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C-34 License: Pipeline Contractor’s Ultimate 2023 Guide!

Table of Contents

A pipeline with a sunset in the background

The C-34 license is for Pipeline Contractors that provide an integral service to the functionality of cities.

Pipeline construction is critical to the delivery of water, gas, treatment of sewage, and basic utilities. 

Pipeline services generally include: 

  • Pipeline Design and Fabrication
  • Lowering and Placing
  • Pipeline Inspection
  • Excavation and Backfilling 
  • Testing and Maintenance of Pipelines
  • Environmental Inspection and Surveying

Jobs You Can Do With a C-34 License!

This article will provide you with everything you need to know about how to become a licensed pipeline contractor.

You will learn about:

C-34 License requirements, exam questions, study guides, blueprint reading, and even how to fill out the C-34 License application. 

What is a Pipeline Contractor?

“A pipeline contractor fabricates and installs pipelines for the conveyance of fluids, such as water, gas, or petroleum, or for the containment or protection of any other material, including the application of protective coatings or systems and the trenching, boring, shoring, backfilling, compacting, paving and surfacing necessary to complete the installation of such pipelines”CSLB.GOV

  • The C-34 license is the classification required in the state of California for all persons looking to bid on pipeline projects where the cost of labor and materials exceeds $500. 
  • A Pipeline Contractor is legally not allowed to bid on a project that falls outside of the spectrum of pipeline installation, repair or fabrication.

Duties of a C-34 License Holder

Some of the duties of pipeline contractors include:

  • Installation of sewer mains, sewage pump systems, subdivision storm drains, and irrigation systems
  • Pre-Construction Job Site Surveying
  • Installation and fabrication of crude oil and natural gas pipelines
  • Clearing and grading of vegetation and erosion control measures
  • Use of a variety of heavy excavation equipment such as backhoes, trenching machines
  • Welding and coating pipes
  • Geological surveying and soil testing
  • Maintaining a safe job site
  • Estimation, bidding, accounting, and book-keeping

You will be tested on all aspects of pipeline construction, maintenance, and safety.

When preparing for the C-34 license exam, make sure that you are familiar with all parts of the trade.

Pipeline Subcontractor and the General A License

Pipeline contractors are typically subcontracted by a  General Engineering Contractor or developer.

The C-34 license is typically held by pipeline construction companies that generally are part of large-scale engineering projects.

A General Engineering Contractor oversees that the pipeline construction phase is executed in adherence to environmental regulations. Learn more about the General Engineering Contractor License.


Logo of the Contractors state license board. Illustration of a paint brush, cement truck and saw

The Contractors State License Board (CSLB) is the governing body for all contractors in the state of California.

Their responsibility is to protect the consumer public and ensure that anyone charging over $500 for construction services is qualified and registered with the state of California. 

The C-34 License is issued to pipeline contractors by the CSLB.

The CSLB administers applications and exams. They also maintain a database of all active and inactive contractor license numbers which are public domain. 

How to get a C-34 License in California

To get a pipeline contractors license in California, you must meet the following requirements:

  • Be at least 18 years of age
  • Have a valid Driver's License or USA Issued Identification
  • Have a Social Security or ITIN #
  • Not Currently on probation or parole

You must also have:

  • 4 Years Journey Level Experience
  • A Certifier to sign off on your experience
  • A way to prove your experience if the state asks for documentation

What is a Journey level experience?

A man working in an excavated area on a pipeline

Journeyman-level experience means that you have worked unsupervised full-time for a pipeline construction company or someone that holds the C-34 license.

  • A journeyman can perform all of the duties associated with his or her trade.

The CSLB will want to see four full-time years over the last ten years. The years do not need to be consecutive, but they do need to be four years in total. 

Signature of a Certifier

The following people may be used as certifiers to sign off on your experience when applying for the C-34 license:

  • Licensed General Contractor
  • C-34 License Holder
  • Fellow Employee (within the last 10 years)
  • Former Supervisor (within the last 10 years)
  • Business Associate
  • Fellow Journeyman
  • Union Representative

How to fill out the C-34 License Application

Your certifier will also need to provide a brief but detailed description of your knowledge and skill set.

The way this description is written will be critical to whether or not your application is accepted. For example:

“Robert has installed pipelines” is not descriptive enough 

 The CSLB will want to see something like:

“Robert has installed and engaged in pre-construction site preparation. He has installed pre-cast manholes, sewer mains, crude oil pipelines, and natural gas”

Work Experience for the C-34 License

Construction worker wearing a protective mask welding a pipeline. The state board may request to see documentation of your experience before you can take the C-34 license exam

You must be prepared to submit documentation supporting the experience you claim to have. The Contractors State License Board gives you a few ways that you can prove your experience.

  • Tax Returns
  • Check Stubs
  • Contracts
  • Material Order Invoices or Receipts

The CSLB  receives thousands of applications per month so there is a good chance they won’t document your experience but if you are one of the applicants that get reviewed you will need to be ready to submit something.

The CSLB does not accept pictures of projects.

C-34 License Application Processing, Fees, and Criminal History

The time it takes to get your application processed and assigned a test date fluctuates throughout the year.

Typically you can expect:

  • 6-8 Week Application Processing Time
  • 3-4 Week wait for an Exam date

I have seen some situations where applicants got their test date sooner and somewhere they got their test date much later.

