All posts by Waterblogger

The author has 35 years of environmental experience primarily with oil and gas and mining development, abandoned mines, and water issues in the private and public sector. A colleague once described the author as being a member of every weird water group in the West. A former Department of the Interior employee, the author received the Department's highest award for Distinguished Service in 2015.

Injunction Delays Implementation of the Environmental Protection Agency’s Clean Water Rule

If you read my last post on the Clean Water Rule then you are probably not too surprised that after the Environmental Protection Agency issued its final Clean Water Rule back in June 2015 that everyone got lawyered up and sued the EPA. I certainly wasn’t surprised. Nor was I surprised about the entities who sued EPA over the new Rule. Specifically it was a bunch of state governments – thirteen of them to be exact. All of the states who sued are west of the Mississippi River, except for Missouri. I don’t know why Missouri joined the lawsuit. Maybe they were just feeling frisky that day. Generally no one in the eastern part of the United States cares so fervidly about water issues as they do in the west. I’ll drag out that old bon mot about water in the west often attributed to Mark Twain: “Whiskey’s for drinking; water is for fighting.”

So a little background on why western states are so up in arms about the Clean Water Rule. As you may recall, the new Clean Water Rule seeks to clean-up the definition of what is and what is not a “water of the United States.” Numerous cases have been dragged up to the Supreme Court regarding the federal government’s interpretation of waters of the United States. The cases are primarily a result of the federal government issuing violations to certain parties who failed to acquire dredge and fill permits under the Clean Water Act. The last time such a case went to the Supreme Court, there were a number of Court members who were a little perturbed that EPA has never cleared up the definition. So EPA set off to write a Rule to clarify the meaning of waters of the United States.

A number of states in the west did not like the fact that EPA was writing a Rule. They didn’t like the Rule when it came out. And they have designated the Rule as a “federal water grab.” Water is managed by the state. In the west, where there is very little water, the state’s right to manage water is inviolate in their eyes. Why? Because, water is a local issue. This inviolate right to manage water is codified in Water Rights legislation throughout the west. There are State Engineers and government boards within the western states that manage the water within the states. Who has the right to each drop of water has been dissected and discerned by these government officials and boards. Still there are constant fights among water users. Lots of the water rights issues end up in court. The state governments are sensitive because they are dealing with a bunch of riled up citizens who have to fight and scrape for their share of water. So you get the picture, anything to do with water and water management in the west is a contentious issue.

Now put on top of that a new federal rule that is fairly encompassing and somewhat confusing. Although EPA sought to clarify the definition and the actual Rule itself is short, there was simply a lot of concern by the states involved in the lawsuit that the Rule was too encompassing. Personally I found the Rule pretty confusing and in seeking to understand it a little better I read the 300 page preamble. Preambles to Rules can be lengthy, but regulators use them to determine what the Rule actually means and how it was derived. By the time I finished reading the preamble I was thinking of the difficulty of determining on the ground what the Rule proposed. For example the Rule says tributaries to rivers are waters of the United States. That makes sense. Any waterway intersecting a river will affect the water quality, the biota in the river, and the physical nature of the river (size, flow, etc.).

The Clean Water Rule went on to include perennial, intermittent and ephemeral tributaries as covered under the Rule. Perennial streams are the ones that flow with water in the surface and alluvium most of the year. Intermittent streams are the ones that flow with water in the surface and alluvium some of the year. Ephemeral streams don’t have regular flow of water in the surface or in the alluvium. Ephemeral streams are precipitation dependent. They are the conduit of what my dad used to call gully washers. We all know that those gully washers can be sudden and huge. The precipitation event may not happen for long, but it can wash a ton of stuff into a gully and downstream into a river. So it makes sense that they are included as waters of the United States because such events can affect water quality. But then the preamble goes on to say that tributaries are characterized by the presence of physical indicators of flow: bed, banks and ordinary high water mark.

EPA uses the Army Corps of Engineer’s definition of ordinary high water mark: “The term ordinary high water mark means that line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.”

This is not a new definition. It has been used for a long time. The Army Corps of Engineer’s guidance on how to determine the ordinary high watermark can be found in their Regulatory Guidance Letter No. 05-05 issued back in December 2005. Making the determination is tough enough in the east where there is a lot of water flow even in ephemeral streams, but trying to make that determination in some of these ephemeral streams in the west? I could see it as a bit hard. I suspect there might be a lot of fighting between two reasonable hydrologists in many such cases.

Frankly I kind of got lost in the preamble on the EPA discussion of adjacent waters. Adjacent waters are included in the definition of the waters of the United States. Adjacent means bordering, contiguous or neighboring rivers and streams, like wetlands, ponds, lakes, oxbows impoundments and the like. EPA gives three further definitions of what is covered. I won’t bore you with what those are. They are quite specific.  But then EPA goes on to say, well there are some adjacent waters that will have to be determined whether they are a water of the United States on a case by case basis. These include prairie potholes, Carolina and Delmarva bays, pocosins, western vernal pools in California, coastal prairie wetlands in Texas, and (oh by the way) waters within the 100 year floodplain of navigable waters and within 4000 feet of the high tide line of navigable waters. Well if you include all that in a case by case designation, then how can you consider the Clean Water Rule as a clarification of the meaning of waters of the United States.

EPA says in writing the Clean Water Rule that they used not only a compendium of scientific analysis from peer reviewed scientific literature, but they also used their forty some years of technical expertise in implementing the Clean Water Act.

EPA’s Clean Water Rule was supposed to take effect on August 28, 2015. What happened instead was that a Federal District Court in North Dakota issued an injunction against implementation of the Clean Water Rule.  That means that the Clean Water Rule will not be implemented until the lawsuit brought by the 13 states is resolved in court (probably the Supreme Court).

I don’t blame EPA for a confusing Rule that broadly captures so much into the definition of waters of the United States. This is tough stuff and not an easy call. I’d say it’s what happens when you have to regulate natural processes like rivers and streams to make sure that the water quality is good and supporting a healthy group of biota, like fish. It is not at all clear-cut. I am going to read the EPA’s Science Report published as a support document for the Clean Water Rule. I suspect it will inform us of the many scientific certainties and uncertainties that EPA had to address in writing the Rule.  I will be writing posts on the report. The EPA report is titled “Connectivity of Streams and Wetlands to Downstream Waters.”

MethylMercury in Streams

The U.S. Geological Survey issued a stream assessment report in November 2014. It is the first comprehensive look at methylmercury in streams within the United States. Although the Environmental Protection Agency (EPA) has conducted methylmercury assessments of water bodies in the past, their efforts have generally been concentrated on lakes. The Geological Survey report says one in four streams in the United States has fish with methylmercury concentrations exceeding EPA’s criteria for the protection of human health. EPA’s criteria for protecting human health are 0.3 parts per million methylmercury in fish tissue. The Geological Survey also said in their report that methylmercury in fish is the primary cause of fish consumption advisories for waterways.

