You are here

Effects of Natural Gas Production on Water Quality in Garfield County, Western Colorado

Morgan Hill

Abstract

Natural gas is a viable energy source that has become increasingly utilized in the last several decades. There are aspects of natural gas activity that could negatively impact the environment. Several of the processes involved with drilling and extraction may release contaminants that can be carcinogenic to humans. While industry proponents claim that drilling activity has little or no effect on surface or groundwater quality, many environmental groups and concerned citizens are sceptical.

While natural gas is a viable energy source that should be explored and utilized, this study hypothesizes that drilling and extraction processes generate potentially harmful wastewater that could migrate into surface and groundwater.

We worked in cooperation with the Center for Environmental Mass Spectrometry at the University of Colorado at Boulder to test for the presence of organic compounds in the surface waters of Garfield County, CO. Mostly compounds of heavier molecular weight and ready ionization were analyzed for using liquid chromatography/mass spectrometry (LC/MS). This was followed by total organic carbon (TOC) and specific ultraviolet absorbance at 254 nm (SUVA254).

One main family of compounds, polyethylene glycols (PEGs), was identified in the chromatograph of a sample. It is confirmed that these compounds are from human activity, however, the source remains unknown. TOC and SUVA254 also indicated that there may be elevated levels of non-natural carbon present in this sample.

Introduction

Since its discovery by explorers in the 1800s, the Western United States has had a long history of natural resource extraction. What began with the gold and silver rushes has developed into a clamoring for energy development and use that continues with relentless force. Coal, oil, and natural gas have become the gold of the West. Natural gas is experiencing an increase in production, perhaps even greater than that of coal or crude oil. Its status as a “transition fuel” to a new energy economy has presently brought it to the forefront of American energy development. Natural gas currently produces 16 percent of the electricity in the United States; with energy as its fastest growing use. It is likely that it will remain indispensible in the energy portfolio for years to come because of its plethora of uses in heating, cooking, and recently, fueling vehicles. Of the three main fossil fuels, it is the most efficient and cleanest-burning (Bryner, 2003).

But is natural gas really as clean as energy developers and the industry claim? Several of the processes involved in drilling and production activities generate the potential for contaminants to be released; and determining their exact effects will continue to be a prevalent field of research and study. A process called hydraulic fracturing, also known as “fracking,” involves the use of millions of gallons of water, sand, and chemicals injected into tightly-packed geologic formations to stimulate the flow of natural gas toward the producing well. While the industry asserts that there is little movement of these fluids away from their target formation, other evidence suggests that fracking fluids can not only migrate into adjoining formations but also facilitate the flow of potentially toxic hydrocarbons towards the earth’s surface.

In Garfield County, CO concerned citizens and stakeholders are speaking out in frustration about what they believe is negligence on the part of the industry in maintaining environmental quality and preventing contamination. While natural gas is a viable energy source that should be explored and utilized, this study hypothesizes that drilling and extraction processes may generate wastewater that is present in concentrations that could be harmful to surface and groundwater quality. We sought to better understand these impacts and determine if they do in fact present a serious problem to regions experiencing natural gas activity.

Background

Before describing our experimental process and results, it is helpful to understand the depth of the issue of natural gas development in the West. We will first explore the geologic sources of natural gas to indicate factors contributing to industry presence in certain regions and the practices they use. We will then examine the various impacts to water quality that may result from natural gas activity and the contaminants associated with them. Finally, the location of our research will be described in depth along with the adverse health impacts that many believe they have experienced there.

Geologic Sources of Natural Gas

In the initial years of natural gas extraction, technological limitations only allowed for the production of conventional natural gas, which is found largely in formations like sands and carbonates. Development is typically much slower, and often only one well can be drilled from a well pad. However, the increased demand for natural gas in the U.S. energy supply has led to a search for more economically viable, efficient and productive sources. New technologies have developed to meet this need, allowing access to previously impossible reserves of natural gas. Termed “unconventional sources,” they now constitute the majority of the market. These are produced mainly from tightly packed coal, shale, and sandstone formations that often require stimulation of new pore spaces to allow gas flow to the surface.

Drilling and Exploration Background and Impacts

The beginning of the completion phase of a well requires what is likely the most controversial and debated component of natural gas extraction: hydraulic fracturing. This process involves injecting tremendous volumes of water, sand and other chemicals into a natural gas-containing formation at very high pressure, causing the rock to fracture and providing a pathway for it to move towards the wellhead and up to the surface. It is the chemical composition of this “fracking fluid” that is of primary concern to public health and wildlife officials; coupled with the fact that miniature earthquakes generated from each fracture are believed to be causing disturbances in groundwater flows and chemistry.

