 7.9 5.8 10.0

Age (years) 1,326 44.0 43.0 45.1Highest level of education:

Less than 9th grade 69 1,464 310 2,619 4.8 1.1 8.49th–12th grade (no diploma) 176 4,502 3,122 5,881 14.7 10.3 19.1HS Graduate or Equivalent (GED) 817 18,394 14,222 22,566 59.9 54.0 65.9Some College, Associate Degree, or 

Technical School

238 5,276 3,850 6,701 17.2 14.4 19.9

Bachelor's Degree or beyond 60 1,065 656 1,475 3.5 2.3 4.6

Ethnicity:

Hispanic or Latino 286 5,154 2,850 7,458 17.5 9.3 25.6Non-Hispanic or Non-Latino 1,027 24,345 18,596 30,093 82.5 74.4 90.7

Race:

American Indian or Alaska Native 28 441 210 673 1.6 0.7 2.5Asian 4 DSU DSU DSU DSU DSU DSUBlack or African American 58 1,109 277 1,940 4.0 1.6 6.3Native Hawaiian or Other Pacific Islander 2 DSU DSU DSU DSU DSU DSUWhite 1,066 26,151 20,354 31,948 94.1 92.1 96.1

Abbreviation: DSU, data suppressed. 
136

Table 52. Occupational Characteristics of Employees at Sand and Gravel Mines 

Occupational Characteristic

Survey

 Count

National

Estimate 95% LCL 95% UCL

National 

Percent 95% LCL 95% UCL

Hours worked (per week) 1,220 46.1 43.6 48.5Experience:

Experience in this Job Title (years) 1,350 7.4 6.2 8.6Experience at this Mine (years) 1,335 7.4 6.2 8.7Total Mining Experience (years) 1,352 10.3 9.5 11.2

Primary Work Location:

Surface Mine: Strip, Open Pit, or Quarry 678 17,029 12,145 21,913 53.0 42.3 63.7Surface Mine: Dredge 171 4,190 2,281 6,100 13.0 7.8 18.3Surface Mine: Other Surface Mining 

(Metal/Nonmetal Only)

244 4,740 2,462 7,018 14.8 7.3 22.2

Independent Shops or Yards 7 153 27 278 0.5 0.1 0.8Mill Operations, Preparation Plants, or 

Breakers

129 2,305 1,078 3,532 7.2 3.3 11.0

Office 162 3,701 2,470 4,932 11.5 8.6 14.4
137

Figure 30. Education Level of Employees at Sand and Gravel Mines. 

3.5%

17.2%

59.9%

14.7%

4.8%

0 2 4 6 8 10 12 14 16 18 20

Bachelor's Degree or beyond

Some College, Associate Degree, or Technical School

HS Graduate or Equivalent(GED)

9th‐12th grade (no diploma)

Lessthan 9th grade

National Estimate (Thousands)
138

Figure 31. Race of Employees at Sand and Gravel Mines. 

94.1%

4.0%

1.6%

0 5 10 15 20 25 30

White

Black or African American

American Indian or Alaska Native

National Estimate (Thousands)
139

Figure 32. Primary Work Location of Employees at Sand and Gravel Mines. 

11.5%

7.2%

0.5%

14.8%

13.0%

53.0%

0 2 4 6 8 10 12 14 16 18

Office

Mill Operations, Preparation Plants, or Breakers

Independent Shops or Yards

Surface Mine: Other Surface Mining (Metal / Nonmetal Only)

Surface Mine: Dredge

Surface Mine: Strip, Open Pit, or Quarry

National Estimate (Thousands)
140 

Table 53. Estimated Number of Administration/Professional Employees at Sand and 

Gravel Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

ADMINISTRATION/PROFESSIONAL 398 9,445 6,998 11,892

Office Staff 65 1,512 745 2,279

Administrative Staff 43 1,098 401 1,795

Administration

Administrative Assistant

Clerk

Customer Service

Office Clerk

Office Staff

Plant Clerk

Receptionist

Secretary

Business 17 350 88 612

Accounting

Bookkeeper

Payroll

Purchasing

Sales

Security 3 DSU DSU DSU

Guard 

Union Representative 2 DSU DSU DSU

Professional 33 596 185 1,007

Engineer 7 61 0 124

Engineer 

(Electrical/Mining/Ventilation)

Engineer, not otherwise specified

Environmental Engineer

Plant Engineer 

Non-engineer 12 302 0 671

Environmental Specialist 

Operating Engineer

Production Scheduler

Technician 14 234 74 393

Sampler/Lab Technician

Technician

Safety 10 165 68 262

Safety

Safety Manager

Safety Supervisor
Table 53. Estimated Number of Administration/Professional Employees at Sand and 

Gravel Mines (continued) 

141 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Supervisory 290 7,172 5,188 9,156

Executive 8 348 147 550

General Manager

Mine Owner

President

Vice President

Foreman 86 1,868 1,352 2,383

Foreman

Foreman/Shift Boss

Lead Man

Maintenance Foreman

Maintenance Lead Man 

Shop Foreman

Plant Foreman 

Superintendent 

Manager 60 1,485 848 2,121

Area Manager

Assistant Manager

Dredge Manager

Dry Plant Manager

Equipment Manager

Manager

Office Manager

Operations Manager

Plant Manager

Production Manager

Purchasing Manager

Quarry Manager

Sales Manager

Shift Manager

Shop Manager

Supervisor 136 3,471 2,234 4,708

Backhoe Supervisor

Dozer Supervisor

Lab Supervisor

Maintenance Supervisor

Mine Operator

Plant Operator

Plant Supervisor

Production Supervisor

Quarry Supervisor

Shift Supervisor

Supervisor

Abbreviation: DSU, data suppressed. 
142 

Table 54. Estimated Number of Maintenance Employees at Sand and Gravel Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

MAINTENANCE 176 2,640 2,135 3,145

Specialty 17 274 88 460

Electrician 6 78 0 184

Electrician/Wireman

Maintenance Electrician

Welder 11 196 40 351

Certified Welder

Repair/Welder

Welder

Welder/Mechanic

Support 159 2,365 1,910 2,820

Maintenance 56 803 583 1,022

Electrical Maintenance

Fixed Maintenance

Greaser/Oiler

Maintenance

Maintenance Planner

Plant Maintenance

Production/Process Maintenance

Truck Maintenance

Mechanic 69 1,125 775 1,476

Aggregate Mechanic

Equipment Mechanic

Maintenance Mechanic

Mechanic

Mechanic Helper

Mechanic/Welder

Mobile Equipment Mechanic

Mobile Maintenance Mechanic

Mobile Mechanic

Plant Mechanic

Repairman 34 437 108 766

Automotive Repairman

Heavy Duty Repairman

Plant Repairman

Repairman

Skilled Repairman
143 

Table 55. Number of Miscellaneous Employees at Sand and Gravel Mines 

Occupation by Category 

Survey 

Count 

MISCELLANEOUS 6 

Trainee 1

 

Unknown 5 

Table 56. Estimated Number of Production Employees at Sand and Gravel Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

PRODUCTION 506 11,971 7,813 16,130

Equipment Operator 311 7,118 4,308 9,927

Dragline Operator 9 194 21 367

Equipment Operator 194 4,530 2,398 6,663

Backhoe Operator

Bobcat Operator

Bulldozer Operator

Dredge Operator

Equipment Operator

Front End Loader Operator

Grader Operator

Heavy Equipment Operator

Highlift Operator

Hopper Operator

Mobile Equipment Operator

Mucking Machine Operator

Rotary Bucket Excavator Operator

Stripping Operator

Tower Operator

Track Hoe

Tractor Operator

Hoist 16 111 0 368

Hoist Engineer 

Material Mover 85 2,174 1,024 3,323

Haul Truck Operator/Driver

Pit Truck Driver

Rock Truck Driver

Stock Truck/Stock Pile Driver

Truck Driver

Water Truck Operator

Operator 4 DSU DSU DSU

Motorman 

Shovel Operator 3 DSU DSU DSU
Table 56. Estimated Number of Production Employees at Sand and Gravel Mines 

(continued) 

144 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Material Preparation 43 1,110 359 1,861

Crusher 26 973 225 1,722

Crusher Operator/Pan Feeder 

Operator

Crusher Plant Operator

Cutter 11 27 0 75

Splitter 

Mill 6 110 0 265

Mill Operator (ball/pebble/rod) 

Process 24 511 224 798

Dry Processing 12 191 37 344

Dry Plant/Process Operator

Dryer Operator

Fluid Bed Dryer Operator

Separation 2 DSU DSU DSU

Pug Operator/Mixer Tender

Slurry Operator

Wash Process 9 267 15 519

Wash Operator 

Wet Process 1 DSU DSU DSU

Wet Plant Operator 

Support 128 3,233 2,071 4,395

Drill Operator 2 DSU DSU DSU

Explosives 2 DSU DSU DSU

Blaster 

Other 107 2,806 1,626 3,987

Dispatcher

Operator, not otherwise specified

Production Operator

Quality Control 17 393 70 716

Quality Control/Quality Assurance 

Abbreviation: DSU, data suppressed. 
145 

Table 57. Estimated Number of Service and Utility Employees at Sand and Gravel Mines 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

SERVICE and UTILITY 306 7,928 6,032 9,824

General Labor 150 3,470 2,119 4,822

Cleaners 1 DSU DSU DSU

Cleanup Man 

Laborer 81 1,916 876 2,957

Ground Hand

Ground Man

Laborer

Plant Helper

Plant Man

Root Picker

Stick Picker

Material Handling 22 380 0 772

Bagger/Bagging Operations 

Worker

Mudpicker

Reclaim Operator

Storeroom

Sweeper Operator

Tradesman 3 DSU DSU DSU

Apprentice/Journeyman 

Weighman 43 1,104 577 1,631

Scale Clerk/Operator

Weighmaster

Support Labor 156 4,458 3,352 5,563

Barge Operations 4 DSU DSU DSU

Barge Attendant/Boat Operator

Deck Hand

Conveyor Operator 4 DSU DSU DSU

Belt Cleaner/Conveyor Man 

Distribution 1 DSU DSU DSU

Packaging Operations Worker 

Loading 123 3,919 2,766 5,072

Bulk Loader

Loader Operator

Loadout Operator

Operator/Loader

Plant Loader Operator

Rail Loader Operator

Shipping Loader

Stock Loader/Piler

Yard Loader Operator
Table 57. Estimated Number of Service and Utility Employees at Sand and Gravel Mines 

(continued) 

146 

Occupation by Category 

Survey 

Count

National 

Estimate 95% LCL 95% UCL

Pumper 1 DSU DSU DSU

Gravel Pumper 

Supplies 2 DSU DSU DSU

Parts 

Utility 21 361 200 523

Equipment Utility

Pit Utility Person

Plant Utility

Utility Beltline

Utility Man

Wet Utility

Abbreviation: DSU, data suppressed. 
147 

 Figure 33. Occupational Categories of Employees at Sand and Gravel Mines. 

13.9%

10.8%

10.1%

1.6%

3.5%

22.3%

7.4%

0.9%

22.4%

0.5%

1.9%

4.7%

012345678

Support Labor

General Labor

Process

Support

Material Preparation

Equipment Operator

Support

Specialty

Supervisory

Safety

Professional

Office Staff

& Service

Utility Production Maintenance

Administration/

Professional

National Estimate (Thousands)
148 
149 

Acknowledgements 

The authors extend their appreciation to the reviewers for their thoughtful and insightful 

comments. We acknowledge the contributions of: Jefferey L. Burgess, M.D., M.P.H., University 

of Arizona, Jeffery H. Kravitz, Ph.D., Mine Safety and Health Administration, Elaine N. 

Rubinstein, Ph.D., University of Pittsburgh, John P. Sestito and William K. Sieber, National 

Institute for Occupational Safety and Health, and Bruce Watzman, National Mining Association. 

Additionally, we appreciate the contributions of our numerous colleagues at the Office of 

Mine Safety and Health Research. In particular, Audrey Podlesny for preparing the maps, 

Michael J. Brnich, Jr., Albert H. Cook, Nathan T. Lowe, Mary Ellen Nelson, Robert H. Peters, 

and Charles Vaught (retired) for their invaluable advice regarding the coding of the mining 

industry job titles, Joseph Schall and Candace A. Wolf for their editorial assistance, Donna Opfer 

and Brittney Warnick for their formatting assistance, Genny Lohr for her work on 508 

Compliance, and David Beshero for the cover design. 

Finally, the authors gratefully acknowledge the survey respondents in the coal, metal, 

nonmetal, stone, and sand and gravel mining sectors. Thank you for your time and effort in 

completing this survey. 
150 
151 

References 

American Geological Institute [1997]. Dictionary of mining, mineral, and related terms. 

Alexandria, VA: American Geological Institute. 

BLS [2010]. Standard occupational classification.Washington, DC: U.S. Department of Labor, 

Bureau of Labor Statistics, Standard Occupational Classifications [http://www.bls.gov/SOC/]. 

Cecala A and Thimons E [1992]. Tips for reducing dust from secondary sources during bagging. 

Powder and Bulk Eng. 7(5):77. 

Cochran WG [1977]. Sampling techniques, 3rd ed. New York: John Wiley & Sons, pp. 127–131. 

Dictionary.com [2011]. [http://www.dictionary.reference.com]. 

DOT [2003]. Dictionary of occupational titles [http://www.occupationalinfo.org]. 

Infomine Inc. [2010]. Dictionary of mining and mineral terms [http://www.infomine.com/ 

dictionary/]. 

Merriam-Webster [2011]. [http://www.merriam-webster.com/]. 

MSHA [2007]. Part 50 data user’s handbook. Denver: U.S. Department of Labor, Mine Safety 

and Health Administration, Office of Injury and Employment Information. 

MSHA [2011]. Program information bulletin No. P11-08. U.S. Department of Labor, Mine 

Safety and Health Administration [http://www.msha.gov/regs/complian/PIB/2011/pib11-08.asp]. 

NCHS [2002]. Statistical notes number 24. Healthy people 2010 criteria for data suppression. By 

Klein RJ, Proctor SE, Boudreault MA, Turczyn KM. Hyattsville, MD: U.S. Department of 

Health and Human Services, Centers for Disease Control and Prevention, National Center for 

Health Statistics. DHHS Publication No. (PHS) 2002-1237 2-0424. 

NCHS [2004]. NCHS staff manual on confidentiality. U.S. Department of Health and Human 

Services, Centers for Disease Control and Prevention, National Center for Health Statistics. 

Thrush P [1968]. A dictionary of mining, mineral, and related terms. Washington, DC: U.S. 

Department of the Interior, Bureau of Mines. 