 

During their study, the Geological Survey sampled 300 streams in the United States for methylmercury in water and methylmercury in fish. Large mouth bass were one of the fish they collected most for testing. Large mouth bass are what biologist call predator fish. Predator fish eat smaller fish as well as insects, frogs, snakes and other things that live in and on top of the water. From all the fishing shows you see on television, I guess it must be a very popular fish for sports fishermen. I don’t know how tasty it is to eat. But sports fisherman might want to note that in half the sites where the Geological Survey tested large mouth bass, these fish exceeded EPA’s methylmercury criteria for human health protection.

 

Now you might think: “Well, yeah that is probably in a bunch of streams near major urban centers.” Right? Well actually no. The Geological Survey found that in major contrast to other contaminants like lead, cadmium, arsenic and so on, methylmercury is highest in fish in undeveloped areas. The reason why methylmercury is highest in fish in rural areas is because of how methylmercury is formed. Mercury is converted into methylmercury via biotic degradation. In other words biota, like microbes and bacteria are taking up the mercury and converting it into methylmercury as they process organic material in the water. This conversion of mercury to methylmercury goes on wherever you have degrading organic material, but wetlands are kind of the hot bed of action for this process. Think about it, you have vast stretches of marsh grasses that die and then are replenished with new grass. These decaying grass mats can be really thick. You’d know this if, like me, you’ve ever waded into a wetland with some of those nutty guys who study coastal processes. Wetlands I can attest have deep organic muck. Wetlands also have something else these microorganisms like. They have very limited dissolved oxygen. These tiny little microbes reduce sulfate and low oxygen zones are where they live. So if an environment has lots of sulfate, then expect lots of these microorganisms and lots of methylmercury. Other environments that host these microorganisms include areas where water levels fluctuate, like in areas that are dammed or areas that flood a lot.

 

So any water basin with lots of wetlands is most likely to have higher methylmercury in fish. That is why most urban streams don’t have a lot of methylmercury. The wetlands in the urban environment have mostly been destroyed over the years. Let’s not let out a collective hurray for the lack of wetlands. Wetlands produce all sorts of other good ecosystem function, like filtering water and providing habitat and food for animals. It would be better to just keep the mercury from getting into the wetland. The only way to do that is to reduce the source of mercury. Most of the mercury in wetlands is being deposited there from the air and mercury gets in the air due to all sorts of human activities, for example burning coal in power plants.

 

One of the most noteworthy observations in the Geological Survey stream assessment was that the amount of actual inorganic mercury in a stream was not the driver for how much methylmercury there would be in fish. The Geological Survey looked at a number of streams in historic mining areas where mercury in the sediment and water is thousands of times greater than unmined areas. Because many of these streams have little organic material or wetlands, there is very little methylmercury in the fish. That is how important organic material and the microorganisms that degrade it are to the production of methylmercury.

Gold King Mine: Why is that Water so Orange?

“Why is the water in the Animas River so Orange after the release from the Gold King Mine?”  I had another environmental scientist ask me this question yesterday. I was surprised at the question, but then I thought well of course I know why the water is so orange, I have been working on abandoned mine issues for over twenty years. I’m used to the way mine drainage looks. It mostly looks orange.

But most people generally think water is blue and the sight of a whole river turning orange even puzzled the scientist who asked me this question and he has worked in environmental remediation for over thirty years.

The water from the Gold King Mine is what is called “acid mine drainage.” It is orange in color because it has a lot of iron in it. It turned the Animas River orange because some three million gallons flowed out of the Gold King Mine and went down Cement Creek into the Animas River in a massive spill. The spill occurred after an environmental cleanup company working for the Environmental Protection Agency (EPA) excavated loose material that had collapsed into the mine entrance. From the EPA’s accounts of the incident, it sounds like the water started leaking into the mine tunnel from above it and then just starting flowing out of the mine.  In this case the mine entrance was an adit. Most people envision vertical shafts when they think of mine entryways. An adit is different. Adits are horizontal entryways into a mine that go into the side of a hill or a mountain. You can walk into them, but you might not walk far, because there are often vertical shafts just a few feet into the mine tunnel. Many an unsuspecting person has entered an old adit and fallen right down a shaft.

The iron in the water comes from pyrite and phyrrotite. Most people know pyrite as fool’s gold. It is an iron sulfide. Phyrrotite is another iron sulfide mineral. Most people have never heard of it. It has a funny mineral formula. Pyrite and to an even greater extent phyrrotite have all sorts of inclusions of other elements in them. Elements like arsenic and nickel. Wait a minute you are probably saying, I thought this was a gold mine, not a fool’s gold mine. Yes you are right, but the precious metals in the area are what geologists call sulfide deposits. The gold and other valuable minerals in the San Juan Mountains in Colorado where the Gold King Mine is located were formed as a result of volcanic activity. The whole area is what geologists call a caldera. Calderas are formed when a volcano or volcanic complex literally blows its top; spews all its lava, ash and rock; and then collapses – kind of like Mount St. Helen but on steroids. So iron sulfides as well as all sorts of trace element sulfide minerals are right there with the valuable stuff like gold and silver.

The old mine workings, like tunnel and shafts, expose these sulfide minerals to water and air and they start to weather and oxidize. As a result you get water with a lot of ferrous iron, sulfate (because the sulfur has combined with oxygen in this oxidation reaction), and lots of free hydrogen ions. If you ever had chemistry in school, you will remember that lots of free hydrogen ions means a solution is more acidic. If you didn’t have chemistry in high school, you still probably have heard of pH. The pH is a measure of acidity and when I went to school the scale of measurement was between 0 and 14. Any solution with a 7 was considered neutral. Acid mine drainage usually falls in the range of 2 to 6. However, years ago it was discovered that there is actually negative pH numbers. These are highly acidic solutions and were first discovered by the U.S. Geological Survey while working at the Iron Mountain Mine in California.

So acid mine drainage can be very acidic and can have lots of iron in it. The iron is initially ferrous iron which is soluble in water. What happens next depends on the presence of some highly specialized microorganisms called iron oxidizing microbes with great names like acidithiobacillus ferroxidan. These little pests oxidize ferrous iron to ferric iron which is not very soluble, so it starts to precipitate out. Ferric iron has another little specialty too. It is an even better oxidizer than oxygen. So the ferric iron is precipitating out into these ugly looking orange minerals called jarosite, goethite, ferrihydrite and so on, and it is also causing more oxidation of pyrite and phyrrotite which create more acidity and more precipitation of more ugly orange minerals.

