We asked our experts:
"In your view, is there enough empirical evidence about hydrocarbon fracking to make an informed decision about whether it should be permitted? What is the most critical piece or type of information we should take into account on this issue?"
Lalita Bharadwaj, PhD. is a Toxicologist in the School of Public Health, University of Saskatchewan. Dr. Bharadwaj served as a member of the Expert Panel on Harnessing Science and Technology to Understand the Environmental Impacts of Shale Gas Extraction. Dr. Bharadwaj’s areas of expertise include: human health and environmental risk assessment, community-based participatory research and environmental health.
The surge in pace, frequency and intensity of shale gas extraction in the United States, accompanied by intensive fracking in Pennsylvania and the release of the anti-shale gas drilling documentary Gas Land in 2010, have led to heightened public concerns. Primary public health concerns relate to direct and indirect exposure to fracturing fluid and wastewater constituents, air and water pollution from industrial operations and accidental spills, as well as psychological and psychosocial stresses related to changes to the social, built and biophysical environments. The dispersal of potential health impacts will vary by geology, geography, proximity to drilling operations, individual characteristics and involvement in the industry. Implications, for local communities, immediate (advantageous or unfavorable), long-term or unknown, make the shale gas industry an emerging public health matter.
Anecdotal reports by residents living near shale facilities describe various health problems deteriorating air and water quality and impacts of rapid social change. These reports however do not provide strong empirical evidence to support or refute observations. A comprehensive literature review, recently conducted by Shonkoff et al., 2014, provides evidence to support that shale gas development contributes to levels of ambient air concentrations known to impact human health and that there is a growing body of evidence suggesting this development contributes to water contamination through several environmental pathways. Although the evidence for environmental impacts is accumulating there still exist a number of gaps in our knowledge as it relates to potential risks to public health. Currently there is limited toxicological information on fracturing chemicals, their mixtures, fate, distribution in the ambient environment, as well as exposure assessment data to determine or evaluate human risk with any certainty. There is an absence of health impact assessments or formal epidemiological studies to establish a definitive link between health impacts and risk factors such as air, water pollution and fracturing chemicals. Additionally a comprehensive risk/benefit analysis could inform decisions around the industry's development and evolution.
Dr. Tony Edmonds is a retired Ontario government scientist who specialized in “hands-on” solutions to drinking water treatment problems. He was directly involved in the writing of advisory documents and regulatory developments after the Walkerton disaster, and has represented Ontario on the highest level Canadian body concerned with drinking water and also on a closely related international body.
Many rural communities and farmers in Canada depend on groundwater wells as drinking water sources. Most of these wells require little or no treatment of the water for it to be suitable for long-term safe consumption. Fracking deliberately disrupts underground rock structures and the result may be either failure of the wells by draining water away, or contamination (from naturally-occurring chemicals in other rock layers, or with chemicals used in fracking). Whether these effects occur can only be predicted reliably when it is known that there are highly ordered and special underground rock structures. This may not be known with any certainty. Contamination of well water may occur and thereafter force farmers and communities to consider fitting treatment. This can be prohibitively expensive leading to major expense or to abandonment of farms/communities.
Contamination of well water with fracking chemicals offers the possibility of introducing unknown health hazards. Many of these chemicals have not been tested for effects on human/animal health, aesthetic (smell or taste) effects, or for feasibility of treatment and removal. Furthermore the names of these fracking chemicals, the timing and amounts being used in each fracking well, as well as the levels of impurities in them, are considered proprietary secrets. Legislation forcing monitoring and provision of enough information for scientific/engineering assessment on this does not appear to be in place.
Finally, legislation thus far does not appear to force the measurement of quantities of, or the contamination level and environmentally safe disposal arrangements for contaminated water released at the fracking well (along with the oil or gas produced by fracking). Spill controls and treatment effectiveness does not appear to be well publicized or under appropriately comprehensive, legislated and independent monitoring and control. Nor does the potential for substantial escapes of gases from improperly sealed fracking wells.
Bart Lavis has been working in land development for 10 years and has experience with Environmental Site Assessments, Ecological Risk Assessments, Ex-situ and In-situ Remediation and Energy Approvals. Bart is a licensed Professional Engineer and under his current and previous roles, provided technical expertise, project management, regulatory understanding and quality assurance.
There currently resides enough knowledge to make a consistent policy framework and permitting platform for fracking in Canada. This is attributed to the scientific awareness and knowledge that has been collected via various forms of underground exploration such as for the petroleum, water and mining industries.
The most critical component in permitting should be the recognition that despite the scientific understanding of rock formations and subsequent stratigraphy there remains no two sites that have the same subsurface conditions. Furthermore, this unpredictable nature is further amplified when one considers the pressures used to fracture shale to release the petroleum products. Despite best efforts the stresses and shear forces applied to the local shale will result in fractures that are financially unfeasible to predict. Although unintended, these fissures/fractures could have a deleterious impact on aquifers through cross contamination from fracking substrates, petroleum products and petroleum byproducts. Similarly, under pressurized scenarios consideration should be had regarding volatile organic compounds released to the atmosphere surrounding the wellhead and surficial vents.
Although the knowledge of geological features is in very capable scientific hands, to decrease the prevalence of cross contamination the following should be implemented in the permitting regime:
1. Observation/monitoring wells installed prior to extraction and pressurization both for soil vapour testing and groundwater/aquifer testing within intervals radiating from the source drilling location
2. Borehole drilling within and around the extraction point to assess stratigraphy including vadose zone, capillary fringe, zone of saturation, aquifer confinement, and/or impermeable rock layers.
3. Baseline delineation seasonally of existing aquifers and chemical composition within the area
4. Background air analysis prior to extraction and pressurization for VOC's
5. Groundwater flow delineation
6. Operational monitoring of background wells, groundwater flow and chemical composition during extraction and pressurization on frequent basis (frequency should be subject to borehole conditions, groundwater flow speed and environmental vulnerability of the site, i.e. confined aquifer or residential area).
John Molson, PhD., is a Professor of Hydrogeology in the Department of Geology and Geological Engineering at Université Laval, and an Adjunct Professor in the Department of Earth and Environmental Sciences at the University of Waterloo. Dr. Molson served on the recent CCA and Quebec panels reviewing the possible environmental impacts of shale gas extraction. He holds a Tier II Canada Research Chair in Quantitative Hydrogeology of Fractured Porous Media and specializes in development and application of numerical simulation models for understanding hydrogeological processes.
First, I would clarify that the real issue may not be the 'fracking' process itself, but wellbore integrity. This is ensuring the wellbore is properly sealed to prevent gas or fluid escape either between the steel casing and rock, or within the borehole for a decommissioned well. This issue applies to all hydrocarbon wells, whether for fracking, or otherwise. In this context, there is not enough evidence yet to make an informed decision. Although growing, there is a current lack of peer-reviewed independent studies documenting the behaviour and impact of these systems and quantifying the risks. There is as yet no consensus on how to best monitor these systems. Some impacts may take decades to develop thus it will take time to collect the needed data, make decisions and develop policies.
E4D would like to thank our experts for their contribution, and helping advance informed discussions around public policy. Please direct media inquiries to firstname.lastname@example.org.