# Calvert Mine

- **MSHA mine ID:** 4103428
- **Status:** Active
- **Type / commodity:** Surface / Coal (Lignite)
- **Location:** Robertson, TX
- **Operator:** NAES Corporation
- **Controller:** ITOCHU International Inc; I Power Investment Inc
- **Public source rows linked:** 5,350
- **Source coverage:** 17 / 20
- **Generated:** 2026-10-18T09:31:49.615Z

## Current entity hierarchy

**ITOCHU International Inc; I Power Investment Inc (0182680) → NAES Corporation (0193893) → Calvert Mine (4103428)**

Current identity source: `msha-mines`. This is a current snapshot, not a historical claim.

## Controller and operator valid-time history

- **Phillips Petroleum Company → Phillips Coal Company:** 1986-07-01 through 1988-05-09; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.
- **Kiewit Peter Sons' Inc → Walnut Creek Mining Company:** 1988-05-10 through 2014-10-13; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.
- **Black Walnut Mining, LLC → Walnut Creek Mining Company:** 2014-10-14 through 2016-07-21; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.
- **Kiewit Peter Sons' Inc → Kiewit Mining Group:** 2016-07-22 through 2020-01-14; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.
- **Black Walnut Mining, LLC → Black Walnut Management Company LLC:** 2020-01-15 through 2023-08-31; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.
- **Forethought Life Insurance Company et al → Panamint Power dba Walnut Creek Mining:** 2023-09-01 through 2024-02-13; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.
- **Panamint Capital LLC et al → Panamint Power dba Walnut Creek Mining:** 2023-09-01 through 2024-02-13; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.
- **I Power Investment Inc et al → NAES Corporation:** 2024-02-14 through current/open; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.
- **ITOCHU International Inc et al → NAES Corporation:** 2024-02-14 through current/open; derived from co-tenure at mine 4103428; source `msha-controller-operator-history`.

- History rows: 9
- Typed edges: 22
- Interval anomalies: 0
- Valid-time bounds: inclusive; date granularity; null end means open-ended in the upstream history row; not independent proof of present control.
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00.

## Assessment signals

1. **SAFETY — 3 since 2021:** Accidents and injuries 18 historical accident/injury rows; 0 coded fatalities and 41 lost days across the published record.
2. **COMPLIANCE — 42 since 2021:** Violations and penalties 349 violation rows across the full record; 46 carry an S&S flag and $91,880 appears in current assessed amounts.
3. **HEALTH — 544 samples:** Occupational health samples 325 coal dust; 3 coal quartz; 216 noise. 0 personal-sample rows have a published C/E ratio above 1; 26 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.
4. **PRODUCTION — 367K tons:** Quarterly production and employment 64K employee hours and 120 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 94 linked rows:** Contests, conferences and decisions 40 contested-violation rows, 40 civil-penalty docket/decision rows, and 14 conference records linked by issuance number.
6. **CONTRACTORS — 20 linked entities:** 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.
7. **INSPECTIONS — 17 since 2021:** Inspections 101 inspection events and 6K published inspection hours across the historical record.

## EIA annual operating context

- **Reporting year:** 2024
- **Production:** 1,783,404 short tons
- **Labor hours:** 181,602
- **Average employees:** 88
- **Coal supply region:** Interior
- **Union code:** Not published
- **Published rows under this MSHA ID:** 1

## Recent Title 30 crosswalk

Snapshot current through 2026-08-19.

- **30 CFR 77.205 — Travelways at surface installations.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-O/part-77/subpart-C/section-77.205
- **30 CFR 77.1607 — Loading and haulage equipment; operation.** (4 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-O/part-77/subpart-Q/section-77.1607
- **30 CFR 77.1104 — Accumulations of combustible materials.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-O/part-77/subpart-L/section-77.1104
- **30 CFR 77.210 — Hoisting of materials.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-O/part-77/subpart-C/section-77.210
- **30 CFR 77.1710 — Protective clothing; requirements.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-O/part-77/subpart-R/section-77.1710
- **30 CFR 47.41 — Requirement for container labels.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-H/part-47/subpart-E/section-47.41

## Source coverage

- **Accident, Injuries, and Illnesses:** 18 rows; 2000-04-10 through 2025-04-14; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 1990-02-20 through 1990-02-20; source ID `msha-addresses`
- **Assessed Violations:** 347 rows; 2000-04-18 through 2026-05-06; source ID `msha-assessed-violations`
- **Civil Penalty Dockets and Decisions:** 40 rows; 2011-11-14 through 2026-04-21; source ID `msha-civil-penalty-dockets-decisions`
- **Coal Dust Samples:** 325 rows; 2000-04-18 through 2026-08-05; source ID `msha-coal-dust-samples`
- **Conferences:** 14 rows; 2016-01-14 through 2018-09-06; source ID `msha-conferences`
- **Contested Violations:** 40 rows; 2010-03-22 through 2026-02-23; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 2,925 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 695 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 9 rows; 1986-07-01 through 2024-02-14; source ID `msha-controller-operator-history`
- **Inspections:** 101 rows; 2000-02-29 through 2026-05-04; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 212 rows; unknown through unknown; source ID `msha-mine-production-quarterly`
- **Mine Employment and Production — Yearly:** 54 rows; unknown through unknown; source ID `msha-mine-production-yearly`
- **Mines:** 1 rows; unknown through unknown; source ID `msha-mines`
- **Noise Samples:** 216 rows; 2000-03-01 through 2026-05-06; source ID `msha-noise-samples`
- **Quartz Samples — Coal:** 3 rows; 2001-10-03 through 2024-10-16; source ID `msha-quartz-samples`
- **Violations:** 349 rows; 2000-04-18 through 2026-05-06; source ID `msha-violations`

## Caveats

- This is public-record decision support, not legal advice or an official MSHA record.
- Missing data can indicate no event, publication delay, an unresolved identity, or inapplicability.
- Contractor production data is entity-level and is not attributed to this mine.

## Alternate representations

- HTML: `/mines/calvert-mine-4103428`
- JSON: `/api/v1/mines/calvert-mine-4103428`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/4103428/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/4103428/relationships`
- MCP resource: `mine://4103428/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`