Martis Valley Plant has $9K in proposed MSHA penalties and $0 outstanding across 5 contested dockets, plus health sampling and the full incident record.
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Fatalities
0
Total incidents
17
Years on record
1989–2022
Latest incident
Apr 2022
Compliance record
MSHA citations since 2000
69
citations
6
significant & substantial
$8,943
proposed penalties
$8,833
paid to date
99% of proposed penalties paid to date, a $110 gap.
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: 721 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Martis Valley Plant has $9K in proposed MSHA penalties and $0 outstanding across 5 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.
$9K
proposed penalties
$9K
current assessed
$9K
paid to date
$0
outstanding
61 assessments are final orders; 5 contested dockets.
Of $1K in penalties contested before the Commission, $1K was upheld in final decisions.
As of the most recent assessment on 2025-05-28.
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.
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.
6citations taken to the federal commission · 9% of citations on record
Settled
3 · 50%
Stood as issued
3 · 50%
50%
S&S designation survived the contest
ⓘCounts a Significant & Substantial citation as surviving when a settlement or judge's decision kept the designation, or the contest was dismissed or defaulted so the citation stands as issued. Vacated and withdrawn citations, and settlements that removed the designation, count against.
of 2 decided S&S contests · industry: 79%
0%
Penalty reduction in decided contests
$1K proposed, $1K 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 2022-05-15.
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.
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: 2026-07-22
0%
of limit-tested samples over the exposure limit
17
samples
1
limit-tested
Most sampled contaminants
Respirable dust, <.1mg8
Unlisted Particulate, respirable, <1% Qtz5
Quartz, respirable, >1% Qtz4
Show the individual readings (17)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2026-07-22
Respirable dust, <.1mg
0
Front-end Loader Operator
2025-05-28
Respirable dust, <.1mg
0
Front-end Loader Operator
2023-07-19
Quartz, respirable, >1% Qtz
0.28
Mechanic
2021-06-10
Quartz, respirable, >1% Qtz
0.32
Laborer, Bullgang
2018-10-10
Quartz, respirable, >1% Qtz
0.28
Laborer, Bullgang
2014-07-01
Unlisted Particulate, respirable, <1% Qtz
0.27
Cleanup Man
2014-07-01
Unlisted Particulate, respirable, <1% Qtz
0.29
Laborer, Bullgang
2014-07-01
Respirable dust, <.1mg
0
Tractor Operator
2009-10-21
Respirable dust, <.1mg
0
Front-end Loader Operator
2009-10-21
Unlisted Particulate, respirable, <1% Qtz
0.31
Laborer, Bullgang
2009-10-21
Unlisted Particulate, respirable, <1% Qtz
0.14
Laborer, Bullgang
2009-10-21
Quartz, respirable, >1% Qtz
0.26
2.08
0.13
Laborer, Bullgang
2005-06-15
Respirable dust, <.1mg
0
Front-end Loader Operator
2005-06-15
Respirable dust, <.1mg
0
Cleanup Man
2005-06-15
Respirable dust, <.1mg
0
Truck Driver
2005-06-15
Unlisted Particulate, respirable, <1% Qtz
0.7
Crusher Oper/Worker
2005-06-15
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.
Martis Valley Plant recorded 8.77 reportable injury cases per 100 full-time workers in 2010.
Injury rate, 2010
ⓘThis rate is reportable injury cases per 100 full-time-equivalent workers per year, computed as 200,000 times cases divided by MSHA operator-reported employee-hours. Cases are injuries MSHA graded degree 01 through 07; accident-only events that hurt no one are excluded, and so are contractor injuries, whose hours do not attach to a single mine. Rates begin in 2000, when quarterly employment reporting starts, and are withheld below 20,000 hours in a year.
8.77
total case rate
0.00
days-away rate
0.000
fatality rate
Above average. The US metal and nonmetal mining average was 2.68 and the all-US-mining average was 3.20 cases per 100 workers.
In California, metal and nonmetal mining averaged 3.23 cases per 100 workers that year.
Under 100,000 employee-hours were reported that year, so a single case moves the rate by two or more. Read the figure as approximate.
