RUM SD PLN 0040 WATER MANAGEMENT PLAN

Transcription

1 WATER MANAGEMENT PLAN Ravensworth Underground Mine 1. COMMITMENT AND POLICY 1.1 Introduction Ravensworth Underground Mine (RUM) is located in the upper Hunter Valley of New South Wales, approximately 25 kilometres [km] north-west of Singleton (refer to Figure 1). Xstrata Coal NSW are the site operators. Mining currently occurs via longwall methods in the Pikes Gully and Liddell coal seams however RUM has approval to mine additional seams (Lemington and Barrett) and consideration is being given to modify the mine plan and access these seams. Development consent was granted to Nardell Coal Corporation Pty Limited for the mining operations on 20 November 1996 (DA 104/96). The Development Consent is provided in full in Appendix A. This (WMP) is specifically required by and has been prepared in accordance with Condition 8, Schedule 2 of the Development Consent, which states that: The Applicant shall prepare and implement a Site for the development to the satisfaction of the Director-General. This plan must: (a) be prepared in consultation with NOW, DECCW and I&I NSW; (b) be submitted to the Director-General for approval by the end of December 2009;and (c) include: - a Site Water Balance; - an Erosion and Sediment Control Plan; - a Surface Water Monitoring Plan; - a Groundwater Monitoring Program; - a Surface and Groundwater Response Plan. Under the three-yearly review requirement, this WMP is to be submitted to the Director-General for approval by the end of December This WMP updates and supersedes the 2009 WMP for the Ravensworth Underground Mine (RUM, 2009). The predicted Site Water Balance (SWB) is discussed in Section 2.0, the Erosion and Sediment Control Plan (ESCP) is provided in Section 3.0, the Surface Water Monitoring Program (SWMP) in Section 4.0, the Ground Water Monitoring Program (GMP) in Section 5.0, and the Surface and Ground Water Response Plan (SWGRP) in Section 6.0. The primary objective of the WMP is to describe management measures that will be used to minimise potential mine-related impacts on water resources. Page 1 of 33

2 After Umwelt (2009) Figure 1 Site Locality Page 2 of 33

3 1.2 Surface Water Management Description Ravensworth Underground Mine Figure 2a shows the mine layout in relation to surface features including watercourses, while Figure 2b shows the layout of the surface facilities (pit top). RUM surface facilities are located adjacent to Bayswater Creek. Existing and future underground operations extend southwards and are located between Bayswater Creek (to the west) and Bowmans Creek (to the east). Bayswater Creek is a heavily modified stream being dammed by Lake Liddell upstream and diverted further downstream around neighbouring mining operations. Bayswater Creek drains southwards joining the Hunter River approximately 40 km upstream of Singleton. Bowmans Creek has a largely unmodified catchment and also flows southwards joining the Hunter River 3 km downstream of the confluence with Bayswater Creek. RUM No.2 Ventilation Shaft and RUM No.3 Ventilation Shaft are located near Bowmans Creek but are separated from the creek by the main northern rail line. Drainage above the RUM longwall panels are dominated by highly modified post-mining landscapes associated with other mining operations. RUM currently holds licences under the Water Act 1912 for the operation of groundwater extraction from mining operations and monitoring bores, and Water Access Licences (WAL) under the Water Management Act 2000 for water extraction under the Water Sharing Plan for the Hunter River Regulated Water Source. A summary of water licences held by RUM is given in Table 1. Table 1 Summary of Water Licences Licence Number Category Limit WAL1046 High Security (Zone 1B) 3 units WAL8964 General Security (Zone 1B) 1590 units WAL1325 Supplementary (Zone 1B) 13 units 20BL Groundwater Extraction 400 ML/year 20BL Groundwater Monitoring n/a RUM holds 1,590 ML/annum of Hunter River General Security Entitlements (GSE), 3 ML/annum of High Security Entitlements (HSE) and 13 ML/annum of Supplementary Entitlement. RUM does not have any pumping infrastructure to allow direct extraction from the Hunter River. Instead RUM have entered into an agreement with Macquarie Generation (MacGen) to source water from Lake Liddell (MacGen power station cooling water reservoir), with MacGen pumping water into Lake Liddell using their pumping infrastructure (debiting RUM s Hunter Licence), and RUM pumping water from Lake Liddell to the surface facilities. RUM also hold 400 ML/year groundwater extraction licence associated with dewatering the underground mining operations. Groundwater is extracted from the underground operations via the mine access portal and no dewatering bores exist. The Ravensworth North Project (RNP) has recently been approved and is inherently linked to the RUM water management system. The RUM CHPP will process coal from the RNP, while the RUM Highway Dam (the CHPP water supply storage) will receive tailings return water from a number of RNP tailings storage facilities. Pumps at the Highway Dam will facilitate transfer of water to and from the RNP via the RNP Booster Dam (refer Figure 2a). Page 3 of 33

