Tag Archives: oil and gas

Refinery tanks.

The U.S. oil and gas industry is leaking a lot of methane — again

The U.S. oil and gas industry emits roughly 13 million metric tons of methane (a potent greenhouse gas) per year. The figure is 60% higher than that estimated by the Environmental Protection Agency (EPA).

Refinery tanks.

Image via Pixabay.

Most of these emissions didn’t come from the industry’s main activity; rather, it oozed out from leaks, malfunctioning equipment, and other “abnormal” operating conditions. Still, irrespective of their source, these emissions do take a toll on the environment. In 2015, the paper notes, these emissions had roughly the same environmental impact as the carbon dioxide emissions resulted from all of the U.S’ coal-fired plants.

Leakie leaks

“This study provides the best estimate to date on the climate impact of oil and gas activity in the United States,” said co-author Jeff Peischl, a CIRES scientist working in NOAA’s Chemical Sciences Division in Boulder, Colorado.

“It’s the culmination of 10 years of studies by scientists across the country, many of which were spearheaded by CIRES and NOAA.”

The paper drew on measurements performed at over 400 well pads in six oil and gas production basins and multiple midstream facilities. The measurements were focused around valves, tanks, and other equipment. In addition, the team also drew on aerial surveys covering large areas of the U.S. oil and gas infrastructure.

Methane was the main focus since it’s the principal component in what we commonly refer to as ‘natural gas’. It’s also a very powerful greenhouse gas, having over 80 times the warming impact of CO2 for the first 20 years after release (it breaks down in the atmosphere after that). The study estimates that methane emissions in the U.S. total about 2.3% of total production — which would negate any potential benefit of the U.S. switching from coal to natural gas in the energy sector over the next 20 years.

The total cost of these methane leakages is around $2 billion, according to the Environmental Defense Fund, “America’s most economically literate green campaigners.” That quantity, they add, would be enough to heat 10 million homes in the U.S.

On one hand, the findings raise concerns around our efforts to mitigate climate change — if the U.S. leaks so much methane under our collective noses, how much does the global oil and gas industry leak? On the other hand, it’s an easily fixable problem. Repairing the leaks and addressing other factors that contribute to the methane emissions would be a quick and cheap way to keep a lot of methane out of the atmosphere. However, this is not the first time the U.S. leaks methane — similar findings were reported on in 2016.

The paper “Assessment of methane emissions from the U.S. oil and gas supply chain” has been published in the journal Science.

The San Ardo Oil Field From the Coast Starlight. Credit: Wikimedia Commons

Scientists find three times more groundwater beneath California’s Central Valley — but a third may already be contaminated

The San Ardo Oil Field From the Coast Starlight. Credit: Wikimedia Commons

The San Ardo Oil Field From the Coast Starlight. Credit: Wikimedia Commons

Stanford researchers found California’s drought-struck Central Valley harbors three times more groundwater than previously thought. That’s bound to come as great news, especially for the farmers who have never seen a water shortage of this kind for 1,200 years.

The researchers, however, stress that the quality of the water is largely unknown. Thousands of oil well stretching from L.A. to Sacramento may have irreversibly contaminated an important fraction of the newly discovered aquifers.

Going deeper than ever before

“It’s not often that you find a ‘water windfall,’ but we just did,” said study co-author Robert Jackson, the Michelle and Kevin Douglas Provostial Professor at Stanford. “There’s far more fresh water and usable water than we expected.”

Previous estimates of California’s water were based on decades-old data and only extended to a maximum depth of about 1,000 feet. But nowadays technology enables us to tap into much deeper aquifers, something that farms and even some residents have been doing for years already. The most severe drought in California’s recorded history is also a strong motivator to invest in deep drilling for water despite only five years ago it wouldn’t have made economic sense.

Using data from 35,000 oil and gas wells, the Stanford researchers were able to characterize shallow and deep groundwater sources in eight California counties. They estimate usable groundwater in the Central Valley amounts to 2,700 cubic kilometers or triple the previous estimate of the state’s water supply.

The findings, though important, are far from being a solution to California’s growing water problem. All of this plentiful water is located between 1,000 and 3,000 feet underground, which makes extraction very expensive. Drilling this deep for water also increases the risk of ground subsidence or the gradual sinking of the land, something that is already happening more often in the Central Valley where some regions have dropped by tens of feet.

Then there’s the issue of quality, which seems to be a gray area at this point since we lack extensive on-site studies. Judging from what data they have at their disposal, the Stanford team says deep aquifer water has a high concentration of salt, so a desalinization process is required to make use of it — yet again, very expensive.

Some water might also be contaminated beyond repair by the numerous oil wells that litter the Central Valley. Right now, many oil and gas wells are drilling directly into usable freshwater or 30 percent of the newly found aquifers.

“We don’t know what effect oil and gas activity has had on groundwater resources, and one reason to highlight this intersection is to consider if we need additional safeguards on this water,” said Jackson, though he later stresses that water near a fracking site doesn’t necessarily mean it’s contaminated.

“What we are saying is that no one is monitoring deep aquifers. No one’s following them through time to see how and if the water quality is changing,” said study co-author Mary Kang, a postdoctoral associate at Stanford School of Earth, Energy & Environmental Sciences. “We might need to use this water in a decade, so it’s definitely worth protecting.”

Yes, we need to protect this water — now, more than ever. However, current EPA guidelines say drillers can operate wells under aquifers if these are not currently being used for drinking water and “cannot now or will not in the future serve as a source of drinking water.” An example of an aquifer that can’t be used as a source of drinking water is a contaminated one. Times have changed, though, and an aquifer 2,000 feet deep can now be called useful. Think Progress reports the Center for Biological Diversity wants to encourage the EPA to reject the applications for aquifer exemptions filled by oil & gas companies looking to drill in new wells.

“I hope that it becomes clear that we need to just not issue any more aquifer exemptions and we need to stop this process of sacrificing our groundwater and start the process of thinking about how we’re going to move beyond that,” Maya Golden Krasner, a staff attorney with the Center for Biological Diversity, told ThinkProgress.