# Laurel Hill Quarry

- **MSHA mine ID:** 1800341
- **Status:** Active
- **Type / commodity:** Surface / Crushed, Broken Stone NEC
- **Location:** Frederick, MD
- **Operator:** Laurel Sand & Gravel INC.
- **Controller:** Aggregate Management, Inc
- **Public source rows linked:** 1,658
- **Source coverage:** 14 / 20
- **Generated:** 2026-10-13T11:26:59.401Z

## Current entity hierarchy

**Aggregate Management, Inc (M10193) → Laurel Sand & Gravel INC. (L06490) → Laurel Hill Quarry (1800341)**

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

## Controller and operator valid-time history

- **Heidelberg Materials AG → Lehigh Portland Cement Company:** 1950-01-01 through 2002-01-31; derived from co-tenure at mine 1800341; source `msha-controller-operator-history`.
- **Heidelberg Materials AG → Lehigh Cement Company:** 2002-02-01 through 2020-08-09; derived from co-tenure at mine 1800341; source `msha-controller-operator-history`.
- **Aggregate Management, Inc → Laurel Sand & Gravel INC.:** 2020-08-10 through current/open; derived from co-tenure at mine 1800341; source `msha-controller-operator-history`.

- History rows: 3
- Typed edges: 9
- 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: 2026-10-13T11:19:05.459773+00:00.

## Assessment signals

1. **SAFETY — 6 since 2021:** Accidents and injuries 43 historical accident/injury rows; 0 coded fatalities and 749 lost days across the published record.
2. **COMPLIANCE — 14 since 2021:** Violations and penalties 305 violation rows across the full record; 87 carry an S&S flag and $108,012 appears in current assessed amounts.
3. **HEALTH — 54 samples:** Occupational health samples 54 personal. 11 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.
4. **PRODUCTION — 0 tons:** Quarterly production and employment 22K employee hours and 46 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 23 linked rows:** Contests, conferences and decisions 18 contested-violation rows, 0 civil-penalty docket/decision rows, and 5 conference records linked by issuance number.
6. **CONTRACTORS — 6 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 — 10 since 2021:** Inspections 52 inspection events and 2K published inspection hours across the historical record.

## EIA annual operating context

No matched record in the 2024 EIA coal-public workbook. This may be inapplicable for a non-coal operation.

## Recent Title 30 crosswalk

Snapshot current through 2026-08-19.

- **30 CFR 56.12020 — Protection of persons at switchgear.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12020
- **30 CFR 56.14107 — Moving machine parts.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14107
- **30 CFR 56.4201 — Inspection.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4201
- **30 CFR 50.20-1 — General instructions for completing MSHA Form 7000-1.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-I/part-50/subpart-C/section-50.20-1
- **30 CFR 56.14110 — Flying or falling materials.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14110
- **30 CFR 56.7002 — Equipment defects.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-F/section-56.7002
- **30 CFR 56.11003 — Construction and maintenance of ladders.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-J/section-56.11003
- **30 CFR 56.12028 — Testing grounding systems.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12028
- **30 CFR 56.13015 — Inspection of compressed-air receivers and other unfired pressure vessels.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-L/section-56.13015
- **30 CFR 56.20003 — Housekeeping.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-S/section-56.20003
- **30 CFR 56.12008 — Insulation and fittings for power wires and cables.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12008
- **30 CFR 56.14132 — Horns and backup alarms.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14132

## Source coverage

- **Accident, Injuries, and Illnesses:** 43 rows; 2000-05-11 through 2026-03-19; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 2023-02-01 through 2023-02-01; source ID `msha-addresses`
- **Assessed Violations:** 300 rows; 2000-04-18 through 2026-08-05; source ID `msha-assessed-violations`
- **Conferences:** 5 rows; 2004-06-25 through 2007-06-19; source ID `msha-conferences`
- **Contested Violations:** 18 rows; 2003-09-17 through 2003-09-24; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 556 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 122 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 3 rows; 1950-01-01 through 2020-08-10; source ID `msha-controller-operator-history`
- **Inspections:** 52 rows; 2000-01-11 through 2026-07-02; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 156 rows; unknown through unknown; source ID `msha-mine-production-quarterly`
- **Mine Employment and Production — Yearly:** 42 rows; unknown through unknown; source ID `msha-mine-production-yearly`
- **Mines:** 1 rows; unknown through unknown; source ID `msha-mines`
- **Metal and Nonmetal Personal Health Samples:** 54 rows; 2001-05-08 through 2026-08-06; source ID `msha-personal-health-samples`
- **Violations:** 305 rows; 2000-02-23 through 2026-08-05; 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/laurel-hill-quarry-1800341`
- JSON: `/api/v1/mines/laurel-hill-quarry-1800341`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/1800341/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/1800341/relationships`
- MCP resource: `mine://1800341/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`