Mining Incidents

PLANT #5: 76 MSHA citations Metal/Non-Metal

ONYX MATERIALS · Surface
corona, Riverside County, CA  ·  Active
MSHA Mine ID: 0405451

PLANT #5 has $13K in proposed MSHA penalties and $151 outstanding across 1 contested dockets, plus health sampling and the full incident record.

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Fatalities
0
Total incidents
2
Years on record
2006–2007
Latest incident
Dec 2007
Compliance record
MSHA citations since 2000
76
citations
13
significant & substantial
$13,433
proposed penalties
$13,282
paid to date
99% of proposed penalties paid to date, a $151 gap.
Source: MSHA violations data, updated weekly.
Inspection activity
MSHA inspections since 2000
49
inspections on record
542
inspection hours
n/a
citations per 100 inspection hours
This rate is recorded citations divided by MSHA inspection hours, per 100 hours. It reflects inspection effort, not mine size or production.
Rate withheld: 542 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.

PLANT #5 has $13K in proposed MSHA penalties and $151 outstanding across 1 contested dockets.

Penalty disposition
Differences between proposed and paid penalties reflect both settlements and conference reductions and amounts still owed. Outstanding is the balance currently owed.
$13K
proposed penalties
$13K
current assessed
$13K
paid to date
$151
outstanding
75 assessments are final orders; 1 contested dockets.
Of $200 in penalties contested before the Commission, $200 was upheld in final decisions.
As of the most recent assessment on 2026-06-30.
Source: MSHA assessed-violations and conference/litigation data, updated weekly.
Violation severity profile
Shares are computed over citations that carry the MSHA gravity and negligence coding; a small share of records are uncoded.
17.1%
significant & substantial
15.8%
high negligence or reckless
17.1%
reasonably likely or greater
55.3%
permanently disabling or fatal if injury occurs
Negligence coding: 0.0% none, 22.4% low, 61.8% moderate, 15.8% high, 0.0% reckless.
Source: MSHA violations gravity and negligence coding, updated weekly.
When citations were contested
Contesting a citation before the Federal Mine Safety and Health Review Commission is a lawful right. These figures state the public outcomes of that process, from MSHA's Contested Violations file.
2 citations taken to the federal commission · 3% of citations on record
  • Settled 2 · 100%
0%
Penalty reduction in decided contests
$200 proposed, $200 after decisions · industry: 39%
Source: MSHA Contested Violations file (public record), updated weekly. A dismissed or defaulted contest leaves the citation standing as issued; a vacated or withdrawn citation is removed from the violation record. Latest contest filed 2009-12-24.
Contested penalties
A reduction or dismissal at the Commission is a lawful outcome of contesting a proposed penalty. Figures are the proposed amount and the amount upheld in the docket's decision.
Largest penalties this mine contested before the Federal Mine Safety and Health Review Commission, with the outcome on record.
Docket Decision Judge Year Proposed / upheld
WEST 2010-427M Settlement Lesnick 2011 $200 → $200
Source: FMSHRC civil penalty dockets and decisions (public record), updated weekly.
Health sampling
A sample is a point in time compliance measurement, not an individual exposure history. These figures describe MSHA sampling records and do not establish causation or personal dose.

Metal and nonmetal contaminants (personal samples)
Many samples are screening measurements of substances with no applicable exposure limit; they are counted as samples but excluded from every over-limit figure. Over-limit shares use only limit-tested samples.

Last sampled: 2025-08-21
5
samples
0
limit-tested
Most sampled contaminants
  • Respirable dust, <.1mg5
Show the individual readings (5)
Date Contaminant Concentration Limit Conc / limit Occupation
2025-08-21 Respirable dust, <.1mg 0 Front-end Loader Operator
2020-09-23 Respirable dust, <.1mg 0 Laborer, Bullgang
2020-09-23 Respirable dust, <.1mg 0 Front-end Loader Operator
2010-05-27 Respirable dust, <.1mg 0 Front-end Loader Operator
2005-09-14 Respirable dust, <.1mg 0 Front-end Loader Operator
Source: MSHA respirable dust, quartz, and noise sampling records, updated weekly. Metal/nonmetal contaminant figures come from MSHA's Personal Health Samples and Area Samples files (public record), updated weekly.
Ownership history
  1. Soil Binder 2000 to 2022
  2. Leinco Enterpises,Inc. 2022 to 2025
  3. ONYX MATERIALS 2025 to present
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year Employees
2026 4
2025 1
2024 3
2023 3
2022 3
2021 3
2020 3
2019 3
2018 3
2017 3
2016 2
2015 2
2014 2
2013 3
2012 2
2011 1
2010 2
2009 3
2008 5
2007 5
2006 3
2005 2
2004 1
2003 1
2002 1
2001 1
2000 2
Source: MSHA quarterly employment and production, updated weekly.

PLANT #5 sits in Riverside County, California, where the Census mining category is 0.1% of county employment.

