MINE DETAILS
Knoxville Mine
MSHA MINE ID1302217
LOCATION
Mine location
1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.
Mine coordinates
- Knoxville Mine41.27000, -93.10806Open map ↗
Quarterly trends
2025 Q1 – 2026 Q4
Database snapshot · 2026-10-13. MSHA quarterly production and employment reports.
Coal production
0reported short tons
Hours worked
41,489reported employee hours
Tons per hour
0.00production ÷ hours worked
Missing values appear as —. Totals use available reports. Tons per hour requires production and hours for the same quarters and a nonzero hours total. * Striped bars mark partial mine coverage or an incomplete quarter. See the table for coverage.
Quarterly data and reporting coverage
| Quarter | Coal (short tons) | Hours worked | Tons / hour | Avg. employees | Coverage |
|---|---|---|---|---|---|
| 2025 Q1 | 0 | 12,690 | 0.00 | 21 | 1/1 mines reporting |
| 2025 Q2 | 0 | 15,752 | 0.00 | 27 | 1/1 mines reporting |
| 2025 Q3 | 0 | 6,431 | 0.00 | 13 | 1/1 mines reporting |
| 2025 Q4 | 0 | 3,851 | 0.00 | 11 | 1/1 mines reporting |
| 2026 Q1 | 0 | 2,765 | 0.00 | 5 | 1/1 mines reporting |
| 2026 Q2 | — | — | — | — | No report |
| 2026 Q3 | — | — | — | — | No report |
| 2026 Q4 | — | — | — | — | No report |
Safety and enforcement
2025-01-01 – 2026-10-13
Violations
204 significant & substantial (S&S)
Accident records
30 records classified as fatality
Proposed penalties · USD
5,184.0019 of 20 violations with amounts
On-site inspection hours
146.7510 inspections · 10 with hours
Counts are published records, including contractor records. * The quarter was incomplete at the snapshot date; recent counts may rise as reports arrive. — means no reported amount or hours. Portfolio totals use current membership.
Quarterly safety data
| Quarter | Violations | S&S | Proposed USD | Accident records | Fatality records | Inspections | On-site hours |
|---|---|---|---|---|---|---|---|
| 2025-Q1 | 6 | 2 | 2,234.00 | 0 | 0 | 4 | 42.3 |
| 2025-Q2 | 5 | 0 | 604.00 | 3 | 0 | 2 | 54.8 |
| 2025-Q3 | 1 | 0 | 151.00 | 0 | 0 | 2 | 5.0 |
| 2025-Q4 | 8 | 2 | 2,195.00 | 0 | 0 | 1 | 38.3 |
| 2026-Q1 | 0 | 0 | — | 0 | 0 | 1 | 6.5 |
| 2026-Q2 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2026-Q3 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2026-Q4 * | 0 | 0 | — | 0 | 0 | 0 | — |
Most cited CFR sections
All violations issued in the selected period. Counts combine subsections.
Safety activity
Regular Safety and Health Inspection · 6.5 on-site hours
57.14101(a)(2) · $151.00 proposed
57.8520 · $151.00 proposed
57.4363(d) · $151.00 proposed
57.4361(a) · S&S · $959.00 proposed
57.3200 · S&S · $288.00 proposed
57.6160(a)(2) · $151.00 proposed
57.3200 · $151.00 proposed
57.11053(a) · $193.00 proposed
Regular Safety and Health Inspection · 38.3 on-site hours
Spot Inspection · 0.0 on-site hours
50.20-1 · $151.00 proposed
Regular Safety and Health Inspection · 5.0 on-site hours
FALL OF ROOF OR BACK · DAYS AWAY FROM WORK ONLY
Accident narrative
The underground mine had a cave-in and employee is experiencing ringing of the left ear and headaches caused by the loud noise and air pressure.
FALL OF ROOF OR BACK · DAYS AWAY FROM WORK ONLY
Accident narrative
The underground mine had a cave-in and the employee is experiencing ringing in the left ear and headaches caused by the loud noise and air pressure.
FALL OF ROOF OR BACK · ACCIDENT ONLY
Accident narrative
An unplanned cave-in / release of material occurred underground during the second shift. During the second shift employees were loading shot rock and transporting to surface storage area when employees heard material falling and an accumulation of dust appeared in their area.
Non-Fatal Accident Investigation · 28.0 on-site hours
Description not reported
57.14207 · $151.00 proposed
56.14112(a) · $151.00 proposed
Regular Safety and Health Inspection · 26.8 on-site hours
56.14112(a) · $151.00 proposed
57.4102 · $151.00 proposed
Verbal Hazard Complaint Inspections · 3.3 on-site hours
103 (g) Written Notification Hazard Complaint Inspectio · 3.5 on-site hours
Safety sources and definitions
MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-13.
