ACTIVE / OPERATOR PORTFOLIO

U.S. Silica Company, LLC

Membership and operating status are from the latest MSHA Mines snapshot. Open a mine for its ownership history.

MSHA OPERATOR IDL14417

MINE PORTFOLIO

24 of 24 mines and facilities

2025-01-01 – 2026-10-13. Active records; production reporting is not required.

MineLocation / typeCoal · short tonsHours workedViolationsAccident recordsOn-site inspection hours
Berkeley Plant4602805 · Active6/8 quarters reportedMorgan, WVSurface · MSHA: Ground Silica0187,508161243.3
Celatom Mine3503237 · Active6/8 quarters reportedMalheur, ORSurface · MSHA: Diatomaceous Earth (Diatomite)071,7481117.8
Celatom Plant3503236 · Active6/8 quarters reportedMalheur, ORFacility · MSHA: Diatomaceous Earth (Diatomite)0194,9033137.0
Clark Operations2600677 · Active6/8 quarters reportedStorey, NVSurface · MSHA: Diatomaceous Earth (Diatomite)0197,59114037.8
Colado Mine2600672 · Active6/8 quarters reportedPershing, NVSurface · MSHA: Diatomaceous Earth (Diatomite)088,6344125.5
Colado Plant2600680 · Active6/8 quarters reportedPershing, NVSurface · MSHA: Diatomaceous Earth (Diatomite)0315,74818271.5
COLUMBIA PLANT3800138 · Active6/8 quarters reportedLexington, SCSurface · MSHA: Sand, Industrial NEC0167,718640256.5
Dubberly Plant1600489 · Active6/8 quarters reportedWebster, LASurface · MSHA: Construction Sand and Gravel051,1164050.5
EP Engineered Clays Corporation2200415 · Active6/8 quarters reportedHinds, MSFacility · MSHA: Clay, Ceramic, Refractory Mnls.0257,89411269.0
Fernley Operations2601950 · Active6/8 quarters reportedChurchill, NVSurface · MSHA: Diatomaceous Earth (Diatomite)095,2929048.8
FOWLKES MINE2200460 · Active6/8 quarters reportedMonroe, MSSurface · MSHA: Bentonite02,4561040.0
Hurtsboro Plant0100617 · Active6/8 quarters reportedRussell, ALSurface · MSHA: Construction Sand and Gravel033,4705045.5
Jackson Plant4002937 · Active6/8 quarters reportedMadison, TNFacility · MSHA: Sand, Industrial NEC035,4440035.3
Mapleton Depot Plant3603122 · Active6/8 quarters reportedHuntingdon, PASurface · MSHA: Sand, Industrial NEC0162,55482136.5
Mauricetown Plant2800526 · Active6/8 quarters reportedCumberland, NJSurface · MSHA: Sand, Industrial NEC096,3946133.3
Middleton Operations4002968 · Active6/8 quarters reportedHardeman, TNSurface · MSHA: Common Clays NEC0220,0580051.8
Mill Creek Plant #373400377 · Active6/8 quarters reportedJohnston, OKSurface · MSHA: Sand, Industrial NEC079,6534029.3
Mill Creek Plant #393400836 · Active6/8 quarters reportedJohnston, OKSurface · MSHA: Crushed, Broken Sandstone0116,67914358.0
Millen Plant0901232 · Active6/8 quarters reportedJenkins, GAFacility · MSHA: Kaolin and Ball Clay095,8351037.8
Montpelier Plant4402829 · Active6/8 quarters reportedHanover, VASurface · MSHA: Aplite080,8175097.5
Ottawa Plant1101013 · Active6/8 quarters reportedLa Salle, ILSurface · MSHA: Ground Silica0455,548774261.3
Pacific Plant2300544 · Active6/8 quarters reportedSt Louis, MOSurface · MSHA: Quartz, Ground0174,13211186.3
Port Elizabeth Plant2800510 · Active6/8 quarters reportedCumberland, NJSurface · MSHA: Construction Sand and Gravel02,9601012.5
Rockwood Plant2000608 · Active6/8 quarters reportedWayne, MISurface · MSHA: Sand, Industrial NEC060,15810081.5

LOCATION

Portfolio map

24 of 24 mines with usable MSHA coordinates. Select a marker to open a mine.

Mine coordinates

2025-01-01 – 2026-10-13Applies to production, safety and portfolio metrics. Silica samples have separate filters.

Violations

287

38 significant & substantial (S&S)

  1. 2025 Q156
  2. 2025 Q226
  3. 2025 Q349
  4. 2025 Q443
  5. 2026 Q135
  6. 2026 Q243
  7. 2026 Q335
  8. 2026 Q4 *0

Accident records

19

0 records classified as fatality

  1. 2025 Q12
  2. 2025 Q22
  3. 2025 Q32
  4. 2025 Q43
  5. 2026 Q15
  6. 2026 Q22
  7. 2026 Q33
  8. 2026 Q4 *0

Proposed penalties · USD

109,171.00

269 of 287 violations with amounts

  1. 2025 Q121,687
  2. 2025 Q28,239
  3. 2025 Q329,813
  4. 2025 Q425,798
  5. 2026 Q17,971
  6. 2026 Q211,291
  7. 2026 Q34,372
  8. 2026 Q4 *—

On-site inspection hours

1,863.75

161 inspections · 161 with hours

  1. 2025 Q1342.00
  2. 2025 Q2286.50
  3. 2025 Q3248.75
  4. 2025 Q4276.50
  5. 2026 Q1249.00
  6. 2026 Q2254.25
  7. 2026 Q3206.75
  8. 2026 Q4 *0.00
Quarterly safety data
QuarterViolationsS&SProposed USDAccident recordsFatality recordsInspectionsOn-site hours
2025-Q156821,687.002027342.0
2025-Q22638,239.002021286.5
2025-Q349429,813.002023248.8
2025-Q443825,798.003023276.5
2026-Q13557,971.005019249.0
2026-Q243411,291.002022254.3
2026-Q33564,372.003024206.8
2026-Q4 *00—0020.0

Most cited CFR sections

All violations issued in the selected period. Counts combine subsections.

Safety activity

  1. inspectionF00AB2A
    Colado Mine · 2600672

    Regular Safety and Health Inspection · 0.0 on-site hours

  2. inspectionF044510
    COLUMBIA PLANT · 3800138

    Compliance Follow-up Inspection · 0.0 on-site hours

  3. inspectionF046BBD
    Mauricetown Plant · 2800526

    Compliance Follow-up Inspection · 0.0 on-site hours

  4. inspectionF02E8DF
    Berkeley Plant · 4602805

    Spot Inspection · 6.0 on-site hours

  5. inspectionF04779C
    Montpelier Plant · 4402829

    Spot Inspection · 13.3 on-site hours

  6. inspectionF04450B
    COLUMBIA PLANT · 3800138

    Verbal Hazard Complaint Inspections · 2.3 on-site hours

  7. inspectionF04450C
    COLUMBIA PLANT · 3800138

    Spot Inspection · 2.0 on-site hours

  8. violation5193150
    COLUMBIA PLANT · 3800138

    56.20003(a) · S&S

  9. violation5193149
    COLUMBIA PLANT · 3800138

    56.20003(a)

  10. violation5193148
    COLUMBIA PLANT · 3800138

    56.12032

  11. violation5193147
    COLUMBIA PLANT · 3800138

    56.14112

  12. inspectionF048DFC
    FOWLKES MINE · 2200460

    Regular Safety and Health Inspection · 18.5 on-site hours

  13. violation5193271
    FOWLKES MINE · 2200460

    56.11003

  14. inspectionF03921C
    Millen Plant · 0901232

    Regular Safety and Health Inspection · 7.8 on-site hours

  15. violation5261125
    Mauricetown Plant · 2800526

    56.14100(b) · S&S

  16. violation5261124
    Mauricetown Plant · 2800526

    56.14100(b)

  17. violation5261123
    Mauricetown Plant · 2800526

    56.14112(a)(1)

  18. violation5261122
    Mauricetown Plant · 2800526

    56.14205 · S&S

  19. inspectionF046BB5
    Mauricetown Plant · 2800526

    Regular Safety and Health Inspection · 13.8 on-site hours

  20. inspection6880761
    Colado Plant · 2600680

    Special Emphasis Programs · 0.8 on-site hours

  21. violation9216896
    Montpelier Plant · 4402829

    56.12028

  22. violation9216895
    Montpelier Plant · 4402829

    56.12008

  23. inspectionF02F03A
    Montpelier Plant · 4402829

    Regular Safety and Health Inspection · 19.3 on-site hours

  24. inspectionF03C6D2
    Berkeley Plant · 4602805

    Impoundment Spot Inspection · 2.8 on-site hours

  25. accident220262530014
    Ottawa Plant · 1101013

    HANDLING OF MATERIALS · DAYS AWAY FROM WORK ONLY

    Accident narrative

    The employee was in the quarry with a 2-gallon jug of def in their hand, they went to turn around and immediately felt a pain in their right knee. Employee has received restrictions for their right knee.

Safety sources and definitions

MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-13.

Counts describe published rows, including contractor records; accident records are not distinct incidents or numbers of people injured.

Zero means no matching records in the imported sources, not proof of no events. Historical coverage differs by source; absence before a source begins reporting is not a zero incident rate. Invalid or absent dates and records after the snapshot are excluded.

S&S means SIG_SUB=Y. Fatality records use DEGREE_INJURY_CD=01. Proposed penalties are not final assessed or paid amounts; missing dollar values are omitted.

Inspection hours are SUM_TOTAL_ON_SITE_HOURS attributed to the inspection start date, without supervisor/trainee hours. Missing hours are omitted; a started inspection may still be open.

Portfolio totals use current mine membership, including events before the current owner or operator's tenure.

CFR headings link to the current Title 30 index; they are not historical legal determinations.

SELECTED PORTFOLIO

1 linked controller.

Relationships reflect the selected mine status and current MSHA controller/operator fields.