MINE DETAILS
3M CORONA PLANT
MSHA MINE ID0400191
LOCATION
Mine location
1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.
Mine coordinates
- 3M CORONA PLANT33.84833, -117.51194Open map ↗
Quarterly trends
2025 Q1 – 2026 Q4
Database snapshot · 2026-10-17. MSHA quarterly production and employment reports.
Coal production
—reported short tons
Hours worked
—reported employee hours
Tons per hour
—production ÷ 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 | — | — | — | — | No report |
| 2025 Q2 | — | — | — | — | No report |
| 2025 Q3 | — | — | — | — | No report |
| 2025 Q4 | — | — | — | — | No report |
| 2026 Q1 | — | — | — | — | No report |
| 2026 Q2 | — | — | — | — | No report |
| 2026 Q3 | — | — | — | — | No report |
| 2026 Q4 | — | — | — | — | No report |
Safety and enforcement
2025-01-01 – 2026-10-17
Violations
357 significant & substantial (S&S)
Accident records
60 records classified as fatality
Proposed penalties · USD
23,607.0034 of 35 violations with amounts
On-site inspection hours
95.7513 inspections · 13 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 | 11 | 0 | 2,373.00 | 2 | 0 | 2 | 15.0 |
| 2025-Q2 | 1 | 0 | 177.00 | 0 | 0 | 1 | 10.0 |
| 2025-Q3 | 7 | 4 | 6,412.00 | 0 | 0 | 2 | 24.8 |
| 2025-Q4 | 4 | 3 | 10,743.00 | 1 | 0 | 2 | 11.0 |
| 2026-Q1 | 5 | 0 | 2,184.00 | 0 | 0 | 2 | 12.0 |
| 2026-Q2 | 6 | 0 | 1,718.00 | 2 | 0 | 2 | 10.5 |
| 2026-Q3 | 1 | 0 | — | 1 | 0 | 2 | 12.5 |
| 2026-Q4 * | 0 | 0 | — | 0 | 0 | 0 | — |
Most cited CFR sections
All violations issued in the selected period. Counts combine subsections.
Safety activity
103 (g) Written Notification Hazard Complaint Inspectio · 7.5 on-site hours
56.14112(a)(1)
Verbal Hazard Complaint Inspections · 5.0 on-site hours
STRIKING OR BUMPING · DAYS AWAY FROM WORK ONLY
Accident narrative
While cleaning pile in walkway between conveyor and elevator, the employee's left knee made contact with a machine guard on conveyor tail pulley. Upon contact, employee felt pain in left knee and was taken to the ER. Employee was given work restrictions and lost time.
HANDLING OF MATERIALS · DAYS AWAY FROM WORK ONLY
Accident narrative
A mechanic was working on a jam of an elevator flop gate. While attempting to remove the jam, the flop gate shifted under pressure and caught the mechanic's wrist. The mechanic sustained a fracture to the right wrist and possible ligament damage. The mechanic was prescribed medication and lost time.
Compliance Follow-up Inspection · 2.5 on-site hours
SLIP OR FALL OF PERSON · DAYS AWAY FROM WORK ONLY
Accident narrative
A miner was working from a ladder while applying a patch to a screener feed box. While reaching, the ladder slid, causing the miner to fall onto the ladder. The miner sustained a laceration to the right knee and a fracture of the right patella. The miner was prescribed medication and lost time.
56.14100(b) · $209.00 proposed
56.14132(a) · $209.00 proposed
56.14132(b)(1)(i) · $209.00 proposed
56.14100(b) · $465.00 proposed
56.14207 · $313.00 proposed
56.14207 · $313.00 proposed
Regular Safety and Health Inspection · 8.0 on-site hours
Compliance Follow-up Inspection · 2.0 on-site hours
56.18002(a) · $398.00 proposed
56.20003(a) · $398.00 proposed
56.15001 · $398.00 proposed
56.4200(b)(2) · $592.00 proposed
56.20003(a) · $398.00 proposed
103 (g) Written Notification Hazard Complaint Inspectio · 10.0 on-site hours
Regular Safety and Health Inspection · 10.0 on-site hours
Verbal Hazard Complaint Inspections · 1.0 on-site hours
56.11002 · S&S · $6,540.00 proposed
56.20003(a) · S&S · $1,968.00 proposed
Safety sources and definitions
MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-17.
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.
—
Minnesota Mining & Manufacturing Companycontrols3M Companyoperates3M CORONA PLANT
msha-controller-operator-history · controller/operator co-tenure derived on mine 0400191Other 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
230 historical accident/injury rows; 1 coded fatalities and 4,168 lost days across the published record.
ACCIDENT + INJURY RECORD30 since 2021
accidentsmine-production-quarterly02 / COMPLIANCEwatch
Violations and penalties
789 violation rows across the full record; 168 carry an S&S flag and $298,140 appears in current assessed amounts.
