Data / Mines / California / Plant #5
Plant #5, Riverside County, California: 28 MSHA citations
Updated November 6, 2026. Source: US Department of Labor, Mine Safety and Health Administration (MSHA), Open Government Data Sets.
Plant #5 is an active construction sand and gravel surface mine in Riverside County, California, operated by Onyx Materials with 3 employees on MSHA's record (mine ID 0405451). Since January 1, 2022 MSHA inspectors issued 28 citations and orders there with $7,884 in proposed penalties, and 0 accident reports were filed there, with no injury or illness cases.
The request: Watch Plant #5 (MSHA mine ID 0405451) in Riverside County, California: each new citation and each accident report. $10 of work on sign-up, no card.
SpecStream is the live web data engine for teams and agents. It reads the mine, citation, inspection and accident files that MSHA publishes, and this page is that reading. Ask for the mines of a commodity, state or operator with the operator's headquarters, website and size added from the web, and new mines, new citations and new accident reports arrive in your sheet, CRM, Slack or agent as MSHA posts them.
- MSHA mine ID
- 0405451
- Status
- Active since October 31, 2022
- Main commodity
- Construction sand and gravel
- Mine type
- Surface
- County
- Riverside County, California
- Nearest town
- Corona
- Operator
- Onyx Materials
- Employees
- 3
- MSHA field office
- San Bernardino CA Field Office
- Citations and orders since January 1, 2022
- 28
- Significant and substantial
- 6 (21.4%)
- Closure orders
- 1
- High negligence or reckless
- 6
- Proposed penalties
- $7,884
- Amount paid so far
- $7,884
- Inspections
- 13
- Inspector hours on site
- 88
- Citations per inspection
- 2.15 (all mines 2.30)
- Accident reports
- 0
- Injury and illness cases
- 0
- Fatalities
- 0
- Latest MSHA record
- July 1, 2026
Citations and injury cases by year
Calendar years since 2022; 2026 runs to the date of the MSHA files.
| Year | Citations and orders | Significant and substantial | Proposed penalties | Injury and illness cases |
|---|---|---|---|---|
| 2022 | 9 | 3 | $2,220 | 0 |
| 2023 | 6 | 1 | $898 | 0 |
| 2024 | 5 | 1 | $3,464 | 0 |
| 2025 | 7 | 1 | $1,151 | 0 |
| 2026 | 1 | 0 | $151 | 0 |
Standards cited most at Plant #5
Sections of Title 30 of the Code of Federal Regulations named on the citations, with the part each belongs to.
| Standard | What the part covers | Citations |
|---|---|---|
| 30 CFR 50.30 | Reporting of accidents, injuries and illnesses | 4 |
| 30 CFR 56.14100 | Surface metal and nonmetal mines | 3 |
| 30 CFR 56.12032 | Surface metal and nonmetal mines | 3 |
| 30 CFR 56.14107 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.16005 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.14112 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.12018 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.9300 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.12008 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.14201 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.12028 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.12005 | Surface metal and nonmetal mines | 1 |
| 30 CFR 46.9 | Training at sand, gravel and surface stone mines | 1 |
| 30 CFR 46.8 | Training at sand, gravel and surface stone mines | 1 |
| 30 CFR 56.14200 | Surface metal and nonmetal mines | 1 |
Other open mines in Riverside County, California
| Mine | Operator | County | Main commodity | Employees | Citations since 2022 |
|---|---|---|---|---|---|
| 3M Corona Plant | 3M Company | Riverside County, CA | Crushed, broken stone | 85 | 66 |
| 3M | Fst Sand & Gravel Inc | Riverside County, CA | Construction sand and gravel | 93 | 47 |
| Coachella Valley Aggregate | Coachella Valley Aggregates Inc | Riverside County, CA | Construction sand and gravel | 11 | 39 |
| Nichols Road Pit | Chandler Aggregates Inc | Riverside County, CA | Construction sand and gravel | 23 | 35 |
| North Fontana | Earth Tek Engineering Corp. | Riverside County, CA | Construction sand and gravel | 6 | 35 |
| HJ Hove | Hi-Grade Materials | Riverside County, CA | Construction sand and gravel | 19 | 34 |
| Chandler Aggregates, Gilman Springs | Chandler Aggregates Inc | Riverside County, CA | Dimension limestone | 20 | 32 |
| Pacific Aggregates Pits | Pacific Aggregates Inc | Riverside County, CA | Construction sand and gravel | 30 | 31 |
| Maitri Sand and Gravel | Hanson Aggregates LLC | Riverside County, CA | Construction sand and gravel | 15 | 30 |
| Thousand Palms Pit | Coronet Concrete Products Inc | Riverside County, CA | Construction sand and gravel | 6 | 28 |
| West Coast Aggregate Supply Inc | West Coast Aggregate Supply | Riverside County, CA | Construction sand and gravel | 11 | 26 |
| Maitri Canyon Plant | Foster Sand & Gravel | Riverside County, CA | Construction sand and gravel | 19 | 24 |
| West Coast Aggregate Supply Inc | West Coast Aggregate Supply | Riverside County, CA | Construction sand and gravel | 6 | 24 |
| All American Aggregates | All American Aggregates | Riverside County, CA | Construction sand and gravel | 55 | 22 |
| Crawford's Mine | Crawford Associates | Riverside County, CA | Construction sand and gravel | 3 | 21 |
US government work, public domain. Counts come from the MSHA files published on November 6, 2026. An open mine is one MSHA lists as Active, Intermittent, New Mine, Temporarily Idled or NonProducing; 13,673 were open that day. Citations, penalties, inspections and accident reports run from January 1, 2022. A citation is an inspector's allegation and an operator can contest it; the penalty is the amount MSHA first proposed, before any contest or settlement. An operator is the legal entity MSHA assesses, and a parent company is its controller. Mines run by sole proprietors or by individuals are counted in every total and are not named. This page uses MSHA data and is not endorsed or certified by MSHA. Free to reuse with credit to SpecStream under CC BY 4.0. Spot a wrong value? Write to [email protected] with the link to this page.