Our gas pipelines deliver natural gas to your household. Get the answers to your questions about our systems.
Discover how we keep our natural gas pipelines safe.
Many homes and businesses are served directly by small-diameter gas pipelines. For security reasons, these pipelines cannot be displayed on an online map. Before you begin any digging or excavation project, we encourage you to call 8-1-1. The 8-1-1 line is a free service that marks underground facilities near you.
Use our online map for information about larger-diameter transmission pipelines. Visit Gas Transmission Pipelines.
You can also call us at 1-800-743-5000 to learn more.
PG&E has a comprehensive inspection and monitoring program to address the safety of our natural gas transmission pipeline system. We regularly conduct leak inspections, surveys and patrols of all of our natural gas transmission pipelines. We immediately address any issues identified as threats to public safety. We monitor our gas pipeline system operations 24 hours a day, seven days a week.
If you want additional information about the pipelines nearest you, call us at 1-800-743-5000.
We work with regulatory agencies that oversee our transmission systems. The groups recommend how to keep our natural gas systems safe. The agencies include:
Our combined work aids us in reviewing our records, and in monitoring, surveying and testing pipelines throughout our entire natural gas pipeline system. Our top priority is the safety of our natural gas system.
We’ve taken significant actions to improve the safety and operations of our natural gas system. We strive to keep you and the communities we serve safe. Our actions included:
After the September 2010 San Bruno pipeline accident, we substantially reduced the pressure on pipelines that had segments with characteristics similar to the pipeline that ruptured. This was performed as a precautionary step until we can confirm the safety of the pipelines.
Remember the following important information:
For safety reasons, we add a sulfur-like, “rotten egg” smell to natural gas. When you smell the odor:
Discover how we survey, inspect and test our natural gas pipelines.
We regularly leak survey and patrol all of our pipelines. We try to identify signs of damage, soil erosion and other concerns that can affect the safety of the line. We also use cathodic protection systems to prevent corrosion.
We follow even stricter safety standards on our larger-diameter transmission pipelines,. We inspect and test larger-diameter transmission pipelines using a variety of methods. The methods include pipeline devices equipped with sensors and cameras that travel the length of a pipeline. One such device, known as a “smart pig,” performs in-line inspections. We also conduct hydrostatic pressure testing. This variant of testing involves charging the pipe with water at high pressures to safely reveal potential weaknesses. We can also dig up the pipelines to directly assess them.
Direct assessment is an effective technique for identifying potential coating damage. Coating is the first level of protection against lead-inducing external corrosion. This technology also assesses the current level of cathodic protection, which helps show the current and future health of the pipe. Direct assessment can be performed on nearly any pipeline, regardless of its diameter or configuration.
Leak surveys help us identify problems in a gas transmission pipeline. The problems can affect the integrity of the pipe or the operation of the transmission system. Leak surveys involve a variety of technologies, ranging from combustible gas indicators to newer infrared and laser devices.
Many internal line inspection, or in-line inspection (ILI) devices are available. The devices can be equipped with robotic cameras and sensors to check pipe thickness and welds while detecting flaws and corrosion. Although smart pigs are effective, their use is limited to certain types of pipes. Many of our pipelines were designed and constructed before smart pig technology was developed. Some of our pipelines require significant reconstruction to accommodate this form of inspection.
Hydrostatic testing involves water-pressure testing a pipeline. It’s a proven method of verifying the actual capability of a natural gas pipeline. We want our system to operate at a safe level of pressure. Hydrostatic testing is also used to test such familiar items as scuba tanks, fire extinguishers and air compressor tanks.
A hydrostatic test involves pressurizing a section of pipe with water. The pressure is tested at a higher percentage of the pipe material's maximum design strength for natural gas. This verifies the capability of a pipeline to safely operate at the desired level or pressure. The test can also reveal weaknesses that can lead to defects and leaks in the pipe. To perform a hydrostatic test, the pipeline must be taken out of service for many days.
Learn how we run general operations for our natural gas systems.
Transmission pipelines are generally larger and operate at a higher pressure than distribution pipelines. Transmission pipelines move natural gas from compressor stations and storage facilities to regulators. Regulators reduce the pressure before reaching the distribution system. The distribution system feeds the smaller lines that deliver gas to your business or home.
Our transmission pipelines typically operate at roughly 60 pounds per square inch gauge (psig). Learn more about our gas transmission pipelines in your area from our interactive map. Visit Gas Transmission Pipelines.
A properly maintained pipe can operate safely for 100 years or more. Pipeline age is a factor, but not the only factor that we consider when we inspect our pipelines.
Federal law requires that we establish MAOP for all pipeline systems. MAOP allows for a wide margin of safety. The MAOP is a fraction of the pipe's actual calculated strength. Pipes and pipelines typically operate well below the MAOP.
MAOP is determined in one of three ways:
Federal law requires that pipeline operators establish MAOP for each section of pipeline or each distinct segment of our gas pipeline system.