So there you go, that is why the water in the Animas River turned orange. A huge load of iron precipitates in the water were swept into the river. It looks bad but it is not the worst problem. The worst problem is all those other elements that are released in oxidation reactions going on in the mine, like arsenic, nickel, zinc, and copper. Those elements are what EPA is worried about because many are toxic. EPA doesn’t want them in drinking water and there are numerous drinking water intakes on the Animas River. Zinc and copper are especially bad for fish and their presence at certain levels in a waterway can deter fish from even venturing there. If the toxic elements settle into the sediments at the bottom of the river, it can be a long term problem that can affect bugs living down there, which can affect the whole ecosystem. But you’ve also got to remember that there are hundreds of mines in the San Juan Mountains that have been leaking out acid mine drainage for a hundred years or more. EPA and other federal agencies have been working to reduce this type of acid mine drainage entering the Animas River for years.

Impacts to Groundwater from Blowout during Hydraulic Fracturing in Dunn County North Dakota

In September of 2010 there was a blowout during early stage hydraulic fracturing of an oil and gas well in Dunn County, North Dakota just a couple of miles from the town of Killdeer. You’ve seen the result of a blowout. Think Gulf of Mexico, British Petroleum, Deep Water Horizon. Strangely the Deep Water Horizon blowout also occurred in 2010. You probably saw those pictures on television of oil flowing from the borehole at the bottom of the gulf. It really made a mess. The reason it made such a mess was the spill was difficult to contain because of the depth of water. When a blowout occurs on land, it is easier to contain but it makes a mess as well. All sorts of hydraulic fluid, oil and formation water come barreling up the borehole and spill all over the ground. If the casing in the borehole is ruptured as it was in this blowout, the fluids are also ejected into other formations, including possibly groundwater aquifers. In Dunn County the blowout spewed up some 90,000 to 100,000 gallons of fluid depending on the press you read. There are no reports of how much might have been lost in the subsurface. The blowout was contained and the North Dakota environmental regulators quickly had the situation at the surface cleaned up and monitoring wells installed in the groundwater aquifer.

 

The Environmental Protection Agency (EPA) chose this blowout site near Killdeer, North Dakota to conduct a “retrospective” study on whether there were impacts to the groundwater from hydraulic fracturing. If you are a regular reader of this blog, you know I am reviewing EPA “retrospective” studies. This is the fourth report I have reviewed and it is titled: “Retrospective Case Study in Killdeer, North Dakota: Study of the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources.” EPA calls these retrospective studies because they are being done after the contamination has occurred without the type of previous groundwater quality characterization and hydrologic study that a scientist would like to have in order to make a solid determination of how groundwater contamination occurred. However these types of studies are done all the time at the EPA when they seek to determine contamination from industrial sites, so they do have a lot of experience and some good tools to use in making their determinations. But with a limited data set, scientists can only go so far in determining how the contamination got to a well.

 

A lot of people probably don’t think about North Dakota much. When they do think of it, they think it is cold and snowy and very flat. They do not load up the motor home and head to North Dakota on summer vacation. But the area around Killdeer is really pretty. It has your typical grasslands of course, but it has badlands as well. There are a number of mesas in the area which they call mountains and just west of the town of Killdeer are the Little Missouri National Grasslands and the Teddy Roosevelt National Park. Set among this landscape is one of the largest oil and gas booms going on in the country.

 

I have actually been to Killdeer, North Dakota. Not many people have. It is a very small town in a lightly populated county. I think EPA’s report said there were about 4000 people in the whole county. I worked at one time down the road in Dickinson, North Dakota. There are a number of towns like Killdeer in the area – small, rural and isolated. Oil and gas production in the area has increased so greatly now that it is the chief industry in the area. I visited long before the ramp up in the recent oil and gas boom. At the time there were not a lot of strangers who visited Killdeer. I stopped in one day at the grocery store to pick up some snacks and a drink after a long day in the field. Everybody in the grocery store turned around to look at me when I walked into the store. Obviously this was a town where everybody knew everybody else. When I got to the checkout counter, the clerk asked me even before she rang me up: “Who are you?” I had to spend ten minutes explaining myself and my presence in town. I can guarantee you it is not like that now. With the exploitation of the Bakken Shale in North Dakota, this previously isolated rural area has changed forever. You read about the expansion of oil and gas in North Dakota in the paper: not enough workers, man-camps because there’s no housing, fast food workers getting paid New York City wages, crime because high-paying jobs attract all kinds of people including criminals. North Dakota is the United State’s second largest producer of oil and gas. Crazy huh?

 

This area of the country has been producing oil and gas since the 1920’s and development in Dunn County began sometime in the 1950’s. The whole area is part of the famed Williston Basin, which consist of thousands of feet of sedimentary rock. Groundwater is the principal source of drinking water in Dunn County and is found in the glacial tills and glacial outwash. This aquifer is called the Killdeer aquifer and can be some 200 feet thick in areas. So no matter how cold it is in North Dakota today, at one time it was even colder with thick continental glaciers the main feature on the landscape.  It is only about 20 to 30 feet to groundwater from the surface. The water is kind of hard and is generally a sodium bicarbonate or sodium sulfate type water. No matter how untasty the water is though, there’s a lot worse in the area from the underlying rock formations. The first time I went to a restaurant in one of the little towns west of Dickinson, North Dakota, the waitress brought a pitcher to the table filled with a brown liquid. I thought it was coffee, but my co-workers quickly told me it was water. A lot of the water at the time came from fractured lignite in the area. Lignite’s are kind of like underperforming coal. It’s one step up from peat. It burns but not well. Underlying the good glacial groundwater in Dunn County is just such a rock formation called the Sentinel Butte.

 

 

The nine monitoring wells that were installed after the blowout were mostly drilled into the Killdeer aquifer except for one, where EPA spying lignite in the drill log decided the well was drilled into the Sentinel Butte formation. EPA therefore only sampled and analyzed the 8 other monitoring wells. Two of the monitoring wells were upgradient of the oil and gas well that had the blowout. I need to explain what groundwater gradient is here. Scientists call it hydraulic gradient. Simply put it describes the direction of groundwater flow (yes groundwater flows). Mostly groundwater flows along the path of least resistance or pressure. The direction groundwater flows is called downgradient. Groundwater aquifers that are like the Killdeer are composed of sand, silt and gravel. The groundwater is actually in the pore spaces between the sand. The Killdeer aquifer is pretty horizontal lying with a slight southern tilt, which is the direction where groundwater is flowing. The Killdeer is what is called an unconfined aquifer, meaning it doesn’t have a layer of non-permeable rock above it creating a lot of pressure on it. The hydraulic gradient of the Killdeer is very low and the flow of water is very slow. EPA’s report cited references to movement of a foot a year.  Groundwater is moving away from the upgradient wells, which means samples from those wells will have uncontaminated groundwater. These samples can then be compared to samples from wells downgradient from the blowout, which is where the water is flowing to.

