gas industry development over the 50-year time frame that is generally assumed for forecasting water production (). By 2050, most areas will have reached the end of their production stage. Table 2.1 Estimated water production rates in the main coal seam gas areas in Queensland and New South Wales. Water production rate Area Comment Source 0.2 – 0.7 GL/y Gloucester (New South Wales) Average total water extraction for an estimated resource life of 14 years RPS 2011 0.028 GL/y Clarence-Moreton (New Wales) Average total water extraction assuming 697 ML over a 25-year period RPS 2011 95 GL/y Basin (Queensland) Average water extraction over the life of the industry based on a regional model predictions 75 GL/y to 98 GL/y Surat Basin (Queensland) Average total water extraction over the life of the industry based on predictions from industry and DNRM (2012) 140 GL/y Surat Basin (Queensland) Peak water production rate around the year 2026 140 GL/y to 281 GL/y Queensland’s Surat and southern Surat Basins. Peak production rates ; CWiMi 2008 150 to 180 GL/y Surat Basin (Queensland) Peak water production rate based on different scenarios for coal seam gas production and assuming operations ceased either in year 2040 or 2060 Source: DNRM (2012) Figure 2.5 Estimated volumes of produced in Queensland
characteristics Coal seam permeability testing Lowering of special purpose packers on slim rods into the wellbores with packers isolating specific target coal seams for small-scale downhole water production and injection tests to determine permeability. 5 days Very low Cementing production casing Full cementation of casing from shoe to surface. Up to 2 days Very low HF fluid injection phase or pressurisation phase Well perforation and hydraulic fracturing Well stimulation through a ‘fracture treatment’ opens up the paths in coal seams so they are wide enough to allow gas flow. Fracture treatment involves pumping water, sand and additives into the selected zones at high rates. Up to 1 week (depending on the number of stages to be performed) 1–3 days to complete hydraulic fracturing Accidental leaks of chemicals during transport and hydraulic fracturing mixing and injection Loss of hydraulic fracturing fluid in the coal seam formation Leaks into overlying aquifer during hydraulic fracturing Leaks from storage ponds containing flowback water Depressurisation phase Production testing Production of gas from coal for evaluation and appraisal. 12-15 months from storage ponds containing produced water Production phase CSG wells pump water and gas from the coal seams. Water and gas are separated on the surface, water is pumped to storage ponds awaiting treatment and / or reuse. Up to several decades for a well (20–30 y) Leaks from storage ponds containing produced water Leaks from pipelines Dust control with produced water Flooding from storage ponds Post-operational or return to equilibrium Site rehabilitation that are unsuitable for production or have ceased producing gas will be plugged with cement. Storage ponds are to be cleaned out, and the liners removed and disposed of in a licensed facility. Days to weeks Improperly plugged wells could provide pathways for contaminated groundwater. Storage remain on site with residual contamination accumulated at its base, followed by leakage through the liner. Monitoring Long-term stewardship, monitoring groundwater level and quality. Up to several decades Very low
4.2 Summary of source characteristics Source type Surface area Volume of fluid released Duration of release Chemical composition Chemical concentration Point sources Flat-bed trucks loaded with containers (hydraulic fracturing) ~ 10 m2 833-1420 L HDPE totes Instantaneous Various; Liquid additives; see Table A1 (Appendix A) Uncertain; NICNAS 2017a Flat-bed trucks loaded with containers (hydraulic fracturing) ~ 1 m2 3.8 L jugs Instantaneous Various; see Table A1 (Appendix A) Uncertain; NICNAS 2017a Flat-bed trucks loaded with containers (hydraulic fracturing) ~ 1 m2 19 L sealed buckets Instantaneous Various See NICNAS 2017c Tanker truck (hydraulic fracturing) ~ 10 m2 Contents of the tanker (e.g. 15 000 L) Instantaneous e.g. Hydrochloric acid Uncertain; NICNAS 2017a Line sources Leaking pipes of produced water transported to water treatment facility Few 100s of m2 Several m3 Instantaneous and long-term (if not immediately detected) Various; see 4.3 Uncertain; refer to typical concentrations in produced water as a guide, Table 4.3 Leaking hoses from blender truck to well (fracturing) Few 10s of m2 Several m3 Instantaneous Various; see A1 (Appendix A) Uncertain; NICNAS 2017a Area sources Storage ponds for flowback and produced water Various sizes (e.g. 1600 m2 and larger) Normal operations with compacted clay or geomembrane liner (DITR 2007): expected leakage rate of 10-9 m/s for compacted clay and Long-term (years) Short-term (flooding) Depending on groundwater geochemistry and degree of interaction Uncertain; refer to typical concentrations in produced water as a guide,
