Author Archives: Ramon Alvarez, Ph.D.

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| Tagged | 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 to plug in different variables and observe the outcome.

For more information, visit

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

The Price We Pay For Outdated Clean Air Standards

The Environmental Protection Agency (EPA) is in the process of updating national safeguards to better protect Americans from the health impacts of natural gas and oil emissions. The standards address the emissions discharged during gas and oil drilling and development practices, known in the industry as ‘upstream’ activities.  

Residents around the growing number of drilling, processing and transmission sites will be relieved to hear this because while industry activity has increased dramatically in the U.S., the Clean Air Act standards that regulate the related air pollution are outdated.  Current standards are limited and fail to adequately protect public health.

These industrial activities discharge a host of air pollutants. Drilling rigs, wells and equipment emit hazardous air pollutants such as benzene, a known human carcinogen.  

A number of other airborne contaminants contribute to ground-level ozone or "smog" pollution, elevated levels of which can lead to:

  • decreased lung function, particularly in children who are active outdoors;
  • respiratory-related hospital admissions and emergency room visits  among both children and adults; and
  • lung inflammation, possible long-term damage to the lungs and premature mortality.

Upstream drilling activities were the single largest source of ozone precursor pollutants in Colorado in 2008. The Texas Commission on Environmental Quality reports that storage tanks used in the exploration and production of natural gas in Texas are the largest source of volatile organic compounds (VOCs) in the state. These contaminants contribute to smog and also are comprised of hazardous air pollutants. And according to a recent inventory, oxides of nitrogen and VOC emissions produced from gas production in the Barnett Shale are comparable to the combined emissions from all the cars and trucks in the Dallas Forth-Worth metro area.

Oil and natural gas activities also are the single largest source of U.S. methane emissions.  Methane is both a potent greenhouse gas and a contributor to smog.   In 2009, methane emitted from these activities was roughly equivalent to the carbon dioxide emissions from 60 coal-fired power plants. 

The media is starting to cover the plights of individuals and families who are suffering from exposure to these pollutants. National Public Radio did a story on a family in Pennsylvania that had a number of health symptoms due to drilling. “First Pam, her husband and two grown kids started getting headaches, and then fatigue set in. They've also had dizziness, nausea and nosebleeds. I've had a sore throat so long that I don't know what it would be to not have a sore throat," Pam says. For a week last summer, Pennsylvania state officials monitored the air at the Judys' house and the compressor station. They found…toxic chemicals they say almost surely came from the compressor station.”

It is vitally important that EPA strengthen national emission standards. Improved emission standards will help protect millions of Americans, urban and rural, who live in the vicinity of oil and gas air pollution discharges.

Rigorous federal guidelines will also foster industry innovation and emerging technologies, and increase profits by using available best practices to capture saleable gas that’s otherwise released into the atmosphere.   

Updated safeguards are long overdue but there is no guarantee that they will be the strong standards that are essential to protect the public's health. You can help ensure that they are.

We encourage everyone who wants to breathe cleaner air to let the EPA know you support strong and comprehensive standards for the natural gas and oil industry.

Please get involved by writing to the EPA in favor of updated protections. We also invite you to join us and share your thoughts with the EPA at the upcoming public hearings in: Pittsburgh, Sept. 27; Denver, Sept. 28; and Arlington, Texas on Sept. 29. If you can't make the hearings, you can submit comments online, via fax or through the mail until Oct. 24. In your correspondence, please be sure to reference Docket Number EPA–HQ–OAR–2010–0505; FRL–9456–2.

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

Energy Producers Capture More Today Than In "Good Old Days" But We'll All Benefit If They Do Better

In the frontier days of drilling in the 1900s, discoveries such as Spindletop in Texas and the Drake in Pennsylvania heralded a new era of energy for America. Back then, the gaseous by-product produced at the wellhead was considered a nuisance and flared (burned) or released into the air. Today, it's considered a valuable energy source and routinely harnessed, which results in economic and  environmental benefits. Capturing gas cuts emissions that contribute to ground-level ozone, cause cancer, and contribute to climate change.

Given that it’s 2011, we’re way past the conditions of the 1900s. But, whereas the process of capturing natural gas as an energy source has come a long way, many improvements must still be made to ensure producers capture the maximum amount of natural gas “upstream” at wellheads and throughout the gas processing and transportation network.

Just because the gas can’t be seen doesn’t mean it isn't hazardous. In the last three years, new data shows that natural gas leaks might be twice as high as previously thought. This means that a lot more air pollution is fouling the air we breathe.

