# Plymouth Meeting Quarry

- **MSHA mine ID:** 3600052
- **Status:** Active
- **Type / commodity:** Surface / Crushed, Broken Limestone NEC
- **Location:** Montgomery, PA
- **Operator:** Heidelberg Materials Northeast LLC
- **Controller:** Heidelberg Materials AG
- **Public source rows linked:** 2,924
- **Source coverage:** 15 / 20
- **Generated:** 2026-10-18T09:31:49.615Z

## Current entity hierarchy

**Heidelberg Materials AG (M00004) → Heidelberg Materials Northeast LLC (L16322) → Plymouth Meeting Quarry (3600052)**

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

## Controller and operator valid-time history

- **Iu Industrials Inc → G & W H Corson Inc:** 1950-01-01 through 1981-09-22; derived from co-tenure at mine 3600052; source `msha-controller-operator-history`.
- **Rangaire Corp → Corson Lime Company:** 1981-09-23 through 1989-08-19; derived from co-tenure at mine 3600052; source `msha-controller-operator-history`.
- **United States Lime & Minerals Inc → Corson Lime Company:** 1989-08-20 through 1997-06-20; derived from co-tenure at mine 3600052; source `msha-controller-operator-history`.
- **Peter DePaul Irrevocable Combined Trust → Highway Materials LLC:** 1997-06-21 through 2024-07-31; derived from co-tenure at mine 3600052; source `msha-controller-operator-history`.
- **Heidelberg Materials AG → Highway Materials LLC:** 2024-08-01 through 2025-04-30; derived from co-tenure at mine 3600052; source `msha-controller-operator-history`.
- **Heidelberg Materials AG → Heidelberg Materials Northeast LLC:** 2025-05-01 through current/open; derived from co-tenure at mine 3600052; source `msha-controller-operator-history`.
- **Hanson PLC → Heidelberg Materials Northeast LLC:** 2025-05-01 through 2007-08-22; derived from co-tenure at mine 3600052; source `msha-controller-operator-history`.

- History rows: 7
- Typed edges: 19
- Interval anomalies: 1
- 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 — 9 since 2021:** Accidents and injuries 40 historical accident/injury rows; 0 coded fatalities and 667 lost days across the published record.
2. **COMPLIANCE — 23 since 2021:** Violations and penalties 172 violation rows across the full record; 28 carry an S&S flag and $34,375 appears in current assessed amounts.
3. **HEALTH — 39 samples:** Occupational health samples 39 personal. 4 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 21K employee hours and 33 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 7 linked rows:** Contests, conferences and decisions 3 contested-violation rows, 3 civil-penalty docket/decision rows, and 1 conference records linked by issuance number.
6. **CONTRACTORS — 8 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 — 18 since 2021:** Inspections 78 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 56.14130 — Roll-over protective structures (ROPS) and seat belts.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14130
- **30 CFR 46.8 — Annual refresher training.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-H/part-46/section-46.8
- **30 CFR 56.4200 — General requirements.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4200
- **30 CFR 46.11 — Site-specific hazard awareness training.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-H/part-46/section-46.11
- **30 CFR 50.20-1 — General instructions for completing MSHA Form 7000-1.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-I/part-50/subpart-C/section-50.20-1
- **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 56.14100 — Safety defects; examination, correction and records.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14100
- **30 CFR 56.14101 — Brakes.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14101
- **30 CFR 56.14112 — Construction and maintenance of guards.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14112
- **30 CFR 56.3131 — Pit or quarry wall perimeter.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-B/section-56.3131

## Source coverage

- **Accident, Injuries, and Illnesses:** 40 rows; 2000-01-17 through 2026-07-16; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 1976-07-04 through 1976-07-04; source ID `msha-addresses`
- **Assessed Violations:** 172 rows; 2000-05-18 through 2026-05-05; source ID `msha-assessed-violations`
- **Civil Penalty Dockets and Decisions:** 3 rows; 2008-03-17 through 2008-05-20; source ID `msha-civil-penalty-dockets-decisions`
- **Conferences:** 1 rows; 2020-11-23 through 2020-11-23; source ID `msha-conferences`
- **Contested Violations:** 3 rows; 2007-06-14 through 2007-06-14; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 1,654 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 354 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 7 rows; 1950-01-01 through 2025-05-01; source ID `msha-controller-operator-history`
- **Inspections:** 78 rows; 2000-05-18 through 2026-05-21; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 318 rows; unknown through unknown; source ID `msha-mine-production-quarterly`
- **Mine Employment and Production — Yearly:** 81 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:** 39 rows; 2003-09-24 through 2026-05-06; source ID `msha-personal-health-samples`
- **Violations:** 172 rows; 2000-05-18 through 2026-05-05; 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/plymouth-meeting-quarry-3600052`
- JSON: `/api/v1/mines/plymouth-meeting-quarry-3600052`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/3600052/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/3600052/relationships`
- MCP resource: `mine://3600052/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`