Crowded Corridors: Population Growth Meets Pipeline Risk
Originally published for customers June 18, 2025.
What’s the issue?
From 2014 to 2024, the population surged in several U.S. states, increasing energy demand and escalating the risks and costs for aging natural gas pipelines.
Why does it matter?
As developments encroach on existing pipelines, risks and costs rise, especially in fast-growing states with older infrastructure.
What’s our view?
Pipeline operators should be aware of encroachment, class changes, and integrity risks in fast-growing states, especially those whose average pipeline vintages fall below the industry average of 1975.
From 2014 to 2024, the population surged in several U.S. states, increasing energy demand and escalating the risks and costs for aging natural gas pipelines. As developments encroach on existing pipelines, risks and costs rise, especially in fast-growing states with older infrastructure. Pipeline operators should be aware of encroachment, class changes, and integrity risks in fast-growing states, especially those whose average pipeline vintages fall below the industry average of 1975.
Where People Moved—And Why It Matters for Pipelines
In 2024, the top five most populous states were California, Texas, Florida, New York, and Pennsylvania, all of which have large urban centers. Population growth tells a different story, however. From 2014 to 2024, the states with the most significant increases were:
- Texas: +4.3 million
- Florida: +3.5 million
- Georgia: +1.1 million
- North Carolina: +1.1 million
- Washington: +900k
Meanwhile, a handful of states — Illinois, West Virginia, Mississippi, and Louisiana — experienced population declines.
Population Growth and Pipeline Age: A Risky Combo
This matters because some legacy transmission pipelines were built decades ago in low-density areas. As populations shift and urban areas expand, those same rights-of-way can sit closer to new development. With increased population can come shifting regulatory safety requirements. And while pipeline technology has varied over the years, vintage can be a useful indicator of potential need for resulting remediation due to safety concerns.
Below, we can see the top 10 states by population growth from 2014 to 2024. Texas and Florida’s growth stands out as much higher than that of the other states. We also calculated the weighted average pipeline vintage for each state to analyze the intersection of population growth and pipeline age. Using gas transmission and gathering data from the Pipeline and Hazardous Materials Safety Administration (PHMSA), we totaled each state’s pipeline miles by installation year. We multiplied each total by its installation year and then divided the sum by each state’s total miles to get a weighted average, capturing the average age of major natural gas transportation lines by factoring in when the infrastructure was built.
This lens shows that most states have an average weighted pipeline vintage above the industry average. Washington, Arizona, California, and Tennessee fall below the average, meaning they not only rank in the top ten for population growth but also have some of the oldest infrastructure of these states, which may indicate a greater need for upgrades in those areas.
Encroachment Costs
As populations grow near pipelines, the cost of maintaining pipeline safety and regulatory compliance also rises, particularly due to right-of-way encroachment. Unauthorized construction, landscaping, or excavation near pipelines can damage infrastructure, trigger emergency responses, or force costly design changes.
One primary cost driver is emergency remediation. When third-party construction strikes a pipeline or destabilizes nearby soil, operators must shut down systems, complete repairs, and coordinate public safety measures. While costs vary widely, incident reports and regulatory filings show that these responses can run into the millions, especially in densely populated areas or where environmental cleanup is required.
Some operators and regulatory bodies have begun exploring investments in right-of-way monitoring systems to mitigate that risk. For instance, one modeled estimate by the California Energy Commission estimated that installing such systems on 10% of California’s gas transmission rights-of-way would cost around $30.5 million but could help avoid $38.9 million in damages.
Encroachment also increases legal and regulatory compliance overhead. Zoning disputes, right-of-way agreements, and permitting challenges all add administrative costs. In some cases, operators must relocate pipeline segments or install protective measures like steel casing or cathodic protection.
Regulatory Modernization: Will PHMSA Offer Flexibility or Raise the Bar?
The regulatory landscape may soon shift for operators grappling with aging infrastructure in growing regions. In April 2025, PHMSA announced a new initiative under the Trump administration’s “Unleashing American Energy” agenda, including plans to:
- Modernize class location requirements to better account for population growth without requiring full pipe replacement;
- Update repair criteria to allow modern technologies and materials;
- Streamline permitting for LNG infrastructure and expand the small-scale LNG export market.
The class location update in particular builds on a long-stalled effort. The last major proposal, issued by PHMSA in October 2020, aimed to give operators more flexibility in how they respond when growing population density triggers stricter safety requirements for existing pipelines. Until PHMSA’s regulatory agenda is released (likely later this summer), whether the new 2025 rulemaking will revive or supersede that effort remains unclear. As these proposals take shape, operators navigating fast-growing states should prepare for both opportunity and added scrutiny.