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POTENTIAL OR ACTUAL RISKS TO PUBLICHEALTH ASSOCIATED WATER CONTAMINATIONDUE TO SHALE GAZ EXPLOITATION ACTIVITIES

Gaétan Carrier, ing., Ph.D., md., C.C.P.Q Médecin conseil, Santé environnementale, INSPQProfesseur associé, Université de Montréal

Collaboration Céline Campagna, Ph.D., INSPQ Patrick Poulin, Ph.D., INSPQ

OEMAC, 31ST Annual Scientific ConferenceMontréal October, 01, 2013

CONCERN ABOUT WATER CONTAMINATION

The debate surrounding the safety of shale gas development has generated increased awareness of drinking water quality in rural communities.

Concerns include drinking water aquifers contamination by hydraulic fracturing flowback fluids; methane and other contaminants originating from

shale gas formations (ethane, butane, propane, metal-rich formation brines, radioactive elements);

risks to health and environment related to this contamination (potential or actual).

Water loss and management of reclaimed water

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PRESENTATION OBJECTIVES

Origin of natural gas (Methane: CH4): biogenicand thermogenic CH4.

Methods of natural gas exploitation Characteristics of hydrocarbons and gas from the

thermogenic zone: shale and tight gas reservoirs Historical background of shale gas exploitation. Summary of current knowledge concerning the

risks of drinking water contamination and related to the exploitation of shale gas.

Summay of current knowledge concerning risks to health related to this contamination.

Reflexing on long-term concerns for public health related to this contamination.

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FORMATION OF FOSSIL FUELS COAL, OIL AND GAS

Coal, oil and gas are formed from living organisms (algae, plankton, continental plants...) accumulated in sediments in geological times.

This represents a long process of sedimentation requiring a series of very specific phases.

The sedimentation occurs in the depths of oceans and lakes

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Period of formation of shale gas.

Time scaleMillion years

FORMATION OF FOSSIL FUELS COAL, OIL AND GAS

Phase1: sedimentation Generally, the biosphere recycles almost all the waste it

produces. A small part of this biomass, found in mineral layers in the

sedimentary formation, settle when they die (usually less than 5% of the volume of sediment).

Phase 2: Formation of a solid compound called kerogen and biogenic methane Over time sediments penetrate slowly into the ground

along the plate tectonics (the movement of continents). The temperature gradually increases due to geothermal

energy resulting from the natural radioactivity of terrestrial rocks.

In shallow depths, the organic fraction trapped in the mineral sediment in formation, undergoes a primary transformation by bacteria.

This leads to the formation of biogenic methane and a solid compound called kerogen disseminated in the mineral, forming small simple nets.

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KEROGEN

Kerogen is the intermediate substance between organic matter and fossil fuels.

On a planetary scale, kerogen represents a total mass of 10 million Gt.

Only 0.1% of the kerogen is transformed into coal (10,000 Gt).

Gas and oil each represent 0.003% of the total kerogen (300 billion tonnes).

71 Gt = 109 tonnes.

PHASE 3: THE EVOLUTION OF KEROGEN AND FORMATIONOF SOURCE ROCKS AND THERMOGENIC METHANE

Over time, sediment penetrates gradually into the ground and the temperature of the sediment increases.

Water is expelled and the sludge sedimentation solidifies into non porous rock, known as shale source rocks, which can be found at a depth of several hundred metres (up to 3 kilometres for the deepest).

From 50°C to 120°C (about 1 to 2 km deep), kerogenundergoes anaerobic thermal decomposition: pyrolysis.

At this depth, kerogen net begins to produce liquid hydrocarbons (oil and ethane to heptane) and natural gas (thermogenic methane).

Water and CO2 are extracted from the kerogen. The rock becomes less and less porous.

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STEP 4: FORMATION OF COMBUSTIBLE

DEPOSITS

Oil and gaz trapped in profond source rock (Shale gas and shale oil) .

Gas and oil escape from the source rock and migrate to the surface. The pressure becomes sufficient to overcome the "impermeability" of the source rock: Conventional gas and/or oil reservoirs. Tight gas reservoirs. Tar sands (oil): bitumen

Firedamp: gas (a little oil) trapped in fossil coal.

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NATURAL GAS RESERVES: CONVENTIONAL ANDNON CONVENTIONAL

10Source: Les hydrocarbures de roche-mère en France, Rapport provisoire, Avril 2011:Conseil général de l'industrie de l'énergie et des technologies, Conseil général de l'environnement et du développement durable.