The industry firmly states that their drilling and extraction processes have minimal impacts to surficial and groundwater systems. The depths to which they drill and extract natural gas are typically thousands of feet below normal residential wells, which they believe should not allow contamination by fracking fluid. Despite all their efforts and claims, residents near drilling activities can sometimes have such high concentrations of methane in their tap water that holding a lighter to it can actually cause it to ignite (Fox, 2010). Contaminated waters full of hydrocarbons (like methane, CH4) sometimes create a plume of contaminants in groundwater surrounding wells (Kharaka et al., 2007). Water protection coalitions are concerned and speaking out; therefore, one must ask where the truth falls in this debate: is drilling an environmentally safe activity, or are advocacy groups and residents correct in their accusations?

Produced waters, the term given to waters that co-reside in natural gas-bearing formations, comes with another set of problems. It is estimated that on average in coal bed methane production (not tight-gas or shale gas) there is one to eight cubic feet of water for each cubic foot of natural gas. Some researchers believe produced waters represent the single largest waste stream from oil and gas exploration and production, and have become a major factor in the feasibility of natural gas development (Mondal and Wickramasinghe, 2008). These waters are often highly saline, with toxic heavy metals and organic compounds like petroleum by-products.

Fracking fluid and produced water often mix before they are brought to the surface, generating a potentially dangerous concoction of synthetic chemicals and naturally-occurring contaminants. While the industry takes precautions to prevent this water from entering local waterways, pipelines burst, trucks spill, and holding ponds can leak or overflow.  Thus, it will be crucial to examine the impacts of these accidents to surface water systems as many towns, particularly those in the west, depend on these water bodies for their municipal, agricultural, and industrial water.

Federal Loopholes in Water Protection for Natural Gas Producers

Citizens of the U.S. would generally like to believe that the stipulations in the Safe Drinking Water Act ensure water coming from municipal water supplies (and from domestic wells) will be clean and safe for them to drink. Thus, there has been a great deal of upset among environmental groups and citizens since an exemption, notoriously called the “Halliburton Loophole” by environmental groups, was passed that prevented natural gas companies from being required to reveal the composition of their fracking fluid and excluded them from the stipulations in the act. The New York Times accurately represented the feelings of many when they stated in 2009: “The safety of the nation’s water supply should not have to rely on luck or the public relations talents of the oil and gas industry.”

Natural Gas Production in the Piceance Basin

While many areas of heavy drilling activity are supported by substantial research on the effects of wastewater on their water quality, the Piceance Basin of Western Colorado has relatively little literature published on this subject. This region has seen high levels of natural gas activity and necessitates further investigation regarding the specific compounds present in wastewater there and how this may impact surface water. The Piceance ranges east to west from Glenwood Springs to Grand Junction, and north to south from Rangeley and Meeker to Delta. It includes Garfield, Rio Blanco, Pitkin, and Delta Counties. For this study, we will focus mainly on the southern portion of the basin and the towns incorporated into Garfield County.

Geology of the Piceance Basin

The geology of the Piceance consists primarily of three formations: the Wasatch Formation, the Mesaverde Group, and the Mancos Shale. The Wasatch Formation is the overlying strata of most of the region. Underlying it is the Mesaverde group, which is composed of two different formations: the Iles and the Williams Fork Formations. These are the most pertinent to our study because they are the primary producers of natural gas in the area. The Williams Fork Formation is thickest along the eastern portion near the Grand Hogback at approximately at a depth of 1100 m - 1.571 m (Hettinger and Kirschbaum, 2002).

Constituents in Fracking Fluid

Many of the potential sources for water contamination come from fracking. While concentrations and usage of certain chemicals used in fluids can vary by company, the Garfield County website lists some of the key compounds (Garfield County Oil and Gas Department, 2009). To prevent undue concern, it provides a disclaimer that toxicological effects of fracking fluid are associated only with certain concentrations and exposure pathways; even household cleaning agents may be toxic in high concentrations. However, this statement has little benefit to researchers or residents considering there is currently no legislation forcing companies to release the concentrations they use. Fracking fluid solutions can include ingredients like biocides, which are designed to prevent bacteria that can cause erosion in pipes and fittings; surfactants, which improve gas flow to the well-bore; acids, which dissolve minerals and clays; and foamers, which increase the carrying capacity of the fluid.