Year
total case rate
days-away
fatal
2010 *
8.77
0.00
0.000
2009 *
0.00
0.00
0.000
2008 *
0.00
0.00
0.000
2007 *
3.71
0.00
0.000
2006 *
5.14
0.00
0.000
2005 *
11.72
5.86
0.000
2004 *
0.00
0.00
0.000
2003 *
0.00
0.00
0.000
* Fewer than 100,000 employee-hours that year; the rate is less stable.
Source: injury cases from MSHA accident and injury records; employee-hours from MSHA quarterly employment reports. Rate is cases per 100 full-time-equivalent workers, operator employees only.
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year
Employees
2026
6
2025
5
2024
8
2023
13
2022
16
2021
9
2020
10
2019
8
2018
10
2017
10
2016
10
2015
12
2014
12
2013
11
2012
12
2011
12
2010
15
2009
17
2008
18
2007
27
2006
18
2005
19
2004
16
2003
16
2002
14
2001
20
2000
23
Source: MSHA quarterly employment and production, updated weekly.
Martis Valley Plant sits in Nevada 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.
Nevada County, California · Population 102,452
0.1%
Mining share of county employment
$84,905
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
1,907
0
0
0.0
2025 Q4
561
0
0
0.0
2025 Q3
2,254
0
0
0.0
2025 Q2
1,410
1
0
709.2
2024 Q4
1,461
0
0
0.0
2024 Q3
3,918
1
0
255.2
2024 Q2
2,658
0
0
0.0
2023 Q4
2,134
0
0
0.0
Show 92 earlier quartersHide earlier quarters
Quarter
Hours worked
Citations
S&S
Per 1M hrs
2023 Q3
6,599
4
0
606.2
2023 Q2
5,521
0
0
0.0
2023 Q1
1,678
0
0
0.0
2022 Q4
2,484
0
0
0.0
2022 Q3
5,234
0
0
0.0
2022 Q2
4,442
0
0
0.0
2022 Q1
2,060
5
3
2427.2
2021 Q4
2,964
0
0
0.0
2021 Q3
4,676
0
0
0.0
2021 Q2
4,325
0
0
0.0
2021 Q1
1,916
0
0
0.0
2020 Q4
2,131
0
0
0.0
2020 Q3
4,830
0
0
0.0
2020 Q2
4,714
0
0
0.0
2019 Q4
3,294
0
0
0.0
2019 Q3
5,309
0
0
0.0
2019 Q2
5,010
0
0
0.0
2019 Q1
730
0
0
0.0
2018 Q4
3,573
1
0
279.9
2018 Q3
5,638
0
0
0.0
2017 Q4
3,405
6
0
1762.1
2017 Q3
6,116
0
0
0.0
2017 Q2
5,221
0
0
0.0
2017 Q1
1,257
4
0
3182.2
2016 Q4
4,140
0
0
0.0
2016 Q3
5,220
1
0
191.6
2016 Q2
5,769
0
0
0.0
2016 Q1
1,599
0
0
0.0
2015 Q4
4,157
0
0
0.0
2015 Q3
5,734
2
0
348.8
2015 Q2
6,289
0
0
0.0
2015 Q1
2,154
0
0
0.0
2014 Q4
4,470
0
0
0.0
2014 Q3
6,324
1
0
158.1
2014 Q2
5,817
0
0
0.0
2014 Q1
1,546
0
0
0.0
2013 Q4
4,164
0
0
0.0
2013 Q3
6,019
0
0
0.0
2013 Q2
5,782
1
0
173.0
2013 Q1
937
0
0
0.0
2012 Q4
4,357
0
0
0.0
2012 Q3
6,586
1
0
151.8
2012 Q2
4,516
0
0
0.0
2012 Q1
671
0
0
0.0
2011 Q4
5,771
0
0
0.0
2011 Q3
6,977
0
0
0.0
2011 Q2
5,563
0
0
0.0
2011 Q1
796
0
0
0.0
2010 Q4
4,943
0
0
0.0
2010 Q3
9,792
2
0
204.2
2010 Q2
7,471
0
0
0.0
2010 Q1
598
0
0
0.0
2009 Q4
5,455
6
1
1099.9
2009 Q3
7,532
0
0
0.0
2009 Q2
6,273
2
0
318.8
2009 Q1
3,540
0
0
0.0
2008 Q4
11,166
4
0
358.2
2008 Q3
9,653
0
0
0.0
2008 Q2
5,036
0
0
0.0
2008 Q1
5,253
0
0
0.0
2007 Q4
10,729
1
1
93.2
2007 Q3
14,711
0
0
0.0
2007 Q2
22,379
0
0
0.0
2007 Q1
6,058
1
0
165.1
2006 Q4
9,989
0
0
0.0
2006 Q3
12,450
2
0
160.6
2006 Q2
9,765
0
0
0.0
2006 Q1
6,680
0
0