Vaught C (Retired) [2008]. Glossary of mining terms. Private email message to Linda 

McWilliams (LMcWilliams@cdc.gov), March 28. 

Wang Z, Waldron W [2010]. Using the SAS® survey procedures for subpopulation analysis with 

jackknife repeated replication methods in SAS 9.2. In: Proceedings of the SAS Global Forum, 

pp. 1–9. 
152 

 
153 

Appendices 
154 
155 

Appendix A. Questionnaire Booklet 
156 

 
157 

 
158 

 
159 

 
160 

 
161 

 
162 

 
163 

 
164 

 
165 

 
166 

 
167 

 
168 

 
169 

 
170 

 
171 

 
172 

 
173 

 
174 
175 

 
176 

 
177 

 
178 

 
179 

Appendix B. Questions and Answers Brochure 

 
180 
181 

 
182 
183 

Appendix C. MSHA Form 7000-2: Quarterly Mine Employment and 

Coal Production Report 

 
184 

 
185 

 
186 
187 

Appendix D. Standard Industrial Classification (SIC) for Active Mines 

in 2007 
188 
189 

Coal Mining Sector 

Anthracite Coal 

Bituminous Coal 

Metal Mining Sector 

Alumina (Mill) 

Aluminum Ore 

Beryl 

Chromite 

Copper Ore 

Gold (Lode & Placer) 

Iron Ore 

Lead and/or Zinc Ore 

Manganese 

Metal Ores, NEC 

Molybdenum 

Platinum Group 

Rare Earths 

Silver Ores 

Titanium 

Uranium 

Uranium – Vanadium Ores 

Vanadium 

Zircon 

Nonmetal Mining Sector 

Aplite 

Barite 

Boron Materials 

Brucite 

Chemical and Fertilizer, NEC 

Clay (Common) 

Clay (Fire) 

Clay, Ceramic and Refractory, NEC 

Feldspar 

Fluorspar 

Gemstones 

Gilsonite 

Gypsum 

Kyanite 

Abbreviation: NEC, not elsewhere classified 

Nonmetal Mining Sector (Cont.) 

Leonardite 

Magnesite 

Mica 

Nonmetallic Minerals, NEC 

Oil Sand 

Oil Shale 

Perlite 

Phosphate Rock 

Pigment Mineral 

Potash 

Potash, Soda, & Borate Minerals, NEC 

Pumice 

Salt (Evaporated) 

Salt (Rock) 

Shale (Common) 

Sodium Compounds 

Talc, Soapstone, & Pyrophyllite 

Trona 

Vermiculite 

Stone Mining Sector 

Cement 

Granite (Crushed & Broken) 

Granite (Dimension) 

Lime 

Limestone (Crushed & Broken) 

Limestone (Dimension) 

Marble (Crushed & Broken) 

Marble (Dimension) 

Sandstone (Crushed & Broken) 

Sandstone (Dimension) 

Slate (Crushed & Broken) 

Slate (Dimension) 

Stone, Crushed & Broken, NEC 

Stone, Dimension, NEC 

Traprock (Crushed & Broken) 

Traprock (Dimension) 

Sand and Gravel Mining Sector 

Sand & Gravel 
190 
191 

Appendix E. Stratification and Sample Size Guidelines 

 
192 

 
193 

Stratification 

The cum f rule is often suggested for use in forming strata for surveys of businesses, 

which typically have a large number of small businesses with very few employees and a small 

number of large businesses with quite substantial payrolls [Cochran 1977]. Using this approach, 

strata that have approximately equal sizes in terms of the square root of the size measure are 

established. The cum f rule was used in determining the initial size-based strata for each 

mining sector with an assumption of about 4–5 strata per sector for underground mines and for 

surface mines. Except for sand and gravel mines, the large mines account for 25 percent or more 

of total employment. These initial stratum definitions for each commodity varied somewhat 

across mining sectors but were similar. 

The next step in stratum formation was to recognize that data from the five mining 

sectors would be combined to study mining as a whole. Using common definitions for strata 

across the five sectors facilitated these combined analyses. The initial stratum definitions were 

compared to determine a common stratification approach. The stratum definitions that met the 

needs for all five commodities were formed by the cross of underground versus surface mines 

with these size groupings of employees: 1–9, 10–25, 26–50, 51–75, 76–100, 101–250, and 251 

and up. 

Sample Size 

To determine the stratum sample sizes, the precision of percentage estimates under 

various sample sizes was considered. Table E-1 presents the half-length of confidence intervals 

around an estimated percentage Pˆ under various sample size and design effects and assuming 

large population sizes. For this table, the confidence interval was approximated for design 

purposes as: 

P z Var (P ) 1- ˆ ˆ   (1) 

Here z1- is the value of the critical point x at which the normal cumulative distribution 

function equals 1-, and )ˆ Var (P is the variance of Pˆ . The half-length HL is: 

 HL = z Var (P) 1- ˆ  (2) 

That is, Pˆ can be expected to fall within the range [PHL, P+HL] with 95 percent 

confidence for the indicated sample sizes. 

To determine these half-lengths of confidence intervals, there is a need to estimate the 

variance of the estimated percentage Pˆ . Ignoring finite population correction factors, Table E-1 

models the variance for an estimated percentage Pˆ as: 
194 

DEFF

n

P( - P ) Var(P) = 100 ˆ (3) 

where n is the sample size, P is the percentage being estimated, and DEFF is the design effect. 

The design effect for a survey estimate is defined to be the ratio of the statistic under the actual 

design divided by the variance that would have been achieved from a simple random sample of 

the same size. The design effect represents the cumulative effect of design components such as 

stratification, unequal weighting, and clustering, and varies with each design. The design effects 

for this survey were estimated to be about 1.00 for mine-level and employee-level estimates 

within strata. Crosscutting estimates were likely to have larger design effects, particularly for 

employee-level estimates. The design effect differs from 1.00 for the crosscutting estimates due 

to the variation in sampling rates used across strata. Fortunately, these crosscutting estimates 

often have large sampler sizes due to combining samples across strata. 

Sample sizes were set with the guideline that the precision for stratum estimates was 

constrained as that shown for sample sizes of 100 in Table E-1. Some mine strata have very 

small population sizes and some mining sectors are small overall. In such situations, the variance 

as given in equation (3) is reduced by the factor(N  n) /(N  1) , where n is the sample size and 

N is the population size. Rather than create versions of Table E-1 for all possible population 

sizes, finite-population-corrected (fpc) sample sizes were developed. An actual sample size of n

for a population of size N is equivalent to the precision achieved with a sample size of 

N n

n N n    ( 1)

from a population so large that fpc effects are ignorable. Initial sample sizes were set for each 

stratum so that the finite-population-corrected sample size was about 100 and then inflated to 

account for a projected 80 percent response rate. These initial sample sizes were then adjusted to 

prevent excessive variations in the sampling rates across strata for mines and for employees. 

Besides the number of mines selected, the employee sample size is affected by the 

eligibility and response rates for mines and the average number of employees sampled per mine. 

The average number of employees sampled per mine would be about 20 except for the smallest 

stratum where approximately 5 employees would tend to be sampled. It was assumed that 80 

percent of all eligible mines would respond, providing both mine-level and employee-level data. 

For sample design purposes, the assumption was made that a variable percentage of mines would 

be eligible for the survey, depending upon employment size. An eligibility rate of 85 percent was 

assumed for mines with 1–9 employees. These mines are most likely to shut down operations or 

go out of business. An eligibility rate of 90 percent was assumed for mines with 10–50 

employees, and 95 percent for mines with 51–100 employees. For very large mines with 

employment of more than 100, an eligibility rate of 99 percent was assumed, as they should be 

most stable in terms of their operations. 

In designing the commodity samples, an effort was made to minimize the design effects 

for mine-level and employee-level analyses. In particular, the goal was to achieve design effects 

of 1.0 for within-stratum estimates and design effects of 2.0 or less for crosscutting estimates. 

Following standard practice, the design effect DEFF was modeled as the product of the design 

effect associated with unequal weighting Dw and the design effect for clustering Dc, that is 
195 

* . DEFF  Dw Dc A simple random sample has both design effect components equal to one—

therefore DEFF=1. 

Both mine-level and employee-level estimates could potentially be subject to an unequal 

weighting effect greater than one, particularly for crosscutting estimates that combine data from 

multiple strata. The design effect for unequal weighting can be estimated as: 

2

1

1

2





 















n

i

i

n

i

i

w

W

n W

D (4) 

where n is the total sample size and Wi is the weight for the i

th observation. When the weights 

(the inverse of the selection probabilities) are equal for all selections, Dw = 1. For mines, Dw = 1 

within all strata for the proposed designs and was often only slightly greater than one across 

strata. For employees, Dw = 1 except for the two largest strata that collapsed employee size 

categories. These strata tended to have all mines selected with certainty, so the only way to 

reduce Dw was to increase the number of employees sampled per mine from 25 to 50. Adjusting 

the sample size for the very large mines could even out the employee-level weights within these 

strata and across strata. However, the increase in employee sample size also increased the burden 

for the mine respondent and increased the design effect for clustering. 

The design effect associated with clustering measures the loss of precision of a clustered 

sample as compared with a simple random sample. Clustered samples tend to have less precision 

than simple random samples of the same size, because units within the same cluster usually are 

more homogeneous than units from different clusters. The design effect for clustering can be 

estimated as: 

 D 1 (b 1) c  (5) 

where ρ is the intracluster correlation coefficient and b is the cluster size. Because stratified 

simple random sampling would be used to select mines, the mines would not be clustered (b = 1) 

and mine-level estimates would not be subject to a clustering effect (Dc = 1). However, multiple 

employees would be selected from each mine, so employee-level estimates would be subject to a 

design effect due to clustering. For the purpose of modeling the clustering design effect, it was 

assumed that variable values for ρ be based upon the size of the mine. Employees within small 

mines with 1 to 50 employees were expected to be more homogeneous, so a value of ρ = 5 

percent was assumed. Medium size mines were assumed to be less homogeneous, so a value of 

ρ = 3 percent was assumed. Large mines with more than 100 employees were expected to be 

quite diverse, so a value of ρ = 1 percent was assumed. A value of ρ = 3 percent was assumed for 

estimates compiled across strata. 
196 

Table E-1. Half-Length of 95% Confidence Intervals in Percentage Points for Various 

Percentages Being Estimated for Domains of Various Sizes with Various Design Effects 

DEFF P 50 75 100 150 200 250 350 400 500

1.00 10 8 7 6 5 4 4 3 3 3

1.00 20 11 9 8 6 6 5 4 4 4

1.00 25 12 10 8 7 6 5 5 4 4

1.00 30 13 10 9 7 6 6 5 4 4

1.00 40 14 11 10 8 7 6 5 5 4

1.00 50 14 11 10 8 7 6 5 5 4

1.25 10 9 8 7 5 5 4 4 3 3

1.25 20 12 10 9 7 6 6 5 4 4

1.25 25 13 11 9 8 7 6 5 5 4

1.25 30 14 12 10 8 7 6 5 5 4

1.25 40 15 12 11 9 8 7 6 5 5

1.25 50 15 13 11 9 8 7 6 5 5

1.50 10 10 8 7 6 5 5 4 4 3

1.50 20 14 11 10 8 7 6 5 5 4

1.50 25 15 12 10 8 7 7 6 5 5

1.50 30 16 13 11 9 8 7 6 6 5

1.50 40 17 14 12 10 8 7 6 6 5

1.50 50 17 14 12 10 8 8 6 6 5

2.00 10 12 10 8 7 6 5 4 4 4

2.00 20 16 13 11 9 8 7 6 6 5

2.00 25 17 14 12 10 8 8 6 6 5

2.00 30 18 15 13 10 9 8 7 6 6

2.00 40 19 16 14 11 10 9 7 7 6

2.00 50 20 16 14 11 10 9 7 7 6

3.00 10 12 10 8 7 6 5 4 4 4

3.00 20 16 13 11 9 8 7 6 6 5

3.00 25 17 14 12 10 8 8 6 6 5

3.00 30 18 15 13 10 9 8 7 6 6

3.00 40 19 16 14 11 10 9 7 7 6

3.00 50 20 16 14 11 10 9 7 7 6

 
197 

Appendix F. Sample Size Allocation Using MSHA Data from the 

Second Quarter of 2002 

 
198 
199 

Table F-1. Sample Allocation for Underground Coal Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–9 102 19% 461 1% 56 85% 80% 3810–25 149 27% 2,589 7% 68 90% 80% 49

26–50 146 26% 5,206 15% 67 90% 80% 4851–75 49 9% 3,098 9% 35 95% 80% 2776–100 22 4% 1,917 5% 22 95% 80% 17101–250 49 9% 8,301 24% 49 99% 80% 39251+ 34 6% 13,477 38% 34 99% 80% 27

Total 551 100% 35,049 100% 331 244

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–9 5 172 2.3 2.3 1.0 1.0 5% 1.2 1.210–25 17 851 2.7 2.7 1.0 1.0 5% 1.8 1.8

26–50 18 860 2.7 5.4 1.0 1.0 5% 1.8 1.851–75 21 561 1.8 5.3 1.0 1.0 3% 1.6 1.676–100 22 364 1.3 5.0 1.0 1.0 3% 1.6 1.6101–250 23 908 1.3 9.1 1.0 1.0 1% 1.2 1.3251+ 24 651 1.3 20.5 1.0 1.1 1% 1.2 1.3

Total 4,366 1.1 1.6 3% 1.5 2.5
200 

Table F-2. Sample Allocation for Surface Coal Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–9 518 46% 2,193 6% 101 85% 80% 6910–25 252 23% 4,166 12% 84 90% 80% 60

26–50 188 17% 6,860 19% 75 90% 80% 5451–75 58 5% 3,500 10% 36 95% 80% 2776–100 24 2% 2,068 6% 20 95% 80% 15101–250 52 5% 8,114 23% 52 99% 80% 41251+ 23 2% 8,823 25% 23 99% 80% 18

Total 1,115 100% 35,724 100% 391 285

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–9 4 291 6.4 6.4 1.0 1.0 5% 1.2 1.210–25 17 1,000 3.8 3.8 1.0 1.0 5% 1.8 1.8

26–50 18 985 3.1 6.3 1.0 1.0 5% 1.9 1.9

51–-75 20 550 2.0 6.0 1.0 1.0 3% 1.6 1.676–100 22 327 1.5 6.0 1.0 1.0 3% 1.6 1.6101–250 23 935 1.3 8.6 1.0 1.1 1% 1.2 1.3251+ 25 461 1.3 19.0 1.0 1.1 1% 1.2 1.4

Total 4,549 1.3 1.4 5% 1.7 2.4
201 

Table F-3. Sample Allocation for Underground Metal Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–9 18 35% 92 2% 18 85% 80% 1210–25 7 14% 123 2% 7 90% 80% 5