Tar sands (oil): bitumen

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SHALE GAS

Shales may range from a few dozen metres to several kilometres in thickness and extend over very vast territories (hundreds or thousands of square kilometres).

Shale gas zones contain several thousand to several billion cubic metres of gas.

The volume of gas contained in a resource zone depends on the thickness and area of the deposit.

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CHARACTERISTICS OF HYDROCARBONS AND GAS FROM

THE THERMOGENIC ZONE: SHALE AND TIGHT GAS

RESERVOIRS

Significant quantities of methane are trapped in the form of methane hydrate (2H-CH4).

Because isotopic disintegration occurred over millions years, the carbon of the methane is not only the fossil carbon 14 (14C), but contains its isotopes, carbon 13 (13C).

Besides methane, the thermogenic zone includes a variable rate of heavier hydrocarbons ranging up to heptane (C2H6 to C7H16).

The following elements can also be found: CO2, SO2, H2S, Sometimes nitrogen (N2), small amounts of helium (He)

and radioactive elements (uranium, thorium and radium). 12

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HYDRAULIC FRACTURING

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Protective encasement of the gas catchment and steel piping systems

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HORIZONTAL HYDRAULIC FRACTURING

To fracture these shale rocks, a large quantity of fluid, basically water, loaded with a support agent of tonnes of grains of sand or ceramic beads (water + sand: 98% of the injected volume) and chemical products are pumped towards the bottom of the wells until the pressure exceeds the strength of the rock and makes the reservoir crack.

This fracturing operation may be repeated several times in the same well over a three to four years period (10 to 15 times).

In general, producers manage to recover an average of 17% to 20% of the gas in the drilled area.

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HORIZONTAL HYDRAULIC FRACTURING

The sand is used to help keep the fractures open since they risk closing again once the pressure is released.

Several chemical products, the composition of which varies depending on the type of soil, are used to extend the duration of the fractures and facilitate capture of the gas: gelling agents, friction reducers, surface active agents, corrosion inhibiters, antibacterial agents, clay stabilizers, etc.

These products can include formaldehyde, boric acid, hydrochloric acid, methanol, isopropanol, benzene, toluene, etc. Over 1,000 of these chemicals identified.

In a single shale gas extraction area, approximately 0.1-0.5 litres of chemical products are injected per sq. m. of surface.

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MICROSEISMIC IMAGERY OF A FRACTUREAT SEVERAL STAGES

17- Each colour represents a fracture in a single stage.- Source: Schlumberger, 2007.

PRODUCTION PROFILES OF SHALE GAS

WELLS ON A DAILY BASIS

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(Data from wells in the Montney shales)

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HORIZONTAL DRILLING AND FRACTURINGARRANGEMENT OF HORIZONTAL WELLS

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20Source: Chesapeake Energy USA;

Tyndall Center, 2011

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DENSITY OF ACTIVE WELLS IN A SHALEBASIN

There may be up to 6 wells/sq. km. In the Barnett Basin in the United States, the

average is 1.15 wells/sq. km.

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THE HISTORICAL BACKGROUNDOF SHALE GAS EXPLOITATION

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THE HISTORICAL BACKGROUND OF THE

EXPLOITATION OF SHALE GAS. The first natural gas well was drilled in the USA in 1821. The first gas company was founded in 1858, the first

hydraulic fracturing was performed in 1986, and the first horizontal drilling in 1992.

Hydraulic fracturing operations, consisting of fracturing rock using fluid under high pressure to release the gas or oil, were not very profitable until the Devon Company mastered the technique of horizontal drilling in 2002 (Barnett reservoir in Texas).

Conclusive tests obtained in 2005, allowed production to take off in United States in 2007. Since then, it has experienced tremendous growth.

Accordingly, in North America, on the average, these gases have been exploited for less than five years.

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SHALE GAS IN THE USA

The production of shale gas is growing rapidly in the United States.

President Barack Obama has made natural gas the pillar of his energy policy, which aims to reduce the country's dependence on oil and its carbon dioxide emissions.

Shale gas now accounts for 23% of the natural gas production in the United States, while it was negligible in 2004.

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SHALE GAS IN CANADA

The main shale reservoirs are located in: Western Canada

The Montney and Horn River Basins located in northeastern British Columbia.