Compounds in Produced Water

Produced waters, particularly from coal bed methane, have been researched extensively in many regions affected by natural gas. They are known to contain concentrations of heavy metals (Rice and Nuccio, 2007; McBeth et al., 2003), be highly saline and sodic (Ganjegunte et al, 2008), and, in many cases of natural gas production, contain high levels of organic compounds (Orem et al., 2003). Many of these can be toxic to humans, including the following family of compounds benzene, ethylene, toluene, and xylene (BTEX). This group is commonly found in diesel fuel, which was formerly a typical constituent in fracking fluid. However, many companies have phased out the use of diesel fuel due to these toxic properties. Regardless, many waters that co-reside in natural gas-containing formations have high concentrations of BTEX because of their close relation with petroleum products, and they have recently appeared in numerous studies on the impacts of natural gas activity to water quality.

Fate and Transport of Natural Gas Wastewaters

There are many unanswered questions about the fate and transport of wastewaters from natural gas activities. Many sources, like the EPA and the Natural Gas Industry, state that the majority of drilling and fracking fluids injected are removed during extraction, leaving a low chance of migration away from the intended formation. However, some studies have shown that over 50% of fluids can remain within a well after it is completed (Sumi, 2005).  In British Columbia, an area also experiencing an expansion of the shale gas industry, “fracture communication incidences” have caused fracking fluids injected into one well to emerge in other wells up to 670 meters away.  There is little way to tell exactly how these fluids will move as often the fractures will open in unpredictable ways (Nikiforuk, 2010).

Mamm Creek—A Hydrogeologic Examination of High Levels of Tight Gas Drilling

In 2008, a study was published on the impacts of natural gas activity to Mamm Creek, near Rifle, CO. The results of this report confirmed that there was a relationship between petroleum activity and impacts to water quality, mainly elevated concentrations of methane and chloride in groundwater wells. Often in testing for methane, researchers use the ratio of C13/C12 to test whether methane present is thermogenic (created by heat and pressure below the earth) or biogenic (created by microbial activity) in origin. This analysis revealed elevated methane levels that were primarily thermogenic in origin. The implications of these results indicate that while many natural gas companies would like to assure there is little to no movement of produced water or fracking fluids out of producing formations, petroleum substances have been detected at the surface.

Human Impacts: Natural gas activity is detrimental to humans on several levels. Noise pollution disturbs the peace of neighborhoods and ranches, 150-foot-tall drilling rigs reduce the aesthetic quality of residential properties, and many of the compounds that are released into the water and air are thought to be damaging to human health. Many constituents in fracking fluids are believed to be harmful to humans; notably, the benzene, toluene, ethylbenzene, and xylene (BTEX), found in produced water, are some of the most well known and understood. Benzene, in particular, is known for harming the hematological system, causing diseases like anemia and leukemia (American Society for Toxilogical and Disease Registry, 2004).

The hundreds of other chemicals used in fracking fluid can also have varying impacts to human health. These can be chronic or acute, depending on the type of chemical, the duration, and the intensity of exposure. Some of the most widespread health effects pertain to the skin, eyes and other sensory organs in addition to affecting the gastrointestinal system and the liver. Over half show effects in the brain and nervous system (Colburn, 2010). Much like BTEX, these compounds can cause long-term health effects like cancer and mutations. However, whether various regulatory entities have something at stake, or because these residents lack strong enough proof of causation, none of the reports or concerns have been legitimately acknowledged or validated.

Research Questions and Objectives

This research sought to indentify if natural gas extraction has an impact on surface and groundwater quality in the Piceance Basin. Since many compounds and chemicals from extraction are released only in small quantities, we attempted to analyze if they are found in levels that are appropriate for human and aquatic health.

Hypothesis: We hypothesize that while natural gas is a viable energy source that should be explored and utilized, natural gas extraction processes may generate wastewater that is present in concentrations that are harmful to both surface and groundwater quality. Little is known about the movement of fracking fluid and other hydrocarbons once fracking has occurred. Based on evidence from other studies investigating thermogenic and biogenic methane, we also hypothesize that there is migration of these contaminants that could allow them to enter surface and groundwater.

Research Description: Approach and Methods

This research included an Outreach Project and an associated grant in which we identified the needs of citizens in Western Colorado and worked with them to solve problems related to their concerns from natural gas development. They had the opportunity to request our assistance, which then allowed us to integrate the findings of our study with the community of Garfield County. In addition to the Outreach Grant, the University of Colorado provided funds in the form of a grant through the Undergraduate Research Opportunities Program (UROP).