26–50 4 8% 171 3% 4 90% 80% 351–75 2 4% 125 2% 2 95% 80% 276–100 3 6% 264 5% 3 95% 80% 2101–250 12 24% 1,844 36% 12 99% 80% 10251+ 5 10% 2,476 49% 5 99% 80% 4

Total 51 100% 5,095 100% 51 37

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–9 5 63 1.3 1.3 1.0 1.0 5% 1.2 1.210–25 18 89 1.3 1.3 1.0 1.0 5% 1.8 1.8

26–50 21 62 1.3 2.5 1.0 1.0 5% 2.0 2.051–75 21 32 1.3 3.8 1.0 1.0 3% 1.6 1.676–100 22 50 1.3 5.0 1.0 1.0 3% 1.6 1.6101–250 23 222 1.3 8.2 1.0 1.1 1% 1.2 1.3

251+ 24 96 1.3 25.4 1.0 1.4 1% 1.2 1.7

Total 613 1.0 2.5 3% 1.5 3.7
202 

Table F-4. Sample Allocation for Surface Metal Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–9 54 34% 235 1% 54 85% 80% 3710–25 27 17% 438 2% 27 90% 80% 19

26–50 10 6% 356 2% 10 90% 80% 751–75 9 6% 591 3% 9 95% 80% 776–100 12 7% 1,094 5% 12 95% 80% 9101–250 19 12% 2,959 13% 19 99% 80% 15251+ 30 19% 17,703 76% 30 99% 80% 24

Total 161 100% 23,376 100% 161 118

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–9 4 160 1.3 1.3 1.0 1.0 5% 1.2 1.210–25 16 315 1.3 1.3 1.0 1.0 5% 1.8 1.8

26–50 18 128 1.3 2.5 1.0 1.0 5% 1.8 1.851–75 22 150 1.3 3.8 1.0 1.0 3% 1.6 1.676–100 23 208 1.3 5.0 1.0 1.0 3% 1.7 1.7101–250 23 344 1.3 8.5 1.0 1.1 1% 1.2 1.3251+ 24 581 1.3 30.2 1.0 1.4 1% 1.2 1.7

Total 1,886 1.0 2.7 3% 1.4 3.9
203 

Table F-5. Sample Allocation for Underground Nonmetal Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–9 12 29% 50 1% 12 85% 80% 810–25 2 5% 38 1% 2 90% 80% 1

26–50 8 20% 290 6% 8 90% 80% 651–75 4 10% 232 5% 4 95% 80% 376–100 1 2% 80 2% 1 95% 80% 1101–250 9 22% 1,634 34% 9 99% 80% 7251+ 5 12% 2,431 51% 5 99% 80% 4

Total 41 100% 4,755 100% 41 30

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–9 4 34 1.25 1.3 1.0 1.00 5% 1.2 1.210–25 19 27 1.25 1.3 1.0 1.00 5% 1.9 1.9

26–50 18 104 1.25 2.5 1.0 1.00 5% 1.9 1.9

51–75 19 59 1.25 3.8 1.0 1.00 3% 1.6 1.6

76–100 20 15 1.25 5.0 1.0 1.00 3% 1.6 1.6101–250 24 169 1.25 9.6 1.0 1.03 1% 1.2 1.3

251+ 24 96 1.25 25.1 1.0 1.26 1% 1.2 1.5

Total 504 1.0 2.18 3% 1.1 2.4
204 

Table F-6. Sample Allocation for Surface Nonmetal Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–9 347 53% 1,454 8% 92 85% 80% 6310–25 136 21% 2,094 12% 65 90% 80% 47

26–50 73 11% 2,768 15% 46 90% 80% 3351–75 45 7% 2,799 16% 34 95% 80% 2676–100 14 2% 1,191 7% 14 99% 80% 11101–250 25 4% 3,790 21% 25 99% 80% 20251+ 10 2% 3,785 21% 10 99% 80% 8

Total 650 100% 17,881 100% 286 207

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–9 4 262 4.71 4.7 1.0 1.00 5% 1.2 1.210–25 15 721 2.62 2.6 1.0 1.00 5% 1.7 1.7

26–50 19 628 1.98 4.0 1.0 1.00 5% 1.9 1.951–75 21 536 1.65 5.0 1.0 1.00 3% 1.6 1.676–100 21 236 1.25 5.0 1.0 1.00 3% 1.6 1.6101–250 23 450 1.25 8.3 1.0 1.04 1% 1.2 1.3251+ 24 191 1.25 19.6 1.0 1.15 1% 1.2 1.4

Total 3,023 1.2 1.65 3% 1.0 1.6
205 

Table F-7. Sample Allocation for Underground Stone Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–9 20 18% 102 3% 20 85% 80% 1410–25 48 43% 766 22% 35 90% 80% 25

26–50 28 25% 955 27% 23 90% 80% 1751–75 10 9% 610 17% 10 95% 80% 876–100 1 1% 91 3% 1 95% 80% 1101–250 3 3% 377 11% 3 99% 80% 2251+ 1 1% 637 18% 1 99% 80% 1

Total 111 100% 3,538 100% 93 67

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–9 5 69 1.3 1.3 1.0 1.000 5% 1.2 1.210–25 16 402 1.7 1.7 1.0 1.000 5% 1.7 1.7

26–50 17 282 1.5 3.0 1.0 1.000 5% 1.8 1.851–75 20 155 1.3 3.8 1.0 1.000 3% 1.6 1.676–100 23 17 1.3 5.0 1.0 1.000 3% 1.7 1.7

101–250 22 53 1.3 7.1 1.0 1.007 1% 1.2 1.2251+ 25 19 1.3 32.5 1.0 1.000 1% 1.2 1.2

Total 998 1.0 2.710 3% 1.0 2.6
206 

Table F-8. Sample Allocation for Surface Stone Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–9 1,698 46% 8,067 11% 116 85% 80% 7910–25 1,304 35% 20,497 28% 114 90% 80% 82

26–50 402 11% 13,862 19% 95 90% 80% 6851–75 104 3% 6,356 9% 51 95% 80% 3976–100 54 1% 4,704 6% 35 95% 80% 27101–250 124 3% 17,528 24% 62 99% 80% 49251+ 6 0% 1,796 2% 6 99% 80% 5

Total 3,692 100% 72,810 100% 479 349

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–9 5 375 18.3 18.3 1.0 1.000 5% 1.2 1.210–25 16 1,290 14.3 14.3 1.0 1.000 5% 1.7 1.7

26–50 17 1,179 5.3 10.6 1.0 1.000 5% 1.8 1.851–75 20 790 2.5 7.6 1.0 1.000 3% 1.6 1.6

76–100 22 579 1.9 7.7 1.0 1.000 3% 1.6 1.6101–250 23 1,126 2.5 15.4 1.0 1.046 1% 1.2 1.3

251+ 24 114 1.3 15.7 1.0 1.028 1% 1.2 1.3

Total 5,453 1.5 1.092 3% 1.0 1.1
207 

Table F-9. Sample Allocation for Sand and Gravel Mines 

Stratum

Number 

of 

Mines

Percentage 

of Total 

Mines

Number of 

Employees

Percentage 

of Total 

Employees

Sample 

Mines

Eligibility 

Rate

Response 

Rate

Responding 

Eligible 

Mines

1–3 2,589 42.6% 5,504 13.3% 119 85% 80% 814–6 1,572 25.9% 7,570 18.4% 80 85% 80% 54

7–9 748 12.3% 5,872 14.2% 37 85% 80% 2510–25 963 15.9% 13,995 33.9% 110 90% 80% 7926–50 168 2.8% 5,743 13.9% 70 95% 80% 5351–75 27 0.4% 1,607 3.9% 16 95% 80% 1276–100 3 0.0% 264 0.6% 3 99% 80% 2101–250 4 0.1% 683 1.7% 4 99% 80% 3251+ 0 0.0% 0 0.0% --- --- --- ---

Total 6,074 100.0% 41,238 100% 439 311

Stratum

Employees 

Sampled Per Mine

Total 

Sample 

Employees

Nonresponse 

Adjusted 

Mine Weight

Average 

Employee 

Weight

Mine 

DEFF

Employee 

Dw

Employee 

ρ

Employee 

Dc

Employee 

DEFF

1–3 2 172 27 27 1.00 1.00 5% 1.1 1.064–6 5 262 25 25 1.00 1.00 5% 1.2 1.19

7–9 8 198 25 25 1.00 1.00 5% 1.3 1.3410–25 15 1,151 11 11 1.00 1.00 5% 1.7 1.68

26–50 17 909 3 6 1.00 1.00 5% 1.8 1.80

51–75 20 241 2 6 1.00 1.00 3% 1.6 1.5776–100 22 52 1 5 1.00 1.00 3% 1.6 1.63

101–250 24 75 1 9 1.00 1.01 1% 1.2 1.24251+ --- --- --- --- --- --- --- --- ---

Total 3,060 1.35 1.37 5% 1.0 1.30
208 
209 

Appendix G. Critical Items from the Questionnaire 

 
210 
211 

National Survey of the Mining Population. 

Final List of Critical Items 

October 31, 2008 

Question Number Variable Name

M1a EMP_TRAIN_REF 

M1b EMP_TRAIN_INEXP 

M1c EMP_TRAIN_EXP 

M10 LANG_NON_ENG 

M11 MATS_NON_ENG 

M14 ADD_MATS_NON_ENG 

M16aa PROD_WORKERS 

SCH_DAYS_PROD 

M16ab SCH_HOURS_PROD 

M16ac ACT_HOURS_PROD 

M16ad CH_SHIFTS_PROD 

M16ae TRAV_HOURS_PROD 

TRAV_MINUTES_PROD 

M16ba PROD_SUP_WORKERS 

SCH_DAYS_PROD_SUP 

M16bb SCH_HOURS_PROD_SUP 

M16bc ACT_HOURS_PROD_SUP 

M16bd CH_SHIFTS_PROD_SUP 

M16be TRAV_HOURS_PROD_SUP 

TRAV_MINUTES_PROD_SUP 

M16ca PREP_WORKERS 

SCH_DAYS_PREP 

M16cb SCH_HOURS_PREP 

M16cc ACT_HOURS_PREP 

M17a PROD_WORKERS 

SHIFTS_DAY_PROD 
212 

Question Number Variable Name 

M17b PROD_SUP_WORKERS 

SHIFTS_DAY_PROD_SUP 

M17c PREP_WORKERS 

SHIFTS_DAY_PREP 

M23a USE_CONT_DEVELOP 

M23b USE_CONT_CONST 

M23c USE_CONT_DEMO 

M23d USE_CONT_DAMS 

M23e USE_CONT_EXCAV 

M23f USE_CONT_EQUIP 

M23g USE_CONT_EQUIP_SRV 

M23h USE_CONT_MATERIAL 

M23i USE_CONT_DRILL 

M23j USE_CONT_PROD 

M23k USE_CONT_MINERAL 

M23l USE_CONT_OTHER 

M24a NUM_CONT_DEVELOP 

M24b NUM_CONT_CONST 

M24c NUM_CONT_DEMO 

M24d NUM_CONT_DAMS 

M24e NUM_CONT_EXCAV 

M24f NUM_CONT_EQUIP 

M24g NUM_CONT_EQUIP_SRV 

M24h NUM_CONT_MATERIAL 

M24i NUM_CONT_DRILL 

M24j NUM_CONT_PROD 

M24k NUM_CONT_MINERAL 

M24l NUM_CONT_OTHER 

Step3 TOTAL_NUMBER 
213 

Question Number Variable Name 

E2 JOB_TITLE 

E3, 

TITLE_EXP_MNTHS 

TITLE_EXP_YRS 

E4, or 

THIS_MINE_MNTHS 

THIS_MINE_YRS 

E5 TOTAL_MINE_MNTHS 

TOTAL_MINE_YRS 

E7 WORK_LOCATE 

E8 GENDER 

E9 or LATINO 

E10 

RACE_INDIAN 

RACE_ASIAN 

RACE_BLACK RACE_HAWAIIAN 

RACE_WHITE 

 
214 

 
215 

Appendix H. Job Titles as Submitted by Survey Respondents 
216 

 
217 

2nd Floor Operator (Froth Cells) 