10-10 m/s for geomembrane (max. permissible leakage rate). Accidental conditions (e.g. flooding): several orders of magnitude higher. Improper rehabilitation after cessation of CSG activities. with hydraulic fracturing fluids Table 4.4 On-site evaporation or brine containment ponds (waste generated from the RO plant) Various (up to several ha) Normal operations with clay liner: estimated leakage 10-10 m/s. Accidental conditions (flooding): several orders of magnitude higher. Long-term (years) (flooding) Depending on groundwater geochemistry and degree of interaction with hydraulic fracturing fluids Uncertain; refer to concentrations in brine water used for by Santos 2013b (Table 4.5) as a guide
characteristics Ogata and Banks (1961) University of Illinois Code, Scheibe (2004) ATRANS, as described by Zheng and Bennett (2002) MODFLOW / MT3DMSv5.3 Definition of model domain, boundary conditions, and sources and sinks Extent of Aquifer Semi-infinite 1D 1D, 2D, 3D Semi-infinite domain, 3D Confined (vertically bounded) 2D, 3D Unconfined or confined Boundary Conditions Continuous Plane source Instantaneous input Line or plane source Four different type of inflow concentration histories Complex boundary conditions of any type Source/Sink Terms No No No Yes Primary simulation parameters (allowing for high-end scenarios) Flow 1D 1D, 2D, 3D 1D 3D Head distribution Dispersion longitudinal 3D 3D 3D Retardation No Yes Yes Yes Chemical concentrations at particular points Yes ADE Yes ADE Yes ADE Yes ADE Spatial distribution of chemical concentration in groundwater Yes ADE Yes ADE Yes ADE Yes ADE Travel time from source to receptors (groundwater wells, springs, discharge zones in river alluvium). No No No Yes (MODPATH) Main aquifer and model properties Key transport parameters Yes Yes Yes Yes Hydraulic conductivity Pre-defined Pre-defined Pre-defined Defined for MODFLOW Hydraulic gradient Pre-calculated Pre-calculated Pre-calculated Calculated in MODFLOW Effective porosity Pre-defined Pre-defined Pre-defined Defined in MODFLOW and MT3DMS
Appendix A - Chemicals identified in hydraulic fracturing fluids and flowback and produced waters A1 Typical chemicals used in Australian coal seam gas hydraulic fracturing fluids (APPEA 2012) CAS no. Chemical type/name Common function Common use Percentage volume of chemical in the HF fluid 7732-18-5 Water Hydraulic fracturing/ proppant suspension Drinking, bathing, cooking 75–99 7727-37-9 Nitrogen Fluid weight reducer/ proppant suspension Used in cryogenic, food processing, medical 0–70 14808-60-7 Crystalline silica (quartz) Proppant Cat litter, tile mortar, arts and crafts, ceramic glaze, glaze, concrete, paint 0–25 14464-46-1 Crystalline silica (cristobalite) Proppant Sand, gravel 0–25 56-81-5 Glycerin Additive Food and pharmaceutical industry, hair products 0–1 26172-55-4 Microbial control Used in toiletries, cosmetics, dishwashing liquids 0–1 2682-20-4 Microbial control Used in toiletries, cosmetics, dishwashing liquids 0–1 7681-52-9 Sodium hypochlorite Microbial control Disinfectant, bleach, milk production, water treatment, dental/medical, wood/deck cleaner, mildew remover 0–1 Phosphonium sulfate Microbial control Cooling systems, paper-making industry 0–1 6410-41-9 C.I. pigment red 5 Microbial control Food colouring, paints, agriculture 0–1 584-08-7 Potassium carbonate Buffer, stabiliser, solvent Soap, glass, and china production 0–1 127-09-3 Sodium acetate Buffer, stabiliser, solvent Flavouring additive in food industry 0–1
1310-73-2 Sodium hydroxide (caustic soda) Buffer, stabiliser, solvent Food preparation, household drain cleaner, paper, soaps, detergents 0–1 144-55-8 Sodium bicarbonate Buffer, stabiliser, solvent Used as baking soda, cleaning, anti-pollutant 0–1 497-19-8 Sodium carbonate (soda ash) Buffer, stabiliser, solvent Water softener, swimming pools food additive (E500), glass 0–1 7647-01-0 Hydrochloric acid (muriatic acid) Buffer, stabiliser, solvent Household cleaning, food additive, swimming pools, drinking water 0–1 463-79-6 Carbonic acid Buffer, stabiliser, solvent Soda drinks 0–1 77-92-9 Citric acid Buffer, stabiliser, solvent Flavour additive, biological, cleaning, pharmaceutical 0–1 64-19-7 Acetic acid Buffer, stabiliser, solvent Vinegar, in citrus