4 The key components of the water management system at RUM are shown in schematic fashion in Figure 3. The catchment area and capacity of each water storage is given in Table 2. Table 2 Ravensworth Underground Mine Water Storages Storage Catchment Area (ha) Surface Area (ha) Capacity (ML) Eastern Dam Highway Dam Office Dam Pit Top Dam ROM Dam Product Coal Collection Dam Product Coal Stockpile Dams Product Coal Construction Dam The Highway Dam is the main water storage on site and is the main source of make-up water for the Coal Handling and Preparation Plant (CHPP) and supply to the underground operations. The CHPP is by far the largest consumer of water on site, using an average of 62.1 ML/month, while dust suppression usage (i.e. of haul roads and stockpiles) is estimated to average around 0.5 ML/month. The majority of CHPP demand is supplied by recycled tailings water from the Ravensworth South Tailings Dam. Additional make-up is provided from water held in other storages on site, including surface facilities dams, which collect runoff from the approximately 132 ha catchment area of the site and groundwater from underground mine dewatering as well as water recycled from underground mining operations. Underground mining operations currently require approximately 17.5 ML/month. Supply of water to the underground is required for various uses such as operation of underground mining equipment and dust suppression. It is anticipated that the underground water use and water make will increase as the mine progresses (refer Section 2.0). Supply of potable water to offices, workshops, bathhouses and underground workings is trucked to site. Sewage treatment at the pit-top facilities is provided by a dedicated Sewage Treatment Plant (STP). The STP has primary and secondary treatment systems. Effluent from the STP is irrigated on dedicated land located within the mine water management system adjacent to the Highway Dam. Page 4 of 33

5 Figure 2a Site Layout General Page 5 of 33

6 Figure 2b Site Layout Surface Facilities Page 6 of 33

7 Figure 3 Ravensworth Underground Mine Water Management System Schematic Page 7 of 33

8 The surface water management system of RUM involves a number of interlinked dams, their catchments, the tailings storage, the underground mining operation, the CHPP and water pumping systems. The main storages/features are as follows: The ROM Dam captures runoff from the run of mine (ROM) coal stockpile area and drains under gravity via a pipeline into the Pit Top Dam. The Pit Top Dam captures runoff from a portion of the pit top and rail loop facilities and, in addition to receiving gravity inflow from the ROM Dam, also receives water pumped from the underground workings. RUM is currently investigating alternative arrangements for underground dewatering to other surface storage dams. Water in the Pit Top Dam is pumped out to the Office Dam. Currently RUM is in the process of designing an upgrade to this system following an offsite discharge event. These works are focused on increasing the capacity of the dam, improving the reliability and capacity of pumping infrastructure and also optimising water management. Preliminary designs (refer Figure 4) suggest a total capacity of approximately 12 ML can be obtained by these works while a rock-lined spillway will provide safe access for de-silting purposes. It is anticipated that the enlargement project will be completed by the end of quarter The Office Dam captures the majority of runoff from surface infrastructure facilities (including the CHPP and the rail loop). Water in the Office Dam is pumped out to the Highway Dam. The Eastern Dam captures runoff from a laydown/storage area and is pumped to the Highway Dam. The Product Coal Construction Dam captures runoff from a small catchment area and is pumped out to the Product Coal Stockpile Dam. The Product Coal Stockpile Dams capture runoff from the product coal stockpile and accumulated water is pumped to the RCT Dam. These dams comprise a sediment dam and a storage dam (the former draining into the latter). The Product Coal Collection Dam captures runoff from the product stockpile. Product Coal Collection Dam is pumped out to the Highway Dam. Water from the CHPP tailings thickener underflow is pumped to a secondary flocculation facility located adjacent to the discharge point at the Ravensworth South Tailings Dam. Water from settling tailings and runoff reporting to the storage is reclaimed via staged settling dams and returned by pumping to the Highway Dam. The Highway Dam is a turkeys nest structure which receives or will receive pumped inflow from the Office Dam, Product Coal Collection Dam, Eastern Dam, Ravensworth South Tailings Dam, Ravensworth North Tailings Storages, Ravensworth North Booster Dam and Lake Liddell (Hunter River WALs). Water is pumped out of the Highway Dam to the underground and CHPP. Page 8 of 33

9 Figure 4 Preliminary Design Layout of Pit Top Dam Upgrade Page 9 of 33

10 RUM currently holds 6 credits under the Hunter River Salinity Trading Scheme (HRSTS). However, RUM do not have discharge infrastructure and there are no licensed discharge points. Therefore these credits are available to transfer to other Xstrata Coal New South Wales (XCN) operations in the event of a discharge opportunity. Current approval allows transfer of water between RUM and Ravensworth Operations (which is being incorporated into the RNP) however this infrastructure is currently being upgraded and transfer is not possible at present. In compliance with Condition L1.1 of Environmental Protection Licence under Section 120 of the Protection of the Environment Operations Act (1997), saline mine water cannot be discharged from RUM. 2. SITE WATER BALANCE A life-of-mine water balance model of the RUM complex has been developed by Gilbert & Associates Pty Limited. The structure of the model is generally per the schematic in Figure 3. The model operates on a sub-daily time-step and can be setup to simulate any period up to the projected end of RUM operations. The simulations reported below correspond to the planned 12 ¼ year mine life - from 1 st May 2012 to 31 st July Surface catchment areas of the mine were simulated using supplied plans and were constant over the life of the mine. Total catchment area reporting to the RUM water management system is 91.3 ha. Annually varying ROM coal tonnages (which affect CHPP water demand) are expected to be between Mtpa and are detailed on an annual basis in Table 3. Underground mine groundwater inflow rates were taken from groundwater modelling by Mackie Environmental Research (MER, 2011) and vary up to 1.6 ML/d for the Liddell seam and 1.2 ML/d for the Pikes Gully seam. Year Table 3 ROM Coal Tonnages ROM Coal (Mt) The AWBM (Boughton, 2004) was used to simulate runoff from rainfall on the various catchments and landforms across the mine area. Model rainfall-runoff parameters have been taken from studies conducted at similar mining operations, along with calibration against local streamflow records and experience with similar projects. Different sub-catchment types were used. Page 10 of 33