The pollution comes from equipment on-site (tanks, valves, compressor engines, flanges), at processing plants (where raw natural gas is purified for residential and commercial use) and throughout the pipeline system.

If you know anyone that lives near drilling sites — such as the Barnett Shale in Texas, the Marcellus Shale in Pennsylvania, Piceance and big chunks of Colorado and Wyoming — you’ve likely heard stories about their public health and environmental impacts.

EDF sponsored a study showing that the emissions produced by natural gas operations around Barnett Shale rival those from 4 million cars and trucks in the Dallas-Fort Worth metro area. Around the country, those who live nearby drilling sites have reported higher incidents of health concerns including respiratory and skin irritation, neurological problems, dizziness and headaches. And in some instances, elevated levels of benzene — a known carcinogen — have been detected.

The Environmental Protection Agency (EPA) has proposed rules that would require use of technologies and practices to capture more of the natural gas now being allowed into the air. These clean air standards are sensible, which makes you wonder why it’s taken a century to put these rules into place at the national level. It also makes you wonder why industry would fight them when they can capture more natural gas and bring it to market. Indeed, in addition to the health and environmental benefits of the rule, there are economic benefits.

A number of natural gas companies already use the practices that the EPA is proposing to cut methane and are touting the resulting economic benefits.

Similar requirements to those the EPA proposed have been in place in Colorado and Wyoming without adverse affects on companies’ profits. Who isn’t for a win-win solution?

I’ll be blogging more about this proposal in the coming days. Please get involved by writing to the EPA in favor of updated clean air protections. We also invite you to join us and share your thoughts with the EPA at the upcoming public hearings in: Pittsburgh, Sept. 27; Denver, Sept. 28; and in Arlington, Texas on Sept. 29. If you can't make the hearings, you can submit comments online until Oct. 24.

There's no better time than now to make your voice heard and show your support for clean air.




Posted in Climate, Natural Gas| Tagged | Comments are closed

Mixed News Coverage Of Report On Climate Pollution From Natural Gas Underscores The Need For Better Data

I blogged last week about the implications of the findings of a paper by Professor Robert Howarth and colleagues at Cornell University.  The paper compares the carbon footprints of natural gas and coal and concludes that – because of methane leakage – natural gas contributes to global warming as much as coal, or even more, when assessed on a life-cycle basis.  While I have questions about the emissions estimates in the paper, it has brought attention to an important fact.

Namely, that we need better data to accurately characterize air pollution from natural gas development and determine with confidence the associated health and climate implications. 

Media coverage over the past week was extensive.  A Washington Post editorial hit the bull’s eye.  Unfortunately, not all the coverage has been 100% accurate – perhaps owing to the technical nature of the issue and the paucity of solid data about methane emissions associated with natural gas systems.

In particular, I want to clarify a reference in a New York Times column to Environmental Defense Fund “estimates of methane gas emissions that are 75 percent lower than Howarth’s.”

Though we appreciate Joe Nocera’s consideration of our work, the statement in the Times’ column is misleading in two ways.  First, the estimates EDF relies on are not our own, but rather taken from the Environmental Protection Agency (EPA), which  just finalized its 2009 inventory of greenhouse gas emissions.   From EPA’s inventory, we estimate that at least 2.2% of gross natural gas produced in the U.S. is released to the atmosphere.   This estimate is highly uncertain, as evidenced by EPA’s recent revision that doubled its estimates from as recently as last year. 

Second, Professor Howarth’s paper uses a different metric:  how much methane is leaked as a percent of the total methane produced over the life of an unconventional gas well.  The paper reports this value to be 3.6% and 7.9% as the low- and high-end estimates.  Assuming these different metrics can be directly compared, EDF’s estimate of the methane leak rate is 39% lower than Professor Howarth’s paper’s low-end estimate and 72% lower than the high-end estimate.  It is unfortunate that the Times’ column only made the comparison with the paper’s high-end estimate.

The only way we can gain confidence about the climate benefits of natural gas relative to other fuels is by obtaining more accurate data about the amount of methane released during the production and distribution of natural gas.  And as I have said before, this is something the natural gas industry – which claims to provide the “low-carbon” fossil fuel – should support.

Posted in Natural Gas| Comments are closed
  • Senior Scientist
    Ramon Alvarez is a Senior Scientist in the Texas EDF office. He works to reduce air pollution, with a current emphasis on emissions from natural gas and oil production. He led EDF's campaign to establish the successful Texas Clean School Bus Program and worked with US-Mexico border industries to find cost-effective methods to reduce waste.

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