Carderock Quarries has $13K in proposed MSHA penalties and $453 outstanding across 23 contested dockets, plus health sampling and the full incident record.
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Fatalities
0
Total incidents
9
Years on record
1995–2013
Latest incident
Aug 2013
Compliance record
MSHA citations since 2001
98
citations
12
significant & substantial
$13,061
proposed penalties
$10,517
paid to date
81% of proposed penalties paid to date, a $2,544 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: 906 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Carderock Quarries has $13K in proposed MSHA penalties and $453 outstanding across 23 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.
$13K
proposed penalties
$11K
current assessed
$11K
paid to date
$453
outstanding
95 assessments are final orders; 23 contested dockets.
Of $10K in penalties contested before the Commission, $7K was upheld in final decisions.
As of the most recent assessment on 2026-04-22.
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.
39citations taken to the federal commission · 40% of citations on record
Settled
36 · 92%
Stood as issued
1 · 3%
Still open
2 · 5%
29%
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 Vacated and withdrawn citations, and settlements that removed the designation, count against.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 17 decided S&S contests · industry: 79%
22%
Penalty reduction in decided contests
$6K proposed, $5K 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 2026-06-30.
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: 2026-04-22
7%
of limit-tested samples over the exposure limit
24
samples
14
limit-tested
Most sampled contaminants
Quartz, respirable, >1% Qtz171 over
Respirable dust, <.1mg6
Unlisted Particulate, respirable, <1% Qtz1
Show the individual readings (24)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2011-05-11
Quartz, respirable, >1% Qtz
1.3
0.52
2.50
Stone Polisher/Cutter
2026-04-22
Respirable dust, <.1mg
0
Utility Man
2026-04-22
Quartz, respirable, >1% Qtz
0.13
Front-end Loader Operator
2026-04-22
Quartz, respirable, >1% Qtz
0.19
0.51
0.37
Stone Polisher/Cutter
2026-04-22
Quartz, respirable, >1% Qtz
0.14
Rotary Bucket Ex. Operator
2025-09-30
Respirable dust, <.1mg
0
Utility Man
2025-09-30
Quartz, respirable, >1% Qtz
0.14
0.46
0.30
Stone Polisher/Cutter
2025-09-30
Respirable dust, <.1mg
0
Forklift Operator
2025-09-30
Respirable dust, <.1mg
0
Front-end Loader Operator
2023-12-14
Quartz, respirable, >1% Qtz
0.25
0.61
0.41
Stone Polisher/Cutter
2023-12-14
Respirable dust, <.1mg
0
Stone Polisher/Cutter
2021-02-18
Quartz, respirable, >1% Qtz
0.34
0.74
0.46
Stone Polisher/Cutter
2021-02-18
Quartz, respirable, >1% Qtz
0.24
Stone Polisher/Cutter
2017-01-10
Quartz, respirable, >1% Qtz
0.12
0.92
0.13
Front-end Loader Operator
2011-07-12
Quartz, respirable, >1% Qtz
0.35
0.44
0.80
Stone Polisher/Cutter
2011-05-11
Respirable dust, <.1mg
0
Truck Driver
2011-05-11
Quartz, respirable, >1% Qtz
0.45
0.59
0.76
Stone Polisher/Cutter
2006-02-23
Unlisted Particulate, respirable, <1% Qtz
0.12
Front-end Loader Operator
2006-02-23
Quartz, respirable, >1% Qtz
0.3
0.51
0.59
Stone Polisher/Cutter
2006-02-23
Quartz, respirable, >1% Qtz
0.22
1.91
0.12
Laborer, Bullgang
2001-07-17
Quartz, respirable, >1% Qtz
0.18
0.78
0.23
Supervisor, Co. Official
2001-07-17
Quartz, respirable, >1% Qtz
0.2
0.52
0.38
Laborer, Bullgang
2001-07-17
Quartz, respirable, >1% Qtz
0.17
0.43
0.40
Laborer, Bullgang
2001-07-17
Quartz, respirable, >1% Qtz
0.15
0.8
0.19
Shovel 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.
Carderock Quarries 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
No reportable injury cases in any year shown. Employee-hours were reported in each of those years, so these are true zeros rather than missing data. Citations, listed in the compliance record above, are inspector-found violations and are counted separately from worker injuries.
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 Maryland, metal and nonmetal mining averaged 1.63 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 *
0.00
0.00
0.000
2023 *
0.00
0.00
0.000
2022 *
0.00
0.00
0.000
2021 *
0.00
0.00
0.000
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
25
2025
27
2024
31
2023
31
2022
29
2021
28
2020
28
2019
30
2018
29
2017
32
2016
24
2015
20
2014
21
2013
22
2012
22
2011
20
2010
22
2009
20
2008
27
2007
30
2006
29
2005
30
2004
22
2003
21
2002
22
2001
22
2000
24
Source: MSHA quarterly employment and production, updated weekly.
Carderock Quarries sits in Montgomery County, Maryland, 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.
Montgomery County, Maryland · Population 1,057,586
0.0%
Mining share of county employment
$128,733
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
While breaking stone, EE was hit in the left forearm by a foreign object, causing a laceration. No stitches were required nor time lost. However, on 9/30/13 a small metal shard was discovered at the healed wound site and removed. EE returned to work 10/14/13 at regular job at full capacity.
Miner was hand loading building stone when his L thumb was caught between 2 stones when another miner inadvertinly dropped a stone. The finger was lacerated, requiring sutures, and is fractured, requiring splinting.
August 8, 2006MD · Metal/Non-Metallaborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitmanHANDLING OF MATERIALS
Miner was hand-loading building stone, when his left thumb was pinched between 2 stones. His thumb is bruised and has a slight fracture. The Dr. splinted the thumb and instructed him not to use his left hand for one week.
EE WAS SCALING THE LEDGE WHEN HE MOVED HIS ROPE WHICH DISLODGED LOOSE MATERIAL FROM ABOVE. THIS MATERIAL KNOCKED HIS HARD HAT OFF AND A SUBSEQUENT PIECE OF FALLING MATERIAL STRUCK HIS HEAD, CAUSING A LACERATION THAT NEEDED STITCHES. FAILURE TO PROPERLY CLEAN THE ROPE'S DRAG PATH CONTRIBUTED TO THE ACCIDENT.
LACERATION LEFT INDEX FINGER. I WAS BREAKING STONE WHEN A STONE HE HAD SPLIT FELL TOWARDS HIM. IN AN ATTEMPT TO STOP IT FROM STRIKING HIS LEG, HE TRIED TO GRAB OR DEFLECT IT. THE SHARP EDGE OF THE STONE CUT THROUGH HIS GLOVE AND LACERATED AND SMASHED HIS FINGER AGAINST ANOTHER STONE.
INJURED WAS SCALING THE SOUTH FACE OF THE QUARRYSOME STONES FELL FROM ABOVE HIS LOCATION, KNOCK ING OFF HIS HARDHAT AND STRIKING HIM ON THE TOP OF THE HEAD, LACERATING HIS SCALP, REQUIRING STITCHES. MINERS FAILURE TO SCALE ABOVE WORK AREA BEFORE HAND CONTRIBUTED TO THE INQUIRY.