ENFORCEMENT ACTIVITY69 since 2021
inspectionsviolationsassessed-violationsorders-107a03 / HEALTHcontext
Occupational health samples
62 personal. 0 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 EXPOSURE62 samples
personal-health-samples04 / PRODUCTIONcontext
Quarterly production and employment
79K employee hours and 135 summed average employees across reported subunits in the latest published quarter.
2002-Q40 tons
mine-production-quarterlymine-production-yearly05 / LEGALwatch
Contests, conferences and decisions
84 contested-violation rows, 83 civil-penalty docket/decision rows, and 66 conference records linked by issuance number.
POST-ISSUANCE LIFECYCLE233 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 CONTEXT19 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations07 / INSPECTIONScontext
Inspections
129 inspection events and 4K published inspection hours across the historical record.
OVERSIGHT COVERAGE21 since 2021
inspectionsviolationsHEALTH SAMPLING
Silica and quartz
Coal quartz, metal/nonmetal personal samples and area samples. Snapshot Oct 17, 2026. 21 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 |
|---|---|---|---|---|---|
| 000000202600831900 | Metal/nonmetal personalQuartz, respirable, >1% Qtz | Laborer, Bullgang | 0.24× published limitConcentration: 0000.28 · limit: 0001.18Source unit unspecified | Not reported | NO ACTIONInspection F037D75 |
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 56.14112Construction and maintenance of guards.1 recent row ↗30 CFR 56.14100Safety defects; examination, correction and records.2 recent rows ↗30 CFR 56.14132Horns and backup alarms.2 recent rows ↗30 CFR 56.14207Parking procedures for unattended equipment.2 recent rows ↗30 CFR 56.18002Examination of working places.1 recent row ↗30 CFR 56.20003Housekeeping.2 recent rows ↗30 CFR 56.15001First-aid materials.1 recent row ↗30 CFR 56.4200General requirements.1 recent row ↗
RECENT PUBLIC RECORDS
Recent violations and samples
Latest records retained for inspection; aggregates above use the full source history.
516608156.14112(a)(1)Citation
516221356.14100(b)Citation
516221256.14132(a)Citation
516221156.14132(b)(1)(i)Citation
516221056.14100(b)Citation
516220956.14207Citation
516220856.14207Citation
989079856.18002(a)Citation
Coal dust, noise and other contaminants. Silica records above ↑
Vanadium dustMechanic
C/E: 00.00Concentration: 0000.00 · limit: 0500.00Source unit unspecified
Nickel dust & saltsMechanic
C/E: 00.00Concentration: 0000.00 · limit: 0001.00Source unit unspecified
Molybdenum dustMechanic
C/E: 00.00Concentration: 0000.00 · limit: 0010.00Source unit unspecified
Manganese dustMechanic
C/E: 00.00Concentration: 0000.00 · limit: 0005.00Source unit unspecified
Lead, inorganic dustMechanic
C/E: 00.00Concentration: 0000.00 · limit: 0150.00Source unit unspecified
Copper dust and mistMechanic
C/E: 00.00Concentration: 0000.00 · limit: 0001.00Source unit unspecified
Cobalt dustMechanic
C/E: 00.00Concentration: 0000.00 · limit: 0100.00Source unit unspecified
Chromium, solubleMechanic
C/E: 00.00Concentration: 0000.00 · limit: 0500.00Source unit unspecified
SOURCE COVERAGE
Reporting dates and coverage
15 datasets contain linked records. Missing datasets are listed below.
DATASETROWSWINDOWSTATUS
Accident, Injuries, and Illnessessafety · contractors230Jan 21, 2000—Jul 24, 2026mine-keyed
Addresses of Recordidentity · logistics1May 25, 1973—May 25, 1973mine-keyed
Assessed Violationscompliance · legal779Jul 27, 2000—Apr 7, 2026mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal83Sep 18, 2001—Sep 13, 2024mine-keyed
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal66Sep 8, 2000—Sep 6, 2022mine-keyed
Contested Violationscompliance · legal84Dec 14, 2000—Jan 9, 2024mine-keyed
Contractor Employment and Production — Quarterlycontractors · production · safety1,547Not published—Not publishedentity-linked
Contractor Employment and Production — Yearlycontractors · production · safety340Not published—Not publishedentity-linked
Controller and Operator Historyidentity · compliance1Jan 1, 1950—Jan 1, 1950mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance36Not published—Not publishedmine-keyed
Mine Employment and Production — Yearlyproduction · safety · compliance63Not published—Not publishedmine-keyed
Inspectionssafety · compliance129Jul 27, 2000—Sep 29, 2026mine-keyed
Minesidentity · production · logistics1Not published—Not publishedmine-keyed
Metal and Nonmetal Area Sampleshealth · safety—No published rowsabsent / not applicable
Metal and Nonmetal Personal Health Sampleshealth · safety62Aug 23, 2000—Apr 7, 2026mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal789Jul 27, 2000—Sep 29, 2026mine-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.