3rd Stationary Equipment Floor SEO 

Operator 

777 Operator 

7820 Operator 

ABMO Operator 

AC Mill/Screen 3 Operator 

Accountant 

Accountant 3 Mine Ops 

Accountant Operations Technician 

Accounting AP-AR 

Accounting Assistant 

Accounting Associate 

Accounting Associate, Senior 

Accounting Clerk 

Accounting Clerk & HR 

Accounting Coordinator 

Accounting Manager 

Accounting Specialist 

Acting CCD Manager 

Additive Press Operator 

Additives Utilityman 

Administration 

Administration Accounting 

Administration Assistant 

Administration Technician 

Administrative 

Administrative Assistant 

Administrative Assistant I 

Administrative Assistant Coordinator 

Administrative Clerk 

Administrative Coordinator 

Administrative Lead Man 

Administrative Manager 

Administrative Office Plant 3 

Administrative Office Plant 4 

Administrative Secretary 

Administrative Services Manager 

Administrative Specialist 

Administrative Superintendent 

Administrative Support 

Administrative Technician 

Administrator 

Administrator III 

Advanced Operator 

Aggregate Area Manager 

Aggregate Plant Laborer 

Aggregate Plant Mechanic 

Aggregate Welder 

A-Helper 

Airplane Pilot 

A/P Clerk 

Apprentice 

A/R/Dispatch 

Area Leader 

Area Manager 

Area Production Manager 

Assay Lab Technician V 

Assayer 

Assistant Accounts Payable 

Assistant Aggregate Mechanic 

Assistant Asphalt Plant Operator 

Assistant Belt Coordinator 

Assistant Filter Evaporation Operator 

Assistant Foreman 

Assistant Manager 

Assistant Mechanic 

Assistant Mine Foreman 

Assistant Mine Supervisor 

Assistant Office Manager 

Assistant Operation Manager 

Assistant Plant Manager 

Assistant Plant Operator 

Assistant Preventative Maintenance 

Engineer 

Assistant Shift Manager 

Assistant Superintendent 

Assistant Supervisor 

Auger Crew Operator 

Auger Crew Supervisor 

Auger Operator 

Auto Bagger 
218 

Automation Engineer 

Automation Process Engineer 

Automotive Mechanic/Standard 

Automotive Repairman 

Automotive Serviceman—Hostler 

Backhoe Operator 

Bag Crew 

Bag Handler 

Bagged Car Loader 

Bagger 

Bagger 50-lb 

Bagger/Labor 

Bagger/Operator 

Bagger/Sealer 

Bagging and Quality Control 

Bagging/Loading 

Bagging Facility Foreman 

Bagging Laborer 

Bagging Operator 

Bagging Operator Supervisor 

Bagging Supervisor 

Baghouse Supervisor 

Ball Mill Operator 

Barge Controller 

Barge Loader 

Barge Tender 

Batch Plant Operator 

Bathhouse/Yard 

Belo Man 

Belt Attendant 

Belt Cleaner 

Belt Crew 

Belt Crew Foreman 

Belt Examiner 

Belt Foreman 

Belt Maintenance 

Belt Man 

Belt Mechanic 

Belt Operator 

Belt Patrolman 

Belt Piler 

Belt Press Operator 

Belt Repairman 

Belt Tender 

Belt Walker Examiner 

Belt Worker 

Belts 

Belts Electrician 

Belts General Labor 

Beneficiator 

Benefits Administrator 

Big Bagger Lead Operator 

Bin Puller 

Bin Tender 

Bin Truck Driver 

Blade Operator 

Blaster 

Blaster Helper 

Blaster/Primary Operator 

Blasting 

Blasting Assistant 

Blasting Supervisor 

Block Press Operator 

Block Sawyer 

Blunging Operator 

Blunging Operator 1 

Blunging Operator 4 

Boat Operator 

Boat Pilot 

Bob Cat Operator 

Bobcat 

Bobcat Operator 

Bobcat & Stone Cutter 

Boiler/Coating Operator 

Boiler Operator 

Boiler Plant Operator 

Boilermaker 

Boilermaker/Welder 

Bolter 

Bolter Operator 

Bookkeeper 

Bookkeeper/Accounts Manager 

Boss 

Bratticeman 

Breaker Operator 

Bridge Operator 
219 

Buggy Runner 

Buggy/Shuttle Car 

Bulk Loader 

Bull Cook 

Bulldozer Operator 

Burner 

Burner Operator 

Business Manager 

Buyer 

Buyer/Coordinator II 

Buying Associate 

Calcine Big Bagger Lead Operator 

Calcine Operator 

Calcine Operator 1 

Calciner 

Car Operator 

Carpenter 

Carpenter/Painter 

Cat Operator 

Cedar Rapids Operator 

Cement Regional Sales Manager 

Central Control Operator 

CEO 

CEO/President 

Certified Welder 

Chief Chemist 

Chief Clerk 

Chief Electrician 

Chief Executive Officer 

Chief Mechanic 

Chief Mechanic/Electrician 

Chief Metallurgist 

Chief Mine Engineer 

Chute Puller 

CKD Dust Truck Operator 

Classification/Operator Sandgrinder 

Clay Operator 

Cleanup Man 

Clerk 

Clerk II 

Clerk Scale 

Clerk/Scale I 

Clerk Scale III 

CM Operator 

CM Unit Operator IV 

CMMS Planner 

Coal Cleaner 

Coal Distribution Coordinator 

Coal Handling Manager 

Coal Hauler 

Coal Hauler Operator 

Coal Miner 

Coal Sampler 

Coal Testing 

Coal Unloader 

Communications Supervisor 

Concentrator Supervisor 

Concrete Man 

Console Operator 

Construction Crew 

Construction Equipment Operator 

Continuous Miner 

Continuous Miner Operator 

Control Analyst 

Control Person 

Control Room 

Control Room Electrician 

Control Room Operator 

Control Room Supervisor 

Controller 

Conveyor Man 

Conveyor Operator 

Conveyor Technician 

Cook 

Co-op Student 

Coordinator 

Coordinator Financial Reporting and 

Controls 

Cost Coordinator 

Cowles Operator 

Craftsman A 

Craftsman C 

Crane Operator 

Crane Operator/Truck Driver 

Crew Foreman 

Crew Leader—Surface 
220 

Crude Clay Controller 

Crude Lab Technician 

Crude Ore Loader 

Crude Pile Operator 

Crude Prep 

Crush & Convey Mechanic 

Crush Operator 

Crusher 

Crusher Attendant 

Crusher Foreman 

Crusher Foreperson 

Crusher Helper 

Crusher Helper III 

Crusher Laborer 

Crusher/Loader Operator 

Crusher Maintenance 

Crusher Man 

Crusher Operator 

Crusher Operator Technician V 

Crusher Plant 

Crusher Plant Operator 

Crusher Repairman 

Crusher Rock Loader 

Crusher Supervisor 

Crusher Technician 

Crusher—Telsmith Operator 

Crusher Utility Person 

Crusher Worker 

Crushing Foreman 

Crushing Leader 

Crushing Plant Loader 

Crushing Plant Operator 

Crushing Supervisor 

CS 

Ctrl/Electrical Systems Integrator 

Curb Cutter 

Curb Shed Foreman/Curb Cutter 

Curtain Man 

Customer Loader 

Customer Loader Operator 

Customer Service 

Customer Service Manager 

Customer Service Representative 

Customer Service—SF 

Cutstone A 

Cutstone B 

Cutter Operator 

D-10 Dozer 

Data Processor 

Deck Hand 

Degritter Operator 

Delivery Driver 

Demurrage Clerk 

Department Helper 

Diagnostic Mechanic 

Diamond Drill Lead Man 

Diamond Sawyer 

Diesel Mechanic 

Digestion Operator 

Director Environmental Services 

Director of Coal Sales 

Director of Engineering 

Director of Scheduling & Logistics 

Dispatcher 

Dispatcher II 

Dispatcher Assistant 

Dispatcher/Weighman 

Distribution Coordinator 

Distribution Manager 

Dock Hand 

Dock Man 

Dock Worker 

Dozer 

Dozer Driver 

Dozer, Excavator, Operator 

Dozer/Hilift Operator 

Dozer Man/Haul Truck Driver 

Dozer Operator 

Dozer Operator 1 

Draftsman 

Dragline 

Dragline Assistant 

Dragline Oiler 

Dragline Operator 

Dragline Technician 

Dredge & Dozer 
221 

Dredge Manager 

Dredge Operator 

Dredge/Plant Operator 

Dredger 

Drill/Blast Supervisor 

Drill Mucker 

Drill Operator 

Drill Rig Operator 

Driller 

Driller III 

Driller Blaster 

Driller/Miscellaneous 

Drilling 

Drilling/Blaster Leader 

Driver 

Driver/Equipment Operator 

Driver Haul Truck 

Driver Haul Truck I 

Driver Haul Truck II 

Driver Off Road Truck 

Driver/Operator 

Driver/Shop Work 

Driver Stockpile Truck 

Dry Attendant 

Dry Plant Lead Man 

Dry Plant Manager 

Dry Plant Operator 

Dry Plant Sacker Operator 

Dry Plant Worker 

Dry Process 

Dry Section Operator 

Dryer 

Dryer/Loader Operator 

Dryer Operator 

Drymill Operator 

Dump Truck Driver 

Dump Truck Operator 

Earth Strip 

EHS Coordinator 

EHS Coordinator Customer Service 

EHS Manager 

EHS Technician 

E/I Technician IV 

Electrical Apprentice 

Electrical Control Technician 

Electrical Coordinator 

Electrical Department Coordinator 

Electrical Engineer 

Electrical Foreman 

Electrical/Instrumentation Apprentice 

Electrical/Instrumentation Coordinator 

Electrical Maintenance 

Electrical Maintenance Level C 

Electrical Resource 

Electrical Supervisor 

Electrical Technician 

Electrical Technician I 

Electrician 

Electrician I 

Electrician II 

Electrician III 

Electrician IV 

Electrician A 

Electrician H 

Electrician/Maintenance 

Electrician/Maintenance Supervisor 

Electrician/Mechanic 

Electrician Mine 

Electrician STD 

Electrician Technician 

Electrician Trainee 

Electro-Instrumentist 

Electronic Repairman 

Electronic Technician 

Electronic Technician—Standard 

Electrowinner 

Emergency Response Coordinator 

End Dump 

End Dump Driver 

End Dump Operator 

End Loader Operator 

Engineer 

Engineer II 

Engineer Analyst Senior 

Engineer/Operations Manager 
222 

Engineer Plant Operator 

Engineering Intern 

Engineering Manager 

Engineering Supervisor 

Engineering Technician 

Entry Bagger 

Entry Level Miner 

Environmental Engineer 

Environmental Engineer I 

Environmental, Health & Safety 

Coordinator 

Environmental Health & Safety Manager 

& RSO 

Environmental Manager 

Environmental Officer 

Environmental Specialist 

Environmental Staff 

Environmental Technician 

E.O. Utility 

Equipment Maintenance Manager 

Equipment Management 

Equipment Manager 

Equipment Mechanic 

Equipment Mechanic/Fueler 

Equipment Oiler 

Equipment Operator 

Equipment Operator I—SF 

Equipment Operator II—SF 

Equipment Operator III 

Equipment Operator III—SF 

Equipment Operator IV 

Equipment Operator V 

Equipment Operator VI 

Equipment Operator/Laborer 

Equipment Operator/Manager 

Equipment Operator—Material Supplier 

Equipment Operator/Mechanic 

Equipment Operator (mobile) 

Equipment Operator/Supervisor 

Equipment Operator—Surface 

Equipment/Plant Operator 

Equipment Relief 

Equipment/Shift Manager 

Equipment Trainer 

Equipment Training Supervisor 

ER Plant 

Euclid 

Euclid Operator 

Evening Dozer/Loader Operator 

Evening Driller 

Evening Loader Operator 

EW Operator 

Examiner 

Excavator 

Excavator Operator 

Executive Assistant 

Executive Assistant to President 

Exploration Driller 

Explosives Loader 

Explosives Specialist 

Explosives Technician 

Extruder Operator 

Fabricator 

Face Boss 

Face Driller 

Face Loader 

Face Loader Operator 

Face Man 

Face Operative 

Facility Manager 

Facility Operator 

Facility Service Maintenance I 

FEL wa 800 

Field Electrical Repairman 

Field Loader 

Field Mechanic 

Field Supervisor 

Filter Operator 

Fine Grind—Surface Plant Manager 

Finish End Plant Trainee 

Finish Grinder Operator 

Fire Boss 

Fire Boss/Belt Man 

Fire Boss Pumper 

Fire Equipment SV 

First Line Supervisor 
223 

Fixed Equipment Maintenance 

Fixed Main Supervisor 

Fixed Maintenance I 

Flagman 

Floating Utility 

Flock 

Flotation Operator 

Flotation Plant Operator 

Fluid Bed Dryer Operator 

Foreman 

Foreman 1st Shift 

Foreman 2nd Shift 

Foreman/Dredge Operator 

Foreman Maintenance 

Foreman/Manager/Staff 

Foreman/Miner 

Foreman Operator 

Foreman/Operator 

Foreman—Quarry 

Foreman Scoop & Buggy Man 

Foreman Trainee 

Fork Truck Operator 

Forklift 

Forklift Operator 

Forklift Operator & Utility 

Front End Loader Operator 

Froth Cell Operator 

Fuel Electrician 

Fuel & Lube Truck Operator 

Fuel Mechanic 

Fuel Mechanic Helper 

Fuel Oiler 

Fuel Operator 

Fuel Technician 

Fuel Truck 

Fueler 

Gantry Crane Operator 

Garage/Machine Shop Maintenance 

Group 

Gate Keeper 

General Foreman 

General Inside 

General Inside Laborer 

General Inside/Roof Bolter 

General Labor & Equipment Operator 

General Labor/Shop Work 

General Laborer 

General Maintenance 

General Manager 

General Mine Foreman 

General Mine Manager 

General Miner Support 

General Operation Manager 

General Outside 

General Outside Laborer 

General Plant Helper 

General Repairer 

General Superintendent 

General Supervisor 

General Underground 

General Underground Laborer 

General Utility 

Geo Technician II 

Geologist 

Geologist II 

Geophysicist 

Gold House Supervisor 

Gradall Operator 

Grader Operator 

Granule Superintendent 

Gravel Pumper 

Gravity Mag Operator 

Greaser 

Greaser & Fueler 

Greaser/Oiler 

Grinder Operator 

Grinding 

Grinding Float 

Ground Control Technician 

Ground Hand 

Ground Man 

Grounds Keeper 

Group Leader 

Group Leader Ground Packaging 

Group Leader Milling 

Grouter 
224 

Guard, Security II 

Gyp Mine Manager 

Hammer Operator 

Haul Truck 

Haul Truck Driver 

Haul Truck Driver I 

Haul Truck Driver II 

Haul Truck Driver—Off Road 

Haul Truck Driver—On Road 

Haul Truck/Loader 

Haul Truck Operator 

Haul Unit Driver 

Haul Unit Operator 

Haul Unit Operator/Stock 

Haulage 

Haulage Driver 

Haulage Operator 

Hauler 

Hauler Operator 

Hauling 

HDR 

Head Blaster 

Head Operator 

Heading Prep 

Health & Safety Manager 

Health & Safety Officer 

Health & Safety Technician 

Heap Leach Operator 

Heavy Duty Mechanic 

Heavy Duty Mechanic Welder 

Heavy Duty Repair 

Heavy Duty Repair Trainee 

Heavy Equipment Electrician 

Heavy Equipment Mechanic 

Heavy Equipment Mechanical Electrician 

Heavy Equipment Operator 

Heavy Equipment Operator B 

Heavy Equipment Operator (Dozer) 

Heavy Equipment Operator—Front End 

Loader 

Heavy Equipment Operator—Haul Truck 

Heavy Equipment Operator—Lead 

Heavy Equipment Operator—Scrapers 

Heavy Equipment Operator—Water 

Truck 

Heavy Equipment Repair MT III 

Heavy Equipment Repairman 

Heavy Mechanic 

Heavy Media Plant Operator 

Helper 

Helper/Laborer 

High Lift Loader Operator 

High Lift Operator 

High Scaler 

Highwall Drill Operator 

HMS Operator 

Hoe Operator 

Hoist Engineer 

Hoist Operator 

Hoisting Engineer 

Hoistman 

Hopper Operator 

Hot Plant Operator/Loader Operator 

HR Generalist II 

HR Manager 

Human Resources 

Human Resources/Accounts Receivable 

Human Resources Area Manager 

Human Resources Assistant 

Human Resources Intern 

Human Resources Manager 

Human Resources Specialist 

Hydraulic Scaler 

Hydromet Helper 

I & C Technician 

Idle Work 

Industrial Diagnostic Electrician 

Industrial Electrician 

Industrial Maintenances Technician IA 

Industrial Maintenances Technician II 

Industrial Plant Bagging 

Information Technology Coordinator 

Inglett Bagger 

Inglett Operator 

Inspector 

Instrument Electrician 
225 

Instrument Repair 

Instrument Repairer 

Instrumentation Supervisor 

Intern 

Intern Student 

IT Support 

IT Technician 

Janitor 

Janitor/Utility 

Jaw Operator 

Jet Mill Operator 

Jig Plant Operator 

Journeyman 

Journeyman Electrician 

Jumbo Driller 

Junior Geologist 

Kiln Assistant 

Kiln Burner 

Kiln Feed Operator 

Kiln Laborer 

Kiln Operator 

Lab 

Lab Analyst 

Lab Assistant 

Lab Chemist 

Lab Clerk 

Lab Electrician 

Lab Manager 

Lab Operator 

Lab Person 

Lab Supervisor 

Lab Systems Technician 

Lab Technician 

Lab Technician I 

Lab Technician II 

Lab Technician III 

Lab Tester 

Lab Worker 

Labor Foreman 

Labor Pool 

Laboratory Technician 

Laborer 

Laborer II—SF 

Laborer Equipment Operator 

Laborer/Ground Person 

Laborer Helper 

Laborer/Maintenance 

Laborer/Plant Operator 

Laborer Roof Slate 

Laborer—Pit 2 

Laborer/Site Manager 

Laborer (Summer) 

