One of the most prominent issues in the environmental and energy debate going on today is that of shale gas drilling, involving hydraulic fracturing processes, commonly given the somewhat derogatory name of “fracking” or “hydrofracking” in the media. This is a topic in New Jersey that we may hear more about than other places in the country, as our neighbors in Pennsylvania, and the large media market in Philadelphia have taken notice to what is going on in their backyard of rural PA, an area which is known as the Marcellus Shale.
For those unfamiliar with fracking let’s go over the basics first. Natural gas (which is primarily CH4 also known as methane), like petroleum, is a fossil fuel, meaning it is buried deep below the Earth, and formed from the breakdown of matter, specifically organic matter, millions of years ago. While natural gas is a cleaner fuel than our various crude oil fuels, it is still a fossil fuel. However, in addition to the benefit of burning cleaner than oil, we also have a lot more of it (87% of the natural gas we use in the U.S. is produced here), in easier to reach places, here in North America, compared to oil.
I think we all know the problems associated with our crippling addiction to importing foreign oil, so I’ll save that discussion for another day. The reason why shale gas has become so critical now is simple; for years it was not something that was cost effective to drill for, trapped in thick layers of rock, meaning we pretty much had all of these energy reserves sitting under us, but couldn’t get to them. In recent years a lot has changed, everyone knows oil is peaking, both in price and production, additionally hydraulic fracturing technology and advances in drilling have made drilling for shale gas a profitable venture.
So how much natural gas do we have, how much of it is from shale deposits, and how long will it last us?
U.S. Energy Information Administration (EIA) 2011 Annual Energy Outlook:
Total Natural Gas Resources Available – 2,552 trillion cubic feet
Shale Gas Resources Available – 827 trillion cubic feet
Annual Rate of Consumption (2009) – 22.8 trillion cubic feet
Years of Natural Gas Remaining – 110+
Based on EIA data nearly one third of our natural gas reserves are in the shale gas deposits, meaning they’ll supply us with over 30 additional years of natural gas based on current usage. Not only that, but the 827 trillion cubic feet available from shale deposits in the 2011 report are double what was published in the 2010 report, with increases expected to continue. The Barnett Shale in Texas is where much of the shale gas drilling work has been done in past years, and technology developed from drilling in Texas has now been brought to the Marcellus Shale and rural Pennsylvania.
So what exactly is hydraulic fracturing (fracking)?
The process involves both vertical and horizontal drilling. Vertical drills are used to reach the shale rock depth, at which point the drill bit then bends and begins a process of horizontal drilling through the hard shale rock in which the natural gas is trapped. Once in the shale layer, water mixed with chemicals and sand are pumped at high pressure into the shale rock, fracturing the tiny cracks in the shale to allow the natural gas to flow out and be collected.
This process is different from traditional natural gas drilling in that conventional natural gas is typically found in permeable rock or soil and his trapped beneath a layer of impermeable rock. In conventional drilling, once the impermeable layer is breached, the natural gas can be collected.
So what’s the big deal? It’s cleaner than oil, and domestic, this is a good thing, right?
Natural gas is cleaner-burning than coal or oil. While natural gas vehicles aren’t widespread in this country, there is a market slowly emerging as oil prices rise; locally the Jitney Association’s buses in Atlantic City, as well as the solid waste collection fleets of the Atlantic County Utilities Authority and Earthtech Contracting have switched to natural gas vehicles. Natural gas vehicles reduce greenhouse gas emissions up to 25%, particulate matter (PM) emissions up to 80%, and carbon monoxide (CO) emissions up to 40% when compared to traditional vehicles. When it comes to electricity generation, combined-cycle power plants that run off of natural gas, which are becoming increasingly popular and more efficient for localized generation will emit approximately half of the CO2 emissions as coal powered plants.