 

EPA conducted three rounds of sampling of the monitoring wells as well as a number of local domestic, municipal and supply wells in the area. The sampling occurred between July 2011 and October 2012. EPA recognized right away that two of the downgradient wells were producing anomalous results compared to the other wells they were sampling. They showed statistically significant water quality differences not only with the other wells in the area being sampled but with historical groundwater data as well. Chloride, calcium, magnesium, sodium and strontium were all much higher in the water from these two monitoring wells. EPA suspected from these analyses that brine had intruded into these two wells. EPA then applied standard analysis of the ratios of a number of these water quality parameters to determine from where the brine might have come. Interestingly enough, EPA found that the brine in the two monitoring wells matched the brine signature from the formation overlying the Bakken Shale. EPA’s curiosity on this point led them to look at the scientific literature on hydraulic fracturing of the Bakken Shale. EPA found out that hydraulic fracturing in the Bakken often produces what is called in the industry: “out of zone fracturing”. In other words, the fractures that are created in the Bakken Shale to get the oil and gas out of the rock actually extend into another formation; in this case the rock formation on top of the Bakken. So EPA seems to be implying that when the blowout occurred, brine from the rock overlying the Bakken Shale must have come up the borehole. I was a little confused about why brine from the Bakken didn’t also come up the borehole, but hey this is what EPA came up with, not me.

EPA also analyzed the monitoring wells for constituents found in hydrofracture fluids. For the first time in all of the EPA “retrospective” reports I have reviewed, they actually found a chemical they could link back to hydrofracture fluid. It is called TBA which stands for tert-butyl alcohol. TBA is not actually used in hydrofracturing fluid. It is what is called a degradation product. This means another more complicated organic chemical underwent a chemical reaction and became TBA. According to EPA, there are several chemicals used in hydrofracture that degrade into TBA. The one that was used in the well that had the blowout was tert-butyl hydroperoxide. The TBA was found (surprise, surprise) in the two monitoring wells where the brine intrusion was noted. The presence of TBA brought EPA to the conclusion that groundwater was contaminated in the vicinity of the well with the blowout; the very near vicinity. According to EPA, the monitoring wells were installed 20 feet from the well with the blowout. Thank goodness the groundwater moves so slowly in the area and no one’s drinking water wells were contaminated.

Hydraulic Fracturing Impacts to Groundwater in Wise County Texas

The increased production of shale gases nationwide has often resulted in complaints by homeowners in some areas that their drinking water wells have been contaminated by nearby hydraulic fracturing activity. As regular readers of this blog know, I have been reviewing the recently released studies by the Environmental Protection Agency (EPA) which attempt to determine in four different areas of the country whether hydraulic fracturing for oil and gas (hydrofracturing or fracking for short) has been the cause of water well contamination. This blog post reviews the EPA’s “Retrospective Case Study in Wise County, Texas: Study of the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources.”

Northern Texas and southern Oklahoma have had traditional oil and gas development areas for nearly a hundred years. Hydraulic fracturing of the Barnett Shale in these areas has brought a boom of new gas development. Hydraulic fracturing started in the Barnett Shale earlier than in most other areas where shale gas formations are located and it really ramped up around the middle part of the last decade.

The EPA selected Wise County in northern Texas for one of their “retrospective” studies. EPA calls them “retrospective” because they are trying to determine, after the fact, whether hydrofracturing activities caused water well contamination. A herculean feat, since there is usually a lack of data on the groundwater in the areas being studied before hydraulic fracturing took place. There were complaints in three different locations in Wise County of drinking water contamination after hydrofracturing. Wise County is just north of Dallas/Fort Worth. Having spent some time in Texas, the area is what I think most people imagine a Texas landscape to look like – flat with lots of cows and lots of oil wells. It is a pretty rural place and most people depend on groundwater for water supply. They have an excellent aquifer in this area of Texas. It is called the Trinity Aquifer and it is kind of famous among us water folk. It is a prolific aquifer producing large quantities of fresh to slightly salty water. It’s used not only for private wells but for municipal wells and industrial wells too. It has been extremely over pumped and the water table has been lowered pretty seriously. In Wise County the Trinity Aquifer is about 700 to 1000 feet below the surface, while the Barnett Shale is 7000 to 8000 feet below the surface – quite a distance between the two.

One of the three areas where there were complaints of water well contamination was near a small lake next to a gas well pad where a fish kill had occurred. The complaint was a concern with the odor and taste of the water. Two other areas had complaints of odor and corrosion of appliances. One of those two areas also had complaints of the water tasting salty. To determine if there had been an impact on the wells, EPA had to rely pretty much on old fashioned water quality work. The reason was that in testing the water wells for organic chemicals used in hydrofracturing there were no contaminants EPA could link back to the shale gas development, nor was there enough methane gas in the water wells to even analyze to determine whether its isotopic signature for the constituents of methane (Hydrogen and Carbon) were similar to that of the Barnett Shale. Methane can form in groundwater from natural bacteria decomposing organic material and the very low methane levels seen in the water wells tested in Wise County were the same as wells in the Trinity aquifer elsewhere. EPA considered the methane in the Wise County wells as normal for the area and not an indication of contamination from methane in the deeper gas formation.

As I’ve explained in previous posts, scientists can use the ratios of different isotopes of an element to determine how and where the isotope originated. For this study, EPA looked at the isotopic signatures for the isotopes of water – hydrogen and oxygen – and strontium. Of the 16 water wells EPA sampled in Wise County, 13 had the same isotopic signature for hydrogen, oxygen and strontium as that generally found in the Trinity aquifer, but 3 wells in one location were significantly different. In fact these 3 wells became really the source of EPA’s interest. Two of these wells were from the location where homeowners complained of a salty taste to the water. The other well tested was a water supply well in the same area. The supply well was not just drilled into the Trinity aquifer but had been left open in rock formations above the Trinity to draw as much water from various aquifers large and small in order to provide a substantial amount of water. When EPA started their water quality parameter investigation of these three wells, they found water in the two homeowner wells to be different from the water in the supply well.

The water types in most of the wells in all three locations with groundwater complaints were either a sodium bicarbonate or calcium bicarbonate, except in the location with the three wells that EPA was now beginning to consider impacted; there about 20 % of the water type was sodium chloride type water. We know sodium chloride as salt. Hence the salty taste. EPA was able to assemble a number of historical water datasets from the area. EPA also looked at the current water quality in other wells in the area to determine background. When scientists talk about background for water, they are referring to the regular, run of the mill, day to day water quality for groundwater in an area. In other words they are looking to establish the waters present natural chemical composition.