Counts describe published rows, including contractor records; accident records are not distinct incidents or numbers of people injured.
Zero means no matching records in the imported sources, not proof of no events. Historical coverage differs by source; absence before a source begins reporting is not a zero incident rate. Invalid or absent dates and records after the snapshot are excluded.
S&S means SIG_SUB=Y. Fatality records use DEGREE_INJURY_CD=01. Proposed penalties are not final assessed or paid amounts; missing dollar values are omitted.
Inspection hours are SUM_TOTAL_ON_SITE_HOURS attributed to the inspection start date, without supervisor/trainee hours. Missing hours are omitted; a started inspection may still be open.
Portfolio totals use current mine membership, including events before the current owner or operator's tenure.
CFR headings link to the current Title 30 index; they are not historical legal determinations.
OWNERSHIP
Operator and controller history
Current ownership comes from MSHA Mines. Historical start and end dates come from MSHA Controller and Operator History.
—
N R HammcontrolsNR Hamm Quarry LLCoperatesKnoxville Mine
msha-controller-operator-history · controller/operator co-tenure derived on mine 1302217—
Summit Materials LLCcontrolsNR Hamm Quarry LLCoperatesKnoxville Mine
msha-controller-operator-history · controller/operator co-tenure derived on mine 1302217—
Greg BrueningcontrolsBruening Rock Products IncoperatesKnoxville Mine
msha-controller-operator-history · controller/operator co-tenure derived on mine 1302217Other historical summaries · source-specific periods
RECORD SUMMARY
Production, safety and enforcement
These summaries use the periods stated on each card, independently of the reporting period above.
01 / SAFETYwatch
Accidents and injuries
10 historical accident/injury rows; 0 coded fatalities and 619 lost days across the published record.
ACCIDENT + INJURY RECORD3 since 2021
accidentsmine-production-quarterly02 / COMPLIANCEwatch
Violations and penalties
798 violation rows across the full record; 213 carry an S&S flag and $454,442 appears in current assessed amounts.
ENFORCEMENT ACTIVITY95 since 2021
inspectionsviolationsassessed-violationsorders-107a03 / HEALTHwatch
Occupational health samples
289 personal; 35 area. 59 personal-sample rows have a published C/E ratio above 1; 0 noise rows have an action-level or PEL dose above 100%. These are separate measures, not a silica exceedance count. Silica results and sample status are shown separately.
OCCUPATIONAL EXPOSURE324 samples
personal-health-samplesarea-samples04 / PRODUCTIONcontext
Quarterly production and employment
3K employee hours and 5 summed average employees across reported subunits in the latest published quarter.
2026-Q10 tons
mine-production-quarterlymine-production-yearly05 / LEGALwatch
Contests, conferences and decisions
110 contested-violation rows, 134 civil-penalty docket/decision rows, and 15 conference records linked by issuance number.
POST-ISSUANCE LIFECYCLE259 linked rows
conferencescontested-violationscivil-penalty-dockets-decisions06 / CONTRACTORScontext
Contractors
Contractors are linked through this mine’s violation or accident records. Their production and hours cover all their operations, so they are not included in this mine’s totals.
ENTITY-LEVEL CONTEXT8 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations07 / INSPECTIONScontext
Inspections
214 inspection events and 5K published inspection hours across the historical record.
OVERSIGHT COVERAGE38 since 2021
inspectionsviolationsHEALTH SAMPLING
Silica and quartz
Coal quartz, metal/nonmetal personal samples and area samples. Snapshot Oct 13, 2026. 26 silica records across the mine’s published history.
Personal silica samples · concentration / limit
Quarterly mean · published C/E ratio
— No eligible measurements. * Quarter in progress. Means describe the available samples, not average exposure across the mine.
Quartz % is the sample’s quartz content; µg/m³ is its reported concentration. Personal C/E is the ratio to the limit published with that sample. Personal and area concentration units and void status are not specified in those source files.
| Date / sample | Dataset / analyte | Occupation / area | Measurement | Sample status | Published action |
|---|---|---|---|---|---|
| No silica records match these filters. Missing samples do not establish safe conditions. | |||||
Sources and interpretation
- Coal means use numeric concentrations from samples marked not voided, excluding control/invalid sample types and dates after the snapshot. Missing values remain null; reported zeroes remain zero.
- Quarterly means describe available samples, not mine-wide or worker-average exposure. Quarters with no eligible measurements remain empty; the current quarter is partial.