11 The model simulates 119, 12 ¼ year mine life sequences, derived using the climatic record from 1892 to The first sequence uses climatic data from , the second the third and so on. The Hunter River IQQM 2 was first run to estimate allocation levels for the next 12 ¼ years (these estimates are affected by current allocation levels, regulating storage levels and the historical rainfall/streamflow data set used). The model used output from the Hunter River IQQM in order to simulate variations in available Hunter River water in parallel with climatic variations. Based on data provided by RUM, approximately 503 ML of water was calculated held in storages on site as at 1 st May The average predicted water balance (averaged over the simulation period) for median, wet (90 th percentile) and dry (10 th percentile) rainfall sequences is summarised in Table 4. Flows Inflows Table 4 Summary of Simulated Annual Inflows and Outflows (ML/annum) 10 th Percentile Rainfall Sequence (Dry) Median Rainfall Sequence 90 th Percentile Rainfall Sequence (Wet) Catchment Runoff Groundwater Hunter River Licensed Extraction Tailings Water 1,399 1,400 1,410 From Ravensworth North Booster Dam (mine runoff) Outflows 1,474 1,735 1,878 CHPP Supply 3,828 3,936 3,936 Evaporation Underground Supply To Ravensworth North Booster Dam Table 4 shows that the main source of supply to site is water reclaimed from the tailings storages and water imported to RUM from the RNP via the Booster Dam. Water supplied to the CHPP dominates the outflows from the RUM water balance. Water supply security can be described in terms of water supply reliability. The average predicted water supply reliability to the CHPP was 97.7 % (that is 97.7 % of the total CHPP demand could be supplied), while the lowest reliability in any 12¼ year sequence was 81.7 %. The average predicted water supply reliability to the underground was greater than 99.9 % (that is more than 99.9 % of the total underground demand could be supplied), and did not drop below this level in any 12 year sequence. An annual retrospective site water balance for the reporting period will be documented in the Annual Environmental Monitoring Report (AEMR). A monthly internal water accounting system summarises water use and volume of water stored on site for XCN. 1 Additional climate data after 2010 was generated by wrapping data from the beginning of the climate record to after In this way, the drought period of 2005/06 and the wet period of 2007 could be simulated as occurring at varying times through the mine life. 2 The integrated quantity-quality model is the model used by the NSW Office of Water to simulate the hydrology of the Hunter River Regulated Water Source. Page 11 of 33

12 Measures to minimise water use include: Ravensworth Underground Mine Tailings thickening and flocculation and the use of water reclaimed from the tailings storage(s) in preference to using Hunter River WALs Future sourcing of excess water from the RNP in preference to using Hunter River WALs Storage and use of runoff from disturbed areas in preference to using Hunter River WALs Use of water reclaimed from underground operations in preference to using Hunter River WALs Inspections and maintenance of water management infrastructure. 3. EROSION AND SEDIMENT CONTROL PLAN The objective of this ESCP is to set out strategies to control soil erosion and sediment generation close to the source and thereby minimise the potential for mine activities to adversely affect downstream water quality. The following principles, which have been taken from the Landcom (2004) guidelines, underpin the approach to erosion and sediment control for the mine site: Minimising surface disturbance and restricting access to undisturbed areas. Progressive rehabilitation/stabilisation of mine infrastructure areas. Separation of runoff from disturbed and undisturbed areas where practicable. Construction of surface drains to control and manage surface runoff. Construction of sediment dams or use of existing/modified water storages to contain runoff up to a specified design criterion. These measures are used to minimise soil erosion and the potential for transport of sediment downstream. Development activities will generally occur in the following order: 1. Construction of diversion drains (typically upslope of disturbance areas) these will only be constructed where they will significantly reduce the catchment reporting to disturbance areas. 2. Construction of sediment dams/sumps where required to provide for temporary retention of runoff from disturbance areas. 3. Construction of collection drains (downslope of or within disturbance areas) where required to convey runoff to sediment dams or other storages. 4. Construction of sediment fences and straw bale filters (downslope of disturbance and stockpile areas) where appropriate. 5. Construction works only taking place once erosion and sediment control measures are in place. The design criteria for sediment control structures are summarised in Table 5 Table 5 Design Criteria for Sediment Control Structures Sediment Control Structure Upslope diversion drains Downslope collection drains Function Reduce runoff from undisturbed areas onto disturbed areas Intercept and convey disturbed area runoff water to sediment dams/sumps Design Capacity Peak flow calculated for 1 in 20 year* critical duration rainfall event (DECCW, (2008), Table 6.1) Peak flow calculated for 1 in 20 year* critical duration rainfall event (DECCW, (2008), Table 6.1) Page 12 of 33

