Author Archives: Ramon Alvarez, Ph.D.

Another Study Confirms Methane Problem Warrants Action

natgaswellThis post was updated on February 10th.

A new study from the U.S. Department of Energy adds to the large and growing body of research on the problem of methane emissions from the oil and gas industry. Methane is both the main component of natural gas and a powerful climate pollutant – which is why regulators, scientists, and industry all have a vested interest in developing a more complete understanding of how much methane is emitted and from which sources.

Researchers with the Department of Energy’s National Energy Technology Laboratory (NETL) used a life cycle model to integrate data from several of EDF’s methane studies, and estimated that 7.3 million metric tons of methane were emitted along the natural gas supply chain in 2012. This value is about 10% higher than the corresponding estimate in the 2016 EPA Greenhouse Gas Inventory (GHGI), although the difference was not statistically significant (the NETL confidence interval ranged from -20% to +30% of the central estimate). Read More »

Posted in General, Methane, Natural Gas| Comments are closed

Our Interpretation of the UT Study Still Holds. Here’s Why.

Worker

In 2012, EDF spearheaded its largest scientific pursuit to date—a collaborative 16-study effort designed to better understand how much methane is being leaked across the natural gas supply chain (and from where). In the coming months, we plan to wrap up and summarize that work, packaging all that we have learned from this undertaking and the growing body of work from other researchers.

The first study was led by the University of Texas (UT Study) and found that methane emissions from equipment leaks and pneumatic devices were larger than previously thought. The study also found that techniques to reduce emissions from hydraulically fractured well completions are effective at capturing 99% of the methane that was previously vented to the atmosphere, and provided a data-based example of EPA regulations working.

After publication of the findings from the UT Study, public debate about the results ensued, with one criticism suggesting that the UT Study underestimated emissions because of a possible malfunction of one of the instruments used for measuring emissions, the Hi Flow Sampler. Read More »

Posted in Methane, Natural Gas| Comments are closed

What the New NASA 'Hot Spot' Study Tells Us About Methane Leaks

splash8

Look up in New Mexico and on most days you’ll see the unmistakable blue skies that make the Southwest so unique.

But there’s also something hovering over the Four Corners that a naked eye can’t detect:  A 2,500-square mile cloud of methane, the highest concentration of the heat-trapping pollution anywhere in the United States. The Delaware-sized hot-spot was first reported in a study  two years ago.

At the time, researchers were confident the cloud was associated with fossil fuels, but unsure of the precise sources. Was it occurring naturally from the region’s coal beds or coming from a leaky oil and gas industry?

Read More »

Posted in BLM Methane, Climate, Colorado, Methane, Natural Gas| Tagged , , | Comments are closed

A New Study Points to the Need for Improved Air Monitoring in Texas

Source: Dallas Observer

Source: Dallas Observer

A new study accepted for publication in Environmental Science & Technology takes a close look at the amount of certain air pollutants in the Barnett Shale, a booming oil and gas region in North Texas. Using public monitoring data from 2010-2011, researchers from the University of Texas at Austin compared air pollution levels measured at a monitor surrounded by oil and gas operations to the levels that would be expected based on available emission estimates. The result brings to light that the emissions inventory from the Texas Commission on Environmental Quality (TCEQ) for the Barnett Shale does not add up to the observations.

There are numerous air pollutants that can be emitted by oil and natural gas development. Depending on the local composition of the produced gas, emissions can often include volatile organic compounds (VOC, such as propane, butane, pentane, etc.) that contribute to the formation of ground-level ozone (also known as smog), and toxic air pollutants like benzene and hexane that are directly hazardous to human health. Methane, the primary ingredient in natural gas and a greenhouse gas catching lots of attention these days, is another powerful pollutant associated with these operations. Unlike the pollutants listed above, methane directly affects the health of our climate rather than human health. Fortunately, available technologies designed to capture methane are also effective in reducing these other pollutants. However, methane controls alone may not ensure that local air quality concerns are addressed – these require special attention. Read More »

Posted in Air Quality, Natural Gas, Texas| Read 1 Response

What Will It Take To Get Sustained Benefits From Natural Gas?