The water from the two potentially impacted homeowner wells had significantly different pH and specific conductance from the historical water data. Specific conductance is a measurement of water’s ability to conduct an electric current. High specific conductance means there are a lot of ions in the water. A lot of ions basically mean there are a lot of dissolved solids in the water. The two wells had higher chloride, bromide, sulfate, potassium, magnesium, sodium, strontium, barium, and boron than historical water data. You get the picture. EPA was now beginning to think that the two homeowner wells had been impacted by brine.  Although the supply well was different in some aspects from background, it was not similar to the water quality issues that the two homeowner wells had.

EPA then looked around for the possible cause of brine intruding into these two homeowner wells. They noted a lot of possibilities, but whittled them down to brine from the Barnett shale or another deep formation coming up through either natural fissures in rock, a historic well or maybe a new well that wasn’t cased properly; leaks from surface impoundments being used to store formation water from the Barnett shale or reserve pits being used to hold cuttings from the borehole of a gas well; a nearby injection well for disposing of brines from the Barnett shale which are brought up during drilling and production; or leachate from a closed landfill within a mile of the wells.

In determining the source, EPA looked at various ratios of one constituent to another. These ratio comparisons have been developed by various researchers to determine if there has been brine entry into a freshwater aquifer. Yes there have been years of studies by those crazy water scientists looking at ratios of the amount of chlorides over the sum of anions in water compared to total dissolved solids; ratios of the amount of chloride to bromide and chloride to iodide; and the amount of potassium over rubidium compared to potassium. I am not kidding you here; people spend their days researching this stuff and coming up with curves in order to compare water samples to various brines. There are curves for brines from the Barnett Shale and other oil and gas formations, curves for road salt, curves for landfill leachate. And these fun loving water scientists put together what they call mixing curves. How much water from the Barnett Shale, landfill leachate, etc. would result in what changes to freshwater. You can put your home well water on the mixing curve and see from where any sort of brine might have come. EPA did the comparison of water from the two homeowner wells and brine from the Barnett Shale and found it to fall on the mixing curve. EPA’s conclusion was that the brine intrusion into the homeowner’s wells was from the Barnett Shale. And the supply well, where did it fall? It apparently looked more like landfill leachate.

How could brine from the Barnett Shale have intruded into these two homeowners wells? EPA couldn’t say and with good reason. This was a “retrospective” study. There was no water quality work done before hydrofracturing began in the area or prior to the installation of the brine injection well. So EPA could make no specific conclusions.

I think it is becoming increasingly clear. EPA says impacts to groundwater quality from hydrofracturing do not occur often. However EPA has now found a number of cases where they have concluded that there are impacts. But the source of the impacts cannot always be readily determined because of the lack of groundwater quality characterization and water well sampling prior to and after hydraulic fracturing activity. If we see new regulation in the next few years as a result of EPA’s studies, I am hoping it will be a requirement for good water quality studies before and after hydraulic fracturing.

Southwest Pennsylvania Case Study of Hydraulic Fracturing Impacts on Groundwater

The Environmental Protection Agency’s (EPA) “Retrospective Case Study in Southwest Pennsylvania: Study of the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources” is a work of nuance and intrigue. An exciting read. Well maybe not to everyone, but for me, it was science done at its best. The scientists used a multiple line theory of investigation to track down the cause of complaints of contaminated water in homeowner’s wells in southwest Pennsylvania. The complaints were similar. After hydraulic fracturing for gas in the Marcellus Shale had occurred nearby, homeowners found water from their wells turbid and odiferous. Their water tasted bad plus it left unsightly stains.

The EPA, as regular readers of this blog know, has been conducting “retrospective” studies of areas with significant complaints of groundwater impacts from hydraulic fracturing to determine if there was actually an impact to people’s drinking water wells and how it might have occurred. The study in southwest Pennsylvania was conducted in Washington County which is a short drive from Pittsburgh. I have visited Washington County and it is a pretty, rolling hill, rural sort of place that has a long history of coal mining and oil and gas development. The first oil well was drilled there sometime in the late 1800’s. Most people get their drinking water from the Monongahela River, but about a quarter of the residents are using groundwater. The groundwater there is pretty shallow, about 50 to 160 feet below the surface and the Marcellus Shale is pretty deep, about 5000 to roughly 7500 feet. The groundwater is generally pretty good, if you are going to drink groundwater. Most domestic wells are primarily producing a nice calcium bicarbonate type water and a lesser number of wells produce a sodium bicarbonate or calcium sulfate type. The problem with groundwater in Washington County is that it has a lot of naturally occurring iron and manganese. The groundwater also has naturally occurring methane gas. Remember methane is one of the components of natural gas but it can also be produced by bacteria as they decompose organic matter.

First, to determine if people’s drinking water wells had been contaminated by hydraulic fracturing fluid, the EPA analyzed for 133 organic compounds commonly used in hydraulic fracturing fluid. This doesn’t mean that companies are using 133 different chemicals every time they conduct hydraulic fracturing. Usually they use less than 10, but the chemical content of the fluid can vary depending on what the company is trying to achieve. So you’ve got to do a full analysis. I am happy to report that EPA found no organic contaminants they could trace to hydraulic fracturing in anybody’s water well.

EPA also analyzed the water for 102 other constituents including metals, stable isotopes, radionuclides, and your basic water quality constituents such as calcium, sodium, chloride and the like. Since there was no smoking gun of organic contamination from hydraulic fracturing in the wells, EPA looked at the results of stable isotope analysis, specifically the stable isotope signatures for the components of water in the drinking water wells – which we all know to be hydrogen and oxygen. The Marcellus Shale has water as well as gas. It is a brine type of water with lots of dissolved solids and other constituents such as sodium, chloride and bromide which make it briny. The brine is called formation or produced water and comes up oil and gas wells during hydrofracturing (remember this tidbit because we’ll come back to it later). Anyway the hydrogen and oxygen stable isotopes of the Marcellus brine and other deep rock formations are very different from shallow groundwater. If there was any movement of the formation water along with hydrofracturing fluid into shallow groundwater, it would show up in these analyses. Even a small amount of this briny fluid entering shallow groundwater would significantly change the stable isotope signature of hydrogen and oxygen in the drinking water wells. Again no bullet holes or dead bodies were found. Hydrogen and oxygen isotopes in people’s drinking water were the same as shallow groundwater in similar aquifers where no hydrofracturing has ever occurred.

Not to be deterred in their investigatory work, the EPA then looked at the stable isotopes of methane. As I mentioned earlier, methane is a component of natural gas and it is also formed by bacterial decomposition of organic material (these are commonly referred to as biogenic methane). The later is very common and occurs in wetlands and other places where you don’t have a lot of free oxygen, such as a groundwater well. Methane, which is composed of carbon and hydrogen, has very distinct stable isotope signatures for those components depending on whether it was produced at depth in an oil and gas formation or at the surface in a groundwater well. Unfortunately there were only two wells sampled that had sufficient methane in the water to analyze for stable isotopes. One sample showed clearly that it was biogenic methane; the other sample was less clear.