Laborer—Utility 

Lamp Man 

Land Manager 

Large Shovel/Backhoe/Load Operator II 

Large Truck Driver 

Leach Pad Operator I 

Leach/Roast Operations Helper 

Leach Utilityman 

Lead Bagger 

Lead Electrician 

Lead Equipment Mechanic 

Lead Laborer 

Lead Man 

Lead Man—Mill 

Lead Man—Mine 

Lead Man—Quarry 

Lead Man Roller Mill Plant Operator 

Lead Man—SF 

Lead Man Wet Process 

Lead Mechanic 

Lead Miner 

Lead Operator Mill 

Lead Operator Quarry 

Lead Payloader 

Lead Person 

Lead Person II 

Lead Plant Operator 

Lead Primary Mobile 

Lead Process Operator 

Lead Warehouse 

Ledge Foreman 

Ledge Worker 

Leech Pad Operator 

Level A Certified Blaster 
226 

Level A Chief Op or PSO 

Level A Millwright 1C 

Level B Millwright 2C 

Level B Miner 

Level C Mine Helper plus Truck 

Level C Supply Specialist 

Level D Entry 

LHD Operator 

Lift Driver Lead 

Light Vehicle Mechanic II 

Limestone Prep Operator 

Line 2 Loadout Operator 

Line Leader 

Liquid Fuel Handler 

Load Explosives 

Load Out Operator 

Loader 

Loader Crusher Operator II 

Loader/Excavator Operator 

Loader/Ground Bagger 

Loader Man/Driller 

Loader Mine 

Loader/Miner 

Loader Operator 

Loader Operator—Feeds Crusher 

Loader Operator—Loads Trucks 

Loader Operator Supervisor 

Loader Operator—Truck Driver 

Loader (Portable) 

Loader - Setter 

Loader/Stock Truck 

Loader, Stockpile 

Loader (Yard) 

Loadhouse Supervisor 

Loading Equipment Operator 

Loading Hauler Trucks 

Loading Rock in Process 

Loading Trucks 

Loading & Warehouse 

Loadman 

Loadout 

Loadout Operator 

Locomotive Engineer 

Longwall Area Manager 

Longwall Foreman 

Longwall Mechanic Operator Helper 

Longwall Production Operator 

Longwall Propman 

Longwall Shearer Operator 

Longwall Support 

Longwall Trainee 

Lube Bay Oiler 

Lube Maintenance 

Lube Man 

Lube Specialist 

Lube Technician 

Lube Truck 

Luber 

Luber—Fixed Equipment 

Lubrication Maintenance 

Lubrication Repairman 

Lubricator 

LWDF Attendant 

M.E.O. 

Machine Loader Operator 

Machine Operator 

Machinist 

Main/Truck Driver 

Maintenance 

Maintenance V 

Maintenance A Electrician 

Maintenance A/Utility Leader 

Maintenance B 

Maintenance Chief 

Maintenance Clerk 

Maintenance Coordinator 

Maintenance Craft 

Maintenance Crew 

Maintenance Electrician 

Maintenance Electrician II 

Maintenance Engineer 

Maintenance/Equipment 

Maintenance Fixed I 

Maintenance Fixed II 

Maintenance Fixed III 

Maintenance Foreman 
227 

Maintenance/General Supervisor 

Maintenance Group 

Maintenance Group Lead Man 

Maintenance Helper 

Maintenance Inspector 

Maintenance Inst. 

Maintenance Journey 

Maintenance Lead Man 

Maintenance Lead Person 

Maintenance Leader 

Maintenance Level C 

Maintenance/Loader Operator 

Maintenance Lube 

Maintenance/Machine Shop Supervisor 

Maintenance Man 

Maintenance Man Level A-1 

Maintenance Man Machine Lube 

Maintenance Manager 

Maintenance Mechanic 

Maintenance Mechanic I 

Maintenance Mechanic II 

Maintenance Mechanic lll 

Maintenance Mechanic—Standard 

Maintenance Mechanic Supervisor 

Maintenance Mobile I 

Maintenance Mobile II 

Maintenance Mobile III 

Maintenance/Off-road Truck Driver 

Maintenance Operator 

Maintenance Planner 

Maintenance Planner II 

Maintenance Planner/Mechanic 

Maintenance/Plant Operator 

Maintenance/Plant Supervisor 

Maintenance Repairman 

Maintenance Superintendent 

Maintenance Supervisor 

Maintenance System Site Administrator 

Maintenance Systems Administration 

Maintenance Team Leader 

Maintenance Team Member 

Maintenance Technician 

Maintenance Technician I 

Maintenance Technician II 

Maintenance Technician Senior 

Maintenance Trainee 

Maintenance Welder 

Maintenance Worker 

Maintenances Facilities Technician 1A 

Maintenances Facilities Technician B 

Maintenances Supervisor 

Makedown Technician 

Management 

Manager 

Manager Assistant Plant 2 

Manager/Global Screening 

Manager—New Polymer Composites 

Manager of Administration 

Manager of Concentrator 

Manager of Engineering 

Manager of Financial Reporting 

Manager/Owner/Equipment Operator 

Manager Plant 3 

Manager Trainee 

Manager Transmission/Sales 

Manager/Vice President 

Managerial 

Manager's Assistant 

Manufacturing Supervisor 

Mark Up/Layout 

Marketing Services Director 

Mass Excavator 5130 cat 

Master Electrician 

Master Heavy Equipment Operator 

Master Mechanic 

Master Mill Technician 

Master Process Operator 

Material Handler 

Material Handler II 

Material Operator 

Material Sampler 

Material Unloader 

Materials Coordinator 

Materials Operator 

Materials Planner 

Materials & Planning Manager 
228 

Materials Technician 

MBC Operator 

Mechanic 

Mechanic I 

Mechanic II 

Mechanic V 

Mechanic A 

Mechanic B 

Mechanic B—Group Leader 

Mechanic/Chief 

Mechanic Clerk 

Mechanic D 

Mechanic Electrician 

Mechanic/Electrician 

Mechanic/Electrician II 

Mechanic/Fabricator 

Mechanic G 

Mechanic Helper 

Mechanic Lead Person 

Mechanic Level IV 

Mechanic Level V 

Mechanic/Maintenance 

Mechanic Mobile 

Mechanic/Operator 

Mechanic—Plant 

Mechanic Specialist 

Mechanic Technician II 

Mechanic Technician III 

Mechanic Technician IV 

Mechanic Trainee 

Mechanic—Truck Driver 

Mechanic—Underground 

Mechanic Utility 

Mechanic/Welder 

Mechanical Engineer 

Mechanical Engineer/EMR 

Mechanical Maintenance 

Mechanical Maintenance A 

Mechanical Repairman 

Mechanical Scaler Operator 

Mechanical Technician 

Mechanics Helper 

Mechanics Helper—Lead 

Mechanics Welder 

Messenger 

Met Lab Technician VII 

Metallurgist 

Metallurgist II 

Mill 

Mill Crusher Operator 

Mill E&I Technician 

Mill Foreman 

Mill Hand 

Mill Helper 

Mill Kiln Operator 

Mill Lead Man 

Mill Lead Technician IV 

Mill Maintenance 

Mill Maintenance Technician 

Mill Manager 

Mill Mechanic 

Mill Mechanic Foreman 

Mill Mechanic Technician II 

Mill Operations 

Mill Operator 

Mill Operator/Lead Man 

Mill/Packaging Operator 1 

Mill/Packaging Operator 2 

Mill/Packaging Operator 3 

Mill Production 

Mill Production Laborer 

Mill Production Worker 

Mill Superintendent 

Mill Technician 

Mill Technician II 

Mill Technician IV 

Mill Utility 

Mill/Warehouse Operator 

Miller 

Millerman 1 

Millerman 1—Lead Man 

Milling Lead Man 

Milling Machine Operator 

Millman 

Millman's Helper 

Millwright 
229 

Millwright I 

Millwright IV 

Millwright STD 

Millwright STR 

Mine A 

Mine Apprentice 

Mine Clerk 

Mine Driller 

Mine Electrician 

Mine Engineer 

Mine Equipment Operator 

Mine Examiner 

Mine Foreman 

Mine Foreman—Miner Operator 

Mine Foreman/Superintendent 

Mine General Foreman 

Mine Haul Truck Driver 

Mine—Haul Truck Driver 

Mine Hauler 

Mine Labor 

Mine Lead 

Mine Lead Man 

Mine Lead Technician IV 

Mine Leader 

Mine Loader 

Mine Loader Operator 

Mine Maintenance 

Mine Maintenance Clerk 

Mine Maintenance Foreman 

Mine Maintenance Mechanic 

Mine Maintenance MT 3 

Mine Maintenance Production Supervisor 

Mine Maintenance Specialist 

Mine/Maintenance Superintendent 

Mine Maintenance Technician II 

Mine Maintenance Technician V 

Mine Manager 

Mine Mechanic 

Mine Mechanic I 

Mine Mechanic II 

Mine Mechanic III 

Mine Mechanic A 

Mine Oiler/Fueler I 

Mine Operations 

Mine Operations I 

Mine Operations—Equipment Operator 

Mine Operations Technician I 

Mine Operations Technician IV 

Mine Operations Technician V 

Mine Operator 

Mine Operator C 

Mine Production 

Mine Production—Hoist operator 

Mine Production Operator 

Mine Production Superintendent 

Mine Production Supervisor 

Mine & Quarry Maintenance 

Mine & Quarry Manager 

Mine Relief Utility 

Mine Shift Supervisor 

Mine Spec I 

Mine Spec II 

Mine Spec III 

Mine Superintendent 

Mine Supervisor 

Mine Supplier 

Mine Support 

Mine Surveyor 

Mine Technician III 

Mine Technician IV 

Mine Truck Driver 

Mine—Truck Driver 

Mine Utility 

Mine Utility B 

Mine Worker 

Miner 

Miner 1 

Miner 1st Class 

Miner 2 

Miner 3 

Miner 4 

Miner 5 

Miner Helper 

Miner Lead Man 

Miner Operator 

Miner Section Operator 
230 

Mines 

Mining 

Mining Engineer 

Mining Lead Man 

Mining Supervisor 

Miscellaneous Operator 

Mix Chemist 

Mix Control Chemist 

Mix Control Fill-in 

Mix Man 

Mixer 

Mixer Operator 

Mobile Bridge Operator 

Mobile Equipment 

Mobile Equipment Maintenance 

Mobile Equipment Mechanic 

Mobile Equipment Mechanic STD 

Mobile Equipment Operator 

Mobile Maintenance 

Mobile Maintenance Foreman 

Mobile Maintenance Mechanic 

Mobile Mechanic 

Mobile Repair 

Mobile Utility Operator 

Motor Grader 873 JD 

Motor Grader Operator 

Motor Grader Operator—Lead 

Motorman 

Mucker 

Mud Picker 

Multi Craft Maintenance 

Nashtec Operator 

Net Work Coordinator 

Night Foreman/Evening Dozer 

Night Lead Man 

Night Mechanic 

Night Supervisor 

Night Watchman 

Nipper 

Off Road Truck Driver 

Off Road Truck Operator 

Off Sider 

Office Administration 

Office Administrator 

Office Assistant 

Office Attendant 

Office Clerk 

Office Coordinator 

Office Manager 

Office Manager Loader Operator/Scale 

Office Salesman 

Office Scale 

Office/Scale 

Office Staff 

Office Staff 1 

Office Staff 2 

Office Staff 3 

Oil Helper 

Oil Pit Technician 

Oiler 

Oiler/Maintenance 

Oiler/Repairman 

On Road Truck Driver/Loader Operator 

Op. Tech. Pel 

Open Pit 1 

Operating Engineer 

Operations 

Operations Administrator 

Operations Associate 

Operations Engineer 

Operations Engineer/Labor Engineer 

Operations Maintenance Technician 

Operations Manager 

Operations Specialist 

Operations Superintendent 

Operations Supervisor 

Operations Support Clerk 

Operations Support Coordinator 

Operations Technician Filter Attendant 

Operations Technician Material Handler 

Operations Technician Prim. Cr. Attd 

Operations Technician/Shovel Operator 

Operator 

Operator I 

Operator II 

Operator III 
231 

Operator III Utility 

Operator IV 

Operator V 

Operator A 

Operator A Prime Leader 

Operator Apprentice 

Operator B 

Operator B—Heavy Equipment Operator 

Operator C 

Operator CM 

Operator/CM 

Operator D 6 

Operator D Utility Equipment Operator 

Operator/Dozer 

Operator/Driver 

Operator Equipment I 

Operator Equipment II 

Operator Equipment III 

Operator Equipment IV 

Operator Equipment V 

Operator (Extra) 