13 Sediment dams Containment of sedimentladen runoff from disturbed areas with more than 150 m 3 /yr estimated soil loss (Landcom (2004), Section 6.3.2(d)) Ravensworth Underground Mine Settling Zone: Capacity to store the runoff produced from the 90 th percentile*, 5-day rainfall event (DECCW (2008), Table 6.1) Sediment Zone: Two months calculated soil loss estimated using RUSLE** (Landcom (2004), Section (i)) Sediment fences and/or straw bale filters Retention/filtration of suspended sediments Peak flow limited to less than 50 L/s in the design 1 in 10 year critical duration rainfall event (Landcom (2004), Section 6.3.7(e)) * Assuming a duration of disturbance greater than 3 years with a standard, not sensitive, receiving environment. ** Revised Universal Soil Loss Equation (RUSLE) Assuming a duration of disturbance between 1 and 3 years with a standard sensitivity receiving environment. To prevent offsite discharge of dirty water from sediment dams, following a rainfall event, water in sediment dams will be pumped back to the mine water system. Sediment dams will be maintained with a minimum practicable volume of water in between rainfall events to ensure sufficient capacity is available when a rainfall event does occur. The 90 th percentile 5-day rainfall event, used in determining the sediment dam settling zone capacity, was calculated to be 39.4 mm from the average of values for Scone and Cessnock 3 as given in Table 6.3a in Landcom (2004). Based on the methodology and parameters contained in Landcom (2004) and DECCW (2008), the settling zone capacity and sediment storage zone capacity and hence required dam capacity are calculated using Equations 1, 2 and 3 below respectively: Settling Zone Capacity (m 3 ) = V settling = x A (1) Sediment Zone Capacity (m 3 ) = V sediment = 0.5 x V settling (2) Required Dam Capacity (m 3 ) = V total = V settling + V sediment (3) Where; V settling = settling volume V sediment = sediment volume V total = total volume A = catchment area of the sediment dam (ha) Water storages at RUM serve both as water management structures and sediment dams. The locations of the sediment control dams employed at RUM are shown in Figure 2b. Table 6 summarises the minimum sediment dam capacity requirements in comparison to existing surveyed capacities. Additional dedicated sediment dams will be constructed as required. Table 6 Comparison of Sediment Dam Requirements to Existing Dam Capacities Sediment Dam Name Eastern Dam Capacity (m 3 ) Required Settling Zone Volume (m 3 ) Required Sediment Zone Volume (m 3 ) Minimum Required Total Volume (m 3 ) Table 6.3a of Landcom (2004) gives 90 th percentile 5-day rainfall depths for Cessnock and Scone of 42.8 mm and 35.9 mm respectively Page 13 of 33

14 Office Dam (inc. Product Coal Construction Dam) Pit Top Dam ROM Dam Product Coal Collection Dam Product Coal Stockpile Dams Dam batters are typically covered with topsoil following construction and/or seeded to promote revegetation and assist with minimising the potential for erosion of the dam batters. Activities that have the potential to cause or increase erosion, and subsequently increase the generation of sediment at the site, include exposure of soils during construction of mine infrastructure (i.e. during vegetation clearance, soil stripping and earthworks activities) and stockpiling mine materials. The following components have the potential to generate sediment: coal handling and preparation plant (CHPP); earthen bunds and temporary topsoil stockpiles; coal stockpiles; access and haul roads; water management infrastructure (pumps, pipelines, dams, sumps and drains); exploration sites; and general construction works on site. Routine inspections of sediment control structures as well as inspections following rainfall events of 25 mm or more in a 24 hour period are conducted by RUM personnel. During these inspections, sediment control structures are inspected for capacity, structural integrity and effectiveness. Inspections are documented using a check sheet developed by RUM. Where inspections indicate substantial accumulation of sediment in a sediment dam, clean-out is undertaken so as to reinstate the minimum required volumes given in Table 6. Silt fences and straw bale filters are inspected and trapped sediment removed or straw bales replaced as necessary. Removed sediment is placed in areas upslope of existing sediment control structures, mine water storages or tailings storages. Page 14 of 33

15 Bowmans Creek Bayswater Creek 4. SURFACE WATER MONITORING PROGRAM Ravensworth Underground Mine The objective of the surface water monitoring program (SWMP) is to provide details of the monitoring program used to monitor the effects of RUM on existing surface water bodies, in order to assist in detecting if any significant off-site impacts occur as a result of mining and to trigger response plans to adverse impacts. 4.1 Baseline Data Bayswater Creek is a highly modified stream due to the construction of Lake Liddell and the creek diversion located between Lake Liddell and its confluence with the Hunter River. Bowmans Creek is a moderately modified stream in its lower reaches with Ashton Coal Operations currently constructing two diversions on this creek. Historical data relating to water quality and flows in Bayswater Creek and Bowmans Creek is summarised below. This data is used as a baseline for on-going monitoring of the impacts of mining activities on surface water in the Bayswater Creek and Bowmans Creek catchment areas. The baseline data end date has been assumed at 14 th of January 2007 as this is the date at which mining of LW1 at RUM began Water Quality Water quality in the downstream watercourses has been monitored since 1993 at GS Water samples have been monitored for ph and total suspended solids (excluding NOW gauging stations) and electrical conductivity (EC). Sampling points include locations along Bayswater Creek and Bowmans Creek. The sampling locations are indicated on Figure 5 and water quality data summarised in Table 7. Table 7 Summary of Baseline Surface Water Quality Monitoring Data Creek Site Data Collection Period * Data source: NOW, 2012 GS210110* 19/1/ /1/2007 Bayswater Midstream Bayswater Downstream 1/7/2004 4/1/2007 1/7/2003 3/1/2006 BCK6 1/6/2002 1/11/2006 GS210130* 28/10/ /1/2007 ph EC (μs/cm) TSS (mg/l Min Max Min Max Min Max Streamflow Streamflow gauging stations on both Bayswater Creek and Bowmans Creek are maintained by the NSW Office of Water (NOW). The locations of these stations are shown on Figure 5 and available streamflow data is summarised in Table 8. As illustrated in Figure 5, the gauging station on Bayswater Creek is immediately downstream of the spillway from Lake Liddell. Page 15 of 33

