MINE DETAILS
Sparta, WI Plant
MSHA MINE ID4703644
LOCATION
Mine location
1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.
Mine coordinates
- Sparta, WI Plant43.92000, -90.85306Open 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
31 significant & substantial (S&S)
Accident records
10 records classified as fatality
Proposed penalties · USD
—0 of 3 violations with amounts
On-site inspection hours
66.504 inspections · 4 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 | 1 | 0 | — | 1 | 0 | 1 | 15.5 |
| 2025-Q2 | 1 | 0 | — | 0 | 0 | 1 | 18.8 |
| 2025-Q3 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2025-Q4 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2026-Q1 | 1 | 1 | — | 0 | 0 | 1 | 19.3 |
| 2026-Q2 | 0 | 0 | — | 0 | 0 | 1 | 13.0 |
| 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 · 13.0 on-site hours
56.4501 · S&S
Regular Safety and Health Inspection · 19.3 on-site hours
56.4201(a)(2)
Regular Safety and Health Inspection · 18.8 on-site hours
FIRE · ACCIDENT ONLY
Accident narrative
While operating the Volvo 550 excavator a hydraulic leak started during operation that led to a fire in the engine compartment. The operator observed the fire and safely exited the equipment.
56.11003
Regular Safety and Health Inspection · 15.5 on-site hours
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.
—
USS Holdings InccontrolsU.S.Silica Energy CompanyoperatesSparta, WI Plant
msha-controller-operator-history · controller/operator co-tenure derived on mine 4703644—
USS Holdings InccontrolsU S Silica CompanyoperatesSparta, WI Plant
msha-controller-operator-history · controller/operator co-tenure derived on mine 4703644Other 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
19 historical accident/injury rows; 0 coded fatalities and 73 lost days across the published record.
ACCIDENT + INJURY RECORD2 since 2021
accidentsmine-production-quarterly02 / COMPLIANCEwatch
Violations and penalties
41 violation rows across the full record; 9 carry an S&S flag and $6,162 appears in current assessed amounts.
ENFORCEMENT ACTIVITY9 since 2021
inspectionsviolationsassessed-violationsorders-107a03 / HEALTHwatch
Occupational health samples
49 personal; 1 area. 2 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 EXPOSURE50 samples
personal-health-samplesarea-samples04 / PRODUCTIONcontext
Quarterly production and employment
The source remains registered, but no mine-keyed quarterly production row was published.
NO CURRENT QUARTERNo published quarter
mine-production-quarterlymine-production-yearly05 / LEGALwatch
Contests, conferences and decisions
6 contested-violation rows, 6 civil-penalty docket/decision rows, and 3 conference records linked by issuance number.
POST-ISSUANCE LIFECYCLE15 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 CONTEXT4 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations07 / INSPECTIONScontext
Inspections
39 inspection events and 1K published inspection hours across the historical record.
OVERSIGHT COVERAGE13 since 2021
inspectionsviolationsHEALTH SAMPLING
Silica and quartz
Coal quartz, metal/nonmetal personal samples and area samples. Snapshot Oct 17, 2026. 11 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 56.4501Fuel lines.1 recent row ↗30 CFR 56.4201Inspection.1 recent row ↗30 CFR 56.11003Construction and maintenance of ladders.1 recent row ↗30 CFR 56.14107Moving machine parts.1 recent row ↗30 CFR 56.12025Grounding circuit enclosures.1 recent row ↗30 CFR 56.4101Warning signs.1 recent row ↗30 CFR 56.12004Electrical conductors.1 recent row ↗30 CFR 56.20003Housekeeping.1 recent row ↗
RECENT PUBLIC RECORDS
Recent violations and samples
Latest records retained for inspection; aggregates above use the full source history.
511860756.4501S&S
873616056.4201(a)(2)Citation
873612956.11003Citation
969445556.14107(a)Citation
969445456.12025Citation
969014856.4101Citation
962188756.12004Citation
867093056.20003(a)Citation
Coal dust, noise and other contaminants. Silica records above ↑
Respirable dust, <.1mgUtility Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgBuilding Repair/Maint.
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgLab Technician
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgSand Filler (Dry)
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgScraper Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgUtility Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Unlisted Particulate, respirable, <1% QtzSand Filler (Dry)
C/E: 00.00Concentration: 0244.43 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgLab Technician
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
SOURCE COVERAGE
Reporting dates and coverage
15 datasets contain linked records. Missing datasets are listed below.
DATASETROWSWINDOWSTATUS
Accident, Injuries, and Illnessessafety · contractors19Jun 14, 2012—Feb 20, 2025mine-keyed
Addresses of Recordidentity · logistics1Oct 17, 2022—Oct 17, 2022mine-keyed
Assessed Violationscompliance · legal38Sep 13, 2012—Jan 17, 2024mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal6May 7, 2014—Aug 23, 2019mine-keyed
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal3Mar 31, 2014—Mar 20, 2026mine-keyed
Contested Violationscompliance · legal6May 7, 2013—Feb 13, 2019mine-keyed
Contractor Employment and Production — Quarterlycontractors · production · safety618Not published—Not publishedentity-linked
Contractor Employment and Production — Yearlycontractors · production · safety120Not published—Not publishedentity-linked
Controller and Operator Historyidentity · compliance2Apr 10, 2012—Mar 28, 2025mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance—No published rowsabsent / not applicable
Mine Employment and Production — Yearlyproduction · safety · compliance31Not published—Not publishedmine-keyed
Inspectionssafety · compliance39Sep 13, 2012—May 12, 2026mine-keyed
Minesidentity · production · logistics1Not published—Not publishedmine-keyed
Metal and Nonmetal Area Sampleshealth · safety1Aug 31, 2017—Aug 31, 2017mine-keyed
Metal and Nonmetal Personal Health Sampleshealth · safety49Feb 27, 2013—Jan 7, 2026mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal41Sep 13, 2012—Jan 6, 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.