Natural gas is reshaping our energy landscape. Though the potential energy security and economic benefits are compelling, the challenge is that natural gas comes with its own set of risks to public health and the environment, including exposure to toxic chemicals and waste products, faulty well construction and design, local and regional air quality issues and land use and community impacts.

There has also been much confusion about the impacts of increased natural gas use on the climate.  While natural gas burns cleaner than other fossil fuels when combusted, methane leakage from the production and transportation of natural gas has the potential to remove some or all of those benefits, depending on the leakage rate.  Methane is the main ingredient in natural gas and a greenhouse gas (GHG) pollutant many times more potent than carbon dioxide (CO2), the principal contributor to man-made climate change.

Proceedings of the National Academy of Sciences (PNAS) Paper

EDF has teamed up with several respected scientists to find a better way to examine the climatic impacts of increased use of natural gas and compare it in place of other fossil fuels in a paper titled “Greater Focus Needed on Methane Leakage from Natural Gas Infrastructure” published yesterday in the Proceedings of the National Academy of Sciences (PNAS).  While methane absorbs more heat energy than CO2, making it a much more potent GHG, it also – luckily – has a shorter duration in the atmosphere.  The combination of these factors makes it difficult to compare methane emissions to other GHGs using conventional methods.

Instead, in the PNAS paper, we propose the use of an enhanced scientific method: Technology Warming Potentials (TWPs).  Specifically, this approach reveals the inherent climatic trade-offs of different policy and investment choices involving electricity and transportation.  It illustrates the importance of accounting for methane leakage across the value chain of natural gas (i.e. production, processing and delivery) when considering fuel-switching scenarios from gasoline, diesel fuel and coal to natural gas.  TWPs allow researchers, policy makers and business leaders to make fuel and technology choices while better accounting for their climate impacts.

PNAS Paper Key Findings

We illustrated the new approach by analyzing commonly discussed policy options.  Using the Environmental Protection Agency’s (EPA) best available estimated leakage rate of 2.1% of gas produced (through long-distance transmission pipelines but excluding local distribution pipelines), generating electricity from natural gas in new combined cycle power plants decreases our contribution to climate change, compared to new coal-fired plants.  This is true as long as methane leakage rates stay under 3.2%.

Natural gas powered cars, in contrast, do not reduce climate impacts unless leakage rates are reduced to 1.6% (compared to our estimate of current "well-to-wheels" leakage of 3.0%).  In heavy trucks, the reduction would need to be even more pronounced—converting a fleet of heavy duty trucks to natural gas damages the climate unless leakage is reduced below 1.0%.

The PNAS paper only provides illustrative calculations with EPA’s current estimate of the methane leakage rate and better data is needed to more accurately determine leak rates.  Measuring how much gas is lost to the atmosphere and where the leaks are occurring will help to further target leak reduction opportunities to ensure that natural gas will help mitigate climate change.  EDF is working to obtain extensive empirical data on methane released to the atmosphere across the natural gas supply chain, since the climatic bottom line of fuel switching scenarios involving natural gas is very sensitive to this parameter.

Not only is the data on methane leakage far from definitive, but climate impacts from leakage – and other key public health and environmental risks – could be reduced by strong standards and improved industry practices.  There are many practices and technologies already being used in states such as Colorado and Wyoming, and elsewhere by natural gas companies to reduce gas losses, which results in greater recovery and sale of natural gas, and thus increased economic gains. The return on the initial investment for many of these practices is sometimes as short as a few months and almost always less than two years.  In these tough economic times, it would seem wise to eliminate waste, save money and reduce environmental impact.

In sum, the paper's results suggest that methane leakage rates matter: they can materially affect the relative climate impacts of natural gas over coal and oil.  While the paper does not draw hard and fast conclusions about the future implications of fuel switching, it does provide guidance in terms of the leak rates necessary for fuel switching to produce climate benefits at all points in time.

EDF Methane Leakage Model

We also released a new methane leakage model, based on the science described in the PNAS paper, which allows anyone to test a range of scenarios to quantify the climate benefits, or damages, of natural gas production and usage given specific methane leakage rates.  Users can vary the key system attributes independently to see how they affect net radiative forcing (the primary index used to quantify the effect of greenhouse gases [GHGs] on global temperatures) from U.S. emissions over time.  Visit http://www.edf.org/methaneleakage to plug in different variables and observe the outcome.

