PITTSBURGH (AP) -- Unions and environmentalists have found one point of agreement in the bitter debate over the natural gas drilling boom: fixing leaky old pipelines that threaten public health and the environment. It's a huge national effort that could cost $82 billion.
The leaks are a problem because methane, the primary component of natural gas, is explosive in high concentrations and is also a potent greenhouse gas that contributes to global warming.
The Department of Transportation estimates that more than 30,000 miles of decades-old, decaying cast-iron pipe are still being used to deliver gas nationwide. In 2011, the American Gas Association estimated the billions in costs for replacement or repair.
The partnership between trade unions and environmentalists might not seem like much of an achievement, but it comes after a year that saw rising tensions between groups that are trying to find a balance between the need for jobs and the need to reduce fossil fuel pollution. Some trade unions have supported the drilling boom, while some environmentalists have pushed for bans on the hydraulic fracturing, or fracking, process.
But the issue of fixing leaks has all sides talking nice.
"To the extent we have a problem we can identify it certainly makes sense to fix it," Delaware Riverkeeper Maya K. van Rossum wrote in an email. "I don't think that calling for the fix of existing leaky pipelines is contrary to a call for ending shale gas development or fracking."
In 2011, a crack in a cast-iron main that was installed in 1928 helped to fuel an explosion that killed five people and destroyed numerous homes in Allentown, Pa., while a 2011 explosion and fire in Philadelphia was traced to a cast-iron main installed in 1942.
There's no exact figure on how much gas is leaking, but old cast-iron pipe is especially at risk. The AGA report estimated that about 500 to 700 miles of repairs are being done each year.
One scientist who has studied the issue of leaky natural gas pipes praised the push for repairs.
Fixing leaks "will save money and lives, improve air quality and health, and slow climate change. What's not to like?" said Duke University scientist Rob Jackson, who was part of research that found extensive leaks throughout Boston and Washington, D.C., neighborhoods.
United Steelworkers president Leo Gerard added in a statement that such projects support "American manufacturing and jobs" and that "replacing aging pipe in our natural gas infrastructure is critical to a cleaner economy" and more efficient gas distribution.
The American Public Gas Association, the Natural Resources Defense Council, the Consumers Union and several other groups are also supporting the push to fix leaky pipelines.
According to the U.S. Department of Transportation, New York City still uses about 3,000 miles of decades-old cast-iron pipe, Boston about 2,000 miles, Philadelphia about 1,500 miles, and the District of Columbia 400 miles. Experts say much of the old pipe dates to before World War II, and some of it may even be more than 100 years old. For example, Philadelphia Gas Works, the nation's largest municipally owned gas utility, was founded in 1834.
Dean Hubbard, the Sierra Club's labor director, says they're working with the AFL/CIO and other unions to identify priorities at the state and national level.
"We are really focused on urban distribution pipelines especially because of public safety concerns," Hubbard said. "We will advocate for repair."
The BlueGreen Alliance, a Washington, D.C.-based group that works with labor unions and environmental groups, is also working with utility companies, state legislatures and Congress to raise awareness and seek funding for the repairs.
U.S. Sen. Edward Markey, D-Mass., introduced two pipeline repair bills last month that the coalition of groups is backing, but it's not yet clear how much support they have in Congress.