The methane that escapes during the drilling process, and later as the fuel is shipped via pipelines, is a significant greenhouse gas. At least one scientist, Robert Howarth at Cornell University, has calculated that methane losses could be as high as 8 percent. Industry officials concede that they could be losing anywhere between 1 and 3 percent. Some of those leaks can be prevented by aggressively sealing condensers, pipelines and wellheads.
But there's another upstream factor to consider: Drilling is an energy-intensive business. It relies on diesel engines and generators running around the clock to power rigs, and heavy trucks making hundreds of trips to drill sites before a well is completed. Those in the industry say there's a solution at hand to lower emissions—using natural gas itself to power the process. So far, however, few companies have done that.
The senator is incorrect. In the past two years alone, a series of surface spills, including two blowouts at wells operated by Chesapeake Energy and EOG Resources and a spill of gallons of fracking fluid at a site in Dimock, Pa. But the idea stressed by fracking critics that deep-injected fluids will migrate into groundwater is mostly false. Basic geology prevents such contamination from starting below ground. A fracture caused by the drilling process would have to extend through the several thousand feet of rock that separate deep shale gas deposits from freshwater aquifers.
According to geologist Gary Lash of the State University of New York at Fredonia, the intervening layers of rock have distinct mechanical properties that would prevent the fissures from expanding a mile or more toward the surface. It would be like stacking a dozen bricks on top of each other, he says, and expecting a crack in the bottom brick to extend all the way to the top one. What's more, the fracking fluid itself, thickened with additives, is too dense to ascend upward through such a channel.
EPA officials are closely watching one place for evidence otherwise: tiny Pavillion, Wyo. Pavillion's aquifer sits several hundred feet above the gas cache, far closer than aquifers atop other gas fields. If the investigation documents the first case of fracking fluid seeping into groundwater directly from gas wells, drillers may be forced to abandon shallow deposits—which wouldn't affect Marcellus wells.
Much of the political opposition to fracking has focused on the Catskill region, headwaters of the Delaware River and the source of most of New York City's drinking water. But the expected boom never happened—there's not enough gas in the watershed to make drilling worthwhile.
The shale is so close to the surface that it's not concentrated in large enough quantities to make recovering it economically feasible. More than a dozen homeowners in central Arkansas claim the disposal of fracking wastewater triggered a swarm of more than 1, minor earthquakes in and that damaged their property. Fracking, like other oil and gas operations, involves intense industrial development.
Well pads, access roads, pipelines, and utility corridors are typically accompanied by intense, round-the-clock noise, lights, and truck traffic. In addition to potentially polluting local water and air resources, this vast web of infrastructure can fragment forests and rural landscapes and degrade important wildlife habitat.
Another study, analyzing the impact of fracking wastewater sprayed on forested land in West Virginia, found that more than half of the trees in the area had died within two years. Since , hydraulically fractured horizontal wells have accounted for the majority of new oil and natural gas wells developed in the United States, surpassing all other drilling techniques. Texas is the top producer of crude oil and natural gas. North Dakota ranks second for crude oil and Pennsylvania second for natural gas.
The most productive U. The fossil fuel industry has also set its sights on areas that offer much less potential output, such as in the Florida Everglades, including the Big Cypress National Preserve, despite tremendous environmental risks. The state also serves as a cautionary tale for the many health and environmental consequences of fracking and other methods of fossil fuel extraction.
Studies have found increased levels of harmful chemicals in water near fracking sites, suggesting that further monitoring is in order. Meanwhile, a state regulation designed to protect the public from the health impacts of fossil fuel extraction may be only loosely enforced , according to a study by Dallas news station WFAA.
Output is expected to continue to grow—though not everywhere. In , New York became the first state with significant natural gas reserves its southern swath sits atop the Marcellus Shale play to prohibit fracking. However, as of , California was still the fourth-largest producer of oil in the nation due to significant ongoing conventional production, from the largely rural Central Valley to some of the densest urban drilling sites anywhere in the world in Los Angeles and surrounding municipalities.
A analysis of oil and gas development in California showed that approximately 5. When fracking does occur in California, it differs from elsewhere in the United States, as it often occurs at shallower depths and in closer proximity to drinking water sources, increasing the risk of water contamination.
