Key Takeaway
Clayton Aggregates is a active surface mine producing Stone, located in clayton, Contra Costa County, CA. It has 200 violations on record (36 S&S) and $44K in proposed penalties. Operated by Martin Marietta Northern California Aggregates,LLC.
Clayton Aggregates
Operator: Martin Marietta Northern California Aggregates,LLC
Controller: Martin Marietta Materials Inc
Location: clayton, Contra Costa County, CA
Employees: 15
Recent Violations
View all 200 →| Date | Section | S&S | Negligence | Penalty |
|---|---|---|---|---|
| 10/08/2025 | 56.14100(b) | Non-S&S | LowNegligence | $151 |
| 07/09/2025 | 56.12004 | Non-S&S | ModNegligence | $226 |
| 07/09/2025 | 62.170(a)(3) | Non-S&S | ModNegligence | $151 |
| 07/08/2025 | 56.12004 | Non-S&S | LowNegligence | $151 |
| 05/09/2024 | 56.13015 | Non-S&S | ModNegligence | $221 |
| 05/09/2024 | 56.13015 | Non-S&S | LowNegligence | $147 |
| 05/07/2024 | 56.20003(a) | Non-S&S | ModNegligence | $147 |
| 05/07/2024 | 56.20003(a) | S&S | ModNegligence | $328 |
| 05/07/2024 | 56.14201(b) | S&S | ModNegligence | $1,098 |
| 05/07/2024 | 56.14112(b) | Non-S&S | ModNegligence | $147 |
| 05/07/2024 | 56.11027 | Non-S&S | ModNegligence | $221 |
| 03/27/2024 | 41.12 | Non-S&S | LowNegligence | $147 |
| 06/15/2022 | 56.11001 | Non-S&S | ModNegligence | $198 |
| 10/26/2021 | 56.14110 | Non-S&S | ModNegligence | $125 |
| 10/20/2021 | 56.12034 | Non-S&S | ModNegligence | $125 |
| 10/20/2021 | 56.14107(a) | Non-S&S | ModNegligence | $125 |
| 10/20/2021 | 56.4101 | Non-S&S | ModNegligence | $187 |
| 10/19/2021 | 56.11002 | Non-S&S | ModNegligence | $125 |
| 10/14/2021 | 56.13021 | Non-S&S | ModNegligence | $125 |
| 10/14/2021 | 56.12032 | Non-S&S | ModNegligence | $187 |
Accidents & Injuries
View all 20 →| Date | Classification | Injury | Days Lost |
|---|---|---|---|
| 12/15/2021 | HANDLING OF MATERIALS | DAYS AWAY FROM WORK ONLY | 129d lost |
| 08/17/2018 | MACHINERY | DAYS RESTRICTED ACTIVITY ONLY | 5d restricted |
| 06/16/2018 | SLIP OR FALL OF PERSON | DYS AWY FRM WRK & RESTRCTD ACT | 2d lost, 33d restricted |
| 10/20/2017 | HANDLING OF MATERIALS | DAYS RESTRICTED ACTIVITY ONLY | 12d restricted |
| 08/15/2014 | POWERED HAULAGE | DAYS AWAY FROM WORK ONLY | 255d lost |
| 10/04/2013 | POWERED HAULAGE | NO DYS AWY FRM WRK,NO RSTR ACT | None |
| 06/25/2013 | SLIP OR FALL OF PERSON | DAYS RESTRICTED ACTIVITY ONLY | 42d restricted |
| 10/15/2012 | MACHINERY | NO DYS AWY FRM WRK,NO RSTR ACT | None |
| 02/13/2011 | SLIP OR FALL OF PERSON | NO DYS AWY FRM WRK,NO RSTR ACT | None |
| 03/09/2010 | HANDLING OF MATERIALS | PERM TOT OR PERM PRTL DISABLTY | None |
Inspections
View all 70 →| Begin | End | Hours | Inspectors |
|---|---|---|---|
| 10/08/2025 | 10/16/2025 | 22.00 | 1 |
| 07/07/2025 | 07/09/2025 | 27.00 | 1 |
| 10/08/2024 | 10/09/2024 | 14.75 | 1 |
| 06/17/2024 | 06/17/2024 | 2.75 | 1 |
| 05/06/2024 | 05/09/2024 | 31.00 | 1 |
| 02/28/2024 | 03/02/2024 | 26.25 | 1 |
| 05/03/2023 | 05/05/2023 | 21.75 | 1 |
| 12/05/2022 | 12/08/2022 | 13.75 | 1 |
| 06/13/2022 | 06/16/2022 | 27.25 | 1 |
| 10/14/2021 | 10/27/2021 | 61.25 | 1 |
Mine Details
Related Mines
Frequently Asked Questions
How many MSHA violations does Clayton Aggregates have?
Clayton Aggregates has 200 MSHA violations on record, of which 36 are classified as Significant & Substantial (S&S). Total proposed penalties amount to $44K.
What type of mine is Clayton Aggregates?
Clayton Aggregates is a Surface mine producing Stone, located in clayton, Contra Costa County, CA. It currently has 15 employees.
Has anyone been injured or killed at Clayton Aggregates?
According to MSHA records, Clayton Aggregates has 20 reported accident/injury records and 0 fatalities on file.
Who operates Clayton Aggregates?
Clayton Aggregates is operated by Martin Marietta Northern California Aggregates,LLC and controlled by Martin Marietta Materials Inc. MSHA Mine ID: 0400159.