SANDISFIELD — Anti-pipeline protesters who still flock to the site of a nearly completed natural gas spur here keep raising questions about methane emissions from leaking pipelines, and the pipeline company says its working to solve this problem.

While there may be a nearly zero rate initially of gas seeping from this new pipeline, there are two older pipelines next to it, and miles of pipeline across the country that are sending up emissions.

Local resident Susan Baxter, a vocal pipeline watchdog, stood on the road in front of Tennessee Gas Pipeline Co. headquarters here while a few activists were arrested, gestured at the newly constructed pipeline, and said, "Ask Kinder Morgan what their leak rate is."

It's not just environmental groups — both scientists and industry consider "lost gas" from natural gas pipelines a contributor to greenhouse gases.

There are also potential health and safety risks, and consumers inherit the cost of unaccounted-for gas, according to a 2013 report for U.S. Sen. Edward Markey, who represents Massachusetts.

In the state alone, an analysis of Department of Public Utilities reports show that between 2000 and 2011 ratepayers spent between $640 million and $1.5 billion on lost gas due to the state's aging infrastructure.

The report made for Markey outlined these numbers, the various risks to the environment and the lack of incentives for gas companies to replace the infrastructure. It said at least 45 percent of the state's methane emissions for large, stationary facilities come from lost gas.

For this reason, the Conservation Law Foundation calls natural gas leaks "Massachusetts triple threat."

But scientists and the natural gas industry also say that it's hard to measure just how much gas is slipping away and into the atmosphere, according to a 2013 article in Scientific American.

Yet the problem is well-enough known that industry has come together and is also partnering with the federal Environmental Protection Agency to try to manage it.

Kinder Morgan is the parent company of Tennessee Gas, which has nearly completed its four-mile stretch of Sandisfield pipeline here for its 13-mile Connecticut Expansion Project, a natural gas spur with lines through parts of New York and Connecticut.

While the newly constructed line is going into an existing corridor, the need to clear a two-mile swath of state owned and protected Otis State Forest, among other things, has thrown together activists, pipeline company officials and state police.

Lost gas and ONE Future

In an email, Kinder Morgan spokesman David Conover told The Eagle the company is a founding member of ONE Future (Our Nation's Future), a coalition of natural gas industry players across the entire chain from production to delivery.

"ONE Future's goal is to enhance the energy delivery efficiency of the natural gas supply chain by limiting energy waste and achieving a total methane rate of one percent or less of natural gas production," he wrote.

Methane makes up about 95 percent to 98 percent of natural gas, according to the Environmental Protection Agency.

ONE Future's website says while natural gas "is the cleanest fossil fuel when burnt to produce energy ... if methane is emitted directly into the atmosphere instead of combusted, it is a potent greenhouse gas that is roughly 25 times more powerful at trapping heat than carbon dioxide."

While ONE Future also points to EPA data showing a 17 percent reduction in methane emissions from natural gas systems since 1990, it also says, "we know that more can be done."

At least one scientist, Robert Howarth, says greenhouse gasses from shale rock sources "are large and will have disastrous consequences for the Earth's climate."

A 2014 report by Howarth, a Cornell University biogeochemist and ecosystem scientist who studies the effects of shale gas, said with both methane and carbon dioxide in the atmosphere, methane "is greater than 100 times more powerful as an agent of global warming."

In 2015 Howarth said that despite a decrease in emissions from carbon dioxide, the more recent increase in shale gas caused greenhouse gas emissions to rise between 2009 and 2013.

Environmental groups and scientists say any benefits to using natural gas instead of oil or coal might be undermined by leakage in the nation's 300,000 miles of pipeline. But preventing lost gas might be one area where there is cooperation, since what industry does for the integrity of its system could contribute to a reduction in methane emissions.

Stemming leaks

In response to The Eagle's questions about Kinder Morgan's leakage rate, Conover said the company is working on it with the coalition.

"ONE Future is focused on identifying policy and technical solutions that result in improvements in the management of emissions," he said, noting that the goal is to make the natural gas delivery system more efficient "by limiting energy waste."

Conover also said the company is participating in the EPA's Methane Challenge, which involves using EPA methods to estimate emissions and reduce them. It also requires transparency in reporting, according to a ONE Future statement.

But the EPA is shifting priorities and policies since Scott Pruitt was appointed commissioner by President Donald Trump. Since early March, for instance, the agency stopped requiring companies to give it information about equipment and strategies that might reduce greenhouse gasses like methane.

Conover said Kinder Morgan is accountable to its stakeholders, and therefore publishes its "environmental, health and safety performance because we are committed to working openly and transparently."

But Conover said the company's ability to calculate the leakage rate in 70,000 miles of pipeline in the U.S. is "challenging" given that suppliers control aspects of volume.

"EPA estimates 0.45% (lost gas) for the transmission and storage sector as a whole," he wrote. "New [pipeline] build approaches zero and when we finish calculations for our entire system, we expect to be under that EPA estimate and therefore well below our 1% goal. I hope to have a solid number in Q4 of this year."

The extent of gas seepage

Solid numbers for leaks and emissions are not easy to come by, according to Nathan Phillips, professor of Earth and Environment at Boston University. Phillips is well-known for his work using a sensitive methane detector to map thousands of subtle leaks in the Boston natural gas distribution system. Phillips said from that study alone he was able to estimate that about 2.7 percent of gas slips from the system.

Phillips said that while a newly joined pipes might not emit methane, there are definite losses of gas along pipeline routes, including at metering and pressuring stations where pressure is stepped down before the gas is pushed into the distribution system.

A new pipeline, he added, is always an opportunity for leaks and emissions that add up.

"A rough guide is that from fracking [hydrofracturing] to your stove, if three percent of gas is leaked then the carbon benefits of gas vs. coal are erased," he said. "That's how potent methane is."

Phillips said this is why it is helpful to "think holistically about the entire system."

The EPA recommends the industry use infrared cameras to help spot leaks, and Kinder Morgan does so, Conover confirmed. This kind of innovation helps, said David Ismay, an attorney with Conservation Law Foundation, which has done extensive work on the leak issue.

Ismay, a former Navy shipboard engineer, said he knows from his previous line of work that valves and joints do have an acceptable leak rate.

"Every valve on a ship leaks a little," he said. "All gas infrastructure leaks and that is just a function of there being no perfect system. Maybe if it was built by NASA to go out into space there could be a zero leak rate."

But Ismay said this is exactly why methane emissions from seepage and leaks are so powerful.

"Pipelines are generally very long, so any small leakage, and you start multiplying that by the number of joints - it's the multiplier effect."

Ismay said climate change and methane emissions have raised these stakes.

"What were previously acceptable levels [of gas leaks] aren't [now] because there's a new game in town."

Reach staff writer Heather Bellow at 413-329-6871.