Conclusion:While ... results should be viewed as hypothesis generating, and the population studied was limited to households with a ground fed water supply, proximity of natural gas wells may be associated with the prevalence of health symptoms including dermal and respiratory......
More than 2 × 104 m3 of water containing additives is commonly injected into a typical horizontal well in gas shale to open fractures and allow gas recovery. Less than half of this treatment water is recovered as flowback or later production brine, and in many cases recovery is <30%. While recovered treatment water is safely managed at the surface, the water left in place, called residual treatment water (RTW), slips beyond the control of engineers. Some have suggested that this RTW poses a long term and serious risk to shallow aquifers by virtue of being free water that can flow upward along natural pathways, mainly fractures and faults.
From: Annual Review of Environment and Resources.
Rising supplies of natural gas could benefit the environment by replacing coal as a fuel for electricity, but hydraulic fracturing poses dangers for people living near the wells, a new analysis finds.
The study reveals that, in the case of the Karoo, fracking will only be successful if and only if the upward methane and fracking fluid migration can be controlled, for example, by plugging the entire fracked reservoir with cement.
Science of The Total Environment, v. 470–471, pp.1114–1119 "Shale gas development is a controversial method of energy production. There are significant uncertainties about the possible harms to human health and the environment that can result from the process and potentially serious societal harm can result that may or may not be offset by overarching benefits. In spite of the uncertainties states must make decisions about how to proceed. We have argued here that states have a prima facie duty to promote policies in relation to shale gas development that minimize false negatives."
Water International,Vol 38, Issue 6, 2013. A policy vacuum exists in relation to the exploration and mining of unconventional gas in South Africa, with a recent survey showing that 86% of the respondents did not know what hydraulic fracturing entails. We conducted a study to determine the opinion of decision makers involved in formulating policy and regulating mining activities related to shale gas mining in South Africa, as this was not covered in the aforementioned survey. Our results demonstrate that the regulation of shale gas mining in South Africa is viewed as extremely important and identifies possible regulatory and monitoring tools to assist in governing this activity.
Various applications for unconventional gas mining have been lodged with the Petroleum Agency of South Africa (PASA). Yet, gaps still exist in the available knowledge on whether economically recoverable quantities of gas exist, and how to manage the possible impacts, should full scale gas mining proceed. Scientists, legislators and regulators are making use of the time available before gas mining applicants start exploration, or possibly mining, in order to develop the necessary strategic plans.
Water Wheel : Groundwater Special Edition : Special Edition
A solicited study funded by the Water Research Commission (WRC) looks at what we know about hydraulic fracturing, and what we should know if this is allowed to go ahead in South Africa.
“The problems we’ve seen are probably more common than people realize,” says Rob Jackson, director of Duke’s Center on Global Change and lead author of the paper. Jackson stresses that the contamination is probably due to poor well construction, rather than hydraulic fracturing itself. But he says that the results are another “wake-up call” for the industry to improve its drilling operation"
Review of Policy Research, Volume 30, Issue 3, pages 321–340, May 2013This article examines the Pennsylvania case and notes that the state's emerging policy appears designed to maximize resource extraction while downplaying environmental considerations.
Science:2013 vol:340 iss:6134. Natural gas has recently emerged as a relatively clean energy source that offers the opportunity for a number of regions around the world to reduce their reliance on energy imports. It can also serve as a transition fuel that will allow for the shift from coal to renewable energy resources while helping to reduce the emissions of CO2, criteria pollutants, and mercury by the power sector. Horizontal drilling and hydraulic fracturing make the extraction of tightly bound natural gas from shale formations economically feasible. These technologies are not free from environmental risks, however, especially those related to regional water quality, such as gas migration, contaminant transport through induced and natural fractures, wastewater discharge, and accidental spills. The focus of this Review is on the current understanding of these environmental issues.
Institute for Security Studies Papers (9), Dec. 2013. As the first country to reverse a moratorium on hydraulic fracturing - more commonly known as 'fracking' - South Africa is now poised to move forward with the controversial process, exploring what experts believe to be the eighth largest shale gas reserve in the world. For a country that is almost wholly dependent on coal production, shale gas development could be a game-changer. Yet, the possible environmental impacts could also be devastating.
The article presents information on various concerns related to the hydraulic fracturing of shale deposits in the U.S. It is stated that fracking is expected to result in a petrochemical industry boom, but it also raises concerns such as groundwater contamination and mini-earthquakes. Fracking was rated at number four in the list of The Top Ten Unfounded Health Scares of 2011, by the American Council on Science & Health (ACSH).
ICIS Chemical Business, 1/23/2012, Vol. 281 Issue 4, p13-13, 1/2p
Environmental Practice / Volume 14 / Issue 04 / December 2012, pp 320-331. High-volume horizontal hydraulic fracturing (fracking) is a new technology that poses many threats to biodiversity. Species that have small geographic ranges and a large overlap with the extensively industrializing Marcellus and Utica shale-gas region are vulnerable to environmental impacts of fracking, including salinization and forest fragmentation. We reviewed the ranges and ecological requirements of 15 species (1 mammal, 8 salamanders, 2 fishes, 1 butterfly, and 3 vascular plants), with 36%–100% range overlaps with the Marcellus-Utica region to determine their susceptibility to shale-gas activities. Most of these species are sensitive to forest fragmentation and loss or to degradation of water quality, two notable impacts of fracking. Moreover, most are rare or poorly studied and should be targeted for research and management to prevent their reduction, extirpation, or extinction from human-caused imp
Focuses on a study 68 private drinking water wells in northeastern Pennsylvania and New York, which found a rise in methane contamination with proximity to natural gas drilling. It is stated that concentrations of gases and certain isotopes of carbon in methane were measured by the researchers.
Environmental Health Perspectives; Jul 2011, Vol. 119 Issue 7
The author, Charles W. Schmidt, MS, an award-winning science writer from Portland, ME, has written for Discover Magazine, Science, and Nature Medicine.
Environ Health Perspect. 2011 August; 119(8): a348–a353.
The Marcellus Shale formation is being harvested for its methane by gas drilling companies in the state of Pennsylvania. This operation has public health significance because the chemicals injected beneath the earth’s surface during the hydraulic fracturing process are known to have adverse health effects ... There is much controversy ... surrounding the use of these chemicals . Despite communication efforts by government agencies with these affected communities, health concerns continue to run high. A literature review performed in regards to the chemicals ... found eleven chemicals to have adverse affects. A qualitative analysis performed on public comments regarding a proposed EPA assessment on hydraulic fracturing found several common themes.
