Class Code 6307
Sewer Construction – Low Wage
California Workers' Comp class code 6307 covers low‑wage sewer construction work — manual and labor‑intensive installation, repair and maintenance of sewer mains, laterals and manholes. The approved pure premium rate for September 1, 2026 is $7.451 per $100 of payroll, which reflects the expected loss cost for these operations and helps employers budget for workers' compensation exposure.
What Class Code 6307 Covers
This classification is for labor‑intensive sewer construction tasks performed by lower‑wage crews on public and private sewer systems. It includes trenching for sewer mains and laterals, hand‑excavation and shoring of trenches, assembling and joining pipe, building and repairing manholes, bypass pumping and dewatering performed by field crews, and preparation/cleaning of lines prior to lining or replacement. Routine maintenance and replacement where the dominant work is manual labor (as opposed to heavy equipment operation or specialty lining contractors) falls here. Work that primarily involves operating vacuum trucks, heavy tunneling equipment, or specialty cured‑in‑place lining may be assigned to different classifications depending on dominant duties.
Who It Applies To
- Small municipal or county sewer crews performing manual installation and repair
- Subcontractor trenching and pipe‑laying crews on sewer projects
- Contractors performing manhole construction and repair with manual labor
- Maintenance crews who clean, bypass or hand‑repair sewer lines
- Utility laborers and general construction helpers assigned to sewer tasks
Common Job Duties
- Hand‑digging and backfilling trenches for sewer mains and laterals
- Shoring, sloping and installing trench boxes for worker access
- Assembling, aligning and joining sewer pipe (PVC, clay, cast iron)
- Constructing, repairing and sealing manholes and inlets
- Bypass pumping, dewatering and temporary flow control during repairs
- Cleaning lines with rods, cutters, or manual augers prior to repair
- Traffic control at work zones and basic site cleanup
Common Injury Risks
Understanding the $7.451 Rate
The pure premium rate of $7.451 per $100 of payroll represents the estimated cost of claims (medical and indemnity) per $100 in payroll for workers in this class. To compute the pure premium for a payroll amount, divide total payroll by 100 and multiply by 7.451. The final premium employers pay will also reflect experience modification, insurer expenses and profit loads, policy minimums, deductible or retrospective rating programs, and accurate payroll classification.
Cal/OSHA Compliance Requirements
Sewer construction work is governed by Cal/OSHA standards for excavation and trenching, permit‑required confined spaces, respiratory protection, bloodborne pathogens and personal protective equipment. Employers must designate a competent person for trenches, maintain shoring/sloping or trench boxes, implement a written confined‑space entry program with gas monitoring and rescue procedures for manholes, and provide training on PPE, respiratory protection and hazard communication. Traffic control and fall‑protection practices around manholes and open excavations are also required.
How Key HR Helps Employers Under Class Code 6307
A PEO like Key HR helps employers in Class Code 6307 by ensuring correct payroll classification, administering workers' compensation coverage, and managing claims with experienced adjusters familiar with sewer‑work exposures. Key HR can implement targeted safety programs — trenching competency checks, confined‑space entry protocols, on‑site audits and training — to reduce frequency and severity of claims and improve experience modification over time.
Get a QuoteFrequently Asked Questions
How do I know if my crew should be classified under 6307 or a different sewer code?
Classification depends on the crew’s dominant duties. If the work is primarily manual labor — hand‑digging, pipe laying, manhole work and bypass pumping by field crews — 6307 is appropriate. If the crew primarily operates vacuum trucks, tunneling machines, or specialty lining equipment, a different class may apply. Consult your insurer or PEO to review job descriptions and payroll allocation.
What steps reduce workers' comp costs for sewer construction crews?
Key steps include implementing a written trenching competent‑person program, confined‑space entry permits and gas monitoring, respiratory and bloodborne‑pathogen training, strict PPE enforcement, ergonomic lifting practices and a return‑to‑work program. Good claims reporting and prompt medical management also reduce indemnity costs and experience‑mod reduction over time.
Are sewer maintenance and cleaning the same classification as construction?
Not always. Routine maintenance and manual cleaning that is labor‑intensive often fits 6307, but mechanized cleaning using vacuum trucks or specialized sewer rehabilitation methods may be classified differently. Accurate classification requires reviewing the primary tasks performed and equipment used by the workers.
Quick Facts
- Class Code
- 6307
- Classification
- Sewer Construction – Low Wage
- Pure Premium Rate
- $7.451 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
Manage Workers' Comp Through a PEO
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Get a Quoteor call (800) 922-4133Ready to Simplify Workers' Comp for Class Code 6307?
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