Class Code 6316
Water/Gas Mains Construction – High Wage
Class Code 6316 covers high-wage workers engaged in construction, installation, repair, testing and tie-in of water and gas distribution mains. The approved pure premium for California (effective Sept 1, 2026) is $3.147 per $100 of payroll — a baseline insurers use to price expected claim costs for these higher-skilled crews.
What Class Code 6316 Covers
This classification applies to crews performing excavation, trenching, shoring, pipe laying, welding or fusion of metallic and plastic mains, valve and hydrant installation, pressure and hydrostatic testing, cathodic protection work, tie-ins to live systems and final backfill and paving restoration. It covers both new construction of distribution mains and major replacement/rehabilitation of existing mains. The “High Wage” designation reflects assignment to higher-paid skilled craftworkers and supervisors — for example journey-level pipefitters, welders, foremen and specialized testing technicians — whose payroll and exposure characteristics differ from general labor crews. Work is typically performed in urban street right-of-ways, easements, and sometimes in confined spaces (manholes, vaults) or adjacent to traffic and other utilities, which increases coordination and safety requirements.
Who It Applies To
- Municipal and private utility contractors installing or replacing potable water mains
- Gas distribution contractors performing main installation, tie-ins, and pressure testing
- Specialty pipeline contractors handling welding, fusion, and cathodic protection
- Foremen, journey-level pipefitters, welders and hydrostatic testing technicians
- Large contractors and union crews performing high-wage skilled pipeline work
Common Job Duties
- Excavating trenches to specified depth and width and installing shoring or trench boxes
- Laying, aligning and joining pipe (welding, fusion, mechanical joints)
- Installing valves, hydrants, service turns and meter or regulator vaults
- Conducting hydrostatic and pressure testing, blowdowns and tie-in procedures
- Cathodic protection installation and testing, and corrosion control measures
- Backfilling, compaction, surface restoration and traffic control setup
- Confined space entry for vaults/manholes with atmospheric monitoring and rescue readiness
Common Injury Risks
Understanding the $3.147 Rate
The pure premium $3.147 per $100 of payroll represents the insurer’s estimated cost of paying claims for losses in this class before expenses and profit. To estimate pure premium, divide total payroll by 100 and multiply by 3.147. Final premiums vary based on your company’s experience modification (XMod), carrier expense loads, state assessments, premium discounts, payroll audits, and whether you participate in deductible or retrospective-rating programs.
Cal/OSHA Compliance Requirements
Cal/OSHA requirements critical to mains construction include a written Injury and Illness Prevention Program (IIPP), competent-person oversight for excavation and trenching, trench protective systems (sloping, benching, shoring or trench boxes), permit-required confined space entry procedures with atmospheric testing and attendant/rescue plans, traffic control plans for work in public rights-of-way, and hot-work and respiratory protection programs where applicable. Employers must document daily inspections, equipment maintenance, and employee training to meet California enforcement and reduce citations and penalties.
How Key HR Helps Employers Under Class Code 6316
A PEO like Key HR can centralize payroll and workers’ comp administration, provide access to specialized carriers and safety consultants with pipeline experience, and implement return-to-work and claim-management programs that reduce costs. Key HR can also deliver tailored safety templates (trenching checklists, confined space procedures, traffic control plans), coordinate training and drug/alcohol testing programs, and help monitor and improve your experience modification to lower future premiums.
Get a QuoteFrequently Asked Questions
What does the “High Wage” designation mean for Class Code 6316?
“High Wage” indicates this class is used for higher-paid skilled craftworkers and supervisors (foremen, journey-level pipefitters, welders, testing techs). It separates those payrolls and exposures from lower-wage labor so insurers can apply a more accurate pure premium for the skill level and loss profile of these crews.
What are the most important steps to meet Cal/OSHA rules on mains work?
Key steps include: establishing an IIPP, assigning a competent person for trenching and excavation, using appropriate protective systems, implementing permit-required confined space procedures with gas monitoring and rescue, maintaining traffic control plans for street work, and documenting daily inspections and employee training.
How can I lower workers’ comp costs for crews in this class?
Reduce costs by enforcing written safety programs, investing in trench protective equipment and confined-space rescue capability, providing journey-level training, maintaining equipment, promptly managing and reporting claims, and working with a PEO or broker to secure tailored carriers, return-to-work programs, and experience-modification monitoring.
Quick Facts
- Class Code
- 6316
- Classification
- Water/Gas Mains Construction – High Wage
- Pure Premium Rate
- $3.147 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
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