Primary Data Collection

Site Identification: Disturbed Locations

For a known disturbed stream we selected West Divide Creek. Water quality may also be affected by substantial agriculture and ranching practices here, which deposit fertilizers, pesticides, and livestock waste into local water bodies. Due to limited time and funding, we collected 10 samples with two replicates each for a total of 20. The primary site selected was on the property of a resident who observed what she believed were impacts from a seep in 2008; we also collected samples from her drinking water well and an EnCana monitoring well in close proximity to the creek.

Site Identification— Reference Locations

In an attempt to establish at least some level of background, samples were collected at a site that had been used as a reference location where a seep resulting from faulty cement casing had occurred in 2004. Some level of natural gas activity has been underway above this location since then, but the bulk of natural gas development is occurring on the lower reaches of the stream. This was site was also on West Divide Creek, approximately two miles upstream of the known affected segment. Two samples with two duplicates were collected. Also, to aid the town of Battlement Mesa in the water quality analysis portion of their Health Impact Assessment, we collected samples at the intake and output from the water treatment plant there.

Sample Collection—Procedures

Samples were taken in September 2010, during a low-flow period to provide a characteristic snapshot of contaminants present. In the process of sample collection, we adhered to the protocols provided by the USGS. All samples were collected in baked, glass, 1-liter, amber bottles complete with Teflon™ lined caps to ensure sample integrity. Each bottle was rinsed in the field three times with sample and filled to the top on the fourth sampling; disposable gloves were used when taking the sample to prevent any personal care products from contaminating sample bottles. Samples were stored in coolers with blue ice packs during transport from sampling locations and refrigerated until samples were extracted for analysis. 

Sample Analysis

Basic water quality characteristics were measured at the time of collection (and subsequently in the event that equipment was not working properly or field conditions did not allow for accurate readings). To test for conductivity (K), a common characteristic of produced water, a standard conductivity meter was used (Orion 122). A pH reading was also taken for each sample at the time of collection (Orion 250A meter and 9107 combination electrode).

Compounds identified in wastewater, from previous sampling done in the area and literature published on coal bed methane produced waters, were tested for in the samples. Distinction between compounds from fracking fluid and those from produced water was based largely off of these sources. Organic contaminants were analyzed in nine of the samples taken by a variety of techniques available in the Center of Environmental Mass Spectrometry in the Department of Civil, Environmental, and Architectural Engineering at the University of Colorado at Boulder. Drs. Michael Thurman and Imma Ferrer, who run the lab, operated the equipment and identified the compounds present. Analysis methods were obtained from their lab.

Sample Extraction

An off-line solid-phase extraction (SPE) was used for the pre-concentration of the water samples. Extraction experiments were performed using an automated sample preparation with extraction columns system (GX-271 ASPEC, Gilson, Middleton, WI, USA) fitted with a 25-mL syringe pump. Water samples were extracted with Oasis hydrophilic-lipophilic balance (HLB) cartridges. The cartridges were then conditioned with 4 mL of methanol followed by 6 mL of high performance liquid chromatography (HPLC) grade water at a flow rate of 1 ml/min. The water samples (100mL) were loaded at a flow rate of 10 mL/min.

Liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) analyses

The separation of the water extracts was carried out using an HPLC system (Agilent Series 1200) equipped with a reversed phase C8 analytical column of 150 mm x 4.6 mm and 5 mm particle size. Column temperature was maintained at 25 ºC. The injected sample volume was 500 mL. Mobile phases A and B were acetonitrile and water with 0.1% formic acid. The flow-rate used was 0.6 mL/min. Data was processed with MassHunter software. Accurate mass measurements of each peak from the total ion chromatograms were obtained by means of an automated calibrant delivery system using a dual-nebulizer ESI.

Total Organic Carbon

To gain a more complete understanding of the potential sources of organic constituents in each of the samples, we also conducted an analysis of total organic carbon (TOC). It is often a highly reliable measure of the many organic molecules that make up the dissolved organic load (Thurman, 1985). Unusual ground water concentrations may receive DOC from organic matter derived from petroleum products (Thurman, 1985). Therefore, if our values were uncharacteristically high it can indicate either migration of naturally occurring organic contaminants from hydraulically fractured formations or the presence of fracking fluids themselves. TOC/DOC (minimum detection level: .02 mg/L) were measured using a Shimadzu TOC-VCSH analyzer in the Environmental Center for Mass Spectrometry.

