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: 715 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
CORUNNA PLANT has $5K in proposed MSHA penalties and $0 outstanding across 0 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.
$5K
proposed penalties
$5K
current assessed
$5K
paid to date
$0
outstanding
51 assessments are final orders; 0 contested dockets.
As of the most recent assessment on 2022-12-15.
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.
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: 2021-01-07, 5 years ago
33%
of limit-tested samples over the exposure limit
12
samples
3
limit-tested
Most sampled contaminants
Quartz, respirable, >1% Qtz31 over
Respirable dust, <.1mg7
Unlisted Particulate, respirable, <1% Qtz2
Show the individual readings (12)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2005-01-20
Quartz, respirable, >1% Qtz
1.69
0.95
1.78
Dry Screen Plant Operator
2021-01-07
Respirable dust, <.1mg
0
Bulldozer Operator
2021-01-07
Respirable dust, <.1mg
0
Truck Driver
2021-01-07
Respirable dust, <.1mg
0
Truck Driver
2018-09-25
Respirable dust, <.1mg
0
Truck Driver
2018-09-25
Respirable dust, <.1mg
0
Bulldozer Operator
2013-01-23
Unlisted Particulate, respirable, <1% Qtz
0.17
Front-end Loader Operator
2013-01-23
Unlisted Particulate, respirable, <1% Qtz
0.2
Mechanic
2013-01-23
Respirable dust, <.1mg
0
Front-end Loader Operator
2005-07-26
Quartz, respirable, >1% Qtz
0.72
0.81
0.89
Dry Screen Plant Operator
2003-03-07
Respirable dust, <.1mg
0
Front-end Loader Operator
2003-03-07
Quartz, respirable, >1% Qtz
0.88
1.25
0.70
Ball Mill 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.
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year
Employees
2026
4
2025
4
2024
4
2023
4
2022
4
2021
4
2020
5
2019
5
2018
5
2017
4
2016
4
2015
4
2014
4
2013
4
2012
5
2011
4
2010
4
2009
4
2008
13
2007
4
2006
6
2005
8
2004
5
2003
5
2002
5
2001
6
2000
6
Source: MSHA quarterly employment and production, updated weekly.
CORUNNA PLANT sits in Shiawassee County, Michigan, 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.
Shiawassee County, Michigan · Population 68,061
0.1%
Mining share of county employment
$64,464
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
EMPLOYEE WAS WALKING DOWN THE SIDE BANK OF THE PIT AND STEPPED ON LOOSE MATERIAL AND TWISTED HIS KNEE. HE WAS GOING TO WORK ON A PIT PUMP. EMPLOYEE THOUGHT HIS KNEE WOULD GET BETTER ON IT'S OWN. ON 8/16/05 HE REQUESTED TO GO TO THE DOCTOR AND HE RECEIVED A PRESCRIPTION FOR THE INFLAMATION.
2004 · 2 incidents
July 1, 2004MI · Metal/Non-Metalwarehouseman, bagger, palletizer/stacker, store keeper, packager, fabricator, cleaning plant operatorSLIP OR FALL OF PERSON