MSHA DATABASEMSHA records · 12 contributing sources · snapshot Oct 18, 2026

MINE DETAILS

FLAT ROCK QUARRY

ActiveSurfaceDimension Limestone
MSHA MINE ID3304375
LOCATIONSeneca, OH
PUBLIC RECORD407 linked rows

LOCATION

Mine location

1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.

Mine coordinates

2025-01-01 – 2026-10-18Applies to production, safety and portfolio metrics. Silica samples have separate filters.

Violations

2

0 significant & substantial (S&S)

  1. 2025 Q10
  2. 2025 Q20
  3. 2025 Q31
  4. 2025 Q40
  5. 2026 Q11
  6. 2026 Q20
  7. 2026 Q30
  8. 2026 Q4 *0

Accident records

0

0 records classified as fatality

  1. 2025 Q10
  2. 2025 Q20
  3. 2025 Q30
  4. 2025 Q40
  5. 2026 Q10
  6. 2026 Q20
  7. 2026 Q30
  8. 2026 Q4 *0

Proposed penalties · USD

302.00

2 of 2 violations with amounts

  1. 2025 Q1—
  2. 2025 Q2—
  3. 2025 Q3151
  4. 2025 Q4—
  5. 2026 Q1151
  6. 2026 Q2—
  7. 2026 Q3—
  8. 2026 Q4 *—

On-site inspection hours

48.25

4 inspections · 4 with hours

  1. 2025 Q18.50
  2. 2025 Q2—
  3. 2025 Q37.75
  4. 2025 Q4—
  5. 2026 Q111.50
  6. 2026 Q2—
  7. 2026 Q320.50
  8. 2026 Q4 *—
Quarterly safety data
QuarterViolationsS&SProposed USDAccident recordsFatality recordsInspectionsOn-site hours
2025-Q100—0018.5
2025-Q200—000—
2025-Q310151.000017.8
2025-Q400—000—
2026-Q110151.0000111.5
2026-Q200—000—
2026-Q300—00120.5
2026-Q4 *00—000—

Most cited CFR sections

All violations issued in the selected period. Counts combine subsections.

Safety activity

    No matching records in this period.

    Safety sources and definitions

    MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-18.

    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.

    CURRENT HIERARCHYThomas Milligan → Western Ohio Cut Stone LLC → FLAT ROCK QUARRY
    HISTORY RECORDS26 relationships
    INTERVAL CHECKPASScontroller/operator overlap
    —

    Thomas MilligancontrolsWestern Ohio Cut Stone LLCoperatesFLAT ROCK QUARRY

    msha-controller-operator-history · controller/operator co-tenure derived on mine 3304375
    —

    Franklin HammondcontrolsF Hammond Rubble Stone SuppliesoperatesFLAT ROCK QUARRY

    msha-controller-operator-history · controller/operator co-tenure derived on mine 3304375
    Other 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 / SAFETYneutral

    Accidents and injuries

    5 historical accident/injury rows; 0 coded fatalities and 135 lost days across the published record.

    ACCIDENT + INJURY RECORD0 since 2021
    accidentsmine-production-quarterly
    02 / COMPLIANCEwatch

    Violations and penalties

    48 violation rows across the full record; 12 carry an S&S flag and $6,306 appears in current assessed amounts.

    ENFORCEMENT ACTIVITY11 since 2021
    inspectionsviolationsassessed-violationsorders-107a
    03 / HEALTHcontext

    Occupational health samples

    36 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 EXPOSURE36 samples
    personal-health-samples
    04 / PRODUCTIONcontext

    Quarterly production and employment

    3K employee hours and 6 summed average employees across reported subunits in the latest published quarter.

    2026-Q20 tons
    mine-production-quarterlymine-production-yearly
    05 / LEGALwatch

    Contests, conferences and decisions

    4 contested-violation rows, 4 civil-penalty docket/decision rows, and 0 conference records linked by issuance number.