Specific Ultraviolent Absorbance

The specific ultraviolet absorbance (SUVA) provides a helpful comparison of the total organic carbon present to what is naturally occurring (Weishaar, 2003). Dissolved organic matter (DOM), a comparable measurement to dissolved organic carbon, constitutes the majority of organic carbon in water, but contaminated samples can have moderately high TOC values that are derived from other sources like synthetic organic compounds. SUVA254 tends to increase when the contribution of organic carbon is primarily from terrestrially derived dissolved organic matter (Jaffe et al, 2008). The analysis for UV absorbance was conducted using a Hach DR 5000 spectrophotometer. We then calculated SUVA254 by dividing this value by the TOC to determine the ratio for eight of the ten samples.

Results

Results of our study can generally be divided into two categories based on analytic methods: TOC, which also includes a measurement of ultraviolet absorbance, and LC/MS. Together they helped paint a clearer picture of our findings.

Total Organic Carbon

This analysis revealed fairly average TOC values for surface water. The sample taken from Battlement Mesa’s water treatment plant intake (labeled BM WTP Intake) showed TOC concentrations very typical of the Colorado River at 2.9 mg/L; the one-unit decrease in TOC for its output was also standard and indicates safety for human consumption. This indicated that its flocculation and sedimentation treatments were working properly to remove organic materials. Samples like the West Divide Creek Rd. 346 Bridge exhibited fairly (although not abnormally) high values of dissolved organic carbon.

TOC results of the two shallow groundwater wells indicated several interesting characteristics about their geology and hydrology. EnCana monitoring well #23 showed what would be unusually high values of TOC had it been purely groundwater. The water from this sample had both a brackish color and a strange smell typical of hydrogen sulfide (H2S), both of which could indicate that TOC values might be higher than usual because of anaerobic, methane-producing activity. However, its concentration of 4.1 mg/L shows what would be normal for surface water. This, along with the TOC value from the residential well, indicates that there are high levels of mixing between ground and surface water in this region, and that this well was receiving high input from the alluvial floodplain of West Divide Creek, which is located only about 40 feet away.

Specific Ultraviolet Absorbance at 254 nm (SUVA254)

Our analysis showed relatively but not abnormally low SUVA254 values compared to creeks and rivers in other studies. Often, rivers like the Colorado will have values around 0.03 Lmg-1cm-1. Aside from an extremely low value for the BM water treatment plant outflow, EnCana monitoring well 23 had the lowest SUVA254 by a significant amount. In fact, the only lower naturally occurring SUVA254 found in a study by Weishaar et al. in 2003 was for the Pacific Ocean at 0.006.

The graph for the absorbance from 200-600 for all eight of the samples also illustrates a low SUVA254 in EnCana Monitoring Well 23 compared to the others. Aside from the Water Treatment Plant, which was clearly successful in removing organic matter through its treatment processes, its curve falls lowest; indeed much lower than that of the other shallow groundwater well only 100 yards away. The curve here is shown in red to distinguish it from the others, shown in blue. Its relationship to the other samples indicates that the organic matter present was likely not from natural biogeochemical activity near the surface, but from other organic carbon sources.

Liquid Chromatography/Mass Spectrometry (LC/MS)

The majority of the results of the LC/MS analysis were fairly typical for surface and shallow groundwater. Samples taken from several points along Divide Creek, as well as those from the Battlement Mesa water treatment plant and domestic well, all indicated relatively normal concentrations of organic matter. The curve in the center is often referred to as “natural organic matter” (also called “unresolved complex mixture”). This sample’s chromatograph, taken from a point below the believed 2008 methane seep, shows what is typically indicative of surface water organic compound concentrations. The tall peak at the initial point along the graph as well as the two spikes, denoting very hydrophobic compounds, towards the end indicate compounds used in the sample preparation and concentration processes and are displayed in every chromatograph from the Center for Environmental Mass Spectrometry.

One sample, however, did reveal the presence of a certain family of compounds. The sample taken from EnCana monitoring well #23 showed a set of five polyethylene glycols (PEGs). Each of these is demonstrated by a different peak, shown below. We estimate that concentrations were likely present in the 100-500 ng/L range, however we cannot say this with certainty as standards for a comparison could not be obtained at this time. The Diagnostic Ion Approach, developed by Thurman and Ferrer, was used to identify these compounds. Diagnostic ions can be particularly useful in identifying PEGs, specifically those at m/z 89, 133, and 177. In this case, they are formed by the fragmentation and cyclization of the ethylene glycol chain (Ferrer and Thurman, 2003). 