While natural gas has clear benefits as an energy source, the fracking process is not without its problems, specifically associated with the use of and disposal of water from the process. The first and obvious problem is the amount of water used. While the northeast has been spared many of the water shortages seen in other regions of the U.S. and world as a whole, potable drinking water is a limited resource; data from Marcellus Shale drilling has indicated that these drilling wells use over 3.8 million gallons of water per day in their drilling operations. While the water can be recycled in some cases, that is still a large amount of water being used; 3.8 million gallons, by one well, in one day… multiply that by hundreds of wells operating on and off year round… you get the picture.
With all this water being used, now we need to figure out what to do with the wastewater. Remember, the water used for the process contains various potentially hazardous chemicals, and while not all drilling companies have disclosed what chemicals are added (claiming it to be a protected trade secret like the formula for Coca-Cola), and 99% of the mixture is water and sand, data has indicated that the remaining 1% can contain BTEX compounds such as benzene, toluene, xylene, and ethylbenzene, known to be toxic.
With all of these chemicals present, there is significant cause for concern, however, if handled properly this drilling process would be no different than thousands of other industrial processes in the United States that create wastewater. The problem is that there have been spills and accidental discharges of the wastewater, which can then contaminate local drinking water supplies.
Additionally, even if properly discharged into the local sewer and wastewater treatment system, the chemicals can still pollute the environment. Remember that local municipal wastewater treatment systems are designed to treat just that; local municipal wastewater, meaning what goes down your sinks, toilets, and showers. Industrial processes frequently are required to pre-treat their wastewater, to remove the chemicals found in it. If directly discharged into the sewer system the chemicals may simply pass through the local treatment facility, since it has not been designed to treat for them or worse yet, the chemicals may disrupt the biological agents that are used to treat the municipal sewage in the system.
Beyond the chemicals added to assist in the drilling process, another concern is what comes back up in the wastewater after it is used. Many people are familiar with Radon detectors in their basements, garages, and poorly ventilated portions of their homes. These detectors are needed to measure the amount of radiation that is naturally coming from the Earth. In a similar fashion, the water used in the drilling process can absorb the naturally occurring radiation. Between the radiation and chemicals, it is critical that the wastewater be monitored and treated under strict standards. This is what the main concern with the hydrofracking process should be. You will often see claims that the chemicals, radiation, and even the natural gas itself will seep up from the shale area and into the aquifer layers of the ground above, contaminating drinking water. While possible, this has been found to be highly unlikely, as the concentrations found in the water and permeability of the soil and bedrock make it very difficult for drinking water to be impacted though this process. While not impossible, it is highly unlikely this is occurring, and there are contamination sources of greater concern either the discharged wastewater, or possible leaks in the well’s lining. Both of these concerns are directly related to the process of the drilling, which if regulated and monitored properly, would be just another of thousands of industries in this country which uses toxic chemicals in their manufacturing processes.
Like any industrial process, clean up technologies are out there, and the Department of Energy(DOE) has announced one such method that could be used to clean up almost all the chemicals found in the wastewater using a simple sand like compound.
It’s important to keep a watchful eye on shale gas drillers, but let’s not turn them into the latest energy taboo. Think of how far behind the U.S. nuclear energy has fallen compared to much of the rest of the world after Three Mile Island. Now we are playing catch up (or were until the problems with Japan’s reactors) to not only bring our nuclear technology up to date but also educate a workforce that has built a new reactor in decades. There is no magic bullet to fix the energy crisis we face, so when you read editorials calling for a ban on shale drilling, remember natural gas is an important part of our energy future, and the environmental concerns associated with shale drilling are not so daunting that we need to grind the industry to a halt; we simply must remain vigilant, and demand responsibility from the industry.
A map of shale gas deposits can be found here:
Diagrams of the drilling process can be found here:
A complete list of the chemicals used in the process as reported by the Pennsylvania DEP can be found here:
Halliburton has listed the fluids used in its process:
A House of Representatives energy committee report on chemicals used can be found here:
Information on hydrofracking water treatment technologies can be found here:
For more information on shale drilling a DOE National Energy Laboratory primer can be found here: