Appalachian Basin

DEP: Airing on the Side of Caution with Natural Gas

A recent headline regarding natural gas emissions in northeastern Pennsylvania was quite misleading and the article left out some critical perspective that might have been gained by incorporating some data from an earlier story and digging deeper into DEP data and regulations.  

There has been a lot written lately about the impacts of natural gas development on air quality in Pennsylvania, all of it stemming from a recent study by the RAND Corporation, combined with data from the Pennsylvania Department of Environmental Protection (DEP).  John did a great job laying out the facts in a post entitled Looking for Facts on Air Quality in Pa.? Read the (Whole) Report on February 5 where he told what had been left out of a story put out by E&E News.  The Marcellus Shale Commission (MSC) also put out a great piece on February 12 offering some further observations.

A couple of weeks ago, the Scranton Times-Tribune offered its perspective with a story headlined as Northern Tier counties top state list of Marcellus air pollution.  The headline left a lot to be desired, of course, because it implied Northern Tier counties were polluted by air contamination from natural gas development.  The story was factually correct and even included this paragraph:

Short-term DEP monitoring at shale sites throughout the state in 2010 did not find any compounds at levels that would trigger air-related health issues or exceed federal ambient air quality limits, DEP spokesman Kevin Sunday said. The state is also conducting a long-term air monitoring study in Washington County and is adding stationary or movable monitoring devices in Bradford, Susquehanna and Wyoming counties to evaluate any shale-related changes.

Unfortunately, and also unsurprisingly, that was the 14th and last paragraph in the story, while the article sub-title was “Bradford, Susquehanna top polluters.”  Once again, moreover, there is a lot left out.

What is principally left out is this is one simple thing; perspective.  Data analyzed in a vacuum is unhelpful.  One must look at trends and compare not only with other activities, but, also, over time.  The Times-Tribune piece, for example, made no direct mention of where things are headed with air emissions from the natural gas industry – down because of green completions and consistently improved technology at compressor stations.  It did, to be fair, acknowledge natural gas use for electricity generation had greatly reduced total pollution from sulphur dioxide, but then concentrated on nitrogen oxides (NOx) to suggest the shale gas industry is a big polluter of the air in Bradford and Susquehanna Counties.

The MSC provided some of the much needed perspective with this chart:

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The MSC also noted the following (emphasis added):

Marcellus Shale development accounts for less than 3 percent of nitrogen oxide (NOx) and 1 percent of the total volatile organic compounds (VOC) emitted each year in the Commonwealth.

Although these are a small percentage of total emissions, natural gas producers continue to leverage new technologies aimed at further reducing the industry’s environmental footprint. These environmentally-focused technologies include the implementation of advanced emissions control equipment at compressor stations, vapor recovery units, the deployment of “green completions” technology as well as the use of drilling and completion engines fueled by natural gas.

“Our industry is driven by continuous improvement and technological advancements that further reduce the relatively minimal and short-term environmental footprint associated with safe, tightly-regulated natural gas development,” said Marcellus Shale Coalition CEO Kathryn Z. Klaber. “And while these data focus on that small percentage of emissions that come from our operations, the increased use of clean-burning natural gas is proving critical in addressing and achieving improved air quality in Pennsylvania and across the nation.”

Let’s put this additional numbers on this.  John addressed it in his post where the reader can find a nice table summarizing the expected results from new air emissions rules being adopted by the DEP.  Interestingly, the Scranton Times-Tribune also covered this story 13 days earlier but never brought the two closely related themes together.  Here’s what the Times-Tribune said then (emphasis added):

Taken together, the state expects the new permit and proposed exemption standards to stem pollution as shale gas well sites and compressor stations multiply.

“The steps we are taking now mean far lower emissions at well sites and more efficient compressor stations, resulting in cleaner air as development, production and transmission take place,” DEP Secretary Michael Krancer said.