Operator Foreman 

Operator/Ground Person 

Operator In Charge 

Operator K 

Operator Loader 

Operator/Loader 

Operator Maintenance 

Operator/Maintenance 

Operator/Maintenance Laborer 

Operator Maintenance Man 

Operator/Mechanic 

Operator—Mobile 

Operator Plant 2 

Operator Plant 4 

Operator/Repairman 

Operator—Scoop 

Operator/Shovel 

Operator/Supervisor 

Operator Supervisor 

Operator Technician II 

Operator Trainee 

Operator/Truck Driver 

Operator—Underground 

Order Processor 

Ore Technician 

Ore Truck 

Ore Truck 77D 

OTR Truck Driver 

Outby 

Outby Electrician 

Outby Foreman 

Outby General Laborer 

Outby Labor 

Outby Support 

Outby Support UG 

Outside 

Outside Clerk 

Outside Communication 

Outside Man 

Outside Utility/Clerk 

Outside Worker 

Outside Yard Man 

Over the Road Truck Driver 

Overburden Driller 

Owner 

Owner/Manager 

Owner/Miner 

Owner Operator 

Owner/Operator 

Owner/Partner 

Owner/Sales/Shipping 

PA 

Pack & Ship Lead Man 

Packaging 

Packaging/Blending 

Packaging Operator 

Packaging Supervisor 

Packaging Team Member 

Packer 

Packer Crewman 

Packer/Forklift 

Packer/Loader 

Packer Man 

Packer Operator 

Packer—Pit 2 
232 

Packer—SS 

Packhouse 

Packhouse Utility 

Packing Operator 

Packing/Shipping Foreman 

Palleter 

Palletizer/Meo 

Pan Operator 

Panel Operator 

Part Time Laborer 

Part Time Shop 

Part Time Yard Worker 

Parts 

Parts Clerk 

Parts Coordinator 

Parts Runner 

Parts Runner/Accounts Payable 

Paver Operator 

Payables Clerk 

Payloader 

Payroll 

Payroll Assistant 

Payroll Clerk 

Payroll/Personnel 

Pebble Mill Operator 

Pellet Plant Technician 

Permit Coordinator 

Physical Tester 

Picker/Laborer 

Pinner Operator 

Pipe Fitter 

Pit and Plant Truck Driver 

Pit Foreman 

Pit Hauler 

Pit Laborer 

Pit Lead Man 

Pit Loader 

Pit Loader Operator 

Pit Operator 

Pit Superintendent 

Pit Supervisor 

Pit Truck Driver 

Pit Truck Operator 

Planner 

Planner I 

Planner II 

Plant 

Plant 1 Operator 

Plant 2 Operator 

Plant 3 Operator 

Plant Accountant 

Plant Administrator 

Plant Attendant 

Plant Clerk 

Plant Controller 

Plant Controlman 

Plant Electrician 

Plant Engineer 

Plant Engineer/HSE 

Plant/Equipment Operator 

Plant Foreman 

Plant Foreman/Loader Man 

Plant Foreperson 

Plant Generalist 

Plant Ground Man 

Plant Helper 

Plant Laborer 

Plant Lead 

Plant Leader 

Plant Loader 

Plant Loader Operator 

Plant Maintenance 

Plant Maintenance Group 

Plant Maintenance Superintendent 

Plant Man 

Plant Manager 

Plant Manager Intern 

Plant Manufacturing Supervisor 

Plant Mechanic 

Plant Mobile Equipment Operator 

Plant Office Administration 

Plant Office Administrator 

Plant Oiler 

Plant Operations 

Plant Operator 

Plant Operator I 
233 

Plant Operator I—SF 

Plant Operator II—SF 

Plant Operator 2A 

Plant Operator IV 

Plant Operator (Apprentice) 

Plant Operator (Beginning Operator) 

Plant Operator—Foreman 

Plant Operator/Truck Driver 

Plant Person 

Plant/Pit Foreman 

Plant/Pit Truck Driver 

Plant Production Worker 

Plant Quality & Shipping 

Plant Repair 

Plant Repair Foreman 

Plant Repair/Welder 

Plant Repairman 

Plant Repairman I 

Plant Repairman II 

Plant Sampler 

Plant Superintendent 

Plant Supervisor 

Plant Supervisor II 

Plant Supervisor Manager 

Plant Technician 

Plant Technician—Crew Leader 

Plant Trainee 

Plant Utility 

Plant Utility Operator 

Plant Wash Operator 

Plant Welder 

Plant Working Foreman 

Plants Manager 

Poly Packer Crewman 

Polygloss Bagger Technician 

Port Operator B 

Portable Plant Operator 

Powder Loader 

Powder Man 

Powder Person 

Power Screen Operator 

Power Systems Operator B 

Prep Plant Mechanic 

Prep Plant Operator 

Prep Plant Technician 

President 

President/COO 

President/Developer/Operator 

President/Owner 

President/Owner/Retired 

Pricing Coordinator 

Primary Control Operator 

Primary Crusher 

Primary Crusher Operator 

Primary Mobile Operator 

Primary Operator 

Primary Operator (Jaw) 

Process Assistant 

Process Attendant 

Process Control Operator 

Process Control Superintendent 

Process Control Supervisor 

Process Control Technician 

Process Engineer 

Process/Equipment Operator 

Process Foreman 

Process Lab Technician 

Process Laborer 

Process Maintenance Mechanic 

Process Maintenance Technician IV 

Process Maintenance Technician VI 

Process Maintenance Utility 

Process Manager 

Process Operations Technician III 

Process Operator 

Process Operator II 

Process Production Engineer III 

Process Supervisor 

Process Technician 

Processing Assistant 1 

Processing Plant 

Processing Team Member 

Processor 

Procurement Manager 

Procurement Specialist 

Product Loading 
234 

Production 

Production 1st shift 

Production 2nd shift 

Production 3rd shift 

Production Assistant 

Production Coordinator 

Production Driller 

Production Employee 

Production Engineer 

Production Expeditor 

Production Foreman 

Production Generalist 

Production Inspector 

Production Journeyman 

Production Lead Man 

Production Lead Operator 

Production Leader 

Production Loader 

Production Loader Operator 

Production Maintenance 

Production/Maintenance Manager 

Production/Maintenance Supervisor 

Production Manager 

Production Mechanic 

Production Miner 

Production Operator 

Production Operator I 

Production Operator II 

Production Operator Level I 

Production Operator Level II 

Production Operator Level III 

Production Operator Screening Plant 

Production Quality Control Manager 

Production Resource Manager 

Production & Sales Service Lab 

Technician 

Production Scheduler 

Production Scheduler/Safety Manager 

Production Shift Foreman 

Production Superintendent 

Production Supervisor 

Production Support 

Production Technician 

Production Technician II 

Production Technician lV 

Production Technician V 

Production Truck 

Production Truck Driver 

Production Utility Man 

Production Worker 

Professional 

Project Engineer 

Project Manager 

Prospecting 

Pug Mill Operator 

Pug Operator 

Pump Man 

Pump Operator 

Pumper 

Purchase Agent 

Purchaser 

Purchasing 

Purchasing Agent 

Purchasing Clerk 

Purchasing Coordinator 

Purchasing Equipment Manager 

Purchasing Manager 

Purchasing/Shop 

Q-line II 

Quality Analyst 

Quality and Safety Manager 

Quality Assistant 

Quality Assurance 

Quality Assurance Coordinator 

Quality Assurance Lab Technician Level 

II 

Quality Assurance Lab Technician Level 

III 

Quality Assurance Manager 

Quality Assurance & Mine Supervisor 

Quality Assurance/Quality Control 

Laboratory Technician 

Quality Assurance Supervisor 

Quality Assurance Technician 

Quality Control 

Quality Control III Lab Technician 
235 

Quality Control/HS&E 

Quality Control Lab 

Quality Control Lead Technician 

Quality Control Man 

Quality Control Manager 

Quality Control Physical Tester 

Quality Control & Sales Coordinator 

Quality Control Supervisor 

Quality Control Technician 

Quality Control Technician II 

Quality Loader Operator 

Quality Manager 

Quality Supervisor 

Quality Technician 

Quarry Coordinator 

Quarry Crusher Operator 

Quarry Driller/Blaster 

Quarry Equipment Operator 

Quarry Extra 

Quarry Foreman 

Quarry Laborer 

Quarry Loader Operator 

Quarry Manager 

Quarry Mechanic 

Quarry Night Foreman 

Quarry Operator 

Quarry Saw Operator 

Quarry Superintendent 

Quarry Supervisor 

Quarry Technician 

Quarry Truck Driver 

Quarry Utility 

Quarry Worker 

Quarryman 

Quarryman A 

Quarryman B 

R&D Supervisor 

Rail Lead Man 

Rail Loader 

Rail Loader Operator 

Rail Loadout 

Rail Loadout Operator 

Rail Operator 

Rail Road 

Rail Runner 

Rail Runner Operator 

Rail Supervisor 

Raisebore Operator 

Rak Handler 

Ram Car Operator 

Raw Material Manager 

Raymond Mill Operator 

Receiving Clerk 

Receiving Supervisor 

Receptionist 

Receptionist/Shipping Coordinator 

Reclaim Operator 

Reclamation Labor 

Refuse Site Operator 

Refuse Truck Operator 

Regional Human Resources Manager—

U.S. 