So EPA conducted a more definitive stable isotope test. This test was for what is called: dissolved inorganic carbon. Methane is considered organic carbon. There is another carbon that is associated with calcite in the rock formation. Calcite is what makes up limestone. It is calcium carbonate. As it moves along in an aquifer, the carbon in carbonate is oxidized, which results in the formation of carbon dioxide. When the carbon dioxide enters a water well (or other oxygen depleted location) the bacteria love it and use it to make biogenic methane, resulting in enriched inorganic carbon. Dissolved inorganic carbon produced this way has a very distinct isotopic signature compared to the inorganic carbon you find in the brine from the Marcellus Shale. The isotopic signature for dissolved inorganic carbon in the two wells tested was the same as other shallow groundwater in similar rock formations where no hydraulic fracturing has taken place and was totally different from the signature of dissolved inorganic carbon from the Marcellus. Evidence of contamination of people’s drinking water wells from hydrofracturing failed to appear.

Strontium isotope analysis of drinking water also failed to show impact from hydrofracturing. The radionuclide radium was then looked at because the Marcellus brine has some pretty extraordinary levels of both radium 226 and 228. Again there was nothing unusual in the drinking water wells to show impacts to groundwater from hydrofracturing.

The interesting find EPA made was simply using good old fashioned water quality data. EPA had several sets of historical water quality data from the area that had been collected decades before hydraulic fracturing even occurred in Washington County. EPA looked at such mundane water quality constituents as chloride, bromide, sodium and calcium and found that two springs in the southern part of Washington County exhibited some strange behavior during the collection of the 3 sets of samples EPA took over a year and a half period. The springs initially had elevated chloride and calcium levels exceeding both historical groundwater data and other groundwater data from wells EPA had sampled. Even more mysterious, those spurious high numbers decreased during the next two sampling rounds. It looked like the type of data you get when sampling groundwater after a spill. EPA looked around for what might be causing such an anomaly. It didn’t take long to find that both springs were close by and downgradient from an impoundment and reserve pit which had been used during the construction and hydrofracturing of a gas well. Remember the tidbit I told you to about where the briny formation water comes back up the hole during hydrofracturing and well production. The surface impoundment was used to store this water. So finally, here was a culprit. There was an extremely limited effect, since it was local and didn’t impact anyone’s personal water well. But obviously the use of a surface impoundment in this particular case caused leaching into groundwater and impacts to the two springs.

So if EPA couldn’t find any suspects from all of this incredible sleuthing, what did they say caused all of the homeowner’s water quality problems after hydraulic fracturing of the Marcellus Shale in southwest Pennsylvania? Here the EPA kind of failed me. They went into the territory of speculation. It is a good speculation though. It’s based on scientific literature and a good knowledge of groundwater reactions. Being water scientists, the EPA investigators looked at the water complaints, saw that there was a lot of naturally occurring iron and manganese in the groundwater and used their noggins to deduce that staining, taste and odor issues were probably a result of high levels of iron and manganese in the water.  In fact, when they tested the water for iron and manganese, they ran both a filtered and an unfiltered sample. The unfiltered sample was much higher for both of these constituents in the water, which leads them to believe the increased turbidity was the result of a lot of undissolved iron and manganese particulates entering the water wells. What was causing the sudden turbidity? EPA made note in their report that other studies have shown the drilling process for an oil and gas well produces a lot of vibrations and that has resulted in mobilization of iron and other rock constituents, like manganese, into water wells resulting in a lot of turbidity in those wells. So there you go, no contamination from hydraulic fracturing in southwest Pennsylvania, but possibly just poor water quality as the result of the drilling of the gas well. Little consolation for the homeowners who had to put up with foul taste and having their laundry stained, but thank goodness they aren’t drinking something really foul from the hydrofracturing fluid.

 

The Mercury Cycle

I thought a long time about the title of this post. At first I wanted to name it “Up in the Air” then I thought maybe “What Goes Up Must Come Down and Then Go Up Again”. But I stuck with the dull title of “The Mercury Cycle” because it is a clear presentation of how mercury acts in the environment. Everybody has heard of cycles: the cycle of life, the lifecycle of a product, lifecycle management, the lunar cycle. Well mercury has a cycle too. The mercury cycle is like a merry go round that never stops.

Before I write about the mercury cycle, I need to discuss metal species. Everybody has heard of species: plants have them, animals have them. We talk about the human species. Well metals have species too, but it is different. When scientists talk about metal species they are often talking about their oxidation state. We have to look back at our basic knowledge gained over the years, whether from a classroom or a Discovery channel special. You know everything is made up of atoms and those atoms are made up of electrons, protons and neutrons. You’ll maybe not remember but the electrons are the ones that are kind of special and exchange themselves to other atoms. Oxidation means that an atom is losing electrons. There is a complimentary process called reduction used to describe the other atom that is gaining the electrons. These exchanges go on at the molecular level too (remember molecules are a bunch of atoms). Mercury has only a few of these types of species. They include elemental mercury that hasn’t undergone any electron exchange and then the mercurous and mercuric forms of mercury which have lost electrons. Mercuric is the mercury that is most common. You will see it described as Hg (II). Hg is the periodic symbol for mercury by the way. People also talk about metal species when a metal bonds with another element. Again it is those crazy electrons who also share themselves between two elements. Mercury bonds with a lot of different elements, especially other metals. But when it comes to the mercury cycle, the species in which scientists are most interested are the ones where mercury bonds with sulfur and carbon. These mercury species are things like mercury sulfide and when you throw in a little hydrogen with some carbon you get your methylated mercury, including methylmercury, ethylmercury, dimethylmercury and so on. People refer to mercurous and mercuric forms of mercury and mercury sulfide as inorganic mercury. People refer to the methylated mercury as organic mercury.

Okay enough for basic chemistry. That is as far as I am going on that subject. It is a lot more complex but I wanted to tell you about metal species because they will play a role in the mercury cycle story.

The story begins with the release of mercury into the atmosphere. This can come from natural sources since mercury is everywhere in the environment to some extent. It is part of the earth. It is in our rocks and therefore our soils and when soils are eroded mercury goes into our streams and out to the oceans. So there is a natural occurrence of mercury in the environment. As mentioned in a previous post, mercury vaporizes at pretty low temperatures. Heat it up to like 357 degrees Centigrade and it boils. It has, I believe, the lowest boiling point for a metal. So natural mercury is being released to the atmosphere all the time, but at really, really low levels. Now add in your average human being who is interested in being warm in the winter, cool in the summer; who is in need of medical care; wants to put the trash out instead of letting it fill the house; and wants to be able to have nice white clothes and a safe drinking water supply free of bacteria. In other words, a person interested in living a modern existence. Now you start getting man-made sources of mercury in the atmosphere through the burning of coal, medical and trash incinerators, and chlor-alkali plants that are producing chlorine and other chemicals associated with the modern existence.