The Colorado Formation located in southern Alberta and Saskatchewan.

Quebec The Utica Formation is located in southern Quebec, between

Montreal and Québec City, near the Appalachians frontal zone.

and in the Maritimes The Horton Bluff Formation is located in New Brunswick and

Nova Scotia. 26

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SHALE GAS IN QUEBEC

Between 150 and 600 horizontal drilled wells are expected each year for several decades.

In Quebec, 30 wells have been drilled for exploration and/or exploitation since 2007. 18 are vertical 11 are horizontal Hydraulic fracturing was performed on 9 vertical

wells and 6 horizontal wells.Data from the BAPE, Quebec.

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PERMITS GRANTED FOR OIL AND GAS DEVELOPMENT IN QUEBEC

(MINISTÈRE DE RESSOURCES NATURELLES ET DE LA FAUNE (MRNF)

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WATER RESOURCES

The quality and quantity of water destined for human consumption are the most important public health issues related to the shale gas industry.

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HORIZONTAL FRACTURING: WATER LOSSAND MANAGEMENT OF RECLAIMED WATER

Each well in the Barnett shale formation in the Fort Worth Basin in Texas requires 11 to 15 million litres of fresh water.

Depending on the site, between 25% to 50% of this contaminated water returns to the surface; the remainder remains in the depths.

The reclaimed water cannot be reintroduced into the watershed without being decontaminated.

This water, contaminated with salt water and chemical products, must therefore be managed very carefully: placed in water retention ponds, if possible, treated in wastewater treatment plants. This appears to be a significant challenge for the industry and the municipalities’ wastewater treatment plants. 30

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MANAGEMENT OF THE WATER AND

DRILLING SLUDGE

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Storage and treatment of waste water and drilling sludge.

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SOURCES OF WATER CONTAMINATION

Surface water or groundwater Incidents: spills, leaks, reflux. Inadequate treatment of wastewater. Migration of gas, fractionning fluids, hydrocarbons.

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WATER CONTAMINATIONEXAMPLES OF DOCUMENTED CASES

Surface water 22/04/2011 The American company, Chesapeake Energy, one

of the largest shale gas producers in Pennsylvania, suspended its hydraulic fracturing operations following an accident in a well which resulted in the pollution of a water course. The spill lasted four days (dissolved salts, solids).

The relation between contamination and health is difficult to evaluate (non consumption notice).

Groundwater Natural gas (inadequate cementation – confirmed in OH and

PA). Turbidity (inadequate drilling – confirmed in NY). Presence of hydrocarbons in the water (11 out of 19 wells),

among others, 2-butoxyethanol (2-BE), an element used in hydraulic fracturing (shale gas suspected – WY Pavilion).

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LEAKS AND MIGRATION: ENCASEMENT

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Source: Association pétrolière et gazièredu Québec, www.apgq-qoga.com Source: Parfitt, 2010: Fracture lines

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IS THE RISK OF LARGE-SCALECONTAMINATION OF WATER INTHE WATER TABLE REAL?

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STUDY ON CONTAMINATION OF THE WATER TABLE

BY RESEARCH SCIENTISTS AT DUKE UNIVERSITY

Stephen G. Osborn et al. (2011): Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing.www.pnas.org/cgi/doi/10.1073/pnas.1100682108.

Study published in the Proceedings of the National Academy of Sciences, USA.

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STUDY PROTOCOL

Comparative contamination study of drinking water wells located less than 1 km from shale gas

drilling (active wells). With drinking water wells located more than 1 km from shale gas

wells.

In this study, the authors analysed the content of various contaminants in 68 private wells, 36 to 190 m. deep in north-eastern Pennsylvania (Catskill and Lockhaven) and in New York State (Genessee).

In the water of 68 wells, they measured dissolved salt, isotopes (18O and 2H), carbon isotopes (13C), boron and radium.

In 60 of the 68 wells, they measured the concentration in methane and light liquid hydrocarbons (ethane, butane, propane).

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DEPTH OF THE WELLS UNDER STUDY

The average depth of the drinking water wells was 60 to 90 metres, while the Marcellus shales in the study area were 900 to 1800 metres deep.

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RESULTS OF THE STUDY

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Mean1,1 mg CH4/L > 1 km

Mean19,2 mg CH4/L < 1 km

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CONCLUSIONS OF THIS STUDY

1. This study clearly shows contamination of drinking water wells by methane and other light hydrocarbons (liquid) coming from the deep thermogenic shales.

