# Santa Margarita Aggregates

- **MSHA mine ID:** 0401616
- **Status:** Active
- **Type / commodity:** Surface / Construction Sand and Gravel
- **Location:** San Luis Obispo, CA
- **Operator:** Martin Marietta Northern California Aggregates,LLC
- **Controller:** Martin Marietta Materials Inc
- **Public source rows linked:** 1,259
- **Source coverage:** 15 / 20
- **Generated:** 2026-10-17T06:17:15.228Z

## Current entity hierarchy

**Martin Marietta Materials Inc (M00174) → Martin Marietta Northern California Aggregates,LLC (0064607) → Santa Margarita Aggregates (0401616)**

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

## Controller and operator valid-time history

- **Koppers Company Inc → Kaiser Sand & Gravel Company:** 1978-01-01 through 1988-11-13; derived from co-tenure at mine 0401616; source `msha-controller-operator-history`.
- **Hanson PLC → Hanson Aggregates West Inc:** 1988-11-14 through 2006-05-31; derived from co-tenure at mine 0401616; source `msha-controller-operator-history`.
- **Hanson PLC → Martin Marietta Northern California Aggregates,LLC:** 2006-06-01 through 2007-08-22; derived from co-tenure at mine 0401616; source `msha-controller-operator-history`.
- **Heidelberg Materials AG → Martin Marietta Northern California Aggregates,LLC:** 2007-08-23 through 2021-09-30; derived from co-tenure at mine 0401616; source `msha-controller-operator-history`.
- **Martin Marietta Materials Inc → Martin Marietta Northern California Aggregates,LLC:** 2021-10-01 through current/open; derived from co-tenure at mine 0401616; source `msha-controller-operator-history`.

- History rows: 5
- Typed edges: 13
- 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: 2026-10-17T05:35:58.500035+00:00.

## Assessment signals

1. **SAFETY — 2 since 2021:** Accidents and injuries 14 historical accident/injury rows; 0 coded fatalities and 8 lost days across the published record.
2. **COMPLIANCE — 31 since 2021:** Violations and penalties 163 violation rows across the full record; 42 carry an S&S flag and $103,493 appears in current assessed amounts.
3. **HEALTH — 21 samples:** Occupational health samples 21 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.
4. **PRODUCTION — 0 tons:** Quarterly production and employment 8K employee hours and 16 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 14 linked rows:** Contests, conferences and decisions 4 contested-violation rows, 4 civil-penalty docket/decision rows, and 6 conference records linked by issuance number.
6. **CONTRACTORS — 4 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 — 16 since 2021:** Inspections 72 inspection events and 1K 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 56.20003 — Housekeeping.** (4 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-S/section-56.20003
- **30 CFR 56.16005 — Securing gas cylinders.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-O/section-56.16005
- **30 CFR 56.14205 — Machinery, equipment, and tools.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14205
- **30 CFR 56.14107 — Moving machine parts.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14107
- **30 CFR 56.11001 — Safe access.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-J/section-56.11001
- **30 CFR 56.12019 — Access to stationary electrical equipment or switchgear.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12019
- **30 CFR 56.12032 — Inspection and cover plates.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12032
- **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

## Source coverage

- **Accident, Injuries, and Illnesses:** 14 rows; 2004-01-06 through 2022-08-26; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 1974-04-23 through 1974-04-23; source ID `msha-addresses`
- **Assessed Violations:** 162 rows; 2001-02-13 through 2026-04-27; source ID `msha-assessed-violations`
- **Civil Penalty Dockets and Decisions:** 4 rows; 2011-10-21 through 2011-10-21; source ID `msha-civil-penalty-dockets-decisions`
- **Conferences:** 6 rows; 2003-04-03 through 2018-05-31; source ID `msha-conferences`
- **Contested Violations:** 4 rows; 2010-01-27 through 2010-01-27; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 589 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 139 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 5 rows; 1978-01-01 through 2006-06-01; source ID `msha-controller-operator-history`
- **Inspections:** 72 rows; 2001-02-13 through 2026-04-27; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 24 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`
- **Metal and Nonmetal Personal Health Samples:** 21 rows; 2004-01-28 through 2026-04-27; source ID `msha-personal-health-samples`
- **Violations:** 163 rows; 2001-02-13 through 2026-04-27; 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/santa-margarita-aggregates-0401616`
- JSON: `/api/v1/mines/santa-margarita-aggregates-0401616`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/0401616/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/0401616/relationships`
- MCP resource: `mine://0401616/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`