16 Table 8 Ravensworth Underground Mine Summary of Recorded Baseline Streamflow Monitoring Data Station: Bayswater Creek GS210110* Bowmans Creek GS210130* Period of Record: 19/01/1994 to 14/01/ /10/1993 to 14/01/2007 No. Missing Days: No. Zero Flow Days: Max. Daily Flow (ML/d): Mean Annual Flow (ML/d): * Data source: NOW, 2012 Figure 5 Surface Water Monitoring Locations Page 16 of 33

17 Bayswater Creek 4.2 Surface Water Impact Assessment Criteria Ravensworth Underground Mine Impact assessment criteria can be described as trigger levels, which, if triggered, would lead to a response in terms of more intensive monitoring, investigation and ultimately, if required, remedial action. The SGWRP contains details of all responses relating to each impact assessment criterion. Surface water impact assessment criteria focus on particular areas and each area may contain more than one criterion. Table 9 shows a summary of each focus area and the associated impact assessment criteria. Table 9 Surface Water Impact Assessment Criteria Focus Area Parameter Trigger Value Surface water quality (local creeks) Riparian and instream vegetation Channel stability ph EC TSS 4.3 Monitoring Program Density of vegetation photographic log Erosion/deposition features photographic log If recorded value at a monitoring site is greater than the 80 th percentile of baseline data for 2 consecutive readings or, for ph, less than the 20 th percentile of baseline data for 2 consecutive readings If photographs suggest a visual degradation in vegetation cover for 4 consecutive monitoring periods If it is obvious that erosional and/or depositional features are changing with time The SWMP for RUM involves the monitoring of all surface water impact assessment criteria (refer Table 9). A summary of the monitoring locations and parameters monitored is provided in Table 10. In accordance with Schedule 2 Condition 11 (d) of the Development Consent, the impacts of the operation on private water users will be monitored, assessed and responded to in accordance with the SWGRP. There are no private water users on Bayswater Creek (NSW Trade and Investment, 2012). There are 10 private water users on Bowmans Creek with 13 extraction licenses (NSW Trade and Investment, 2012). The existing water monitoring points shown in Figure 5 will be used to monitor and assess any impacts on these users. A summary of the surface water monitoring program is provided in Table 10. Table 10 Summary of Surface Water Monitoring Program Creek Site Monitored By Parameters Frequency GS NOW Flow, EC Continuous Bayswater Midstream Bayswater Downstream W114 Liddell Coal Operations** Liddell Coal Operations** Ravensworth Operations** ph, EC, TSS, photo point* ph, EC, TSS, photo point* ph, EC, TSS Monthly Monthly Monthly W115 Ravensworth ph, EC, TSS Monthly Page 17 of 33

18 Bowmans Creek BCK6 BMC4 Operations** Liddell Coal Operations** Xstrata Coal Mt Owen** ph, EC, TSS ph, EC, TSS Ravensworth Underground Mine Monthly Monthly GS NOW Flow, EC Continuous EPL3 EPL4 Ravensworth Operations** Ravensworth Operations** ph, EC, TSS ph, EC, TSS Monthly Monthly * Monitoring performed by RUM on a quarterly basis ** Xstrata Coal NSW Managed Operation 4.31 Water RUM undertake routine monitoring of water usage, water imported to the mine & volumes of water stored onsite, as part of a program of monitoring & reporting undertaken by XCN. The data is used to: monitor trends in water use and efficiency; check stored water inventory; and assist in future mine water supply and management planning. Table 11 provides a summary of monitoring undertaken for the water balance. Table 11 Summary of Water Balance Monitoring Monitoring of Description Location Frequency Site Water Supply CHPP Water Usage Underground Mine Extraction Underground Mine Supply Water imported to site using Hunter River WALs via agreement with Macquarie Generation (Lake Liddell) Water supplied to the CHPP from the Highway Dam Water volume pumped from underground operation into surface water management facilities Water volume pumped from Highway Dam to underground operations Flow meter west of the Highway Dam Flow meter at the CHPP Flow meter at the portal Flow meter at the Highway Dam Storage Volume Water level Individual storages Continuous Continuous Continuous Continuous Continuous and/or monthly Streamflow RUM will continue to make use of the streamflow monitoring data collected by NOW. Page 18 of 33

