Onyx Sterling Pit has $331K in proposed MSHA penalties and $308K outstanding across 1 contested dockets, plus health sampling and the full incident record.
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Fatalities
1
Total incidents
3
Years on record
2024–2026
Latest incident
Aug 2026
Compliance record
MSHA citations since 2019
66
citations
22
significant & substantial
$331,089
proposed penalties
$23,311
paid to date
7% of proposed penalties paid to date, a $307,778 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: 780 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Onyx Sterling Pit has $331K in proposed MSHA penalties and $308K 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.
$331K
proposed penalties
$331K
current assessed
$23K
paid to date
$308K
outstanding
59 assessments are final orders; 1 contested dockets.
As of the most recent assessment on 2025-04-02.
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.
5citations taken to the federal commission · 8% of citations on record
Still open
5 · 100%
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 A dismissed or defaulted contest leaves the citation standing as issued; a vacated or withdrawn citation is removed from the violation record.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 2025-03-26.
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: 2024-02-21
3
samples
0
limit-tested
Most sampled contaminants
Respirable dust, <.1mg3
Show the individual readings (3)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2024-02-21
Respirable dust, <.1mg
0
Backhoe Operator
2019-05-15
Respirable dust, <.1mg
0
Backhoe Operator
2019-05-15
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.
Onyx Sterling Pit recorded 0.00 reportable injury cases per 100 full-time workers in 2025.
Injury rate, 2025
ⓘ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.
0.00
total case rate
0.00
days-away rate
0.000
fatality rate
Below average. The US metal and nonmetal mining average was 1.65 and the all-US-mining average was 1.97 cases per 100 workers.
In Massachusetts, metal and nonmetal mining averaged 2.42 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
2025 *
0.00
0.00
0.000
2024 *
5.53
5.53
5.531
2023 *
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
11
2025
14
2024
13
2023
9
2022
8
2021
6
2020
10
2019
8
Source: MSHA quarterly employment and production, updated weekly.
Onyx Sterling Pit sits in Worcester County, Massachusetts, where the Census mining category is 0.0% 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.
Worcester County, Massachusetts · Population 861,664
0.0%
Mining share of county employment
$93,561
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
Onyx Corporation · Caught in, under or between collapsing material or buildings
A miner died when a highwall collapsed on the excavator the miner was operating.
Reportable incidents
2 on file (excluding fatalities above)
2026 · 2 incidents
August 19, 2026MA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techHANDLING OF MATERIALS
A mechanic working in the garage reported having some dirt in EE's eye. EE was not able to state a specific event on how the dirt got into EE's eye. After flushing the eye out, an appointment with an eye doctor was made so EE could be evaluated. It was determined that EE has a minor scratch on the eye and was prescribed antibiotic eye ointment.
April 6, 2026MA · Metal/Non-Metallaborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitmanSLIP OR FALL OF PERSON
EE had a knee injury that was exacerbated as EE was walking through the garage after putting oil canisters away in a conex box behind the garage. EE felt a tweak in EE's left knee as EE stepped. On Wednesday 4/8/26 at approx 1PM, this injury was reported to have happened at work, and that it originated while shoveling one month prior near the scalper screen.