8/3/2015 OVERVIEW RISK PERCEPTIONS. CSG is a controversial industry

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1 RISKS ASSOCIATED WITH CSG ACTIVITIES Alternative Energy Seminar Risks vs Benefits Jackie Wright Environmental Risk Sciences Pty Ltd OVERVIEW CSG is a controversial industry Perception of risk vs technical evaluations What are the key issues associated with CSG Overview of situation where science tells us the pathways are not complete or are not significant Address hydraulic fracturing, potential for impacts to surface water and groundwater, and fugitive emissions RISK PERCEPTIONS Risk assessments are used to evaluate the potential for a project to cause impacts to human or ecological health National and international guidance is available for undertaking such an assessment Not common to address in detail issues that are not expected to be of major concern Language of risk assessments often technical and targeted at regulators This approach can be perceived by the community as ignoring or brushing aside their concerns CSG is used as an example such a situation 1

2 COAL SEAM GAS Extraction of methane from coal seams for domestic use has become enormously controversial Unconventional gas is gas obtained from coal seams, shale or tight gas formations Involves use of drilling techniques that have grown out of the ones used in conventional gas In Australia most of the conventional gas is located offshore while much of the unconventional gas is inland Reservoirs of conventional gas usually need fewer wells to access the gas than unconventional gas Footprint for unconventional gas can be much larger Abstract No. E??? (NSW Chief Scientist 2013) 2

3 COAL SEAM GAS RESOURCES AND ENVIRONMENT Barrett et al 2013) KEY ISSUES HIGH RISK Perceived Issues Technical Assessment New process not well CSG been around for a long time, drilling methods well established understood Highly toxic chemicals used in drilling Requirement to disclose the chemicals used, management of the chemicals (underground and at surface) often a risk assessment done on these chemicals Hydraulic fracturing Method been undertaken for long time, not used for every project but applications often include so it can be used if needed Potential for surface water and Assessed with hydro/geo data, need to demonstrate careful/sound groundwater contamination water management measures at ground surface Subsidence Assessed for each project typically very low risk Seismic activity Assessed for each project typically very low risk Fugitive emissions Not considered an issue, more evaluation now being undertaken to address perceived risk Poor practices Have to follow Codes of Practice and Regulatory requirements/ monitoring Lack of regulator oversight All aspects of CSG require regulator approval Land access Negotiated for each project Impacts on small communities Managing large workforce during construction important HYDRAULIC FRACTURING One of the techniques used to enhance the recovery of methane from coal seams Injection of high pressure water into the coal seam to open up fractures in the existing cleats (natural fractures) Sand is also injected to prop open the fractures to allow gas to flow from coal seam to well for extraction 3

4 WHY USE CHEMICALS? CSG operations minimize the use of chemicals to only what is needed Regulations prevent the use of any chemicals or products containing BTEX this is often applied to oil and grease on all equipment including surface equipment So what chemicals are used and why? What are these? GUAR/XANTHAM GUM OR GELATINE Sand and water don t mix Sand does not naturally stay suspended in water Thickeners are added to thicken the water to hold the sand in the water so the sand gets into the fractures BIOCIDES Commonly use sodium hypochlorite, ammonium compounds, THPS Guar gum is a food product and the bacteria underground love this Biocides are used to reduce bacteria growth (so the guar gum stays long enough to do the job required and the system does not get clogged with bacteria) 4

5 CLAY STABILISERS Commonly use choline chloride, sodium chloride Used to prevent the clay in the coal seam from swelling during the fracturing and blocking pores and reduce permeability Chicken feed enhance growth Supplements ACIDS AND CORROSION INHIBITORS Commonly use acetic acid, citric acid, hydrochloric acid, ground coffee beans to keep the bore perforations clean and to stop equipment down hole corroding BREAKERS AND PH ADJUSTMENT Used after the sand has been injected into the fractures Need to adjust ph of water being removed (after the use of more acidic chemicals) and to ensure the breakers work - commonly used sodium or potassium hydroxide Breaks down the fluid so that it is more viscous and can be pumped back out of the coal seam, along with water already in the coal seam Include hemicellulase enzyme and monoethanolamine borate 5