In previous research on polyethylene glycols, conducted by Professors Mike Thurman and Imma Ferrer, the family of compounds was identified through several characteristics. First, they observed several sequential chromatographic peaks (much like those observed in the chromatograph for EnCana monitoring well 23) that were close in retention time and had apparently protonated molecules [M+H]+ and that the atomic masses of each peak increased at an equal interval, in this case by 44 units. The same three ions also appeared in each of the chromatographic peaks, suggesting a homologous relationship between them.

Discussion

Our results yielded little evidence of the presence of toxic compounds in West Divide Creek or Battlement Mesa Water treatment plant. However, this does not discount the fact that cases of contamination have been occurring in regions like Garfield County which are in the midst of natural gas activity. Many other studies have shown that toxic metals and metalloids, dangerous organic compounds, and elevated salinity are present in wastewaters from drilling and extraction; limitations of this study may have prevented them from being discovered had they been present in Garfield County previously or currently. This section will seek to explore what we did discover and its potential sources.

PEGs: Industrial Uses, Potential Toxicity, and Fate

The discovery of polyethylene glycols in EnCana monitoring well #23 near West Divide Creek could be attributed to several sources. There is a tremendously wide range of uses for the compound, which posses dispersing properties valuable for operations in a variety of industries.  They possess a very low toxicity to humans, but they can cause indigestion. Its uses range from pesticide application to flocculation (Sheftel, 2000). It can also serve as a thickening agent in hydraulic operations, and as water-soluble film in food packaging (ChemIndustry.ru).

Surfactants like PEGs are sometimes used in drilling and fracking operations, as they are believed to cause easier flow of natural gas to the wellbore. If high levels of migration were occurring from a fractured formation, the possibility may exist for us to detect some concentrations of a solvent. However, our limited knowledge of the exact composition of fracking fluids made it impossible to determine if this set of PEG compounds came from that source; and there is no guarantee that EnCana, the company responsible for many of the wells in the area, has used PEGs in their natural gas drilling operations. In order for LC/MS to determine with high levels of accuracy if compounds present were from fracking fluid, a sample of the fluid would need to be obtained for a compound-by-compound comparison.

Despite our uncertainty about the exact source of these PEGs, we can conclusively state that they are man-made and not from natural causes. Due to our knowledge of their use in drilling processes, it seems probable that PEGs could have been used as a lubricant or other fluid thickener in the process of drilling EnCana monitoring well #23. PEGs of varying molecular weights may persist for several years in water depending on microbial activity, so it would be possible for constituents used in the 2008 drilling of the well to remain present at the time of our sample collection. It is unconfirmed if EnCana used PEGs in their drilling processes.

Study Limitations

Our examination of the impacts of natural gas activity to water quality in Garfield County was limited by several factors that may have prevented us from finding potential contaminants. For example, the preliminary nature of the study only allowed for sample collection over a period of a day. Studies with a greater abundance of resources, both financially and temporally, would have taken more samples from a broader range of locations over a sustained period of time. This would account for changes in stream-flows and relationship to drilling and fracking operations.

Analysis methods could also have limited our findings. LC/MS is extremely accurate in analyzing compounds of a particular nature, typically those that are of heavier molecular weights and ionize easily. However, many of the compounds we identified in previous water quality studies and government reports had a low molecular weight, often less than 100 g/mol. This typically means that they readily volatilize (indeed, many of them are identified as volatile organic compounds). The BTEX compounds, as well as many fracking fluid constituents, are of a low molecular weight and do not ionize largely due to their heterocyclic nature; yet they remain one of the greatest concerns related to water contamination from natural gas activity. To more comprehensively study these compounds, use of gas chromatography/mass spectrometry is recommended.

Industry Best Practices and Policy Recommendations

Improving technology

The technology involved in natural gas extraction has made huge leaps in the last few decades, improving the efficiency and in many cases, reducing the environmental impacts of natural gas activity. While directional drilling, produced water recycling, and pipelines are all a step in the right direction, the potential exists for many companies to further improve their practices. Reduction in the use of toxic chemicals or conversion to non-toxic ones in the drilling and fracking process can be just as efficient and far less harmful. Evidence suggests that wells fractured with simply water and proppant, which is far less toxic, are just as efficient at production if not more so than those fractured with a gel-based solution (Mall, 2007).

