Class Code 6308
Sewer Construction – High Wage
WCIRB Class Code 6308 (Sewer Construction 1 High Wage) covers construction and rehabilitation work on sanitary sewer systems where employees are paid at higher wage rates. The approved California pure premium rate for this classification effective September 1, 2026 is $4.117 per $100 of payroll. Correct classification matters because sewer construction carries elevated excavation, confined-space and utility hazards that drive workers' comp costs.
What Class Code 6308 Covers
This classification applies to employees engaged in the construction, replacement, major rehabilitation and related heavy civil work on sanitary sewer systems: open-cut trenching to install pipe, manhole installation, dewatering, backfill and compaction, and trenchless rehabilitation methods (CIPP, pipe bursting) when performed by higher-paid crews. It includes on-site operations such as cutting/fusing plastic pipe, welding, concreting manhole bases, setting precast units, and operating heavy equipment (excavators, loaders, backhoes, trenchers). Routine sewer cleaning, small repairs or purely maintenance activities are typically classified differently; 6308 is for construction-level activities with the higher wage designation used when payroll is above the low-wage threshold for sewer construction.
Who It Applies To
- Sewer installation and replacement contractors working on sanitary lines
- Trenchless rehabilitation contractors performing CIPP or pipe bursting
- Municipal or county sewer construction crews on capital projects
- Heavy equipment operators, pipe layers and skilled journeymen on sewer jobs
- Foremen, superintendents and higher-wage field supervisors assigned to sewer construction
Common Job Duties
- Excavating trenches and setting trench shoring or trench boxes
- Laying, aligning and joining sewer pipe (PVC, HDPE, concrete)
- Constructing and setting manholes, inverts and concrete collars
- Operating backhoes, excavators, vacuum trucks and trenchers
- Dewatering trenches and controlling groundwater
- Confined-space entry for inspection, connection or manhole work
- Backfilling, compaction and site restoration
Common Injury Risks
Understanding the $4.117 Rate
The pure premium rate of $4.117 per $100 of payroll is the WCIRB-approved measure of the expected claim cost for this class. To estimate pure premium, divide payroll by 100 and multiply by 4.117 (for example, $100,000 payroll -> $4,117 pure premium). Final premiums carriers charge will also include experience modification, insurer expense loads, policy-level adjustments, audits and any credits or debits for safety programs and deductible choices.
Cal/OSHA Compliance Requirements
Employers must follow California Title 8 Construction Safety Orders specific to excavation and trenching, and implement a competent person for trench inspections and shoring/benching requirements. Permit-required confined space procedures, atmospheric testing and continuous gas monitoring are mandatory for manhole and sewer-entry operations, along with Cal/OSHA respiratory protection, lockout/tagout where applicable, traffic control for open trenches in public streets, and documented employee training on hazards and PPE.
How Key HR Helps Employers Under Class Code 6308
A PEO like Key HR helps employers in this classification by ensuring accurate payroll classification, providing tailored safety program templates (trench, confined-space and respiratory), coordinating Cal/OSHA-compliant training and documentation, and managing claims and return-to-work to reduce lost-time costs. We also negotiate on behalf of clients for competitive workers' comp pricing and help implement prevention strategies that lower experience modification factors.
Get a QuoteFrequently Asked Questions
Does Class Code 6308 cover routine sewer cleaning and CCTV inspection?
No. 6308 is intended for construction-level sewer installation and major rehabilitation. Routine sewer cleaning, CCTV inspection, and minor maintenance are typically classified under different WCIRB codes; classification depends on the scope of work and the payroll of the employees performing the tasks.
What does the 'High Wage' designation mean for my premium?
'High Wage' indicates this version of the sewer construction classification applies when employees in the class are paid at higher wage levels. The pure premium is the same defined rate, but employers must correctly allocate payroll between low- and high-wage codes where applicable, because misclassification can lead to audits and premium adjustments.
What practical steps reduce workers' comp costs on sewer construction jobs?
Key actions include enforcing competent person trench inspections, written permit-required confined-space programs with gas monitoring, trained operators and riggers, use of trench boxes and dewatering systems, rigorous pre-job hazard assessments, preventive maintenance of equipment, and a documented return-to-work program to limit lost-time claims.
Quick Facts
- Class Code
- 6308
- Classification
- Sewer Construction – High Wage
- Pure Premium Rate
- $4.117 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
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