Local economic context
County figures come from the US Census Bureau's American Community Survey, 5-year pooled estimates, so the 2023 vintage covers 2019 through 2023. The Census category is 'mining, quarrying, and oil and gas extraction', which is broader than MSHA jurisdiction and includes oil and gas workers no mine employs. These figures describe the surrounding county, not this mine, and are not a factor in any specific incident.
Riverside County, California · Population 2,449,909
0.1%
Mining share of county employment
$89,672
Median household income
Source: US Census Bureau, American Community Survey 2023 5-year estimates.
Quarterly safety rates
Citations per million reported employee-hours. Rates begin in 2000, when MSHA's quarterly employment data starts; earlier incidents are counted but cannot be rate-adjusted. Quarters under 100,000 reported hours are greyed: too few hours for a stable rate.
Citations per million employee-hours, as reported to MSHA
Quarter Hours worked Citations S&S Per 1M hrs
2026 Q2 4,200 1 0 238.1
2026 Q1 700 0 0 0.0
2025 Q4 700 2 0 2857.1
2025 Q3 700 1 0 1428.6
2025 Q2 700 0 0 0.0
2025 Q1 700 4 1 5714.3
2024 Q4 700 0 0 0.0
2024 Q3 1,202 1 0 831.9
Show 85 earlier quarters
Quarter Hours worked Citations S&S Per 1M hrs
2024 Q2 929 0 0 0.0
2024 Q1 1,079 4 1 3707.1
2023 Q4 1,583 0 0 0.0
2023 Q3 1,611 6 1 3724.4
2023 Q2 1,498 0 0 0.0
2023 Q1 1,397 0 0 0.0
2022 Q4 1,511 5 2 3309.1
2022 Q3 1,910 0 0 0.0
2022 Q2 2,054 4 1 1947.4
2022 Q1 1,815 0 0 0.0
2021 Q4 1,755 0 0 0.0
2021 Q3 1,950 4 0 2051.3
2021 Q2 1,755 0 0 0.0
2020 Q3 1,650 0 0 0.0
2020 Q2 1,950 0 0 0.0
2020 Q1 1,430 1 0 699.3
2019 Q4 1,200 0 0 0.0
2019 Q2 1,680 0 0 0.0
2019 Q1 1,040 0 0 0.0
2018 Q4 1,950 0 0 0.0
2018 Q3 2,210 0 0 0.0
2018 Q2 2,038 0 0 0.0
2018 Q1 2,022 2 0 989.1
2017 Q4 1,698 0 0 0.0
2017 Q3 450 0 0 0.0
2017 Q2 930 0 0 0.0
2016 Q1 220 0 0 0.0
2015 Q4 524 0 0 0.0
2015 Q2 315 0 0 0.0
2015 Q1 840 0 0 0.0
2014 Q4 110 1 0 9090.9
2014 Q3 480 0 0 0.0
2014 Q2 1,020 0 0 0.0
2014 Q1 1,478 0 0 0.0
2013 Q4 2,574 0 0 0.0
2013 Q3 2,730 0 0 0.0
2013 Q2 2,047 0 0 0.0
2013 Q1 1,461 0 0 0.0
2012 Q4 1,469 0 0 0.0
2012 Q3 1,534 0 0 0.0
2012 Q2 216 0 0 0.0
2011 Q4 130 0 0 0.0
2011 Q1 550 0 0 0.0
2010 Q4 1,170 0 0 0.0
2010 Q3 585 0 0 0.0
2010 Q2 585 0 0 0.0
2010 Q1 1,170 0 0 0.0
2009 Q4 1,690 3 0 1775.1
2009 Q3 1,170 0 0 0.0
2009 Q2 1,755 0 0 0.0
2009 Q1 880 1 0 1136.4
2008 Q4 2,184 1 0 457.9
2008 Q3 3,120 0 0 0.0
2008 Q2 3,575 0 0 0.0
2008 Q1 3,932 0 0 0.0
2007 Q4 3,250 4 1 1230.8
2007 Q3 2,640 0 0 0.0
2007 Q2 3,120 0 0 0.0
2007 Q1 3,432 0 0 0.0
2006 Q4 3,575 7 0 1958.0
2006 Q3 1,610 3 1 1863.4
2006 Q2 0 0 0
2006 Q1 1,350 0 0 0.0
2005 Q4 1,525 0 0 0.0
2005 Q3 240 0 0 0.0
2005 Q2 480 0 0 0.0
2005 Q1 0 0 0
2004 Q4 1,170 0 0 0.0
2004 Q3 0 0 0
2004 Q2 390 0 0 0.0
2004 Q1 720 0 0 0.0
2003 Q4 600 0 0 0.0
2003 Q3 500 0 0 0.0
2003 Q2 520 0 0 0.0
2003 Q1 480 0 0 0.0
2002 Q4 780 9 2 11538.5
2002 Q3 500 0 0 0.0
2002 Q2 720 3 1 4166.7
2002 Q1 780 0 0 0.0
2001 Q4 203 4 1 19704.4
2001 Q3 150 0 0 0.0
2001 Q2 203 0 0 0.0
2001 Q1 90 0 0 0.0
2000 Q4 70 2 0 28571.4
2000 Q3 860 3 1 3488.4
No fatalities recorded at this mine.

Reportable incidents

2 on file

2007 · 1 incident

December 4, 2007 CA · Metal/Non-Metal ledgeman/hand, quarry man POWERED HAULAGE
Soil Binder · Struck by... (Not Elsewhere Classified)

Got hit in the head with knuckle boom on boom truck. Worker was too close to boom during operation. 4 stitches required for small cut on forehead.

2006 · 1 incident

October 12, 2006 CA · Metal/Non-Metal maintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service tech OTHER
Soil Binder · Unclassified, insufficient data

The miner was hit on the head and received a scrape on the arm approximately 1"x 2". His head required 4 stitches. It is unknown what contributed to the accident the miner does not remember and there was no witnesses. I assumed he either fell or was hit by a bar while prying on something.