While much of the focus of the booming natural gas market is drilling, production and new pipelines, in the background is a drive to speed up repair and replacement of older lines that are straining under new, heavier loads.

It’s not a new problem. Pipelines and their regulators have long focused on upgrading infrastructure with a view toward safety. Lately that campaign has been getting a new push from environmentalists who have complained of the effect of methane leaks from old pipes contributing to greenhouse gas (GHG) emissions and worsening climate change impacts.

Those environmentalists are enlisting the aid of labor unions seeking an expanded job market. The unions have their eyes on what some estimate as an $82 billion repair job to fix and replace leaky pipes and related equipment.

According to the U.S. Environmental Protection Agency (EPA), methane accounts for an estimated 9% of U.S. GHG emissions. The Energy Department’s Energy Information Administration (EIA) estimates that less than 1.5% of the total volume of produced natural gas is released as it travels from the wellhead to homes and businesses.

In November, EPA said it has been meeting with other federal agencies in recent months to find ways to cut methane emissions, including actions they could take using existing regulatory authority, an EPA official told a Senate subcommittee.

It’s a problem that has two faces: air pollution from methane leaks or worse, when those leaks cause explosions. New federal regulations for pipeline and distribution operations have resulted in recent years after an explosion on a Pacific Gas and Electric Co. (PG&E) pipeline in September 2010 killed eight people. Within days of the PG&E incident, Department of Transportation Secretary Ray LaHood sent legislation to Capitol Hill seeking to increase oversight and requirements, along with higher penalties for failure to properly maintain elements of the nation’s aging pipeline system (see Daily GPI, Sept. 16, 2010). An amended measure was signed into law in December 2011.

The American Gas Association (AGA), representing U.S. gas utilities, contends on its website that the relative amount of emissions coming from utility pipelines is less than 1%. Only 0.3% of produced natural gas is emitted from gas utility pipes, AGA claims.

“All natural gas utilities work to upgrade and modernize their systems by replacing pipelines that may no longer be fit for service, and there has been a concerted effort to increase and accelerate this activity,” said incoming AGA chairman and Northwest Natural CEO Gregg Kantor.

Speaking at a recent AGA function, Kantor said 34 states have programs designed to accelerate replacement and modernization. “I believe the momentum is there for additional states to adopt similar programs.”

Earlier this year, Pennsylvania regulators approved a Columbia Gas of Pennsylvania plan to repair and replace its existing gas distribution system, portions of which are 100-200 years old and vulnerable to cracking