2. The average concentration of methane was 18 times higher in the wells in the active zone and concentrations reached levels requiring interventions to prevent explosions.

3. There was no evidence of contamination of the drinking water by mineral salts or by saline water contained in the shales. N.B.: The active life of the wells less than < 1 year to less than 4 years.

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THE AUTHORS’ HYPOTHESES CONCERNING

THE CONTAMINATION MECHANISMS

Fissures in the protective encasement of the gas catchment and piping systems. These fissures occur at depths of hundreds of metres. The methane and light liquid hydrocarbons pass laterally or vertically through the system fractures.

The hydraulic fracturing procedure generates new fractures or increases existing fractures above the fracturing zone. The gas infiltrates through these new fractures up to the water table.

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INCREASED STRAY GAS ABUNDANCE IN ASUBSET OF DRINKING WATER WELLS NEARMARCELLUS SHALE GAS EXTRACTION (2013)

Robert B. Jacksona,b , Avner Vengosha, Thomas H. Darraha, Nathaniel R. Warnera, Adrian Down a,b, Robert J. Poredac, Stephen G. Osborndd, Kaiguang Zhaoa,b, and Jonathan D. Karra,b

www.pnas.org/cgi/doi/10.1073/pnas.1221635110 a Division of Earth and Ocean Sciences, Nicholas

School of the Environment and b Center on Global Change, Duke University,

Durham, NC 27708; cDepartment of Earth and Environmental

Sciences, University of Rochester, Rochester, NY 14627;

d Geological Sciences Department, California State Polytechnic University, Pomona, CA 91768

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RESEARCH PROTOCOLE

141 drinking water wells were analyzed across the Appalachian Plateaus physiographic province of northeastern Pennsylvania,

Proximity to shale gas wells were analysed for: natural gas concentrations CH4/L and isotopic signatures (δ13C-CH4, δ13C-C2H6,

and δ2H-CH4), hydrocarbon ratios (methane to ethane and

propane), and the ratio of the noble gas 4He.

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Ethane/methane

Propane/methane

RESULTS

Methane was detected in 82% of drinking water samples, with average concentrations six times higher for homes <1 km from natural gas wells (P = 0.0006).

Ethane was 23 times higher in homes <1 km from gas wells (P =0.0013);

propane was detected in 10 water wells, all within approximately 1 km distance (P = 0.01).

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CONCLUSION

For ethane concentrations, distance to gas wells was the only statistically significant factor (P < 0.005).

Isotopic signatures (δ13C-CH4, δ13C-C2H6, and δ2H-CH4), hydrocarbon ratios (methane to ethane and propane), and the ratio of the noble gas 4He to CH4 in groundwater were characteristic of a thermally postmature

Marcellus-like source in some cases. Overall, our data suggest that some homeowners living <1 km from gas wells have drinking water contaminated with stray gases.

GEOCHEMICAL EVIDENCE FOR POSSIBLENATURAL MIGRATION OF MARCELLUSFORMATION BRINE TO SHALLOW AQUIFERSIN PENNSYLVANIA (2012)

Nathaniel R. Warner, Robert B. Jackson, Thomas H. Darrah, Stephen G. Osborn, Adrian Down, Kaiguang Zhao, Alissa White, and Avner Vengosh

www.pnas.org/lookup/suppl/doi:10.1073/pnas.1221635110/-/DCSupplemental.

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RESULTS

Integration of chemical data (Br, Cl, Na, Ba, Sr, and Li) and isotopic ratios (87Sr/86Sr, 2H/H, 18O/16O, and 228Ra/226Ra) from this and previous studies in 426 shallow groundwater samples and 83 northern Appalachian brine samples suggest that mixing relationships between shallow ground water and a deep formation brine causes groundwater salinization in some locations.

The strong geochemical fingerprint in the salinized (Cl > 20 mg/L) groundwater sampled from the Alluvium, Catskill, and Lock Haven aquifers suggests possible migration of Marcellus brine through naturally occurring pathways.

The occurrences of saline water suggests that conductive pathways and specific geostructural and/or hydrodynamic regimes in northeastern Pennsylvania are at increased risk for contamination of shallow drinking water resources, particularly by fugitive gases, because of natural hydraulic connections to deeper formations.

HEALTH IMPACT

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ACUTE HEALTH AND SAFETY RISK

Methane poses a potential explosive threat when build-up occurs in confined spaces.

