MOBILE CRUSHER #3 FRONTERA MATERIALS has $179K in proposed MSHA penalties and $0 outstanding across 4 contested dockets, plus health sampling and the full incident record.
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Fatalities
2
Total incidents
5
Years on record
2003–2024
Latest incident
Jul 2024
Compliance record
MSHA citations since 2001
203
citations
67
significant & substantial
$178,711
proposed penalties
$146,315
paid to date
82% of proposed penalties paid to date, a $32,396 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.
203 citations across 1,418 inspection hours.
Source: MSHA inspections data, updated weekly.
MOBILE CRUSHER #3 FRONTERA MATERIALS has $179K in proposed MSHA penalties and $0 outstanding across 4 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.
$179K
proposed penalties
$146K
current assessed
$146K
paid to date
$0
outstanding
192 assessments are final orders; 4 contested dockets.
Of $98K in penalties contested before the Commission, $66K was upheld in final decisions.
As of the most recent assessment on 2026-01-13.
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 · 3% of citations on record
Settled
6 · 100%
100%
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 Vacated and withdrawn citations, and settlements that removed the designation, count against.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 4 decided S&S contests · industry: 79%
33%
Penalty reduction in decided contests
$98K proposed, $66K 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 2025-03-10.
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: 2024-07-17
9%
of limit-tested samples over the exposure limit
22
samples
11
limit-tested
Most sampled contaminants
Quartz, respirable, >1% Qtz111 over
Respirable dust, <.1mg9
Nuisance dust, respirable, <1% Qtz2
Show the individual readings (22)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2009-09-16
Quartz, respirable, >1% Qtz
1.04
0.49
2.12
Crusher Oper/Worker
2024-07-17
Respirable dust, <.1mg
0
Crusher Oper/Worker
2024-07-17
Respirable dust, <.1mg
0
Crusher Oper/Worker
2023-02-01
Respirable dust, <.1mg
0
Crusher Oper/Worker
2023-02-01
Quartz, respirable, >1% Qtz
0.15
0.85
0.18
Crusher Oper/Worker
2021-03-31
Respirable dust, <.1mg
0
Screen/Scalper Operator
2021-03-31
Quartz, respirable, >1% Qtz
0.15
Front-end Loader Operator
2021-03-31
Quartz, respirable, >1% Qtz
0.32
1.03
0.31
Crusher Oper/Worker
2021-03-31
Quartz, respirable, >1% Qtz
0.16
Crusher Oper/Worker
2017-07-19
Respirable dust, <.1mg
0
Dry Screen Plant Operator
2017-07-19
Respirable dust, <.1mg
0
Front-end Loader Operator
2017-07-19
Quartz, respirable, >1% Qtz
0.14
0.49
0.29
Dry Screen Plant Operator
2017-07-19
Respirable dust, <.1mg
0
Truck Driver
2012-12-13
Quartz, respirable, >1% Qtz
0.56
2.4
0.23
Scraper Operator
2012-12-13
Quartz, respirable, >1% Qtz
0.17
0.42
0.40
Crusher Oper/Worker
2010-01-06
Respirable dust, <.1mg
0
Crusher Oper/Worker
2009-09-16
Quartz, respirable, >1% Qtz
0.77
0.78
0.99
Scraper Operator
2001-12-19
Quartz, respirable, >1% Qtz
0.22
1.74
0.13
Scraper Operator
2001-12-19
Nuisance dust, respirable, <1% Qtz
0.28
10
0.03
Scraper Operator
2001-12-19
Respirable dust, <.1mg
0
Front-end Loader Operator
2001-12-19
Nuisance dust, respirable, <1% Qtz
0.13
10
0.01
Front-end Loader Operator
2001-12-19
Quartz, respirable, >1% Qtz
0.44
1.5
0.29
Scraper 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.
MOBILE CRUSHER #3 FRONTERA MATERIALS 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 Texas, metal and nonmetal mining averaged 1.17 cases per 100 workers that year.
Year
total case rate
days-away
fatal
2025
0.00
0.00
0.000
2024
1.66
1.66
1.664
2023
0.00
0.00
0.000
2022
0.00
0.00
0.000
2021
1.84
1.84
1.838
2020
0.00
0.00
0.000
2019 *
0.00
0.00
0.000
2018 *
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
38
2025
38
2024
39
2023
40
2022
37
2021
38
2020
33
2019
25
2018
24
2017
25
2016
23
2015
20
2014
18
2013
17
2012
16
2011
16
2010
19
2009
16
2008
14
2007
14
2006
14
2005
8
2004
5
2003
15
2002
11
2001
9
Source: MSHA quarterly employment and production, updated weekly.
MOBILE CRUSHER #3 FRONTERA MATERIALS sits in Hidalgo County, Texas, where the Census mining category is 1.8% 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.
Hidalgo County, Texas · Population 880,921
1.8%
Mining share of county employment
$52,281
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
An over the road truck driver was crushed while trying to unload gravel. Driver was parked in a jackknife position while trying to unload some of the gravel in EE's bed. While attempting to dump, EE's lift cylinder snapped and the trucks trailer fell on top of the driver's side killing the driver. 911 was called immediately and MSHA was called after.
Miner left haul truck running without setting the parking brake and/or chocking the wheels. The haul truck rolled forward and pinned the miner between the haul truck and miner's personal vehicle. Miner did not survive miner's injury.
Reportable incidents
3 on file (excluding fatalities above)
2024 · 1 incident
July 18, 2024TX · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techMACHINERY
EE made contact with an exposed fan blade on a generator motor as EE was diagnosing the engine for repairs. Guarding had been removed prior to the day of incident.
2011 · 1 incident
May 6, 2011TX · Metal/Non-Metalrotary bucket excavator operatorMACHINERY
EE WAS STANDING GUARD OUTSIDE CRUSHER WHILE WELDER WAS INSIDE DOING REPAIRS, WHEN WELDER SAW HIM HOLDING ON TO THE HANDRAILS AND THEN SAW HIM COLLAPSE ON THE GROUND. CPR WAS ADMINISTERED BUT HAD NO RESPONSE.