Mercury in the atmosphere is mostly in three forms: gaseous elemental mercury, the mercuric form, and particulates. The elemental form of mercury can be oxidized in the atmosphere, which results in even more of the mercuric form. Here’s the “what goes up must come down” portion of this post. Mercury comes down in the rain and snow. This is what is known as wet deposition. Mercury also just falls out of the air. Sure there is gravity involved but as usual it’s a lot more complicated. I’m not going into it, because I would have to explain Brownian motion and whole lot of other things. Just know that it is occurring and that it is called dry deposition.

The mercury falls on the ground and in the water. Mercury has a variety of things it can do.  In the ground it can get tied up in the soil thanks to all that organic matter. Or it can run off into the water or percolate down into the groundwater. If the soil is eroded, mercury can enter surface water that way too. Or it can enter surface water directly through wet or dry deposition.

Now that mercury has entered the environment from man-made and natural sources it can immediately get back into the mercury cycle and return to the atmosphere, it can get frozen into a great big glacier, it can get all tied up with the organic material in soil, it can float around in the water (although mercury is not very soluble), or it can settle down in the sediment. When it settles down in the sediment, mercury can undergo methylation if the right conditions exist. The methylation process results in methylmercury. Remember methylmercury is the bad stuff. Methylmercury is taken up by algae and bacteria then ingested by invertebrates living down there in the gunk. Algae and invertebrates are eaten by fish. Methylmercury is accumulated in fish tissue. Birds, animals and people eat fish. Not all birds, animals and people, but osprey, eagles, minks, otters and people along the coasts and lakes are usually chowing down on them. Hey I found a fish in my back yard that an osprey must have dropped! The ants were eating it, so you could probably include insects too.

Fish

There has been a lot of research going on in the past few years on how methylmercury is formed in the environment, but one of the interesting things I have read about is that methylation and demethylation can be going on in the same water body. So mercury is not tied up for all time as methylmecury but can get right back into the mercury cycle.

Now you have the low down on the mercury cycle – not a like a uni-cycle or a motorcycle – but a cycle that needs balance none the less. If humans continue to add to the mercury cycle, there could be a terrible wreck.

Supreme Court Makes Decision on the Environmental Protection Agency’s Mercury Air Toxics Standards Regulations

You don’t often find anything amusing about Supreme Court decisions. They are usually laced with stuffy legal language on prior court decisions and how it applies to a case, but every once in a while you can get a good laugh. And that is the case in the June 29, 2015 Supreme Court decision on Michigan et al. versus the Environmental Protection Agency (EPA). You may recall that this case is a result of a bunch of state governments and industry groups suing the EPA over the Mercury Air Toxics Standards Regulations issued back in February of 2012.

The regulations basically imposed pollution controls on power plants to reduce mercury emissions. The lawsuit was over the fact that the EPA didn’t consider the costs of health and environmental benefits achieved by the regulation versus the cost to industry for complying with the regulation. The cost of the regulation to industry was estimated at $9.6 billion a year. The EPA only conducted a partial cost benefit for reduction of mercury that established a yearly benefit of $4 to 6 million a year. Additional benefits for reduction of sulfur dioxide and particulates would occur as a result of the pollution controls and those were estimated to be $39 to 90 billion a year. But the EPA didn’t use those figures or any others in determining under their Clean Air Act authority that they should regulate power plant mercury emissions.

In deciding the case, the Supreme Court looked at the Clean Air Act which says: the EPA must conclude “regulation is appropriate and necessary” after studying hazards to public health posed by power plant emissions. The Court found that the agency considered regulation “appropriate” because mercury poses a risk to health and the environment and because pollution controls exist to reduce mercury. The agency also found the regulations “necessary” because other Clean Air Act regulations did not eliminate the risk of mercury. The Court held that the EPA interpreted the Clean Air Act unreasonably when it deemed cost irrelevant to the decision to regulate, because the Clean Air Act specifically required power plants to be treated differently from other sources (other sources don’t require a cost benefit analysis to regulate). The Clean Air Act specifically required a cost study for the regulation of power plants.

The Supreme Court decided that the EPA must consider cost, including the cost of compliance, before deciding whether the Mercury Air Toxics Standards Regulation is appropriate and necessary. But the Court said it is up to EPA to decide how to account for cost.

Good grief! All this decision does is “kick the can down the road.” Now the EPA must go back and do the full calculations of the regulations benefits. EPA even stated in the regulations that their calculation of $4 to $6 million was only a partial cost analysis based on IQ loss of recreational fishermen who caught and ate mercury contaminated fish. EPA acknowledged that this was a small subset of the overall benefits of reducing mercury. Now the EPA will have to engage in a much longer and more expensive cost analysis. The analysis will have to show the economic benefits to not only human health but the environment as well. That includes impacts to wildlife like ospreys and eagle, minks and otters, and the many other animals that eat a lot of fish. They will have to look at reproductive and other impacts to the fish themselves. EPA will also have to look at subsistence populations who regularly eat fish and to the population at large who are eating fish from mercury impacted waters. And will the decision to regulate based on the cost benefit study change? I doubt it. If you start looking at impacts to wildlife and fisheries including reduction of recreational uses of streams with consequent losses to local economies and impacts to the fishing industry, well you are going to get an enormous figure. Add on top of that the cost of the side health benefit for the easier to calculate reductions in sulfur dioxide and particulates and I would expect the annual benefits to be in maybe the trillion dollar range.

I thought to myself, surely these state governments and industry groups thought about this in advance before they took this case all the way to the Supreme Court. Of course this is all handled by the lawyers and they may not know much about the cost calculation of damages to health and the environment, but they have scientists on staff who should be very well aware. That’s when I started laughing. Of course they must have known. Maybe all they were doing in taking this case to court was fishing for a delay in implementation of the regulations.

Stray Gas from Hydraulic Fracturing for Natural Gas in Northeast Pennsylvania

Stray natural gas is common in northeast Pennsylvania. It existed before hydraulic fracturing for gas began in the area. The Marcellus Shale is the main rock formation from which natural gas is being extracted, but all the formations above the Marcellus also have natural gas. The Lockhaven and Catskill are the main drinking water formations that people in the area drill into for water supply and are located several thousand feet above the Marcellus Shale. There is plenty of water monitoring data showing natural gas already existed in the water supply formations before hydrofracturing occurred in the area. But between 2009 and 2011, the Pennsylvania Department of Environmental Protection investigated somewhere around 90 complaints of stray gas in domestic water wells. Obviously something new was happening.