19 4.312 Water Quality Ravensworth Underground Mine Table 10 summarises surface water quality monitoring undertaken at sites within and surrounding RUM. Site locations are also shown on Figure 5. The results of water quality monitoring are reported in the AEMR. The AEMR includes an assessment of results in terms of off-site impacts as a result of mining. Surface water quality monitoring and sample collection, storage and transportation will be undertaken in accordance with the procedures outlined in the relevant sections of the Australian Standard for Water Quality Sampling AS/NZS Laboratory analysis will be undertaken by a laboratory which has relevant accreditation by the National Association of Testing Authorities (NATA), Australia Stream Health and Channel Stability The stream condition and stream health of Bayswater Creek is heavily influenced by the releases from Lake Liddell. RUM do not undertake licensed discharges. Accordingly, the impact of RUM on Bayswater Creek stream health is considered to be low. Notwithstanding, RUM will undertake photo point monitoring along Bayswater Creek at the two stations nearest RUM surface facilities: Bayswater Midstream and Bayswater Downstream (refer Figure 5). Monitoring of riparian vegetation and channel stability is to be undertaken quarterly by taking four photographs at each surface water monitoring site on Bayswater Creek; looking upstream, looking downstream, looking at the left bank 4 and looking at the right bank 5. These photographs are to be documented with the location, direction and date. 5. GROUNDWATER MONITORING PROGRAM The aim of the GMP is to provide details of the monitoring program used to monitor the effects of RUM on surrounding groundwater aquifers. The GMP also exists in order to assist in detecting if any significant off-site impacts occur as a result of mining and to trigger response plans to adverse impacts. 5.1 Baseline Data Groundwater levels and basic groundwater quality parameters (ph and EC) have been measured routinely at a number of piezometers across and external to the site. Historical groundwater level and quality data collected at the piezometers shown in Figure 6 are summarised in Table 12. Table 12 Historical Water Quality Results (Ravensworth Operations) Seam Monitoring Bore ph EC (μs/cm) Min Max Mean Min Max Mean Bayswater NPZ3 Mid ,780 12,990 11,570 NPZ4 Mid ,470 6,440 6,113 Lemington NPZ1 Tall ,740 10,400 9,310 4 Left bank refers to the bank to the left when looking in a downstream direction. 5 Right bank refers to the bank to the right when looking in a downstream direction. Page 19 of 33

20 NPZ2 Tall ,460 9,830 9,613 NPZ3 Tall ,410 9,830 9,041 NPZ4 Tall ,800 8,330 7,803 Pikes Gully CS4641C Pumps ,170 7,700 6,969 CS4539A (S2) Hill ,850 7,560 6,983 CS4536 (HF7) ,170 14,900 13,261 CS4545 (S4) ,990 10,700 8,427 Liddell CS4547C (EE4) ,180 13,700 12,552 Borehole P / SDH17 / SDH ,590 8,900 7,573 Barrett Site 11 Conveyor ,200 10,630 10,343 Site 3 Inside Gate ,060 10,600 10,270 Note: Data in the table above is after Umwelt (2009) Page 20 of 33

21 Figure 6 Groundwater Monitoring Locations Page 21 of 33

22 5.2 Groundwater Assessment Criteria Ravensworth Underground Mine Impact assessment criteria can be described as trigger levels, which, if triggered, would lead to a response in terms of further, more intensive monitoring, investigation and ultimately, if required, remedial action. The SGWRP contains details of all responses relating to each impact assessment criterion. Groundwater impact assessment criteria focus on particular areas and each area may contain more than one criterion. Table 13 provides a summary of each focus area and the associated nominated impact assessment criteria. Table 13 Groundwater Impact Assessment Criteria Focus Area Parameter Trigger Value Groundwater Level and Baseflow in Watercourses Groundwater Inflow to the Underground Riparian Vegetation Drawdown Inflow Density of vegetation photographic log The larger of: * Groundwater model documented in MER (2011) a) 10% greater than model prediction*; or b) 1 m greater than model prediction. If: i) Three or more alluvial bores exceed the above in one round of monitoring ii) OR Any alluvial bore exceeds the above for three consecutive readings Average drawdowns for the fractured rock bore network exceed the above for two consecutive readings Sustained exceedence 10% greater than model prediction* for a period greater than 6 months. If photographs suggest a visual degradation in vegetation cover for 4 consecutive monitoring periods There are no known Groundwater Dependant Ecosystems (GDEs) within the RUM complex (Umwelt, 2011) and therefore no impact assessment criteria have been set for groundwater ecology Groundwater level impact assessment criteria have been designed to ensure that measured depressurisation due to mining of the coal measures and associated impacts on the alluvial aquifer systems do not significantly vary from modelled predictions (MER, 2011). 5.3 Monitoring Program 5.31 Monitoring Bores Monitoring of water levels and water quality parameters is undertaken at a number of bores/piezometers as summarised in Table 14. Chemical speciation is also undertaken in selected bores as indicated in Table 14 twice yearly. Bore locations are shown in Figure 6. RUM is pursuing a data sharing agreement with the Ashton Coal Project in order to access information collected from Page 22 of 33

23 Ravensworth Operations seven known bores: WML115, WML175, RSGM1, RM3, RM4, RM5, and RM6. Monitored by Table 14 Summary of Groundwater Monitoring Program Piezometer No. Coffey Dam Borehole Ravensworth Underground Mine Target Seam Parameters Frequency Liddell Level, ph, EC CS4545 (S4) Liddell Level, ph, EC CS4641C Lower Pikes Gully Level, ph, EC CS4655 Bayswater, Lemington LMH, Lemington LMA, Upper Pikes Gully, Upper Arties, Upper Liddell, Lower Liddell, Barrett Note: Data in the table above is after Umwelt (2009) Level Monthly (Level), Quarterly (Quality) Monthly (Level), Quarterly (Quality) Monthly (Level), Quarterly (Quality) 12 hourly Page 23 of 33

