Fracking’s Threats to Drinking Water Call for a Precautionary Approach
Posted Jul 1, 2013 by Sandra Postel (originally posted by the National geographic)
A Marcellus shale gas well operation in Scott Township, Pennsylvania. Photo credit: wcn247/Flickr Creative Commons
At least one aspect of fracking’s risks to drinking water became a little clearer this week.
A study led by Rob Jackson of Duke University’s Nicholas School of the Environment, and published in the Proceedings of the National Academy of Sciences, found that drinking water wells located within 1 kilometer of a shale gas well in a region of northeastern Pennsylvania are at high risk of contamination with methane.
Fracking, shorthand for hydraulic fracturing, is the process of blasting water mixed with sand and chemicals deep underground at high pressure so as to fracture shale rock and release the gas it holds.
Colorless, odorless, and highly flammable, methane is the primary component of natural gas. It is not regulated as a drinking water contaminant, but it poses potential health and safety hazards. If the gas builds up in a basement or other confined space, for example, it can set off an explosion or start a fire. If breathed in high enough concentrations, it can cause dizziness, headaches and nausea.
The risks of long-term exposure and of secondary water quality changes due to high levels of dissolved methane are not known.
The research team analyzed 141 drinking water wells in northeastern Pennsylvania’s gas-rich Marcellus shale region and detected methane in 82 percent of them. For homes within 1 kilometer of a gas well, the average methane concentration was six times higher than in water wells located further away.
Nearly 1 in 11 of the household wells analyzed had methane concentrations above the threshold level set by the U.S. Department of Interior for immediate remediation; all but one of those drinking water wells was within 1 kilometer of an active shale gas well.
By analyzing the isotopic signature of the gases, Jackson’s team determined that the methane found in the drinking water was of fossil origin, not from current biological activity. The presence of ethane and propane, constituents of natural gas that are not produced by microbes, also signaled that the contamination was coming from nearby fracking operations.
Ethane was detected in 30 percent of the home water wells sampled, and concentrations of this gas were 23 times higher on average for homes less than one kilometer from a fracking well.
“Overall, our data suggest that some homeowners living <1 km from gas wells have drinking water contaminated with stray gases,” Jackson’s team concluded.
Stray gases are those that leak out of the production wells and enter the surrounding environment, including groundwater. The leaks can occur, for example, from faulty steel casings, which are supposed to keep the gas inside the well. Or they can occur from imperfections in the cement sealing between the well casing and the surrounding rock that permit fluids to migrate up the outside of the gas well.
While compelling, the study is not definitive because of the lack of data on the quality of the drinking water wells before the fracking began.
To better gauge fracking’s risks to drinking water, the natural gas industry should be required to disclose its well records or pay for the state or a third party to collect water quality data before fracking operations are allowed to begin.
Without those data, we are flying blind about where, how and under what conditions fracking poses threats to drinking water.
As the Jackson team concludes: “Ultimately, we need to understand why, in some cases, shale gas extraction contaminates groundwater and how to keep it from happening elsewhere.”
The migration of methane into groundwater is only one possible risk to water quality from fracking. Another is the potential for the fracking fluids – the toxic mixture of sand, water and chemicals used to break open the gas-holding shale formations – to move through natural or secondary fractures into groundwater. And yet another is the contamination threat posed by the discharge of toxic wastewater produced by fracking operations.
In all these cases, more scientific research is needed. Much of it requires that industry not only collect and make available pre-fracking water quality data, but also release the names of the chemicals they are using, instead of hiding them behind the veil of company secrets.
Ultimately, more transparent and safer fracking operations will benefit the industry as well as the families living in fracking territory. Until the public has full confidence that its drinking water is being safeguarded from contamination, it will continue to protest fracking’s expansion.
If hydraulic fracturing is as safe as its proponents claim, then the industry should welcome the scientific studies needed to prove it so.
Until such studies are completed, the public is wise to call for precautionary measures – including moratoriums on fracking.
Originally published at National Geographic Newswatch
Posted by Sandra Postel of National Geographic’s Freshwater Initiative in Water Currents on July 18, 2013
Riverbend Steam Station, a coal-fired power plant on North Carolina’s Catawba River. Nationwide, thermoelectric power production requires more than 200 billion gallons of water a day, most of it to cool the plants. Duke Energy plans to retire Riverbend in 2015 as part of its effort to modernize its power stations. Photo: Flickr/cc/Duke Energy
When we flip on a light, we rarely think about water. But electricity generation is the biggest user of water in the United States. Thermoelectric power plants alone use more than 200 billion gallons of water a day – about 49 percent of the nation’s total water withdrawals.
Large quantities of water are needed as well for the production, refining and transport of the fuels that light and heat our homes and buildings, and run our buses and cars. Every gallon of gasoline at the pump takes about 13 gallons of water to make.
And of course hydroelectric energy requires water to drive the turbines that generate the power. For every one-foot drop in the level of Lake Mead on the Colorado River, Hoover Dam loses 5-6 megawatts of generating capacity – enough to supply electricity to about 5,000 homes.