Methane becomes an explosion hazard at concentrations of 5 - 15 % by volume in air.

The toxicity of methane is very low, however at high concentrations, it actsas an asphyxiant.

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CHRONIC EFFECTS ON HEALTH?

Average operational life: less than 5 years. It is therefore impossible to observe a chronic

effect on health, such as cancer or damage to the nervous system.

Generally, such effects occur one or more decades after repeated exposure over long periods.

Industry workers are most liable to be exposed to toxic or carcinogenic contaminants since they are the ones who handle them.

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CONCLUSION: QUESTIONS RAISED

Can we really prevent contamination of the water table using current operating techniques?

What will happen to the retention reservoirs if they are left untended at the end of the drilling activities of a well? Is there a risk of perforation?

Is it possible that the materials used to seal wells that are abandoned after being exploited could alter over the years to the point of giving way?

In 25, 50, 100 years, will the water in the water table of the Saint Lawrence Valley still be fit for drinking?

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REFERENCES

État préliminaire des connaissances sur la relation entre les activités reliées au gaz de schiste et la santé publique. http://www.inspq.qc.ca

Michaels, C., Simpson, J. L., Wegner, W. (2010). Fractured Communities: Case Studies of the Environmental Impacts of Industrial Gas Drilling. September 2010.

Osborn SG, Vengosh A, Waner NR, Jackson RB (2011) Reply to Saba and Orzechowski and Schon: Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing. Proc. Natl. Acad. Sci. USA, 108 (37) E665-E666.

United States Environmental Protection Agency (EPA), Office of Research and Development. (2011). Draft Plan to Study the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources. February 2011.

Jean-Louis DURVILLE., Jean-Claude GAZEAU: Conseil général de l'industrie, Conseil général de l'environnement de l'énergie et des technologies et du développement durable (Les hydrocarbures de roche-mère en France. Rapport provisoire. Avril 2011.

Weymuller Bruno: Les perspectives du shale gas dans le monde. Gouvernance européenne et géopolitique de l’énergie. Décembre 2010.

DIRECTORATE GENERAL FOR INTERNAL POLICIES POLICY DEPARTMENT A: ECONOMIC AND SCIENTIFIC POLICY. DIRECTORATE GENERAL FOR INTERNAL POLICIES POLICY DEPARTMENT A: ECONOMIC AND SCIENTIFIC POLICY. European parliament. Executive summary 2011.

Jackson RB, Vengosh A, Darrah TH, Warner NR, Down A, Poreda RJ. (2013). Increased stray gas abundance in a subset of drinking water wells near Marcellus shale gas extraction. www.pnas.org/lookup/suppl/doi:10. 1073/pnas.1221635110/-/DCSupplemental.

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Alleman, David (ALL Consulting). “Treatment of Shale Gas Produced Water for Discharge.” Presentation at the EPA Technical Workshops for the Hydraulic Fracturing Study – Water Resources Management, Washington, D.C., March 29-30, 2011.

USGS, 2011. Dissolved Methane in New York Groundwater. In collaboration with the New York State Department of Environmental Conservation. http://ny.water.usgs.gov

Adair SK, Pearson BR, Monast J, Vengosh A, Jackson RB. 2012. Considering shale gas extraction in North Carolina: Lessons from other states. Dike environmental law and policy forum. Duke University Nicholas Institut for Environmental Policy Solutions. http://nicholasinstitute.duke.edu/climate/policydesign/nc-hydraulic-fracturing

MDDEP – Ministère du Développement durable, de l’Environnement et des Parcs du Québec (2010) Les enjeux environnementaux de l’exploration et de l’exploitation gazières dans les basses-terres du Saint-Laurent. Document de travail. Québec , MDDEP.

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United States Environmental Protection Agency (EPA), Office of Research and Development. (2011). Draft investigation of ground water contamination near Pavillion, Wyoming. December 2011. www.epa.gov/ord

Ressource for the futur (RFF). 2012. Shale gas development and property values. Discussion paper by Muehlenbachs L, Spiller E, and Timmins C. www.rff.org

Tollefson, J. (2012). Air sampling reveals high emissions from gas field. Nature 482, 139-140.

Tollefson, J. (2012). Méthane leaks erode green credentials of nature gas. Nature 493, 12

QUESTION PERIOD

Thank you for your attention

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