Pipeline Integrity Management Program

As your local natural gas provider, ensuring the safety of our pipeline system is our top priority.

With support from regulators and consumer advocate groups, we’ve developed one of the most proactive pipeline safety programs in the nation.

We were one of the first gas utilities in the U.S. to replace all cast iron pipe, and to replace our bare steel system with new coated steel and polyethylene pipes. These modern, flexible materials have the following benefits:

  • Are highly resistant to corrosion
  • Perform better in landslides or seismic events
  • Keep gas in the pipelines, making our system safer and better for the environment
  • Have a lifespan of up to 100 years

Our pipelines are designed, built, operated and maintained to meet or exceed federal pipeline safety regulations. And we inspect them many times throughout the year.

Additionally, we regulate the flow of gas throughout NW Natural’s system, including at each meter to protect homes and businesses from a pressure change in the pipeline system.

All these safeguards allow us to deliver natural gas safely and reliably to the communities we serve.

Watch the following video to learn how system integrity is a part of our jobs every day.


NW Natural has a “Pipeline Integrity Management Program” in place, which identifies: pipeline segments to be assessed; methods selected to assess each pipeline segment; the basis for selecting each assessment method; and a priority based schedule for completing the assessment.

NW Natural will select the method(s) best suited to address the issues identified in each segment. They include: internal inspection tools; pressure tests; direct assessments (a process that includes data gathering, indirect examination, direct examination, and post-assessment evaluation; and other proven technologies.

Pipelines are the most efficient and safe method by which to transport and deliver natural gas, and they are inherently safer than other modes of transportation, such as rail, barge and truck.

As part of our advanced safety and pipeline integrity programs, and as required by federal law, our employees and authorized contractors conduct about 250,000 routine walking surveys a year.