Urgent Alert

Sewer cleaning safety

Learn how to prevent natural gas accidents when doing sewer work

Gas lines can intersect with sewer lines, creating "cross bores"


To help minimize sidewalk and landscaping damage, new service lines such as gas, electric and cable TV are usually installed by drilling holes horizontally beneath the ground. A "cross bore" is when the new pipe or cable accidentally goes through another underground pipe or cable.


Today, when PG&E installs smaller natural gas lines using underground drilling, we utilize the 811 service. This free service notifies utility companies to mark the location of their lines. It helps:

  • make digging safe
  • prevent digging into other lines

The 811 system does not yet include a vast majority of residential sewer lines. To install gas lines safely, we may have to:

  • locate and inspect sewer facilities using our camera equipment, or
  • use more invasive methods, such as trenching and excavation, if necessary.


Image of a gas pipe running through a sewer pipe

If a gas line goes through a sewer line, it can obstruct the flow of waste and may eventually lead to a blockage or backup. Further, a natural gas leak can occur if a plumber damages the gas line while cleaning a sewer line with a gas line cross bore.

We have a dedicated program to proactively identify and repair cross bores through wastewater system inspections. We also use video cameras to inspect some of our newly installed gas lines. If we identify a natural gas cross bore, we will cover the cost of any associated sewer line repairs. We will leave you a courtesy notice if we are planning to work in your area.

A clogged sewer line may be the result of a cross bore with a gas line. Take precautions before any sewer cleaning. Ask your plumber or contractor to use a camera to assess the cause of the blockage and to clear the sewer using a plumbing snake or water jet rather than a cutting tool. Please call us at 1-800-743-5000 if you have any questions or concerns.

  1. Stop all work immediately.
  2. Call 1-800-743-5000 to alert PG&E that you have identified a cross bore. We will safely remove the gas line and make any necessary repairs.
  3. If you or your contractor accidentally damages a gas line, do not attempt to stop the flowing gas or extinguish any fire. Leave the area and move to an upwind location. Call 9-1-1, then contact us at 1-800-743-5000.

Be safe: Call before you clear. Assume that all obstructions involve a cross bore.

Before you begin

  • Look for trees or landscaping that could possibly be causing an obstruction.
  • Ask the resident if there has been any recent utility work in the area.
  • Use an in-line video inspection device if you have access to one, as it will help you to better assess the blockage.

During the cleaning

  • Clear without a cutting tool. Use minimally invasive equipment, such as a plumbing snake or water jet, to attempt to clear the blockage.
  • Feel for obstructions that do not seem to resemble tree roots or other common obstructions as the tool moves through the sewer line.

After your finish

  • Check the blades for yellow or orange plastic when it is withdrawn from the sewer line. Natural gas utility lines are typically made of these colors of plastic.
  • Watch for bubbles caused by natural gas escaping from the toilet or other entry point of the cutting equipment.
  • Inspect the area with a Combustible Gas Indicator (CGI) or other gas-detection equipment, if available.
  • The loss of gas service may not be immediately apparent. Provide the customer with the number for PG&E's Customer Service Line: 1-800-743-5000.

  • Alert everyone nearby and leave the area immediately to an upwind location.
  • Do not use anything that could be a source of ignition including cell phones, light switches, matches or vehicles until you are a safe distance away.
  • Call 9-1-1 for emergency assistance and then call PG&E at 1-800-743-5000.

Recognize signs of a natural gas leak

Please report any signs of a gas leak immediately. Your awareness and action can improve the safety of your home and community.


We add a distinctive, sulfur-like, rotten egg odor so you can detect even small amounts of natural gas. However, DO NOT rely only on your sense of smell to detect the presence of natural gas.


Pay attention to hissing, whistling or roaring sounds coming from underground or from a gas appliance.


Be aware of dirt spraying into the air, continual bubbling in a pond or creek, and dead or dying vegetation in an otherwise moist area.

Inspections are taking place system wide by subcontractors listed below:


  • AirX Engineering
  • APS Environmental
  • Champion Cleaning Specialists, Inc (CCSI)
  • Exodigo, Inc
  • Express
  • Fletcher Plumbing
  • G2 Integrated Solutions LLC
  • Innerline Engineering
  • Monarch Pipeline & Hydrovac Inc
  • Pinnacle Pipeline Inspection, Inc (PPI)
  • Pipeline Video Inspection & Cleaning LLC (AIMS / PVIC)
  • Professional Pipe Services (ProPipe)
  • Quam
  • ULC Robotics, Inc
  • Video Inspection Specialist (VIS)

Working in your area

If you have received a notification that sewer inspections are beginning in your area, we have contacted you for one of two reasons:


  • Access may be required to your sewer clean-out or roof vent during these inspections. If so, our contractor will contact you beforehand.
  • No inspection is needed at your property. We simply want you to be aware of the work that our contractor will be performing nearby.

The applicable checkbox will be marked on your notification.

Sewer inspection date

You will receive a notification that sewer and natural gas lines have been inspected at your property. The notification will inform you of the following information:


  • Complete: No issues were found, or issues were found and repaired.
  • Incomplete: Our contractor will be returning to complete your inspection on the date written on your notification, or we need to schedule an appointment with you for additional access to your sewer line. Please call PG&E's contractor to make an appointment. The contractor's name and telephone number will be listed on your notification.

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