Key Takeaway
Mason City Plant is a active facility mine producing Stone, located in Mason City, Cerro Gordo County, IA. It has 2,361 violations on record (519 S&S) and $3.3M in proposed penalties. Operated by Heidelberg Materials US Cement LLC.
Mason City Plant
Operator: Heidelberg Materials US Cement LLC
Controller: Heidelberg Materials AG
Location: Mason City, Cerro Gordo County, IA
Employees: 143
Recent Violations
View all 2,361 →| Date | Section | S&S | Negligence | Penalty |
|---|---|---|---|---|
| 02/17/2026 | 56.14103(b) | Non-S&S | HighNegligence | $0 |
| 02/17/2026 | 56.14103(b) | Non-S&S | HighNegligence | $0 |
| 02/17/2026 | 47.41(a) | Non-S&S | ModNegligence | $0 |
| 02/12/2026 | 56.5001(a)/56.5005 | Non-S&S | ModNegligence | $0 |
| 02/12/2026 | 56.5001(a)/56.5005 | Non-S&S | ModNegligence | $0 |
| 02/11/2026 | 56.14132(a) | Non-S&S | ModNegligence | $0 |
| 02/11/2026 | 56.4201(b) | Non-S&S | ModNegligence | $0 |
| 02/10/2026 | 56.20003(c) | Non-S&S | ModNegligence | $0 |
| 02/10/2026 | 56.12004 | Non-S&S | ModNegligence | $0 |
| 02/10/2026 | 56.12032 | Non-S&S | ModNegligence | $0 |
| 02/10/2026 | 56.16006 | Non-S&S | ModNegligence | $0 |
| 02/10/2026 | 56.12004 | Non-S&S | ModNegligence | $0 |
| 02/10/2026 | 56.20003(a) | Non-S&S | LowNegligence | $0 |
| 02/10/2026 | 56.12004 | Non-S&S | ModNegligence | $0 |
| 02/10/2026 | 56.4201(a)(2) | Non-S&S | ModNegligence | $0 |
| 02/04/2026 | 47.44(b) | Non-S&S | ModNegligence | $0 |
| 02/04/2026 | 56.14107(a) | Non-S&S | ModNegligence | $0 |
| 02/04/2026 | 56.14100(a) | Non-S&S | ModNegligence | $0 |
| 02/04/2026 | 56.4102 | Non-S&S | ModNegligence | $0 |
| 02/04/2026 | 56.4102 | Non-S&S | ModNegligence | $0 |
Accidents & Injuries
View all 229 →| Date | Classification | Injury | Days Lost |
|---|---|---|---|
| 02/12/2026 | SLIP OR FALL OF PERSON | DAYS AWAY FROM WORK ONLY | 5d lost |
| 10/22/2025 | MACHINERY | NO DYS AWY FRM WRK,NO RSTR ACT | None |
| 05/13/2025 | SLIP OR FALL OF PERSON | DAYS AWAY FROM WORK ONLY | 33d lost |
| 03/13/2025 | HANDLING OF MATERIALS | DAYS AWAY FROM WORK ONLY | None |
| 08/22/2024 | HANDTOOLS (NONPOWERED) | NO DYS AWY FRM WRK,NO RSTR ACT | None |
| 08/07/2024 | HANDTOOLS (NONPOWERED) | NO DYS AWY FRM WRK,NO RSTR ACT | None |
| 10/22/2023 | MACHINERY | DYS AWY FRM WRK & RESTRCTD ACT | 2d lost, 2d restricted |
| 09/25/2023 | HANDLING OF MATERIALS | DAYS RESTRICTED ACTIVITY ONLY | 16d restricted |
| 07/06/2023 | DISORDERS (PHYSICAL AGENTS) | OCCUPATNAL ILLNESS NOT DEG 1-6 | None |
| 05/05/2023 | HANDLING OF MATERIALS | NO DYS AWY FRM WRK,NO RSTR ACT | None |
Inspections
View all 210 →| Begin | End | Hours | Inspectors |
|---|---|---|---|
| 01/21/2026 | 02/18/2026 | 198.25 | 4 |
| 01/20/2026 | 01/20/2026 | 6.25 | 1 |
| 05/27/2025 | 06/12/2025 | 185.75 | 2 |
| 02/24/2025 | 02/24/2025 | 4.25 | 1 |
| 02/21/2025 | 02/24/2025 | 10.50 | 1 |
| 01/29/2025 | 01/29/2025 | 3.25 | 1 |
| 01/21/2025 | 01/21/2025 | 7.25 | 1 |
| 01/13/2025 | 01/13/2025 | 5.50 | 1 |
| 12/02/2024 | 01/07/2025 | 171.25 | 1 |
| 10/21/2024 | 01/08/2025 | 21.50 | 2 |
Mine Details
Related Mines
Frequently Asked Questions
How many MSHA violations does Mason City Plant have?
Mason City Plant has 2361 MSHA violations on record, of which 519 are classified as Significant & Substantial (S&S). Total proposed penalties amount to $3.3M.
What type of mine is Mason City Plant?
Mason City Plant is a Facility mine producing Stone, located in Mason City, Cerro Gordo County, IA. It currently has 143 employees.
Has anyone been injured or killed at Mason City Plant?
According to MSHA records, Mason City Plant has 229 reported accident/injury records and 0 fatalities on file.
Who operates Mason City Plant?
Mason City Plant is operated by Heidelberg Materials US Cement LLC and controlled by Heidelberg Materials AG. MSHA Mine ID: 1300095.