- Personal C/E is MSHA's published concentration-to-limit ratio. A value above 1 is not by itself a citation or a determination under the 2024 silica rule. Personal and area files do not publish a void-status field.
- Area records include bulk-dust analyses and are kept separate from personal exposure results. Their concentration units are not specified in the source dictionary.
- Missing samples do not establish safe conditions. Coal quartz percentage and concentration are separate measures. No compliance threshold is inferred for coal samples.
Coal quartz field definitions ↗Metal/nonmetal personal field definitions ↗Metal/nonmetal area field definitions ↗
EIA + TITLE 30
EIA production and cited regulations
EIA annual figures are reported separately from MSHA. Regulation links use the current eCFR snapshot.
Not present in the 2024 EIA coal workbook.
This can mean the operation is non-coal, inactive for the annual period, or outside the EIA-7A reporting population.
30 CFR 57.14101Brakes.1 recent row ↗30 CFR 57.8520Ventilation plan.1 recent row ↗30 CFR 57.4363Underground evacuation instruction.1 recent row ↗30 CFR 57.4361Underground evacuation drills.1 recent row ↗30 CFR 57.3200Correction of hazardous conditions.2 recent rows ↗30 CFR 57.6160Main facilities.1 recent row ↗30 CFR 57.11053Escape and evacuation plans.1 recent row ↗30 CFR 50.20-1General instructions for completing MSHA Form 7000-1.1 recent row ↗
RECENT PUBLIC RECORDS
Recent violations and samples
Latest records retained for inspection; aggregates above use the full source history.
511390157.14101(a)(2)Citation
511390057.8520Citation
511389957.4363(d)Citation
511389857.4361(a)S&S
511389757.3200S&S
511389657.6160(a)(2)Citation
511389557.3200Citation
511389457.11053(a)Citation
Coal dust, noise and other contaminants. Silica records above ↑
Respirable dust, <.1mgTruck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgTruck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
TC from EC @ 160Scaling (mechanical)
C/E: 00.00Concentration: 0000.00 · limit: 0160.00Source unit unspecified
TC @ 160Scaling (mechanical)
C/E: 00.00Concentration: 0000.00 · limit: 0160.00Source unit unspecified
ORGANIC CARBONScaling (mechanical)
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
EC @ 160Scaling (mechanical)
C/E: 00.00Concentration: 0000.00 · limit: 0160.00Source unit unspecified
TC from EC @ 160Drill Operator, Jumbo Perc.
C/E: 00.00Concentration: 0000.00 · limit: 0160.00Source unit unspecified
TC @ 160Drill Operator, Jumbo Perc.
C/E: 00.47Concentration: 0075.00 · limit: 0160.00Source unit unspecified
SOURCE COVERAGE
Reporting dates and coverage
16 datasets contain linked records. Missing datasets are listed below.
DATASETROWSWINDOWSTATUS
Accident, Injuries, and Illnessessafety · contractors10Jan 7, 2000—Jun 25, 2025mine-keyed
Addresses of Recordidentity · logistics1May 28, 2026—May 28, 2026mine-keyed
Assessed Violationscompliance · legal780Mar 29, 2000—Dec 16, 2025mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal134Nov 26, 2001—Feb 28, 2022mine-keyed
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal15Jun 2, 2000—Sep 25, 2019mine-keyed
Contested Violationscompliance · legal110Jun 13, 2005—Apr 20, 2021mine-keyed
Contractor Employment and Production — Quarterlycontractors · production · safety1,794Not published—Not publishedentity-linked
Contractor Employment and Production — Yearlycontractors · production · safety350Not published—Not publishedentity-linked
Controller and Operator Historyidentity · compliance3Mar 1, 1998—Nov 25, 2024mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance303Not published—Not publishedmine-keyed
Mine Employment and Production — Yearlyproduction · safety · compliance70Not published—Not publishedmine-keyed
Inspectionssafety · compliance214Mar 29, 2000—Feb 23, 2026mine-keyed
Minesidentity · production · logistics1Not published—Not publishedmine-keyed
Metal and Nonmetal Area Sampleshealth · safety35Aug 13, 2009—May 7, 2025mine-keyed
Metal and Nonmetal Personal Health Sampleshealth · safety289Nov 20, 2002—Dec 17, 2025mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal798Mar 29, 2000—Dec 16, 2025mine-keyed
107(a) Orders Issuedsafety · compliance—No published rowsabsent / not applicable
NOTES
Limitations
- Contractor production is entity-level and is never represented as mine-attributable.
- Missing rows can mean no event, publication delay, identity mismatch, or inapplicability.