Regulatory Manager 

Reliability Engineer 

Repair Lead Man 

Repair Worker 

Repairman 

Repairman A 

Representative Trade Relations 

Research Scientist 

Road Grader Operator 

Road Maintenance 

Robot Operator 

Rock Breaker 

Rock Breaker Operator 

Rock Crusher Superintendent 

Rock Duster 

Rock Haul Driver 

Rock Plant Operator 

Rock Truck 

Rock Truck/Dozer Operator 

Rock Truck Driver 

Rock Truck Operator 

Roller Mill Operator 

Roller Mill Plant Operator Fine Grind 

Roller Operator 
236 

Rolling Stock Crew 2 

Rolling Stock Crew 4 

ROM Operator 

Roof Bolter 

Roof Bolter Operator 

Roof Bolter—Scaler 

Roof Control 

Roof Control Operator 

Roof Drill 

Roof Person 

Roofing Slate Splitter 

Roofing Slate Trimmer 

Roofing Slate Trimming Machine 

Operator 

Root Picker 

Rotary Drill Operator 

Rotary Dump Operator 

Rotex Operator 

Roustabout 

Roving Clerk 

RP Operator 

Rubber Tire Operator 

Sacker 

Sacking 

Safety 

Safety Advisor 

Safety Clerk 

Safety Coordinator 

Safety Director 

Safety Engineer 

Safety & Health 

Safety & Health Professional 

Safety/HR Manager 

Safety & Inventory Coordinator 

Safety Manager 

Safety Officer 

Safety Representative 

Safety/Security Director 

Safety Specialist 

Safety Supervisor 

Safety Technician 

Sales 

Sales Administration Manager 

Sales Coordinator 

Sales Loader 

Sales Manager 

Sales & Marketing 

Sales Person 

Sales Representative 

Sales Representative l 

Sales/Safety Director 

Sales & Technical Manager 

Sales/Traffic 

Salesman 

Salesman Manager 

Sample Prep 

Sampler 

Sampler—Lab 

Sampler Technician 

SAMS Technician 

Sand Plant Lead Man 

Sand Plant Operator 

Saw 

Saw & Equipment Repair 

Saw Operator 

Saw & Stone Cutter 

Saw Table Laborer 

Sawyer 

Scale 

Scale Attendant 

Scale Clerk 

Scale House 

Scale House Clerk 

Scale House Master 

Scale House Operator 

Scale Man 

Scale Master 

Scale Office 

Scale/Office 

Scale Office Dispatcher 

Scale Office Manager 

Scale Operator 

Scale Operator/Office 

Scale Operator/Parts 

Scale Person 

Scale/Sales Office 
237 

Scaler 

Scaler Operator 

Scales/Weights 

Scheduler 

Scoop 

Scoop Loader 

Scoop Man 

Scoop Operator 

Scoop Tractor Operator 

Scraper Operator 

Screed Person 

Screen & Mill Operator 

Screen Operator 

Screen Plant Labor 

Screen Plant Operator 

Screenhouse/Crusher 

Seasonal Production 

Secondary Foreman 

Secondary Plant Operator 

Secretary 

Secretary—Treasurer 

Section Boss 

Section Electrician 

Section Foreman 

Section Trainee 

Section Trainee IV 

Sectional Dock Manager 

Security 

Security Chief/Safety Trainer 

Security Guard 

Security Guard/General Laborer 

Security Officer 

Security Supervisor 

Security Watch 

Senior Accountant 

Senior Accountant II 

Senior Accounting Assistant 

Senior Accounting Clerk 

Senior Administrative Clerk 

Senior Controller 

Senior Designer 

Senior Drafter 

Senior Engineer 

Senior Geologist 

Senior Human Resources Manager 

Senior Human Resources Representative 

Senior Lab Technician 

Senior Lead Plant Operator 

Senior Maintenance Mechanic 

Senior Maintenance Planner 

Senior Maintenance Planner I 

Senior Mill Operator 

Senior Mine Engineer 

Senior Mine Geologist 

Senior Mining Engineer 

Senior Operator 

Senior Operator Maintenance 

Senior Planning Clerk 

Senior Plant Office Administrator 

Senior Plant Operator 

Senior Process Control Engineer 

Senior Process Control Specialist 

Senior Process Controller 

Senior Process Operator 

Senior Quality Control Technician 

Senior Research Technician 

Senior Stores Specialist 

Senior Vibration Technician 

Senior Welder 

Service Foreman 

Service Man 

Service Mechanic 

Service Technician 

Service Truck Driver 

Setup Foreman 

Shaft Crew 

Shaft Repair 

Shearer Operator 

Shedder 

Shift Foreman 

Shift Foreman Mill 

Shift Laborer 

Shift Maintenance 

Shift Manager 

Shift Mine Manager 

Shift Repairman 
238 

Shift Supervisor 

Shift Tire Attendant 

Shift Utility 

Shift Welder Repair A 

Shiftbreaker—Lewis 

Shiftbreaker—Pit 2 

Shifter 

Shipping 

Shipping Assistant 

Shipping Clerk 

Shipping Coordinator 

Shipping Foreman 

Shipping Lead Man 

Shipping Loader 

Shipping Loader Operator 

Shipping Manager 

Shipping Operator 

Shipping & Receiving 

Shipping & Receiving Clerk 

Shipping Scales Lead person 

Shipping Specialist 

Shipping Supervisor 

Shipping Team Member 

Shipping Technician 

Shooter 

Shop 

Shop/Drag Line 

Shop Foreman 

Shop Manager 

Shop Mechanic 

Shop Person 

Shop/Plant 

Shop Serviceman 

Shop Supervisor 

Shot Crew 

Shot Firer 

Shovel Dragline Operator 

Shovel Loader Operator 

Shovel/Loader Operator 

Shovel OB pc1800 

Shovel Operator 

Shovel Pit Loader Operator 

Shuttle Car 

Shuttle Car Driver 

Shuttle Car Operator 

Shuttle Car Operator 21 

Silo Operator 

Site Mechanic/Welder I 

Site Superintendent 

Skid Steer Operator 

Skilled Instrument Electrician 1C 

Skilled Laborer 

Skilled Maintenance Mechanic 

Skilled Maintenance Worker 

Skilled Repairman 

Skip Loader 

Skip Tender 

Slate Carrier 

Slate Splitter 

Slate Trimmer 

Sloop Operator 

Slurry Operator 

Slurry Operator 1& 2 

Slurry Track Technician 

Small Bagger Lead Operator 

Special Loader 

Splitter 

Stacker 

Stacker Operator 

Staff Accounting Specialist 

Staff Chemical Engineer 

Station Operator 

Stationary Equipment Operator 

Steamer 

Stick Picker 

Stock Loader 

Stock Out Truck Driver 

Stock Pile Driver 

Stock Pile Hauler 

Stock Pile Loader 

Stock Pile Operator 

Stock Pile Truck 

Stock Pile Truck Driver 

Stock Piler 

Stock Truck 

Stock Truck Driver 
239 

Stock Truck/Plant Operator 

Stockroom Attendant 

Stone Cutter 

Stone Cutter, Driver—MAC 

Stone Packaging Operator 

Stone Splitter 

Stone Stacker 

Storage Operator 

Storeroom 

Storeroom Attendant 

Storeroom Clerk 

Storeroom Floorman 

Storeroom Manager 

Storeroom Supervisor 

Stove Plant Operator 

Stripping Dredge Operator 

Stripping Operator 

Sublevel Miner 

Summer Grounds Keeper 

Super Sack Operator 

Superintendent 

Superintendent/Secretary 

Superintendent Maintenance 

Supervisor 

Supervisor 2nd Shift 

Supervisor & Backhoe Operator 

Supervisor Concentrator 

Supervisor Crush/Convey 

Supervisor/Dozer Operator 

Supervisor Leach Pad 

Supervisor Mechanics 

Supervisor Mine 

Supervisor—Mine 

Supervisor Mobile Equipment Quarry 

Supervisor —Moly Processing 

Supervisor/Operator 

Supervisor Plant 1 

Supervisor Plant 2 

Supervisor/Plant Operator 

Supervisor Quality Assurance 

Supervisor—Shovel/Drill Maintenance 

Supervisor—Tailings 

Supervisor Trainee 

Supply Clerk 

Supply Hauler 

Supply Man 

Supply/Track Man 

Support Foreman 

Support Opr. 5 

Surface 

Surface Coordinator 

Surface Electrician 

Surface Foreman 

Surface General Laborer 

Surface Laborer 

Surface Maintenance 

Surface Maintenance Manager 

Surface Maintenance Mechanic 

Surface Manager 

Surface Mechanic A 

Surface Mechanic C 

Surface Mine Supervisor 

Surface Operations Manager 

Surface Operations Technician IV 

Surface Operator B 

Surface Operator C 

Surface Outside 

Surface Plant Operator 

Surface Production 

Surface Production Operator 

Surface Production Supervisor 

Surface Shift Foreman 

Surface Supervisor 

Surface Support 

Surface Utility 

Surface Utility Man 

Surveyor 

Sweeper Operator 

Swingman 

SX Helper 

SX Operator 

System Administrator 

Systems Analyst 

Tailings Dam Operator 

Tailings Foreman 

Tailings Pond Operator 
240 

Tailings Repairman 

Tandem Tractor 

Tank Car Washer 

Tank Car Washout Technician 

Tank House Harvestor 

Team Leader 

Teamster 

Tech II 

Tech III 

Technical Coordinator 

Technical Services Manager 

Technical Specialist I 

Technician 

Technician Quality Control 

Technician Quality Control II 

Technician Quality Control IV 

Technician Quality Control V 

Technician Senior 

Technologist—Analytical Lab 

Temporary Section Foreman 

Temporary Worker 

Terminal Operator 

Thickener Operator 

Third Shift Foreman 

Tipple Foreman 

Tipple Helper 

Tipple Hilift Operator 

Tipple Operator 

Tire Man 

Tire Technician 

Top Lab Analyst 

Top Operator 

Tower Cleaner 

Tower Operator 

Tower Ranger 

Track 

Track Bolter 

Track Driller 

Track Foreman 

Track Hoe 

Track Hoe Operator 

Track Man 

Track Operator 

Tractor Operator 

Tractor Operator Loader 

Tractor Trailer Driver 

Tractor Worker 

Trades Person I 

Trades Person II 

Traffic Coordinator 

Traffic Representative 

Train Engineer 

Train Operator 

Trainee 

Trainer/Assessor 

Trainer Electrician 

Transportation 

Coordinator/Administrative Assistant 

Transportation Supervisor 

Treasurer 

Truck Bin Attendant 

Truck Driver 

Truck Driver I 

Truck Driver II 

Truck Driver 50T 

Truck Driver/Blaster Helper 

Truck Driver Heavy 

Truck Driver/Mechanic 

Truck Dump Operator 

Truck Lead Man 

Truck Loader 

Truck Maintenance 

Truck Operator 

TSP General Laborer 

TSP Mobile Equipment Operator 

TSP Pumper 

TSP Worker 

Undercutter Operator 

Underground Belt Man 

Underground Blaster 

Underground CM Maintenance 

Operations 

Underground CM Production 

Underground CM Set-up 

Underground Construction 

Underground Construction I 
241 

Underground Construction Crew 

Underground Electrician 

Underground Equipment Operator 

Underground Foreman 

Underground Laborer 

Underground Lead Man 

Underground Loader Operator 

Underground Manager 

Underground Mechanic 

Underground Miner 

Underground Miner 2/1 

Underground Miner 3/1 

Underground Miner 3/2 

Underground Miner 3/3 

Underground Operator 

Underground Operator I 

Underground Plant Operator 

Underground Roof Bolter Operator 

Underground Scaler 

Underground Shift Foreman 

Underground Superintendent 

Underground Supervisor 

Underground Truck Driver 

Underground Utilityman 

Unit Helper 

Universal Operator 

Utility 

Utility/Beltline 

Utility/Belts 

Utility/Bolter 

Utility Centrifuge Technician 

Utility Engineer Technician 

Utility Equipment Operator 

Utility Field 

Utility Laborer 

Utility Lubricator 

Utility Man 

Utility Man/Surface 

Utility Operator 

Utility Operator C 

Utility Person 

Utility Person Field 

Utility Person Laborer 

Utility Person Pit 

Utility Person Plant 

Utility Person/Warehouse 

Utility Scaler 

Utility Technician 

Utility Technician Equipment Cleaner 

Ventilation 

Vertical Driller 

Vice President 

Vice President Cement Operations 

Vice President & General Manager 

Vice President/Manager of Aggregate 

Division 

Vice President of Finance/CAO 

Vice President/Office Manager 

Vice President Sales 

Vice President Sales & Marketing 

Vice President/Secretary 

Vice President Technology 

Warehouse 

Warehouse 1 

Warehouse Coordinator 

Warehouse Man 

Warehouse Meo 

Warehouse Operator 

Warehouse Person 

Warehouse Supervisor 

Warehouse Supervisor/Purchasing Agent 

Warehouse Team Leader 

Warehouse Technician 

Warehouse Worker 

Warehouser 

Wash Operator 

Wash Plant 

Wash Plant Operator 

Wash Plant Super 

Watchman 

Water/Sweeper Truck Operator 

Water Truck 

Water Truck Driver 

Water Truck/Fueler 

Water Truck Operator 

Water Wagon Operator 
242 

W'Coat Packer 

Weigh Man 

Weigh Scale Operator 

Weighmaster 

Weighmaster/Dispatch 

Weld Shop Maintenance Manager 

Welder 

Welder I 

Welder/Fabricator 

Welder/Laborer 

Welder/Maintenance 

Welder/Mechanic 

Welder Mill Maintenance 

Welder/Pipe Fitter 

Welder/Plant Maintenance I 

Welder/Plant Maintenance III 

Welder/Plant Operator 

Welder Repair A 

Welder/Repairman 

Welder—Standard 

Wet Grind Operator 

Wet Plant 

Wet Plant Attendant 

Wet Plant Operator 

Wet Process Operator 

Wet Utility 

Worker 

Working Foreman 

Working Foreman Loading 

Working Foreman Quarry 

Wrens Maintenance II 

Wrens Maintenance IV 

Wrens Maintenance V 

Yard 

Yard Foreman 

Yard Laborer 

Yard Loader 

Yard Loader Operator 

Yard Loaderman (Front End Loaders) 

Yard Production Laborer 

Yard Truck Driver 
243 

Appendix I. Glossary 

Unless otherwise noted, the source of the definitions in this Glossary is the Dictionary of Mining, 

Mineral, and Related Terms [American Geological Institute 1997]. 

 
244 
245 

Auger. A rotary drilling device used to drill shot holes or geophone holes in which the cuttings 

are removed by the device itself without the use of fluids. 

Backhoe. A versatile rig used for trenching. 

Bagger/bagging operations worker. A worker who typically works at a two or four station 

filling machine, placing empty bags (generally 50 or 100 lb capacity) on each of the machine's 

fill nozzles. When each bag is filled, either the filling machine mechanically ejects the bag onto 

a conveyor, or the operator manually removes the bag and places it on a conveyor or on a pallet 

for shipping [Cecala and Thimons 1992]. 

Belt vulcanizer. Equipment that consists essentially of two heavy metal plattens that are placed 

one on each side of the previously prepared joint and clamped firmly together. Each platten is 

heated, and this combined application of heat and pressure over a period completes the joint. 

Beltman/conveyor man. A worker who sets up and tends chain, belt, or shaker (reciprocating) 

conveyors to transport coal or metal ore about a tipple at the surface from working the working 

face in a mine. 

Bin puller. A worker who transfers material from a storage bin or chute into mobile equipment 

for transportation. 

Blunging. The process of amalgamating, blending, or beating up or mixing in water. 

Bob cat. A miniature front-end loader. 

Brattice. A wall or petition in underground mines to control proper circulation of air through 

work places and passageways. Can be made of wood, canvas, or other materials. 

Breakers. A machine used for the primary reduction of coal, ore, or rock [Thrush 1968]. 

Bull dozer. A tractor on the front end of which is mounted a vertically curved steel blade held at 

a fixed distance by arms secured on a pivot or shaft near the horizontal center of the tractor. The 

blade can be lowered or tilted vertically by cables or hydraulic rams. It is a highly versatile piece 

of earth excavating and moving equipment especially useful in land clearing and leveling work, 

in stripping topsoil, in road and ramp building, and in floor or bench cleanup and gathering 

operations. Also called dozer. 

Calcine. By heating, to expel volatile matter as carbon dioxide, water, or sulfur, with or without 

oxidation; to roast; to burn. 

Cleanup man. A worker who collects all the valuable product of a given period of operation in 

a stamp mill, or in a hydraulic or placer mine. Collects and loads spillage resulting from normal 

operations. 

Coal sampler. A worker who cuts a representative part of an ore (or coal) deposit, which should 

truly represent its average value, and who collects and prepares samples of coal for analysis. 

Continuous miner. A mining machine designed to remove coal from the face and to load that 

coal into cars or conveyors without the use of cutting machines, drills, or explosives. 

Controller. Any mechanical or electrical device that is part of or added to a machine or device 

for automatic regulation or control. 
246 

Crude pile. A substance in its natural unprocessed, unrefined state. Crude ore or crude oil, for 

example. In a natural state; not cooked or prepared by fire or heat; not altered or prepared for 

use by any process. 

Crusher operator/ pan feeder operator. In the mineral and nonmineral industry, including 

coal, quarry products, mineral and nonmineral ores, a worker who operates a machine that 

crushes rock or other material and regulates the flow of such material into and from the crusher 

to the next point of processing or use. 

Culm. In anthracite terminology, the waste accumulation of coal, bone, and rock from old dry 

breakers. In bituminous coal preparation, culm corresponds to slurry or slime, depending upon 

the size distribution of the suspended solids. 

Culm bank. The deposit on the surface of culm usually kept separate from deposits of larger 

pieces of slate and rock. 

Curb. A timber frame, circular or square, wedged in a shaft to make a foundation for walling or 

tubbing, or to support, with or without other timbering, the walls of the shaft; the heavy frame or 

sill at the top of a shaft. 

Cutting machine. A power-driven machine used to undercut or shear. 

Dragline. A type of excavating equipment that casts a rope-hung bucket a considerable distance, 

collects the dug material by pulling the bucket toward itself on the ground with a second rope, 

then elevates the bucket, and dumps the material on a spoil bank, in a hopper, or on a pile. 

Digestion operator. A worker who tends the battery of digester vessels that dissolve bauxite in 

plant liquor by: turning valves on pumps to transfer liquid and bauxite slurry through heaters into 

digester vessels, turning valves to inject milk of lime into vessels, adjusting pumps and valves to 

circulate cleaning solution through process lines, and collecting samples of slurry and alumina 

solution for laboratory analysis [DOT 2003]. 

Dredge. A large floating machine used in underwater excavation for developing and 

maintaining water depths in canals, rivers, and harbors; raising the level of lowland areas and 

improving drainage; constructing dams and dikes; removing overburden from submerged ore 

bodies prior to open pit mining; or recovering subaqueous deposits having commercial value. 

Dry plant/dry process. A method of treating ores by heat as in smelting; used in opposition to 

the wet process. 

End dump. Process in which earth is pushed over the edge of a deep fill and allowed to roll 

down the slope [Infomine Inc. 2010]. 

Face. The exposed surface of a coal or ore deposit in the working place where mining is 

proceeding. 

Fire boss. A person designated to examine the mine for gas and other dangers usually before but 

also during the shift. Also known as a mine examiner. 

Floatation/concentrator. A plant where ore is separated into values (concentrates) and rejects 

(tails) or an appliance in such a plant, e.g., flotation cell, jig, electromagnet, shaking table. 

Front end loader. A tractor loader with a digging bucket mounted and operated at the front end 

of the tractor that both digs and dumps in front. 
247 

Froth cell. The process for cleaning fine coal, copper, lead, zinc, phosphate, kaolin, etc. with the 

aid of a reagent; the coal or minerals become attached to air bubbles in a liquid medium and float 

as a froth. 

Geologist. One who studies planet Earth, the materials of which it is made, the processes that 

act on these materials, the products formed, and the history of the planet and its life forms since 

its origin. 

Grader. A self-propelled or towed machine provided with a row of removing or digging teeth 

and (behind) a blade to spread and level the material. 

Ground control/timberman. A worker who installs timbers in a mine to support the roof and 

walls of haulage ways, passageways, and the shaft. 

Hammer mill. A pulverizing unit consisting of a rotor, fitted with movable hammers that is 

revolved rapidly in a vertical plane within a closely fitting steel casing. The hammers hit falling 

rock, which is fractured on impact, or by collision with other rocks or with the casing. When 

sufficiently reduced in size, the pulverized rock escapes through grids in the casing. 

Haulage. The drawing or conveying, in cars or otherwise, or movement of workers, supplies, 

ore, and waste both underground and on the surface. Generally refers to track mining as opposed 

to conveyor mining, although belt conveyor systems are sometimes referred to as belt haulage; 

the system of hauling coal or minerals out of a mine. 