fruits, descaling agent 0–1 533-96-0 Carbonic acid, sodium salt Buffer, stabiliser, solvent Food additive 0–1 64-02-8 Tetra sodium Chelating agent Cosmetic industry 0–1 67-48-1 Choline chloride Clay management Poultry feed additive 0–1 7447-40-7 Potassium chloride Clay management Table salt substitute, medical treatments, garden products, pet supplements, hair products 0–1.5 chloride Clay management Water treatment (drinking, wastewater), textiles, cosmetics, paper-making, soil treatment, drinking, bathing, cooking 0–1 75-57-0 Tetramethyl ammonium chloride Clay management Type of salt 0–1 593-81-7 chloride Clay management Dyeing 0–1 9000-70-8 Gelatin Corrosion inhibitor Capsules for medicines, desserts, 0–1
jellies, ice cream 100-43-52-4 Calcium chloride Filler, stabiliser Detergents, cosmetics, deodorant, pet products, desiccant (moisture absorber), food additive, sports drinks, pickles 0–1 107-21-1 Ethylene glycol Filler, stabiliser Anti-freeze agent, deicing, printer inks 0–1 91053-39-3 Diatomaceous earth, calcined Filler, stabiliser Toothpaste, hydroponics, agriculture storage), filter media (drinking water) 0–1 14807-96-6 Magnesium silicate hydrate (talc) Filler, stabiliser Talcum powder, cosmetics, food additive, soaps, paper, paints, rubber, pottery 0–1 7631-86-9 Non-crystalline silica Filler, stabiliser Glass, paints, coatings, fillers, plastics 0–1 10043-35-3 Boric acid Gel management Cosmetics, skin care products 0–1 102-71-6 Triethanolamine Gel management Cosmetics, skin care products 0–1 1303-96-4 Sodium tetraborate Gel management Component of many detergents, cosmetics, texturing agent in cooking 0–1 25038-72-6 Vinylidene Gel management Plastic wrap for foods 0–1 26038-87-9 MEA borate Crosslinker Cosmetics, hair texturiser, hairspray, antiseptic, laundry detergent 0–1 7647-14-5 Sodium chloride Gel management Food production, food additive, detergents, hair products, softener 0–1 7722-84-1 Hydrogen peroxide Gel management Hair bleach, food processing 0–1 7727-54-0 Diammonium peroxidisulfate Gel management Hair bleach 0–1
area 35 Santos [Santos purchased Eastern Star Gas in Nov. 2011 and discovered an internal report indicating this incident, which had been unreported to the Gov.] Leaking CSG well on 25 June 2011. 10 000 L of untreated saline CSG water leaked from a pipe going into the reverse osmosis plant in NSW. Onsite and in the Pilliga State Forest, NSW Santos 2012b (factsheet) and Cubby 2012 (media report) Company report factsheet Media report 36 Santos / Eastern Star Gas in NSW discharge into Bohema Creek, NSW. Discharge of CSG water Offsite Santos 2012b Company report factsheet 37 Santos / Eastern Star Gas in NSW Water from an untreated CSG water pond overflowing during rain. Overflow (flooding) Offsite Santos 2012b Company report factsheet 38 Camden Gas Project; originally under Sydney Gas Ltd and now owned by AGL Energy Ltd (CSG project) in NSW CSG well blowout on 17 May 2011. A foamy liquid was propelled into the air from a degasser on a mud tank unit attached to the well and was carried by winds toward residential housing (Glen Alpine suburb) and Sydney’s water channel, the Upper Canal. Degasser unit did not operate properly. Both Kirby 2011 (community group) and NSW OEH 2011 (Gov.) Community group for landholders and residents Gov. Media Release
42 Metgasco operating in NSW June 2012 Operation of temporary holding ponds with inadequate freeboard levels; no spillage reported, but the company was fined for multiple offences of non-compliance with regulations relating to wastewater storage Incident alerts: with regulations regarding wastewater storage Onsite et al. 2012 (media) NSW DTI 2012b (Gov.) Media report Gov. Compliance Report 43 Metgasco operating in Dyraaba, NSW in 2011 Failed to clean up two water storage ponds after drilling at a site at Dyraaba, NSW was abandoned. Torn liner and overflowing evident. Pond did not contain hydraulic fracturing fluid or produced water. Overflow Onsite Weekes 2011 report 44 Arrow Energy CSG operation in Dalby, Qld in 2011 Gas and salty water burst out of a CSG well on farmland. According to the landowner, it was the fourth gas incident on his property in two years. These other incidents did not involve the well, but from a leaking pipe. Spill Offsite Berry 2011 Media report 45 Arrow Energy near Mackay, Qld Arrow Energy confirmed traces of toxic chemicals (benzene, toluene, ethylene and xylene=BTEX) detected in wells at a hydraulic fracturing operation for CSG. BTEX was not used in its hydraulic fracturing chemicals and could be related to Other; contamination detected in wells at a gas site Onsite Cubby 2010a report