24 Ravensworth Operations Table 14 continued Ravensworth Underground Mine Monitored by Piezometer No. NPZ1 NPZ2 Summary of Groundwater Monitoring Program Target Seam Parameters Frequency Alluvium, Bayswater, Lemington Alluvium, Bayswater, Lemington Level, ph, EC Level, ph, EC NPZ5 Alluvium, Broonies Level, ph, EC NPZ6 Alluvium, Broonies Level, ph, EC NPZ7 (SP1) RNVW1 RNVW2 Alluvium, Broonies, Bayswater Bayswater, Lemington LMH, Lemington LMA, Upper Pikes Gully, Upper Arties, Upper Liddell, Lower Liddell, Barrett Bayswater, Lemington LMH, Lemington LMA, Upper Pikes Gully, Upper Arties, Upper Liddell, Lower Liddell, Barrett Note: Data in the table above is after Umwelt (2009) Level, ph, EC Level Level Monthly (Level), Quarterly (Quality) Monthly (Level), Quarterly (Quality) Monthly (Level), Quarterly (Quality) Monthly (Level), Quarterly (Quality) Monthly (Level), Quarterly (Quality) 12 hourly 12 hourly Page 24 of 33

25 Mt Owen Table 14 continued Ravensworth Underground Mine Monitored by Piezometer No. RNVW4 RNVW5 RNVW6 NPZ13 NPZ16 Summary of Groundwater Monitoring Program Target Seam Parameters Frequency Bayswater, Lemington LMH, Lemington LMA, Upper Pikes Gully, Upper Arties, Upper Liddell, Lower Liddell, Barrett Alluvium, Unnamed, Bayswater, Lemington H, Lemington A, Upper Liddell, Barrett Alluvium, Unnamed, Bayswater, Lemington H, Lemington A, Upper Liddell, Barrett Swamp Creek Alluvium, Lower Pikes Gully, Lower Liddell Swamp Creek Alluvium, Lemington, Upper Liddell Level Level Level Level, ph, EC Level, ph, EC GA1 Swamp Creek Alluvium Level, ph, EC GA2 Swamp Creek Alluvium Level, ph, EC 12 hourly 12 hourly 12 hourly Quarterly (Level), Six Monthly (Quality) Quarterly (Level), Six Monthly (Quality) Quarterly (Level), Six Monthly (Quality) Quarterly (Level), Six Monthly (Quality) BC-SP19 Bayswater Creek Alluvium Level, ph, EC 12 hourly BC-SP22 Bayswater Creek Alluvium Level, ph, EC 12 hourly Note: Data in the table above is after Umwelt (2009) 5.32 Underground Inflow Groundwater model predictions (MER, 2011) provide an estimate of the expected rate of groundwater seepage to mining operations. This seepage may be increased by dewatering of local storage in joints and fractures which typically occurs over a period of 1 to 3 months after mining. The summation of both contributions represents the maximum predicted groundwater seepage to the underground operations. Monitoring of seepage and comparison between measured and predicted rates may therefore provide early indication of leakage from a remote source such as alluvium. Volumes of water pumped from the underground operations may be calculated monthly from flow meter readings at the dewatering point (refer Table 11) and flow meter readings at the underground Page 25 of 33

26 supply point at the Pit Top. An estimate of net groundwater inflow to the mine can then be calculated by subtracting the supply to the underground from the dewatering volumes, with an allowance for ventilation rise losses. Water quality monitoring is undertaken at the dewatering point on a monthly basis. Table 15 provides predicted groundwater inflow rates to the underground and rates including provision for dewatering of localised storage without contributions from rainfall seepage to the underground mine via the subsidence zone. Table 15 Predicted Groundwater Inflow to Underground (MER, 2011) Year Estimated Strata Seepage (ML/d) To determine the impact RUM may have on regional and surrounding aquifers, groundwater levels are monitored as per the groundwater monitoring schedule in Table 14. MER (2011) state there are no identified private boreholes within or near the approved or proposed modified operations that are likely to be affected. There are no known Groundwater Dependant Ecosystems (GDEs) within the RUM complex (Umwelt, 2011). Future revisions of this will include copies of future bore construction logs as required. The results of groundwater monitoring are reported in the AEMR. The AEMR includes an assessment of results in terms of off-site impacts as a result of mining. 6. SURFACE AND GROUNDWATER RESPONSE PLAN 6.1 Objective The objective of this SGWRP is to present a set of protocols to be followed and actions for implementation should the surface or groundwater assessment criteria be exceeded. These protocols will be followed in addition to the RUM Incident Management Procedure (2012) which states: Should the incident be deemed a notifiable incident to the Environmental Protection Authority (EPA), (that is, pollution incidents threatening material harm to the environment) this must be done immediately. Upon becoming aware of the incident notification of the necessary stakeholders must be completed immediately. Five different authorities must be notified in the following order: Page 26 of 33

27 Information that must be reported at the time of notification includes: The type of pollution; Its concentration; The circumstances in which the pollution incident occurred The names, positions and 24 hour contact details for those personnel who are involved in managing the incident; and The action taken to deal with the incident. Any required information that is not known at the time of notification must be communicated to each of the relevant authorities immediately after it becomes known. These authorities must continue to be notified each time new information becomes available. 6.2 Protocol for Exceedence of Surface Water & Groundwater Trigger Values In the event of a surface water or groundwater assessment criterion being exceeded, the following protocol will be followed: 1. Check and validate the data which indicates an exceedence of the criterion. 2. A preliminary investigation will be undertaken to establish the cause(s) and determine whether changes to the water management system are required. This will involve the consideration of the monitoring results in conjunction with: a) site activities being undertaken at the time; b) baseline monitoring results; c) surface water/groundwater results at nearby locations; d) the prevailing and preceding meteorological conditions; e) available data indicating releases from Lake Liddell; f) changes to the land use/activities being undertaken in the contributing catchment area; and g) hydrological conditions. 3. If the preliminary investigation shows that the impact is linked to activities undertaken by RUM, a report will be ed to the Department of Planning & Infrastructure (DPI) and any other relevant department. Causal factors will be addressed and rectified if possible. Contingency measures will be developed in consultation with the DPI and any other relevant department and implemented in response to the outcomes of the investigation. 4. Remedial/compensatory measures will be developed in consultation with DPI and any other relevant department and implemented in response to the outcomes of the investigations. 5. Monitoring would be implemented as required to confirm the effectiveness of remedial measures. Page 27 of 33