For more information, visit http://www.edf.org/methaneleakage.

Posted in Methane, Natural Gas| Read 1 Response

Strong Standards Are Needed To Protect Human Health From Harmful Air Pollution Emitted From Oil And Gas Activities

Update: Please note that the EPA is now due to finalize the national emission standards for oil and gas activities by Tuesday, April 17.

On April 3, 2012 the Environmental Protection Agency (EPA) is due to finalize national emission standards to limit some of the harmful air pollutants discharged from a variety of oil and gas activities.   As Environmental Defense Fund (EDF) has noted in past blogs, leaks, venting and flaring of natural gas from oil and gas activities contribute to ground-level ozone ("smog") and toxic air pollution.  As proposed, EPA's standards would reduce volatile organic compounds that contribute to smog by 25% and hazardous air pollutants by 30%, through the implementation of proven and highly cost-effective practices and technologies. 

Emissions from Oil and Gas Activities Linked to Unhealthy Levels of Ozone "Smog" Pollution

Extensive oil and gas development in parts of rural Wyoming and Utah, where little other industrial activity occurs, has led to dangerous ozone levels, higher than those recorded in some of the most heavily polluted cities. Last year, families in Wyoming’s Upper Green River Basin suffered over forty days in which ozone concentrations exceeded the current health standard.  In Utah’s Uintah basin, residents experienced twice this number of unhealthy ozone days, with one monitor located in Ouray recording forty exceedances alone.

In 2009 then Governor of Wyoming Dave Freudenthal requested EPA designate counties within the Upper Green River Basin as out of attainment with the current ozone health standard explaining the link between natural gas emissions and the serious ozone problems: 

"The State of Wyoming is also challenged by the need to reduce emissions from the natural gas industry which has not traditionally been regulated for ozone nonattainment problems….Therefore, the Wyoming Department of Environmental Quality (WDEQ) has already identified the sources that require controls such as drill rigs, pneumatic pumps, dehydration units and small heaters."

EPA  in turn concluded “[t]he [Wyoming] AQD’s analysis provided with its recommendation shows that elevated ozone at the Boulder monitor is primarily due to local emissions from oil and gas development activities: drilling, production, storage, transport and treating of oil and natural gas.”

In Colorado and Texas, smog-forming emissions from the oil and gas industry have exceeded other major sources of pollution such as vehicles.   In 2008, the Colorado Department of Public Health and Environment concluded that the smog-forming emissions from oil and gas operations exceeded vehicle emissions for the entire state.  Similarly, a 2009 study found that summertime emissions of smog-forming pollutants from oil and gas sources in the Barnett Shale were roughly comparable to emissions from all of the motor vehicles in the Dallas Fort-Worth area.

Oil and Gas Activities Emit Benzene-A Known Carcinogen-and other Air Toxics

Venting, flaring and equipment leaks also emit hazardous air pollutants or air toxics, including hydrogen sulfide, formaldehyde and benzene into the environment.  Elevated levels of benzene have been detected near gas production sites in Texas and Colorado. In 2010 the Texas Commission on Environmental Quality (TCEQ) measured acute concentrations of benzene that exceeded the state’s health-based risk levels at two exploration and production sites in the Barnett Shale in Texas. Research based on air samples taken from oil and gas sites in the Piceance Basin in Colorado in 2008 determined that emissions from well completions, dehydration units, and condensate tanks posed an elevated cancer risk to nearby residents. Similarly, atmospheric measurements collected by researchers at the National Oceanic and Atmospheric Administration concluded that “oil and gas operations in the DJB (Denver-Julesburg Basin) could be the largest source of C6H6 (benzene) in Weld County.”

As oil and gas development continues to expand across the country, strong, national clean air standards are essential to protect public health.  EPA’s standards, which build on clean air measures already in place in states with extensive oil and gas activities, such as Colorado and Wyoming, are an important first step in strengthening clean air protections for human health and the environment.

Posted in Climate, Natural Gas, Washington, DC| Read 1 Response
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