When I envision stray gas, I always get this picture in my head of stray cats. You leave the door open one day and your cat slips out. It becomes a stray, living in the woods, killing songbirds for food, trespassing into people’s backyards, and generally making a nuisance of itself. Stray natural gas is really the same thing, you don’t do such a good job cementing your casing and you leave the door open for natural gas to come up the sides of the casing, it enters into groundwater rock formations and sometimes travels through natural fractures in the rock, it slips into people’s water wells and sometimes their basements, it can cause groundwater in the well to become discolored and turbid as iron and other minerals precipitate out of the water, and it generally makes a nuisance of itself because after all natural gas can explode.

The Environmental Protection Agency selected Northeast Pennsylvania for one of their five “Retrospective Studies.”  The selections were made based on complaints of water well contamination in areas that were undergoing hydraulic fracturing for oil and gas. The study being “retrospective” was designed to determine through various chemical tests whether the Environmental Protection Agency could determine if the gas in people’s water wells in northeast Pennsylvania came from hydrofracturing activities in the area.

Based on the Environmental Protection Agency’s research, two main water types are being used for water supply in the study area. There is a nice calcium bicarbonate water in the upland areas and in the river valleys a sodium chloride or sodium bicarbonate type water. Geologists in the area have proposed that rivers followed weaker naturally fractured rock to form the valleys. The geologists further theorize that brines from lower rock formations moved upward through these highly fractured rocks underneath the valleys into the shallower drinking water formations, hence the chloride and sodium. Methane is common in the valley groundwater both in wells and in springs but is uncommon in the upland wells.

The main line of evidence that hydraulic fracturing in the area is the cause of stray gas in water wells comes from stable isotope work conducted by the Environmental Protection Agency and others. In a previous post I mentioned that stable isotopes have a signature. Remember from high school or college science: atoms have electrons, neutrons, and protons. So let’s take carbon as an example, it has 6 neutrons and 6 protons. That is called carbon 12. Get it, six and six is twelve. Okay, about one percent of carbon has 7 neutrons and 6 protons. It is called carbon 13. Since it has one less neutron, carbon 12 is lighter and reacts a little quicker in chemical bonding than its heavy brother. So various compounds that contain carbon have different amounts of carbon 13 to 12 based on their origin. These ratios are expressed in parts per thousand and give a signature that can be used in this case to determine the origin of methane.

Methane, a component of natural gas, is a compound of carbon and hydrogen. Hydrogen also has a stable isotope signature. Methane can be produced by bacteria in surface water. Methane in natural gas and methane produced by bacteria have two different carbon and hydrogen signatures. Methane is just one component of natural gas. Other components include ethane, propane and butane which are also compounds of carbon and hydrogen. And guess what? Each component of natural gas has a very specific ratio of carbon isotopes in relation to the other components for most of the oil and gas deposits around the world. Except in gas shales like the Marcellus where the ratio is reversed. If you got this reversal of the methane and ethane isotopic signatures in water wells, you would know immediately from where the gases originated. The problem is that there is usually not enough ethane found in water wells to analyze.

Okay enough for our background science. The Environmental Protection Agency tested 36 drinking water wells over a one and a half year period. They did three rounds of sampling and analysis. All wells sampled were within a mile of a hydraulic fracturing site. In addition to stable isotopes, the drinking water was tested for chemicals used in hydrofracturing fluid. The good news is that no drinking water wells tested were found to have hydrofracturing chemicals in them.

Some of the 36 drinking water wells the Environmental Protection Agency tested had natural gas that originated in deep rock formations. Three wells had isotopic signatures of natural gases from rock formations above the Marcellus and five had isotopic signatures of possibly the Marcellus or other deep rock formations. What is the cause of the movement of the stray gas? The Environmental Protection Agency cites a 2012 report by the Groundwater Protection Council that blames inadequate cementing of the casing that allowed gas to move from depth into shallower formations. However, the Environmental Protection Agency says that without having been able to sample the water wells before the hydraulic fracturing occurred in the area, it is difficult to determine exactly what the impacts have been to drinking water in the area.

It sounds to me like there is a strong need for groundwater assessment and sampling before hydraulic fracturing is conducted in an area instead of having to ferret out environmental impacts after the fact. The Environmental Protection Agency cites a study in Northeast Pennsylvania done by an oil and gas company prior to fracturing a well 800 feet from a drinking water well. Multiple rounds of sampling were conducted before and after the hydrofracturing occurred. Data showed a 7 fold increase in methane and a 1000 fold increase in ethane in the drinking water well after the hydraulic fracturing took place. Isotopic testing showed the gas entering the drinking water well came from deep gas bearing rocks but not the Marcellus itself. Little consolation to the homeowner I suspect who probably didn’t care where the gas came from, just that it hadn’t been there prior to hydrofracturing.

Can Hydraulic Fracturing for Oil and Gas Cause Groundwater Contamination?

Can hydraulic fracturing for oil and gas cause groundwater contamination? This is the question I have been waiting to find out from the U.S. Environmental Protection Agency’s hydrofracturing scientific investigation and studies. Of course if you have a spill, there is always the potential for contamination. But does the actual process of inducing fractures through injecting water and chemical additives under pressure down a well actually cause contamination, either from the hydrofracturing fluid or natural gas migrating into the groundwater. I’ve read through the Environmental Protection Agency’s “Draft Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources.” I didn’t have to read all 998 pages, just the Executive Summary and the Chapter on Injection. The answer is there are documented cases where the hydrofracturing process itself has contaminated groundwater. Incidences, as the Environmental Protection Agency has stated before, are rare. The evidence comes primarily from the case studies that the Environmental Protection Agency conducted. They have released the case studies as well as the Draft Assessment and I plan to take a look at the case studies in the next few weeks and provide more information on how they determined contamination did or did not come from the hydrofracturing process.

The Environmental Protection Agency always does a good job on their reports. The Draft Assessment is an excellent compilation of the scientific literature on the subject. They have summarized dozens of published research papers. As you can imagine, there has been a lot of recent research in the area of hydraulic fracturing and its possible impact on drinking water. The Draft Assessment also looks at data on well construction and practices. This data was gathered through a survey of service companies that perform hydraulic fracturing for oil and gas companies. The Environmental Protection Agency used the collected data to determine what practices are being used to protect groundwater. As advertised in the Study Plan for the current report, a numerical model was conducted and has been published in the scientific literature. I hope to get a copy of that in the next few months and take a look at it.

The Environmental Protection Agency also gives a litany of possible ways natural gas and chemicals from fracturing fluid could enter the groundwater. These include everything from poor cementing of the casing protecting groundwater to casing failure during hydrofracturing. You could say that the Environmental Protection Agency has validated Murphy’s Law: anything that can go wrong will go wrong.

Right now the Draft Assessment is undergoing review. With the amount of scientific literature quoted in the report, the review needs to be conducted before I write anything further on the Assessment Report as interpretations made in the report may change. So I’m going to concentrate on reviewing and writing about the case studies while that process is ongoing.