6 CHEMICALS Chemical Hydraulic Fracturing Toothpaste Water yes yes Silica yes (sand) yes (hydrated silica) Guar gum yes yes (cellulose gum) Biocide yes Yes (triclosan) Stabilisers (clay) yes yes (some contain sodium chloride) Acids and corrosion inhibitors yes no ph adjustment/breakers yes yes (sodium hydroxide) ISSUES WITH FRACTURING FLUIDS Range of perceived issues that include cross-contamination of aquifers, leaks and spills, use of unknown toxic chemicals For there to be a risk chemicals need to get into an environment where exposure may occur, not biodegrade, and be at sufficiently high concentrations to cause harm Most readily breakdown in the environment Most coal seams well separated from viable aquifers Well installation prevents cross contamination Required to removed volume of hydraulic fluid plus water in coal seam WHAT ARE RISKS OF CSG?: - AFFECTING GROUNDWATER AND WATERWAYS - FUGITIVE EMISSIONS How do you address perceived risks where the above are not normally calculated (cannot occur or so low it is not evaluated in detail)? 6

7 PERCEIVED RISKS WHAT CAN HELP? Use Risk Assessment methods/approaches to quantify the perceived risks Requires risk assessors to develop hypothetical scenarios to address those questions typically these would normally not be assessed as the exposure pathway is not complete or potential for exposure very low Requires identification and consultation with credible community adviser (health authority) EXAMPLE CAMDEN IN NSW Abstract No. E??? 7

8 EX AM PLE 8/3/2015 EXAMPLE Prepared a HIA for the proposed expansion Included a number of hypothetical scenarios to provide information for NSW Health Release of gas from well head concentrations at nearest receiver Movement of all water (and chemicals used) injected during a hydraulic fracturing event from the coal seam up through bedrock to reach accessible aquifers Slow loss (over a month) of contents of whole water storage tank (drilling chemicals, produced water or flowback water) into farm dam or nearby creek AIR EMISSIONS Coal seam gas was analysed using US EPA TO15 method to demonstrate that benzene and other petroleum hydrocarbons were not present and obtain levels of individual hydrocarbons for risk assessment Sourced information on fugitive emissions from well heads to determine how much may leak from a well head Assumed all fugitive emissions for the project happened at 1 well; modelled dispersion of such emissions using conservative simple screening model to predict concentrations at the nearest receiver (50m from well head) All concentrations more than 1000 times lower than air guidelines SURFACE LEAKS IMPACTS ON SURFACE WATER AND GROUNDWATER Proposed to store all fluids in tanks on the well pad including produced water/flowback (no storage ponds for this project) Sourced information on size and number of tanks at a well pad as well as location of accessible groundwater, farm dams and local waterways Assumed L tank of produced water could lose its entire contents over a one month period and that this would mix with perched groundwater or may flow on surface to dam/creek Dilution in dam/creek or in groundwater Used the maximum concentrations of contaminants that could be present in produced water in calculations All levels in groundwater >50 times lower than DWG In surface water most are <DWG with the exception of a few (biodegradable chemicals) 8

9 HYDRAULIC FRACTURING IMPACTS ON AQUIFERS Also determined potential concentrations in accessible groundwater if all fluids using during hydraulic fracturing of a well reached an accessible aquifer At Camden this means approximately L of drilling muds and fracturing fluids need to rise vertically 400 to 700 m through cracks in bedrock (claystone, sandstone and shale) Assumed to mix into a box of groundwater and be extracted Used maximum concentrations of all components in drilling fluids and fracturing fluids in calculations All concentrations > 20 times less than DWG TAKE HOME.. There is a lot of misinformation available on CSG Most of the issues relate to perceived risks Where hydraulic fracturing is undertaken the process uses minimal chemicals The chemicals used are ones we commonly use and experience in daily living It is important that when addressing risks of operations perceived risks are treated equally with technically feasible risks to enable the magnitude of these risks to be communicated to regulators and community QUESTIONS Jackie Wright jackie@enrisks.com.au