The new compressor station permit will require a sharp reduction in pollution from the current standard. Allowable levels of smog-forming nitrogen oxides, or “NOx,” will be cut 75 percent in the most common, lean-burn compressor engines, and 90 percent for less common, rich-burn engines. Allowable emissions of volatile organic compounds and carbon monoxide will also be reduced by between 87 and 93 percent.

So, we now know two things; 1) NOx emissions in Bradford and Susquehanna Counties do not reach levels that would trigger air-related health issues or exceed federal ambient air quality limits, and 2) they will be reduced sharply going forward for new operations both at shale gas development sites and at compressor stations.

We also know the levels of volatile organic compounds or VOC’s are even smaller in consequence and scheduled to be cut by the same amount, but let’s stay focused on NOx levels, which as I noted in an earlier post had already, by 2004, declined some 38% nationwide for the petroleum industry, with it accounting for no more than 0.7% of total U.S. emissions.

DEP data indicates NOx emissions from unconventional (shale) gas production are very small compared to total point sources, accounting for only 8.6% of those point sources, which have, themselves, been reduced by an amount roughly 2.5 times the total emissions from shale gas production (non-point and natural sources including forest fires and lightening are among the largest sources of NOx, but not included in this total). Why?  Because electricity generation using natural gas produces far less NOx and conversions to natural gas are producing major reductions.

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Interestingly, the conversion of rigs, other equipment used in natural gas production and at compressor stations (not to mention trucking fleets) will have some of the same impacts on the totals for unconventional gas as well.  This chart compares NOx and VOC rig emissions to natural gas production  from 2005 to 2009  in one of Encana’s production fields after switching to natural gas powered rigs.  Pretty stunning, and we can expect a lot more of the same.


This is on top of the positive effects to be had from green completions and new DEP standards.  Compressor station impacts are not included in the DEP analysis quoted in the second Times-Tribune piece, so improvements on that score are not reflected in that particular piece, but they are substantial as well, as is more than clear from their earlier report; with reductions of 75-90% in NOx.

So, when we get to the bottom line, that second headline about Northern Tier counties topping the list for Marcellus Shale air pollution reflects little more than simple arithmetic; more natural gas wells equals more emissions, but even that is now questionable as new technology and increasing use of natural gas allows production to go up as emissions go down.

Looking at the DEP numbers by county and region provides further insights.  DEP, for example, has calculated Marcellus Shale activities within its Wilkes-Barre region, for example, accounted for 3,077 tons of NOx emissions.  This might sound like a lot until you realize the region has, in the just the last five years, reduced its NOx emissions from other point sources by 5,956 tons or roughly one-third.  Additionally, those reductions have received an important assist from natural gas.

All but 2.17 tons of the NOx point source emissions in Wyoming County, for example, is attributable to the Proctor and Gamble facility in Mehoopany where they manufacture Bounty, Charmin and Pampers products.  Those NOx emissions have been reduced from 671.5 tons in 2006 to 652.3 tons in 2011 and now they’ll be going down further because the plant rolling equipment (forklifts, etc.) have been converted to natural gas that has been developed on-site.

Likewise, UGI has converted its Hunlock Creek power plant in Luzerne County to natural gas as a direct consequence of Marcellus Shale development next door providing an inexpensive nearby source.  The result is this; power production went up significantly while NOx emissions dropped from 495 tons in 2006 to 17.2 tons in 2011.  This is a 477.8 ton or 96.5% reduction in NOx emissions from just one conversion and others are happening as well.  UGI is also converting tens of thousands of homes to natural gas with NOx reductions of as much as 28% each, based on conversion studies from New York City.

So, now we know a third and final fact; natural gas development, thanks to DEP and company initiatives, is powering an actual net reduction in NOx emissions in northeastern Pennsylvania.  We are at safe levels, there will be major reductions from even these levels going forward and natural gas is making it simultaneously possible to reduce other NOx emissions as well.  What we have, then, contrary to the misleading headline, is a triple winner.

Natural gas associated emissions may be higher in some of our counties than in others with less development activity, but that misses the point – natural gas is reducing NOx levels overall and that’s what’s important.  Interesting what you can learn when you go beyond the headline, isn’t it?


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