    POST-ISSUANCE LIFECYCLE8 linked rows
    conferencescontested-violationscivil-penalty-dockets-decisions
    06 / 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 CONTEXT0 linked entities
    contractor-production-quarterlycontractor-production-yearlyaccidentsviolations
    07 / INSPECTIONScontext

    Inspections

    53 inspection events and 705 published inspection hours across the historical record.

    OVERSIGHT COVERAGE14 since 2021
    inspectionsviolations

    HEALTH SAMPLING

    Silica and quartz

    Matching records20 coal · 2 personal · 0 area
    Sample status0 not voided0 voided · 2 status not reported
    Personal samples with C/E > 102 published ratios · not a citation count
    2026 · Sep 16, 2026–Sep 16, 2026
    Date / sampleDataset / analyteOccupation / areaMeasurementSample statusPublished action
    000000202603836500Metal/nonmetal personalQuartz, respirable, >1% QtzFront-end Loader Operator0.4× published limitConcentration: 0000.67 · limit: 0001.67Source unit unspecifiedNot reportedNO ACTIONInspection F02BDE7
    000000202603836400Metal/nonmetal personalQuartz, respirable, >1% QtzFront-end Loader Operator0× published limitConcentration: 0000.14 · limit: 0000.00Source unit unspecifiedNot reportedNO ACTIONInspection F02BDE7
    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.

    RECENT PUBLIC RECORDS

    Recent violations and samples

    Latest records retained for inspection; aggregates above use the full source history.

    VIOLATIONS12 latest shown
    507661756.12028Citation
    507094756.14100(c)Citation
    980531856.14112(b)Citation
    980531756.4201(a)(1)Citation
    985452256.14207Citation
    985452156.9300(b)Citation
    971882056.4104(b)Citation
    971400556.14112(b)Citation
    OTHER HEALTH SAMPLES4 latest shown

    Coal dust, noise and other contaminants. Silica records above ↑

    Nuisance dust, total, <1% QtzUtility Man
    C/E: 00.14Concentration: 0001.35 · limit: 0010.00Source unit unspecified
    Respirable dust, <.1mgForklift Operator
    C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
    Nuisance dust, respirable, <1% QtzUtility Man
    C/E: 00.02Concentration: 0000.24 · limit: 0010.00Source unit unspecified
    Respirable dust, <.1mgFront-end Loader Operator
    C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified

    SOURCE COVERAGE

    Reporting dates and coverage

    12 datasets contain linked records. Missing datasets are listed below.

    DATASETROWSWINDOWSTATUS
    Accident, Injuries, and Illnessessafety · contractors5Oct 20, 2009—Dec 7, 2016mine-keyed
    Addresses of Recordidentity · logistics1Oct 1, 2014—Oct 1, 2014mine-keyed
    Assessed Violationscompliance · legal48Jun 14, 2000—Jan 7, 2026mine-keyed
    Civil Penalty Dockets and Decisionscompliance · legal4Apr 14, 2014—Dec 3, 2020mine-keyed
    Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
    Conferencescompliance · legal—No published rowsabsent / not applicable
    Contested Violationscompliance · legal4Oct 30, 2013—Jun 17, 2020mine-keyed
    Contractor Employment and Production — Quarterlycontractors · production · safety—No published rowsabsent / not applicable
    Contractor Employment and Production — Yearlycontractors · production · safety—No published rowsabsent / not applicable
    Controller and Operator Historyidentity · compliance2Jun 1, 1996—Aug 21, 2009mine-keyed
    Mine Employment and Production — Quarterlyproduction · safety · compliance167Not published—Not publishedmine-keyed
    Mine Employment and Production — Yearlyproduction · safety · compliance38Not published—Not publishedmine-keyed
    Inspectionssafety · compliance53Jun 14, 2000—Sep 14, 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 · safety36Nov 17, 2004—Sep 16, 2026mine-keyed
    Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
    Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
    Violationscompliance · safety · legal48Jun 14, 2000—Jan 7, 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.