The most common reasons your application would get held up are:

  1. Time of year (processing time slows down during the holidays) 
  2. Criminal History 
  3. Proving Experience
  4. Mistakes on your application 

Application Costs for the C-34 License

The Current CSLB fees are: 

Can you get a Contractor's License with a Felony in California?

A hand holding a black pen filling out a criminal background check

Having a criminal record in no way stops you from getting a C-34 License. Many contractors get licensed in California each year despite having a criminal record. Some of whom obtain multiple licenses.

 The key is, to be honest on the application, even if the felony or misdemeanor happened years ago and even if it was expunged.

See the CSLB's verbiage below:

Just because you have been convicted of a crime does not automatically mean
your application will be denied. CSLB's Criminal Background Unit (CBU) reviews
all criminal convictions to determine if the crime is substantially related to
the duties, qualifications, and/or functions of a contractor. Since no two
conviction records are the same, they are reviewed on a case-by-case basis. The
criteria used by CSLB include whether the crime shows the present or potential
unfitness of an applicant or licensee to perform the functions authorized by
the license in a manner consistent with the public health, safety, or welfare.
In addition, CSLB reviews and considers any evidence of rehabilitation
submitted by the applicant or licensee. Please see the above link to the
California Code of Regulations sections 868 and 869 for more specific
information on the criteria for determining substantial relationship and

Learn more about the Background Check Process here:

BE 100% HONEST ON THE APPLICATION, because they will see everything anyway when you do fingerprinting. The CSLB handles criminal records on a case-by-case basis.

Remember, their responsibility is to protect the public. In my experience, they are primarily concerned with criminal charges associated with Fraud, Embezzlement or Forgery

Contractor License Exam

The exam will be:

  • 115 Questions of Contractor LAW
  • 115 Questions of Pipeline Construction
  • 3 hours to complete each portion
  • Multiple choice exam
  • Done on a computer
  • Closed Book

The Pipeline (C-34 license) Examination is divided into five separate sections:

  1. Planning and Estimating (22%)
  • Project scope planning
  • Cost and material calculation
  1. New Pipeline Installation (36%)
  • Preparing job sites
  • Installing pipeline projects
  • Cleaning, testing, and finishing pipelines
  1. Removal, Repair, and Maintenance of Existing Systems (11%)
  • Locating and inspecting pipes
  • Repairing or abandoning the pipeline system
  1. Specialty Pipeline Projects (11%)
  • Installing grease interceptors
  • Installing fire hydrants
  1. Safety (20%)
  • Employee safety
  • Job site and equipment safety
  • Trench and confined space work
  • Hazardous materials

Recommended Resources

CSLB Test Locations

The CSLB has exam centers all over the state of California. Once your
application is approved you will be given a list of locations you can go and
take the exam based on your zip code.

These are proctored facilities with cubicles where you take the exam on a
computer. The computer will have a calculator for your use. You will not be
able to bring in a phone, notes, or personal calculator to the exam center.

  • You get 18 months after your application is accepted to pass both examinations.
  • ($100 per retake)

Learn more about Contractor License LAW

Contractor License Exam Prep

Grid paper with a calculator, pencil and ruler

Some things to remember:

  • The questions you will see on the exam may use outdated terms
  • Processes may be completely different from how things are done on the job site
  • You will see questions about things you may have never done before
  • Questions will be presented to you as if you are running a large scale construction business with several employees and jobs happening all at once. 
  • Know all aspects of your trade

I have helped natural gas pipeline companies from all over the country get licensed in California. Many are startled by how strict the laws are here. 

Be as prepared as you possibly can. Studying just 10 minutes a day consistently can dramatically increase your chances of passing the test on your first try.

Focus on and study ONLY the information that you need to pass the C-34 License.

Pipeline Construction Apprenticeships

a long pipeline beginning the excavation process

If you don’t have the 4 years required journeyman level experience to get a C-34 license, your journey begins here.

Generally, someone looking to get into this trade would begin by finding a union or apprenticeship program.

For a detailed explanation of this process, check out my article: Apprentice vs Journeyman.

Blueprint Reading Course

A group of construction workers analyzing a construction blueprint

It is critical for pipeline contractors to be able to read blueprints or at least be able to recognize lines and symbols.

Construction blueprints communicate important information about how a structure must be built as well as what materials are necessary for its construction.

Being comfortable with construction blueprints is an invaluable skill for all tradesmen but is especially important for those looking to get the C-34 license.

See our Free Blueprint Reading Course.

OSHA Certification

OSHA training is often a requirement for all construction industry professionals

Statistically, 21% of all work-related fatalities are in construction.

That equals about 1 and 5 worker deaths on average.

In the construction industry, the leading cause of worker deaths is reported as falls, struck by an object, electrocution, and caught-in/between.

The pipeline construction industry can be very dangerous, especially if your workers are not properly trained. For employment with an engineering contractor, typically you have to complete some level of OSHA training.

Learn more about OSHA Training.

Get Started!

As populations around the world grow, maintaining infrastructure that delivers water, gas, and sewage treatment will be increasingly important

Pipeline Construction Companies that obtain the C-34 License that abide by environmental regulations can become highly in demand as they provide a service that large segments of the population depend on. 

Getting the C-34 License can be a huge step up in your career if you are looking to start your own company or become an RMO for an existing firm! The key is to take action and follow these steps from beginning to end. 

If you have found this article helpful feel free to drop a comment below and be sure to check back for updates!