In short, energy production is deeply dependent on the availability of water. And, as a report released last week by the U.S. Department of Energy (DOE) makes clear, as climate change brings hotter temperatures, more widespread and severe droughts, and lower river and lake levels, the nation’s energy supply is becoming more vulnerable.
Consider these examples from the DOE report:
- In September 2010, Lake Mead dropped to levels not seen since the drought of 1956; as a result, the Bureau of Reclamation cut Hoover Dam’s generating capacity by 23 percent.
- In 2009, NV Energy abandoned plans for a 1,500 Megawatt (MW) coal-fired power plant that would have used more than 7.1 million gallons of water per hour.
- Extreme drought in the fall of 2011 led the city of Grand Prairie, Texas, to ban the use of municipal water for hydraulic fracturing in order to save the city’s dwindling drinking water supply.
- In 2007, 2010 and 2011, the Tennessee Valley Authority had to reduce power output from its Browns Ferry Nuclear Plant in Alabama because the temperature of the river into which the plant discharges was high enough to raise ecological risks.
- In the summer of 2012, low snowpack in the Sierra Nevada curtailed California’s hydroelectric generating capacity by 8 percent.
- At the Martin Lake Steam Electric Station in Texas, drought so reduced the level of its cooling pond that cooling water had to be piped in from another water source eight miles away.
One particularly interesting figure in the report compares the water requirements of seven different types of electric power facilities – nuclear, coal, biopower, natural gas combined-cycle, concentrated solar, photovoltaic solar and wind. The last two come out as by far the most water-conserving electricity sources. In contrast to the 20,000-60,000 gallons per megawatt-hour needed for nuclear and coal plants with “once-through” cooling systems, PV solar and wind require only negligible quantities.
Locations of the 100 coal-fired power plants most vulnerable to water stress. Courtesy U.S. Department of Energy.
Of the one hundred coal-fired power plants deemed to be most vulnerable to water shortages, most are located in the southeastern states of Alabama, Florida, Georgia, North Carolina and South Carolina (see map). In these states, water for cooling may be constrained by low river flows, high water temperatures or both – forcing utilities to cut back on power generation.
On balance the study’s findings make a strong case for a more rapid shift to renewable energy sources to shore up the nation’s energy security in the face of climate change.
If there’s a call to action in the DOE assessment, it’s this: If, by 2050, the United States could get 80 percent of its electricity from renewable sources – with nearly half coming from water-thrifty wind and solar photovoltaic generation – then total water consumption in the U.S. power sector would decline by about half.
Given the projections for climate-related disruptions to the water cycle, there is little time to waste in making this transition.
Sandra Postel is director of the Global Water Policy Project, Freshwater Fellow of the National Geographic Society, and author of several books and numerous articles on global water issues. She is co-creator of Change the Course, the national freshwater conservation and restoration campaign being piloted in the Colorado River Basin.
MGM Resorts raises stakes with giant Vegas solar system
By BusinessGreen Staff Published July 10, 2013
In Las Vegas, everything is on a grander scale, so it should come as no surprise the gambling capital of the world soon will be home to one of the world’s largest rooftop solar systems.
NRG Energy last week announced plans to install a 6.2 megawatt (MW) installation on top of the Mandalay Bay Resort Convention Center. At peak production, the array should produce enough electricity to meet around a fifth of the building’s energy demand, while reducing pressure on the grid at the hottest time of the day.
“The new 20,000-panel solar rooftop array at Mandalay Bay will effectively enable the resort to lock in a substantial component of its energy costs at a very competitive rate,” Tom Doyle, president and chief executive of NRG Solar, said in a statement.
“Our expectation is that other corporations will follow thought leaders like MGM Resorts to protect our planet.”
Once the project is completed, Mandalay Bay will buy the electricity generated through a power purchase agreement.
The system is the latest in a series of environmental measures taken by parent company MGM Resorts under its Green Advantage sustainability initiative.
Over the past five years, the company has reduced its energy intensity by more than 12 percent and has saved more than 2.5 billion gallons of water.
The news comes as U.S. developer SolarCity announced it has started fitting 3.4 MW of solar rooftop systems at Holloman Air Force Base in New Mexico.
The project will see solar systems installed on more than 600 military homes as part of the company’s SolarStrong program to power 120,000 military residences.
Similar schemes are underway at bases in Texas, Hawaii, Los Angeles and Colorado, contributing to the Department of Defense’s target to meet a quarter of its energy requirements from renewable sources by 2025.
In other solar industry news, the investment arm of insurance giant Aviva has acquired a 12.3 MW portfolio of residential solar systems built on 4,000 U.K. homes from Ecovision Renewable Energy Ltd.
Aviva Investors will collect revenue generated through the feed-in tariff subsidy scheme, while residents continue to save money on their electricity bills.
“This acquisition continues the expansion of our activities in the U.K. renewable sector and is in line with our strategy of investing in high quality infrastructure assets with attractive yields,” Ian Berry, fund manager of infrastructure and renewable energy at Aviva Investors, said in a statement.
“As institutions continue to look towards assets that offer secure and long-dated income streams in order to meet their liabilities, we believe infrastructure opportunities such as this offer the potential to meet these needs.”
Image courtesy of MGM Resorts International.