The EPA’s Natural Gas STAR program encourages natural gas companies to adopt technologies and practices that are proven cost-effective in improving operational efficiency and reducing methane emissions (EPA, 2010). Because methane is one of the most potent greenhouse gases, reducing its emissions from natural gas operations can be tremendously beneficial to the environment. On their website, the EPA has listed some of the best practices for the industry to use in their compressors/engines, dehydrators, pneumatics/controls, pipelines, tanks, valves, and wells. Technologies like “green completion” involve bringing equipment on site to clean up produced gas as it is initially being brought to the surface; the EPA also recommends installing velocity tubing strings, down-hole separator pumps, and compressors to capture casing-head gas.

Policy recommendations

There are several policy changes that many believe could alter the political landscape surrounding natural gas, and in turn improve its safety. Currently, a bill is waiting for review that has the potential to change entirely the way the industry is regulated. Named the Fracturing Responsibility and Awareness of Chemicals Act, it contains provisions that would require natural gas companies to release the composition of their fracking fluid to both regulatory agencies and medical professionals. It also states that the state or the administrator must make the information contained in each disclosure of chemical constituents available to the public. This would give the EPA and other agencies, such as the state, the authority to monitor and control the use of fracking fluid.

Some states have decided they were unwilling to wait for this bill to be passed or for the EPA to conduct its proposed study. Wyoming is now the first state in the nation to declare that natural gas companies must make public the ingredients used in their fracking fluids. In June of this year (2010) the Wyoming Oil and Gas Conservation Commission unanimously ruled that ingredients would be reported at the insistence of Governor Dave Freudenthal. According to ProPublica, the nonprofit journalism outfit that has been looking into the effects of fracking over the last few years, as much as 85 percent of the fracking fluids are left underground after wells are drilled (NewWest, 2010).

Conclusion

Our study could make no real case for natural gas activity seriously impacting water quality in Garfield County. However, studies like those conducted on the Mamm Creek Field and, in 2004, on the Divide Creek seep have provided strong evidence for contamination. Residents in areas like Pavillion, WY, and Dimock, NY are almost certainly being affected by natural gas activity. While companies drilling and fracking in these areas assert that they are not responsible for these impacts, it seems highly unlikely that the presence of hydrocarbons in domestic wells could be attributed to other sources. These cases of contamination indicate the need for improved operational practices and technology as well as stronger regulatory power over fracking and drilling fluid use.

Bibliography

ChemIDPlus Advanced.  (Accessed September 2010). United States National Library of Medicine..  < http://chem.sis.nlm.nih.gov/chemidplus/>

ChemIndustry.RU. (2010). Polyethylene Glycol. <http://chemindustry.ru/Polyethylene_Glycol.php>.

Cole, R. and Pranter, M. (2009). From Rocks to Models: Outcrop-Based Analysis and Statistics for Subsurface Characterization of Fluvial Reservoir Geometry and Connectivity, Williams Fork Formation, Piceance Basin, Colorado. Energy and Minerals Applied Research Center.

Colborn, T., Kwiatkowski, C., Schultz, K., & Bachran, M. (2010). Natural Gas Operations from a Public Health Perspective. International Journal of Human and Ecological Risk Assessment.

Colson, J. (2010). Gas Company has Plans to Drill 284 Wells South of Silt. Glenwood Springs Post Independent.

Energy Policy Act of 2005. Pub.L. 109-58. (2005).

Department of Energy. (2009). Modern Shale Gas Development in the United States: A Primer.

Environmental Protection Agency. (2004). Evaluation of Impacts to Underground Sources of Drinking Water by Hydraulic Fracturing of Coalbed Methane Reservoirs.

Environmental Protection Agency. (2004). Understanding the Safe Drinking Water Act.

Environmental Protection Agency. (2009). Natural Gas Star Program: Recommended Technologies and Practices. <http://www.epa.gov/gasstar/tools/recommended.html>.

Editorial Desk. (2009). The Halliburton Loophole. New York Times.

Farquhar, B. (2010). Wyoming First in Nation to Require Public Disclosure of Chemicals used in Gas, Oil Drilling. NewWest.net.

Ferrer, I., Furlong, E. T., & Thurman, E. M. (2003). Identification of Homologue Unknowns in Wastewater by Ion Trap MSn: The Diagnostic Ion Approach. Liquid Chromatography/Mass Spectrometry, MS/MS and Time-of-Flight MS: Analysis of Emerging Contaminants. ACS Symposium Series 850, 376-396.

Fracturing Responsibility and Awareness of Chemicals (FRAC) Act,  June 9, 2009

Henni, A., Tontiwachwuthikul, P., & Chakma, A. (2005). Solubilities of Carbon Dioxide in Polyethylene Glycol Ethers. The Canadian Journal of Chemical Engineering, 83.

Hettinger, R. D., & Kirschbaum, M. A. (2002). Stratigraphy of the Upper Cretaceous Mancos Shale (Upper Part) and Mesaverde Group in the Southern Part of the Unita and Piceance Basins, Utah and Colorado. Geologic Investigation Series, I.2764.

Ganjegunte, G. K., King, L. A., & Vance, G. F. (2008). Cumulative soil chemistry changes from land application of saline-sodic waters. Journal of Environmental Quality, 37(5): S128-S138.

Fox, J. (Director). (2010). Gasland. United Kingdom.

Hawthorne, S. E., & Siever, R. E. (1984) Emission of Organic Air Pollutants from Shale Oil Wastewaters. Environmental Science Technology, 18(6).

Jaffe, R., McKnight, D., Maie, N., Cory, R., McDowell, W. H., & Campbell, J. L. (2008). Spatial and Temporal Variations in DOM Composition in Ecosystems: The Importance of Long-Term Monitoring of Optical Properties. Journal of Geophysical Research, 113.

Kharaka, Y. K., Kakouros, E., Thordsen, J. J., Ambats, G., & Abbott, M. M. (2007). Fate and Groundwater Impacts of Produced Water Releases at OSPER “B” Site, Osage County, Oklahoma. Applied Geochemistry, 22(10): 2164-2176.

Mall, A., Buccino, S. & Nichols, J. (2007). Drilling Down: Protecting Western Communities from the Health and Environmental Effects of Oil and Gas Production. Natural Resource Defense Council.

McBeth, I., Reddy, K. J., & Skinner, Q. D. (2003) Chemistry of Trace Elements in Coalbed Methane Product Water. Water research, 37(4): 884-890.

Mylott, R. & Abrams, V. (2010, April 14) EPA Releases Results of Pavillion, Wyo. Water Well Testing. Oil & Gas Department of Garfield County. <http://www.garfield-county.com/Index.aspx?page=570>.

Nikiforuk, A. (2010). A Fracking Disaster in the Making: Report. The Tyee.

Orem, W. H., Tatu, C. A., Lerch, H. E., Rice, C. A., Bartos, T. T., Bates, T., & Corum, M. D. (2007). Organic Compounds in Produced Waters from Coalbed Natural Gas Wells in the Powder River Basin, Wyoming, USA. Applied Geochemistry, 22(10): 2240-2256.

Oil & Gas Department of Garfield County. (2010, 14 April). <http://www.garfield-county.com/Index.aspx?page=570>.

Oil and Gas Accountability Project: Best Practices. (2008). <http://www.earthworksaction.org/ogapbestprac.cfm>.

Ryan, J. (2010). Fate and Transport of Mercury and Organic Thiol Compounds from Coal Bed Methane Discharge Waters in the Rocky Mountain Region.

Sheftel, V. O. (2000). Polyethylene Glycols (PEGs)- Indirect Food Additives and Polymers: Migration and Toxicology.Web. <http://www.mindfully.org/Plastic/Polymers/Polyethylene-Glycols-PEGs.htm>.

Sumi, L. (2005). Our Drinking Water at Risk: What the EPA and the Oil and Gas Industry Don’t Want Us to Know about Hydraulic Fracturing. Oil and Gas Accountability Project.

Thurman, M. & Ferrar, I. Analysis Methods. The University of Colorado Environmental Center for Mass Spectrometry.

Organic Chemistry of Natural Waters. (1985). Thurman, M. (Ed.) Kluwer Academic Publishers.

Thyne, G. (2008). Review of Phase II Hydrogeologic Study: Prepared for Garfield County.

University of Colorado Environmental Center for Mass Spectrometry. (2009). CEMS Sampling Protocols.

University of Colorado Environmental Center for Mass Spectrometry.  (2010) Sampling Methods.

Weishaar, J. L., Aiken, G. R., Bergamaschi, B. A., Fram, M. S., Fujii, R. & Mopper, K. (2003). Evaluation of Specific Ultraviolet Absorbance as an Indicator of the Chemical Composition and Reactivity of Dissolved Organic Carbon. Environmental Science Technology, 37.

Wilbur, S., & Bosch, S. (2004). Interaction Profile for: Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX). U.S. Department of Health and Human Services, American Society for Toxilogical and Disease Registry.

Witter, R., McKenzie, L., Towle, M., Stinson, K., Scott, K., Newman, L. & Adgate, J.  (2010). Health Impact Assessment for Battlement Mesa, Garfield County, Colorado. University of Colorado Denver, Colorado School of Public Health.

Category:

Issue: