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 – 2026-10-18. 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 Silica0187,508161250.3
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)088,6344132.5
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 – 2026-10-18Applies 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

112,008.00

275 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 Q37,209
  8. 2026 Q4 *—

On-site inspection hours

1,877.75

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 Q2261.25
  7. 2026 Q3206.75
  8. 2026 Q4 *7.00
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-Q243411,291.002022261.3
2026-Q33567,209.003024206.8
2026-Q4 *00—0027.0

Most cited CFR sections

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

Safety activity

  1. violation5118296
    Ottawa Plant · 1101013

    56.16005 · $504.00 proposed

  2. violation5118295
    Ottawa Plant · 1101013

    56.13010(a) · $226.00 proposed

  3. inspectionF02500D
    Ottawa Plant · 1101013

    Regular Safety and Health Inspection · 65.3 on-site hours

  4. violation5118294
    Ottawa Plant · 1101013

    56.20003(a) · S&S · $2,503.00 proposed

  5. violation5071095
    Mauricetown Plant · 2800526

    56.14132(a) · $151.00 proposed

  6. violation5004719
    Mill Creek Plant #37 · 3400377

    56.12028 · $177.00 proposed

  7. violation5004718
    Mill Creek Plant #37 · 3400377

    56.14100(b) · $151.00 proposed

  8. violation5004717
    Mill Creek Plant #37 · 3400377

    56.14100(b) · $151.00 proposed

  9. inspectionF019DD5
    Mill Creek Plant #37 · 3400377

    Regular Safety and Health Inspection · 11.5 on-site hours

  10. accident220252190007
    Celatom Plant · 3503236

    STRIKING OR BUMPING · DAYS RESTRICTED ACTIVITY ONLY

    Accident narrative

    Employee struck the back of EE's left hand on metal supporting structure while ascending stairway. Resulting in a fracture to the third metacarpal of the left hand.

  11. inspectionF0190EF
    Hurtsboro Plant · 0100617

    Regular Safety and Health Inspection · 14.0 on-site hours

  12. inspectionF024784
    Mauricetown Plant · 2800526

    Regular Safety and Health Inspection · 10.0 on-site hours

  13. inspectionF01FB96
    Rockwood Plant · 2000608

    Compliance Follow-up Inspection · 1.0 on-site hours

  14. inspectionF02ADE2
    COLUMBIA PLANT · 3800138

    Verbal Hazard Complaint Inspections · 3.3 on-site hours

  15. accident220253170413
    Ottawa Plant · 1101013

    STEPPING OR KNEELING ON OBJECT · DYS AWY FRM WRK & RESTRCTD ACT

    Accident narrative

    The employee was working on mineral separators when they stepped on a mesh cleaning ball and twisted their right knee. They did not fall but, felt soreness the next day.

  16. inspectionF01421C
    Dubberly Plant · 1600489

    Regular Safety and Health Inspection · 8.8 on-site hours

  17. inspectionF024781
    Port Elizabeth Plant · 2800510

    Compliance Follow-up Inspection · 0.8 on-site hours

  18. violation5007605
    Dubberly Plant · 1600489

    56.14112(b) · $151.00 proposed

  19. violation9602299
    Mapleton Depot Plant · 3603122

    56.14132(a) · $151.00 proposed

  20. violation5071085
    Port Elizabeth Plant · 2800510

    56.4130(b) · $151.00 proposed

  21. inspectionF02477E
    Port Elizabeth Plant · 2800510

    Regular Safety and Health Inspection · 4.5 on-site hours

  22. inspectionF015776
    COLUMBIA PLANT · 3800138

    Compliance Follow-up Inspection · 2.3 on-site hours

  23. violation6553523
    Rockwood Plant · 2000608

    56.12002 · $151.00 proposed

  24. violation6553522
    Rockwood Plant · 2000608

    56.14101(a)(2) · $151.00 proposed

  25. inspectionF01FB94
    Rockwood Plant · 2000608

    Regular Safety and Health Inspection · 15.3 on-site hours

Safety sources and definitions

MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-18.

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.