0.0
2005 Q4
9,716
0
0
0.0
2005 Q3
10,566
0
0
0.0
2005 Q2
8,754
1
0
114.2
2005 Q1
5,090
0
0
0.0
2004 Q4
8,326
3
0
360.3
2004 Q3
9,086
0
0
0.0
2004 Q2
8,062
0
0
0.0
2004 Q1
6,349
0
0
0.0
2003 Q4
8,225
0
0
0.0
2003 Q3
10,363
0
0
0.0
2003 Q2
9,438
0
0
0.0
2003 Q1
6,868
0
0
0.0
2002 Q4
7,722
1
1
129.5
2002 Q3
9,067
0
0
0.0
2002 Q2
8,325
0
0
0.0
2002 Q1
6,062
0
0
0.0
2001 Q4
9,753
0
0
0.0
2001 Q3
12,876
0
0
0.0
2001 Q2
12,196
0
0
0.0
2001 Q1
9,131
0
0
0.0
2000 Q4
13,535
4
0
295.5
2000 Q3
10,671
9
0
843.4
2000 Q2
13,250
0
0
0.0
2000 Q1
9,374
0
0
0.0
No fatalities recorded at this mine.
Reportable incidents
17 on file
2022 · 1 incident
April 27, 2022CA · Metal/Non-Metallaborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitmanSLIP OR FALL OF PERSON
While operating a front end loader, the operator ran over a 1' rock. This jerked him and resulted in a strain to his lower back. The Operator did not report the incident to management until 11-3-2010.
While drilling into rubber stock, the drill bit caught on the underlying surface causing drill to jerk. As a result, ee's hand was strained. On 9/14/07 he reported he was having problems with the hand & requested a medical evaluation. diagnosis required physical therapy resulting in a recordable injury.
2006 · 1 incident
September 30, 2006CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techPOWERED HAULAGE
October 25, 2005CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techSLIP OR FALL OF PERSON
As employee exited the cab of the Bobcat Skid Steer, he hit his head on the saftey bar that goes across the operators chest and stores up above the rear view mirror.
February 22, 2005CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techMACHINERY
LOADER #172 BACKED INTO #173 JARRING THE OPERATOR WITH THE SIDE IMPACT.
2000 · 1 incident
December 28, 2000CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techHANDLING OF MATERIALS
AFTER INSPECTING THE CABLE SCREEN HE TURNED TO DESCENT LOOKING THROUGH BIFOCAL GLASSES GAVE A FICTI TIOUS LOCATION OF WHERE HE WAS TO STEP THIS CAUSED HIM TO MISS THE STEP & FALL CAUSING HIM TO LAND FEET FIRST ON THE COBBLES & INJURING HIS RT FOOT & HEEL
1993 · 1 incident
January 11, 1993CA · Metal/Non-Metaloutside foreman, leadmanPOWERED HAULAGE
INJURED WAS DRIVING DOWN INTO THE PLANT AND A LOADER OPERATOR WAS DRIVING UP. DUE TO THE WHITE-OUT CONDITIONA ND SUN LIGHT THE LOADER OPERATOR, COULD NOT SEE INJURED. THE LOADER HIT INJURED' S VEHICLE ON THE DRIVER'S SIDE, CAUSIGN HIM TO HIT HIS HEAD ON THE STEERING WHEEL. HEW AS KNOCKED OUT FOR A FEW SECONDS AND RECEIVED A CUT ON HIS NOSE. NO MEDICAL TREAMENT WAS NEEDED.
WHILE PUTTING THE SHIM ON THE BAR UNDER THE PILLOW BLOCK BEARING, THE BLOCK FELL ON HIS RIGHT HAND INDEX FINGER.
1989 · 1 incident
February 23, 1989CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techHANDLING OF MATERIALS