Head area. The top portion of a seam in the coal face. 

Highwall. The unexcavated face of exposed overburden and coal or ore in an opencast mine or 

the face or bank on the uphill side of a contour strip mine excavation. 

Hoist operator. In mining, a person who operates steam or electric hoisting machinery used to 

lower cages (elevators) and skips (large, metal, boxlike containers) into a mine and to raise them 

to the surface from different levels. The worker may be designated according to the type of 

power used, as an electric-hoist person or steam-hoist person. 

Hopper. A storage bin or a funnel that is loaded from the top and discharges through a door or 

chute in the bottom. 

Inby. Toward the working face, or interior, of the mine; away from the shaft or entrance; 

opposite of outby. 

Inspector. One who checks the mine to determine the health and safety conditions. This person 

makes examinations of and reports on mines and surface plants relative to compliance with 

mining laws, rules and regulations, safety methods, etc. State inspectors have authority to 

enforce State laws regulating the working of the mines. Federal inspectors have authority to 

enforce Federal laws in coal mines. 

Jack setter. Miner who assists in the operation of an auger-type underground mining machine; 

duties include seeing that the roof of the mine at or near the machine is in a safe condition. 

Jaw operator. One who operates a machine for reducing the size of materials by impact or 

crushing between a fixed plate and an oscillating plate, or between two oscillating plates, 

reducing large rocks, or ores to sizes capable of being handled by any of the secondary crushers. 

Kiln. A large furnace used for baking, drying, or burning firebrick or refractories, or for 

calcining ores or other substances. 
248 

Lab technician. One who conducts chemical and physical laboratory tests to assist scientists in 

making qualitative and quantitative analyses of solids, liquids, and gaseous materials for research 

and development of new products or processes, quality control, maintenance of environmental 

standards, and other work involving experimental, theoretical, or practical application of 

chemistry and related sciences [BLS 2010]. 

Lampman. In mining, one who cleans, tests, and repairs lamps used underground by miners. 

Leaching operator. In ore dressing, smelting, and refining, one who dissolves valuable metal 

out of ore or slime, using chemical solutions. 

Longwall. A long face of coal. A method of working coal seams. The workings advance (or 

retreat) in a continuous line, which may be several hundred yards in length. The space from 

which the coal has been removed (the gob, goaf, or waste) which is either allowed to collapse 

(caving) or is completely or partially filled or stowed with stone and debris. 

Metallurgist. One who is skilled in, or who practices, the science and art of separating metals 

and metallic minerals from their ores by mechanical and chemical processes; one involved in the 

preparation of metalliferous materials from raw ore. 

Mill (rod/ball/pebble). A mineral treatment plant in which crushing, wet grinding, and further 

treatment of ore is conducted. The plant separates components, such as ball mill, hammer mill, 

and rod mill that grinds material, with or without liquid, using a rotating cylinder or conical mill, 

and using balls, rods, or pebbles as grinding material. 

Millwright. One who installs, dismantles, or moves machinery and heavy equipment according 

to layout plans, blueprints, or other drawings [BLS 2010]. 

Mine examiner. A person designated to examine the mine for gas and other dangers usually 

before but also during the shift. Also known as a fire boss. 

Mobile bridge. A continuous haulage system commonly consisting of an alternating series of 

piggyback mobile bridge carriers (MBCs) and chain bridge conveyors. They are either 

physically attached to the continuous miner or detached and independently trammed behind the 

miner [MSHA 2011]. 

Mucker. In mining and quarrying, a laborer who shovels ore or rock into mine cars or onto a 

conveyor from which mine cars are loaded and at some point are removed from the working face 

or surfaces of natural stone deposits; or one who works in a stope shoveling ore into chutes from 

which it is loaded into cars on haulage level below. 

Open pit. A mining operation designed to extract minerals that lie near the surface. Waste, or 

overburden, is first removed, and the mineral is broken and loaded, as in a stone quarry. 

Outby. Nearer to the shaft, and therefore away from the face, toward the pit bottom or surface; 

toward the mine entrance. The opposite of inby. 

Overburden. Material of any nature, consolidated or unconsolidated, that overlies a deposit of 

useful materials, ores, or coal, and especially those deposits that are mined from the surface by 

open cuts. 

Palletizer. One who secures battens (grooved strips of wood) around bundles of packaged metal 

extrusions to form protective shipping pallets, using strapping tool [DOT 2003].

Payloader. Equipment used for excavating. 
249 

Pelletizing operations worker. An operator of an apparatus in which finely divided material is 

formed into small spherical pellets by the use of pressure, centrifugal force, or additives. 

Pit. A mine, quarry, or excavation worked by the open-cut method. 

Preparation plant. Any facility where coal, or other mixed material, is prepared for market; 

through common usage, it has come to mean a rather elaborate collection of facilities where 

mixed material is separated from its impurities, washed and sized, and loaded for shipment. 

Pug operator/mixer tender. One who mixes ground preheated magnesia and carbon with hot 

asphalt in a pug mill to form a viscous mixture suitable for processing into pellets. 

Pumper. In bituminous coal mining, a person who works a hand pump to force water, 

accumulated underground in low places, into a drainage ditch flowing to a natural outlet or 

pumping station. 

Quarry. An open or surface mineral working, usually used for the extraction of building stone, 

such as slate, limestone, etc. It is distinguished from a mine because a quarry usually is open at 

the top and front, and, in ordinary use of the term, by the character of the material extracted. 

Raise borer. A machine used to produce a circular excavation either between two existing 

levels in an underground mine or between the surface and an existing level in a mine. In raise 

boring, a pilot hole is drilled down to the lower level; the drill bit is removed and replaced by a 

reamer head having a diameter with the same dimension as the desired excavation. This head 

then is rotated and pulled back up towards the machine. 

Reclaim. The process of digging from stockpiles; also, the reprocessing of previously rejected 

material. 

Refuse (pile). Waste material in the raw coal that has been removed in a cleaning or preparation 

plant; also called tailings. 

Rock breaker. A kind of hammer which is used to crush (break) rocks; it is a static piece of 

equipment; to be operated, it must be attached to another implement [Infomine Inc. 2010]. 

Rock duster. In bituminous coal mining, a laborer who sprinkles rock dust by hand or with a 

machine throughout mine workings as a precaution against explosions. 

Rolling mill. A rolling mill or establishment for rolling metal into forms. 

Roof bolter. In bituminous coal mining, one who reinforces roofs of mine haulage ways, side 

drifts, and working places with metal or timber to prevent rock and slate falls. 

Rotary excavator. Earth-moving machine with a vertical wheel that carries digging buckets 

peripherally. These loosen soil and deliver to a short conveyor loader, the assembly being 

mounted on crawler track. Capacity up to 5,000 st/h (4,500 t/h). Also called bucket wheel 

excavator. 

Rotary dump car. A standard small car in which the car body is mounted on a turntable in the 

car frame. The car body may be swung by hand to dump over either side or either end. 

Rubber-tired haulage. The underground use of tractors and dump truck haulage, of the battery 

or diesel type, and battery-driven shuttle cars. 

Safety director. One who promotes worksite or product safety by applying knowledge of 

industrial processes, mechanics, chemistry, psychology, and industrial health and safety laws

[BLS 2010]. 
250 

Sawyer. In stonework industry, a general term applied to workers engaged in cutting stone with 

power-driven saws. 

Scaler (hand or mechanical). A laborer who knocks the roasted lead ore off grates with a bar 

as it is dumped from conveyors into cars below, prior to melting, to separate and recover the 

lead. Lead ore is loaded on grates attached to a conveyor and carried through a furnace in which 

the sulfur is driven off by roasting. 

Scoop car. Diesel or battery-powered equipment with a scoop attachment for cleaning up loose 

material, for loading mine cars or trucks, and hauling supplies. 

Scraper. a. A rod for cleaning out a shothole prior to charging with explosives. b. A 

mechanical contrivance used at collieries to scrape the culm or slack along a trough to the place 

of deposit. c. A machine used in mines for loading cars and transporting ore or waste for short 

distances. There are two basic types of scraper: (1) the hoe or open type, which is particularly 

suitable for moving coarse, lumpy ore; and (2) the box or closed type, which is particularly 

suited for handling fine material, especially on a loading slide. d. A digging, hauling, and 

grading machine having a cutting edge, a carrying bowl, a movable front wall (apron), and a 

dumping or ejecting mechanism. Also called carrying scraper or pan. e. An apparatus used to 

take up coal from the floor of a mine, after it has been shot and deposit it either in cars or in a 

conveyor [Infomine Inc. 2010]. 

Screed. a. A strip of plaster or wood applied to a surface to be plastered to serve as a guide for 

making a true surface. b. A wooden strip serving as a guide for making a true level surface on a 

concrete pavement. c. A board or metal strip dragged across a freshly poured concrete slab to 

give it its proper level [Dictionary.com 2011]. 

Screening machine. An apparatus having a shaking, oscillatory, or rotary motion, used for 

screening or sifting coal, stamped ores, and the like. 

Shaft. An excavation of limited area compared with its depth; made for finding or mining ore or 

coal, raising water, ore, rock, or coal, hoisting and lowering workers and material, or ventilating 

underground workings. The term is often specifically applied to an approximate vertical shaft, as 

distinguished from an incline or inclined shaft. A shaft is provided with a hoisting engine at the 

top for handling workers, rock, and supplies; or it may be used only in connection with pumping 

or ventilating operations. 

Shaft mine. A mine in which the coal seam is reached by a vertical shaft which may vary in 

depth from less than 100 ft (30 m) to several thousand feet. 

Shearer operator. In bituminous coal mining, one who operates a type of coal-cutting machine 

that shears (cuts) out a channel down the sides of the working face of coal (as distinguished from 

undercutting) prior to blasting the coal down. 

Shooter. One who sets off blasts in a mine or quarry. 

Shuttle car operator. One who operates a vehicle on rubber tires or continuous treads to 

transfer raw materials, such as coal and ore, from loading machines in trackless areas of a mine 

to the main transportation system. 

Skip tender/cager/station attendant. One who directs station operations and movement of 

cages used to raise and lower workers, mine cars, and supplies between various levels and 

surface; one who works at the top of a shaft or at an intermediate level inside a mine. 
251 

Slurry operator. In ore dressing, smelting, and refining, a laborer who sprays the inner surfaces 

of furnace walls and roofs with a slurry of silica, water, and fireclay to protect brick, using a 

compressed-air gun. 

Splitter. One who separates blocks of rough dimension stone from quarry mass using 

jackhammer and wedges [BLS 2010]. 

Stope. An excavation from which ore has been removed in a series of steps. A variation of 

steps. This term is usually applied to highly inclined or vertical veins. 

Strip. In mining, to remove the earth, rock, and other material from the mineral to be mined, 

usually by power shovels. Generally practiced only where the mineral lies close to the Earth's 

surface. 

Surface shops. Mining operations do much of their repair work in-house. This work is carried 

out in shops located on the surface [Vaught 2008]. 

Surveyor/transit man. One who applies special knowledge and techniques gained through 

experience or training to make surface and underground surveys at a mine, locating 

himself/herself on the Earth's surface by taking instrument shots of the sun or stars and making 

necessary calculations, surveying and calculating the volume of material in dumps, carrying 

survey lines underground by shaft plumbing (cord or wire with attached bob is suspended from 

the shaft surface) and instrument shots taken on the bob at a shaft station, controlling by 

underground surveys and calculations, the driving and connection of underground passages on 

and between various levels, computing the volume of coal in portions of the mine from survey 

notes, and drafting maps of the mine workings. 

Tailings. a. The gangue and other refuse material resulting from the washing, concentration, or 

treatment of ground ore. b. Those portions of washed ore or coal that are regarded as too poor to 

be treated further. c. Applied to sectional residue, e.g., table tailings, which is the residue from 

shaking screens and tables. d. The reject from froth flotation cells. 

Tailings machine. A machine for sifting the tailings and collecting the gold from the detritus 

after it has passed through the washer. 

Thickener. The concentration of the solids in a suspension with a view to recovering one 

fraction with a higher concentration of solids than in the original suspension. 

Tipple. Originally the place where the mine cars were tipped and emptied of their coal, and still 

used in that sense, but more generally applied to the surface structures of a mine, including the 

preparation plant and loading tracks. 

Top operator. A worker who is employed at surface jobs around the mine plant. 

Tower crane. A swing-jib (crane with one horizontal boom on which there is a counterweight) 

or other type of crane mounted on top of a tower, the base of which may sometimes move on 

rails. These cranes are especially effective in congested sites. 

Tram. a. A trip of coal cars or a single tramcar. b. Generally, to move a self-propelled piece of 

equipment other than a locomotive. c. A boxlike wagon of steel, running on a tramway or 

railway in a mine, for conveying coal or ore. 

Trimmer. An apparatus for trimming a pile of coal into a regular form (such as a cone or 

prism). 
252 

Undercutter. In salt mining, an electrically driven machine somewhat like a gigantic chain saw. 

It has a long, thin horizontal bar, about which revolves an endless chain with cutting bits. The 

most common type is an adaptation of the shortwall coal cutter, a drag-type machine with 

continuous pick-filled chains to cut at the floor or bottom of the seam. It can make a rapid, 

continuous cut across the entire width of the face. 

Underground mine. A mine that accesses a coal seam or other mineral through a shaft instead 

of removing the overburden to expose the seam [Vaught 2008]. 

Utility man. A worker expected to serve in any capacity when called on [Dictionary.com 2011]. 

Ventilation. Mine workings are usually subdivided to form a number of separate ventilating 

districts. Each district is given a specified supply of fresh air and is free from contamination by 

the air of other districts. Accordingly, the main intake air is split into the different districts of the 

mine. Later, the return air from the districts reunites to restore the single main return air current 

at or near the upcast shaft. 

Wash plant. The place at which ore, coal, or crushed stone is freed from impurities or dust by 

washing. 

Washery. A place at which ore, coal, or crushed stone is freed from impurities or dust by 

washing. Also called wet separation plant, washing plant, dense-medium washer, or efficiency 

of separation [Infomine Inc. 2010]. 

Weighman. One who weighs, measures, and checks materials, supplies, and equipment for the 

purpose of keeping relevant records [BLS 2010]. 

Wet plant operator. A person who works as a member of a crew performing any one or a 

combination of duties concerned with extracting cadmium, lead sulfate, and zinc oxide from dust 

recovered in Cottrell precipitators. 

Yard. An area on the surface where mines store many of their supplies, such as bundles of roof 

bolts. These supplies are then sent underground or to the surface area of mining when needed 

[Vaught 2008]. 
DHHS (NIOSH) Publication No. 2012-152

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