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Sioux Rock Quarry: 7 MSHA citations Metal/Non-Metal

Comfery, Brown County, MN  ·  Intermittent
MSHA Mine ID: 2103504

Sioux Rock Quarry has $598 in proposed MSHA penalties and $0 outstanding across 1 contested dockets, plus health sampling and the full incident record.

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Fatalities
0
Total incidents
1
Years on record
2015
Latest incident
Jan 2015
Compliance record
MSHA citations since 2005
7
citations
0
significant & substantial
$598
proposed penalties
$598
paid to date
100% of proposed penalties paid to date, a $0 gap.
Source: MSHA violations data, updated weekly.
See Martin Marietta Materials Inc.'s full MSHA compliance history →
Inspection activity
MSHA inspections since 2005
24
inspections on record
186
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: 186 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.

Sioux Rock Quarry has $598 in proposed MSHA penalties and $0 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.
$598
proposed penalties
$598
current assessed
$598
paid to date
$0
outstanding
7 assessments are final orders; 1 contested dockets.
Of $100 in penalties contested before the Commission, $0 was upheld in final decisions.
As of the most recent assessment on 2018-05-07.
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.
0.0%
significant & substantial
42.9%
high negligence or reckless
0.0%
reasonably likely or greater
71.4%
permanently disabling or fatal if injury occurs
Negligence coding: 0.0% none, 28.6% low, 28.6% moderate, 42.9% 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.
1 citations taken to the federal commission · 14% of citations on record
  • Vacated or withdrawn 1 · 100%
100%
Penalty reduction in decided contests
$100 proposed, $0 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 2009-09-28.
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
LAKE 2009-747M Withdrawal Lesnick 2010 $100 → $0
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: 2025-09-23
4
samples
0
limit-tested
Most sampled contaminants
  • Respirable dust, <.1mg4
Show the individual readings (4)
Date Contaminant Concentration Limit Conc / limit Occupation
2025-09-23 Respirable dust, <.1mg 0 Utility Man
2018-05-23 Respirable dust, <.1mg 0 Front-end Loader Operator
2014-11-05 Respirable dust, <.1mg 0 Front-end Loader Operator
2012-04-03 Respirable dust, <.1mg 0 Washer 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. Southern Minnesota Construction Company, Inc. 2005 to 2008
  2. Minnesota Paving & Materials 2008 to 2026
  3. Martin Marietta Materials Inc. 2026 to present
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year Employees
2026 3
2025 1
2020 2
2019 2
2018 1
2017 1
2016 1
2015 1
2014 2
2013 2
2012 2
2011 2
2010 2
2009 2
2008 3
2007 2
2006 2
2005 2
Source: MSHA quarterly employment and production, updated weekly.

Sioux Rock Quarry sits in Brown County, Minnesota, 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.
Brown County, Minnesota · Population 25,826
0.1%
Mining share of county employment
$68,690
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 549 0 0 0.0
2026 Q1 0 0 0
2025 Q4 0 0 0
2025 Q3 146 0 0 0.0
2020 Q4 173 0 0 0.0
2020 Q3 331 0 0 0.0
2020 Q2 420 0 0 0.0
2020 Q1 35 0 0 0.0
Show 58 earlier quarters
Quarter Hours worked Citations S&S Per 1M hrs
2019 Q4 119 0 0 0.0
2019 Q3 303 0 0 0.0
2019 Q2 363 0 0 0.0
2019 Q1 43 0 0 0.0
2018 Q4 74 0 0 0.0
2018 Q3 369 0 0 0.0
2018 Q2 446 1 0 2242.2
2018 Q1 0 0 0
2017 Q4 74 0 0 0.0
2017 Q3 584 0 0 0.0
2017 Q2 763 0 0 0.0
2017 Q1 108 0 0 0.0
2016 Q4 285 0 0 0.0
2016 Q3 441 0 0 0.0
2016 Q2 367 0 0 0.0
2016 Q1 152 0 0 0.0
2015 Q4 120 0 0 0.0
2015 Q3 314 0 0 0.0
2015 Q2 366 0 0 0.0
2015 Q1 0 0 0
2014 Q4 174 0 0 0.0
2014 Q3 1,553 0 0 0.0
2014 Q2 1,603 0 0 0.0
2014 Q1 0 0 0
2013 Q4 1,176 0 0 0.0
2013 Q3 978 0 0 0.0
2013 Q2 1,047 0 0 0.0
2013 Q1 80 1 0 12500.0
2012 Q4 282 0 0 0.0
2012 Q3 944 0 0 0.0
2012 Q2 788 0 0 0.0
2012 Q1 246 0 0 0.0
2011 Q4 747 0 0 0.0
2011 Q3 648 0 0 0.0
2011 Q2 572 0 0 0.0
2011 Q1 1 0 0 0.0
2010 Q4 413 0 0 0.0
2010 Q3 802 0 0 0.0
2010 Q2 715 0 0 0.0
2010 Q1 170 0 0 0.0
2009 Q4 204 0 0 0.0
2009 Q3 525 2 0 3809.5
2009 Q2 262 0 0 0.0
2009 Q1 1 0 0 0.0
2008 Q4 164 0 0 0.0
2008 Q3 201 0 0 0.0
2008 Q2 161 0 0 0.0
2008 Q1 188 0 0 0.0
2007 Q4 321 0 0 0.0
2007 Q3 1,006 0 0 0.0
2007 Q2 302 0 0 0.0
2007 Q1 1 0 0 0.0
2006 Q4 624 0 0 0.0
2006 Q3 775 0 0 0.0
2006 Q2 1,495 0 0 0.0
2006 Q1 1 0 0 0.0
2005 Q4 241 0 0 0.0
2005 Q3 361 3 0 8310.2
No fatalities recorded at this mine.

Reportable incidents

1 on file

2015 · 1 incident

January 5, 2015 MN · Metal/Non-Metal warehouseman, bagger, palletizer/stacker, store keeper, packager, fabricator, cleaning plant operator DISORDERS (REPEATED TRAUMA)
Minnesota Paving & Materials · (Not Elsewhere Classified)

Recordable hearing loss.