PG&E controls pressure on our pipeline system through a series of safety measures, including pressure regulator stations and overpressure protection devices. The systems operate to keep pressure within specified limits. They are surveyed and maintained regularly. Learn more about how our natural gas system operates. Visit Natural Gas System Overview.
We have hundreds of automatic over-pressure protection control valves. The valves protect pipelines and are activated when the pressure gets too high. We also have some lines with rupture-control valves for specific needs. Our 24-hour Gas Control Center has the ability to shut down some pipeline systems via remote control.
The valves that we use differ in the following ways:
Discover how we plan to protect our natural gas system during earthquakes.
Gas transmission pipelines are generally resistant to earthquake damage. We expect our pipelines to continue working after earthquakes occur. In locations where there is believed to be a greater risk of pipeline failure from an earthquake, we work to manage the risk of damage to the pipeline. We’re also replacing some pipeline sections with a design that is more earthquake-resistant.
PG&E immediately walks the system after an earthquake occurs. Shortly thereafter, we evaluate the lines by helicopter. The inspections help us confidently determine whether our system has been damaged.
PG&E works with first responders to foster early response safety. Learn how we coordinate with them.
We work with external partners such as first responders and public safety officials. Our goal is to enhance training for emergency preparedness and response. Enhanced emergency prevention, preparedness and response programs consist of education programs. The programs are designed for first responders, contractors, infrastructure departments, community members, schoolchildren and other stakeholders.
We created educational programs with the following objectives:
PG&E wants to create an emergency response plan that incorporates learning from prior experience and industry benchmarks. A coordinated plan can help ensure that emergency response preparedness is embedded in our operations.
We expect the following benefits from our safety programs:
Learn about our system-wide gas pipeline class location study.
We’re conducting a full review of our gas operations to improve our performance. PG&E is striving to bring our system to industry-leading levels. We initiated this review following a CPUC request. The result is the implementation of a new procedure that calls for annual class reviews.
The pipelines are rated through federal and state regulations. The class designation of a pipeline is based on the types of buildings, population density or level of human activity near the segment of pipeline. This classification determines the pipeline's MAOP.
Pipelines are rated by the following four classes based on population:
The review indicated that some segments of pipe have a MAOP higher than appropriate for the current class location. As a result, PG&E identified 7.5 miles of pipeline where we must reduce operating pressure. The length of the pipeline consists of multiple shorter segments in our service area.
We already completed pressure reduction on approximately 3.5 miles of pipelines. We’re continuing to lower the pressure on the other 4 miles. The effort involves more than 30 different locations. We’re carefully planning how to lower the pressure to ensure safety.
We’re still evaluating location data and operating pressures for approximately 100 miles of pipeline. We’re trying to complete the work as quickly as possible.
Safety is our top priority. We’re verifying that operating pressure on all of our lines is appropriate for each location. Where necessary, we’re lowering the pressure.
We’re continuing our engineering work and field upgrades of our newly classified segments. We’re bringing our system back up to the operating pressures needed, providing longer-term reliability.
Find out more about our plan to enhance the PG&E natural gas pipeline system.
The PG&E Pipeline Safety Enhancement Plan can allow us to:
The PG&E Pipeline Safety Enhancement Plan was developed in response to the CPUC decision concerning new pipeline safety regulations. We plan to implement any new CPUC rules and regulations that it adopts.
The CPUC ordered California gas utilities to file implementation plans in June 2011. Before that date, PG&E already started taking action to fix our gas transmission pipelines. The steps were all taken prior to the CPUC order, and we’re continuing the work today.
No, the plan represents only part of our overall plan to enhance gas transmission safety. We’re improving our overall gas operations by strength testing or replacing all pre-1970’s pipelines. The plan also includes:
PG&E created a separate operating unit for our gas operations. The team is led by a gas operations expert who brings 30 years of experience in improving some of the nation's oldest gas systems. We’re also implementing broad changes across the company to increase public safety.
The Pipeline Safety Enhancement Plan reflects new regulatory requirements. The requirements establish a known margin of safety across our gas transmission system. The plan incorporates the following considerations:
Our plan also considers feedback from key regulators, industry experts, utilities and other interested parties.
The pressure testing and replacement work can be conducted in a manner that helps ensure the safety of the surrounding community. Our customer outreach plan is designed to provide the following information:
In certain limited cases, we may have to close streets or ask customers to vacate their homes while a test is conducted. Our customer outreach efforts are designed to minimize inconvenience. We want to provide clear information so that customers and the community know what to expect.
The PG&E plan proposes to automate 228 valves in Phase 1.
Approximately 60 percent of automation miles can be installed on pipelines located in the Bay Area. In 2011, we automated 29 valves on the San Francisco Peninsula.
Automatic valves have the following benefits:
A typical residential customer might have an average monthly gas bill increase of $1.93, from $45.23 to $47.16. A typical small business customer might have an average monthly bill increase of $14.96, from $279.80 to $294.75.
Contact us with more questions. Call our Natural Gas System Help Line at 1-800-743-5000.
The American Gas Association also provides FAQ. Download Get The Facts: Pipeline Safety (PDF, 67 KB).