Nevertheless, the Trump administration has made moves to open more than one million acres of public land in the state—much of which supplies water for agricultural and urban areas—to oil and gas drilling. This boom in production has come at a cost, however, particularly to land, air, and water resources. According to a study by the National Oceanic and Atmospheric Administration, drilling and fracking operations in the Bakken oil and gas fields alone contributed as much as 3 percent of global emissions of ethane a greenhouse gas and precursor for ozone formation.
Although fracking is typically associated with big producers like Texas, states with far more limited oil and gas reserves are affected too. According to an expert report obtained by NRDC, both current production and the prospects for future expansion in Florida are minimal. Aquifers—crucial sources of drinking water—are vulnerable to contamination because large areas are characterized by sandy soils and porous limestone.
Since Florida oil fields generally lie deeper than the shallow aquifers that provide the state with fresh drinking water, acidizing techniques threaten groundwater resources.
Additionally, wastewater from acidizing techniques can contain hazardous pollutants and pose threats to underground aquifers. Proposals for a statewide legislative ban on fracking and acidizing techniques have been introduced, with bipartisan support, in both houses of the state legislature. Dozens of counties and municipalities have already said no to fracking within their respective borders—and for good reason. Oil and gas production threatens public lands, natural resources, wildlife, water supplies, and Florida tourism, a vastly larger industry in the state than oil.
Although evidence continues to mount about the negative impact of fracking on our water, air, and health, the industry remains seriously underregulated. Oil and gas operations benefit from a range of exemptions or limitations in regulatory coverage within the bedrock environmental statutes that are meant to protect Americans from contaminated water, hazardous waste, and polluted air. Unless diesel is used in the fracking fluid, it exempts hydraulic fracturing from regulation under the Underground Injection Control Program of the Safe Drinking Water Act , the law protecting our drinking water from pollutants.
Such oil and gas exploration and production wastes could include used fracking fluids, produced water, and many other types of waste. The industry also enjoys a loophole in the Clean Air Act that exempts oil and gas wells, compressor stations, and pump stations from aggregation as major sources that would otherwise have to implement pollution controls once emissions hit a certain threshold.
As to the Clean Water Act , Congress exempted stormwater runoff from oil and gas exploration, production, processing, or treatment operations or transmission facilities from certain permitting requirements, provided that such stormwater is not contaminated. Bills seeking to close these and other statutory loopholes and exemptions were introduced in Congress in but have made little progress. Meanwhile, the Trump administration is aggressively opening up more public land to fracking and proposing rollbacks of existing regulations on oil and gas operations.
The rules, which have been held up in the courts, impose safeguards to protect water supplies from fracking on federal lands—safeguards that health and environmental advocates already believe do not go far enough. Stricter federal oversight of the oil and gas industry would go a long way toward protecting our communities and environment, but state and local agencies can also play a significant role in governing the industry.
Fracking also uses a lot of water. Each and every well requires millions of gallons of water — In arid places like the West, this could mean less water for fish and wildlife. Search Search Clear. Join Donate. Where We Work. About Us. This creates a dense network of small fractures in the rocks, releasing gas or oil that moves into the water stream and is pumped or carried to the surface. Earthquakes can occur when fracking takes place near a geological fault.
If frack fluid is pumped into a geological fault, it can also slip more easily. Fracking can also change the stress on the fault, causing it to release, and a big enough fault shift will be felt as an earthquake. The new paper , published in Geomechanics and Geophysics for Geo-Energy and Geo-Resources, tries to predict how far from a geological fault it is safe to frack a well without causing an earthquake. Such research is important as it could lead to areas of land being ruled out for fracking, prevent earthquakes and, of course, save the fracking industry from a PR disaster.
To make this prediction, the researchers from Keele and Birmingham universities ran 50 models of a fracking operation based loosely on a site in north-west England and modelled the extent of the expected change in underground stresses.
They combined this with an estimation of the smallest stress change that geoscientists think could trigger an earthquake. The results show any fracking site needs to be at least 63 metres away laterally from any fault, and perhaps as far as metres. But it partly reflects our limited knowledge of the complex underground landscape and how fracking interacts with it.
0コメント