Class Code 4000
Sand Or Gravel Digging; Clay Digging; Salt Production; Dredging
Class Code 4000 covers work extracting and handling sand, gravel and clay, commercial salt production and dredging operations. These are physically intensive, equipment-driven activities with a September 1, 2026 approved pure premium rate of $3.488 per $100 of payroll — a key cost input California employers must manage.
What Class Code 4000 Covers
This classification applies to ground-level and open-pit extraction of sand, gravel and clay, commercial salt harvesting and processing (including solar-evaporation pans and mechanical harvesting), and in-water dredging to remove or relocate sediment from channels, harbors or waterways. Activities include operating excavators, loaders, front-end scrapers, suction and cutterhead dredges, pump systems, screening and washing plants, loading barges or trucks, stockpiling and routine maintenance of that equipment. It captures both land-based pit/quarry operations and marine dredging crews working from barges and workboats. Support tasks such as surveying, sampling, plant maintenance, and deckhand duties integral to extraction and dredging are also included.
Who It Applies To
- Sand and gravel pit operators and aggregate suppliers
- Quarry and clay extraction operations supplying construction materials
- Commercial salt producers (solar-evaporation or mechanical harvest)
- Dredging contractors performing channel maintenance, harbor dredging or sediment removal
- Marine crews and barge operators supporting dredging and transport
- Contractors who operate onsite screening, washing and stockpiling plants
Common Job Duties
- Operating heavy equipment—excavators, loaders, bulldozers and haul trucks to extract and move material
- Running dredging equipment: cutterhead/suction dredges, pumps, winches and hydraulics
- Loading and securing material onto trucks and barges and handling conveyor systems
- Screening, washing, stockpiling and sampling aggregate and salt products
- Routine maintenance and repair on engines, pumps, conveyors and dredge components
- Deckhand and diver support on workboats, including line handling and winch operation
- Site surveying, grade checking and environmental monitoring of sediments and ponds
Common Injury Risks
Understanding the $3.488 Rate
The pure premium rate of $3.488 per $100 of payroll represents the expected cost of future claims for this class before insurer loading and adjustments. An employer's actual workers' comp premium is calculated by multiplying payroll (divided by 100) by the rate, then applying experience modification, insurer expense factors, schedule credits, policy deductibles and any state or insurer-specific surcharges.
Cal/OSHA Compliance Requirements
Employers must follow Cal/OSHA construction and general industry safety orders relevant to excavation, trenching, marine operations, confined space entry and respiratory protection (including controls for crystalline silica). Title 8 requirements emphasize protective systems for excavations, competent person inspections, respiratory and dust control programs, fall protection on barges and heat illness prevention for outdoor crews. Maintain documented training, exposure monitoring, respirator fit testing and written safety procedures required by Cal/OSHA.
How Key HR Helps Employers Under Class Code 4000
A PEO like Key HR helps control costs for Class Code 4000 by ensuring accurate payroll classification, centralized claims management and timely reporting to limit reserves and litigation risk. Key HR can implement site-specific safety programs—trenching/excavation procedures, silica and respirator programs, marine safety and return-to-work plans—plus OSHA recordkeeping and training to reduce frequency and severity of claims.
Get a QuoteFrequently Asked Questions
If my crew does both land excavation and occasional dredging, which classification applies?
Assign payroll to the class that reflects the employee's primary duties by time spent. If workers split time, allocate payroll by hours in each activity so land excavation wages go to Class Code 4000 and other duties to their respective codes.
How can I lower workers' comp costs for sand, gravel or dredging operations?
Focus on reducing claim frequency and severity: implement competent-person trenching programs, engineering and water control for stockpiles, a written silica control and respiratory program, scheduled equipment maintenance, marine safety procedures, and structured return-to-work plans. Improved loss history and formal safety programs lower experience mod and insurer pricing.
Does salt production have unique compliance issues compared with aggregate pits?
Yes. Salt operations add corrosion risks, concentrated particulate exposure during harvesting, and long-duration outdoor work on reflective pans that amplify heat stress. Employers should add corrosion-resistant PPE, specific dust suppression for salt crystals, and robust heat illness prevention tailored to solar-evaporation sites.
Quick Facts
- Class Code
- 4000
- Classification
- Sand Or Gravel Digging; Clay Digging; Salt Production; Dredging
- Pure Premium Rate
- $3.488 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
Manage Workers' Comp Through a PEO
Key HR provides pay-as-you-go workers' comp for California employers — no large deposits, no audits, better rates.
Get a Quoteor call (800) 922-4133Ready to Simplify Workers' Comp for Class Code 4000?
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