Workers’ Comp for California Sewer & Underground Contractors
Deep trenches, manholes, street-crossing tunnels and underground utilities — sewer and underground work combines collapse, confined-space and traffic exposures that many carriers decline. For contractors with 20 to 500 employees and $50,000+ in annual workers’ comp premium, we place this work with markets built for it.
California Workers’ Comp Class Codes We Place
| WCIRB Code | Classification |
|---|---|
| 6307 / 6308 | Sewer Construction — all operations, including laterals and tunneling at street crossings (dual-wage pair) |
| 6315 / 6316 | Water or Gas Mains or Connections Construction (dual-wage pair) |
| 6218 / 6220 | Excavation and Grading Land — N.O.C. (dual-wage pair) |
| 6325 | Conduit Construction or Underground Wiring |
Several construction classes are “dual-wage” pairs: employees at or above an hourly wage threshold set by WCIRB go in the lower-rated code. Missing wage records push payroll into the higher-rated code at audit — one of the most common reasons contractors overpay.
Why This Work Is Hard to Place
Trench collapse is one of construction’s deadliest hazards, and sewer work adds confined spaces with toxic or oxygen-deficient atmospheres, street-crossing tunneling, and crews working beside live traffic. Because these exposures can produce multiple serious injuries in a single event, standard carriers frequently exclude the classes or price them out.
What Underwriters Want to See
- A competent person and protective systems (shoring, sloping, trench boxes) on every trench over five feet
- A permit-required confined space program with atmospheric monitoring
- Traffic control plans for street work
- Dig Alert (811) and potholing procedures
- Rescue and emergency procedures for trench and confined-space work
How Specialty Markets Look at Your Account
Standard carriers often decide on class code alone. The specialty markets we work with for high-hazard classes underwrite the company in front of them: your safety program, training and certifications, loss frequency versus severity, how your experience mod is trending, and how claims are managed when they happen. A contractor that has invested in safety can be priced on that record instead of the worst operators in its class.
That doesn’t mean every account saves money — and if your current program is the right fit, we’ll tell you. But if your premium hasn’t moved after years of clean operations, it’s worth a second look.
Situations We Help With
Municipal infrastructure contracts
City sewer and water replacement programs grew your crews and your premium.
Depth restrictions
Your carrier limits trench depth or is pulling back from the class.
Confined-space questions
Underwriters are asking for confined-space documentation you already have — and should get credit for.
Dual-wage audit issues
Wage records don’t support the lower-rated code at audit.
On State Fund now? See how contractors move off State Fund at renewal, or browse all contractor workers’ comp classes we place.
What We Need to Shop Your Account
- Completed ACORD 130 workers’ comp application (we can help you fill it out)
- Your current experience mod worksheet from WCIRB
- 3–5 years of currently valued loss runs
- Your expiring policy and premium, plus payroll by class code
- Your written safety program or IIPP, if you have one
Missing something? Start anyway — with your authorization we can request loss runs and your mod worksheet for you.
Common Questions
Do your markets restrict trench depth?
The specialty markets we use for this program write construction without depth restrictions, subject to normal underwriting.
Is sewer work classified differently from water mains?
Yes. Sewer construction is the 6307/6308 pair; water and gas mains and connections are the 6315/6316 pair.
What documentation helps most?
A written trench and excavation program, confined-space program, and training records. Underwriters weigh documented controls heavily for these classes.
What size companies do you work with?
Typically 20 to 500 employees with $50,000 or more in annual workers’ comp premium.
Request a Workers’ Comp Review
For California contractors paying $50,000+ a year in workers’ comp.
Class codes shown are California WCIRB classifications. Your actual classification depends on your operations and payroll records. Coverage is subject to underwriting; general information, not legal advice.