28 6.3 Protocol for Exceedence of Stream Health and Channel Stability Triggers In the event of a stream health assessment criterion being exceeded, the following protocol will be followed: 6. The area will be inspected to confirm the condition of vegetation in the photograph and the condition of vegetation in other similar areas of the site. 7. An preliminary investigation will then be undertaken and will involve the consideration of the visual inspection documented above in conjunction with: a) site activities being undertaken at the time; b) baseline surface water and groundwater monitoring results; c) surface water and groundwater results in nearby locations; d) the prevailing and preceding meteorological conditions; e) available data indicating releases from Lake Liddell; f) hydrological conditions; and g) changes to the land use/activities being undertaken in the contributing catchment or hydrogeological regime. 8. If the investigation shows that the vegetation impact is linked to activities undertaken by RUM, a report will be ed to the DPI and any other relevant department. Causal factors will be addressed and rectified if possible. Contingency measures will be developed in consultation with DPI and any other relevant department and implemented in response to the outcomes of the investigation. Such contingency measures could involve direct revegetation or vegetation offsets. 9. Monitoring would be implemented as required to measure the effectiveness of contingency measures if appropriate. In the event of a channel stability assessment criterion being exceeded, the following protocol will be followed: 1. Undertake a ground inspection to validate the photograph and confirm the magnitude of the change (increase in erosion/deposition) evident in the photograph. 2. If this observation confirms that significant additional erosion or deposition has occurred and is likely to have been caused by RUM, DPI and any other relevant department will be notified via An investigation will then be conducted in consultation with DPI and any other relevant department and will involve the consideration of one above in conjunction with: a) site activities being undertaken at the time; b) the prevailing and preceding meteorological conditions; c) available data indicating releases from Lake Liddell; d) hydrological conditions; and in particular any high runoff events which may have preceded the change; and e) changes to the land use/activities being undertaken in the contributing catchment area. 4. If the investigation shows that the creek channel impact is linked to activities undertaken by RUM, a report will be ed to the DPI and any other relevant department. Causal factors will be addressed and rectified if possible. Contingency measures will be developed in consultation with DPI and any other relevant department and implemented in response to the outcomes of the investigation. Such contingency measures could involve bank and channel stabilisation methods (i.e. promotion of riparian vegetation, use of rip-rap or removal of sediment accretion). Page 28 of 33

29 5. Additional monitoring will be implemented as required to measure the effectiveness of contingency measures. 6.4 Protocol for Impacts on the Water Supply of Private Landowners No privately owned groundwater bores exist within or near the approved or proposed modified operations that are likely to be affected (MER, 2011); hence an impact on the groundwater supply of private landowners is not expected. There are no privately owned surface water storages within the RUM colliery holding boundary and hence impacts of the surface water supply of private landowners is not expected. In the event that a complaint is received, this would be handled in accordance with RUM procedures, which includes recording the details of the complaint, providing feedback to the complainant (including corrective actions) and reporting of investigation outcomes and corrective actions. Compensation would be developed in consultation with the private landowner where it can be demonstrated that RUM has adversely affected the water supply. To date, no complaints have been received in relation to groundwater or surface water supply of private landowners. 6.5 Roles and Responsibilities The roles and responsibilities assigned to water management on site under this WMP are outlined in Table 16. Table 16 Roles and Responsibilities for Site Water Management Water Management Component Provide resources required to implement the WMP Review and updates of WMP Management and maintenance of water management infrastructure Monitoring Investigation of incidents Reporting (including AEMR and incident reporting) Responsible Entity Operations Manager Environment and Community Manager Services Superintendent and CHPP Manager Environment and Community Manager Environment and Community Manager Environment and Community Manager 7. REFERENCES 7.1 Legislation Environmental Planning & Assessment Act 1979 Protection of the Environment Operations Act Australian Standards Australian Standard for Water Quality Sampling AS/NZS Xstrata plc Xstrata plc Sustainable Development Standard 10 Environment, Biodiversity and Landscape Functions Page 29 of 33

30 7.4 Xstrata Coal NSW Ravensworth Underground Mine XCN SD GDL Environment, Biodiversity & Landscape Functions XCN SD ANN Water Management Strategy XCN SD ANN Pipeline Management XCN SD ANN Erosion and Sediment Control Management 7.5 Ravensworth Underground Mine RUM SD PRO 0057 Underground Water Sample Collection RUM SD FRM 0036 XCN Water Management / Water Supply Questionnaire RUM SD PRO 0054 Raw Water Access (Surface Water Licences) System Procedure RUM SD PRO 0055 Dam Water Response System Procedure - Pit Top and Office Dams RUM SD PRO 0056 Dam Levels Operating System Procedure RUM SD PLN 0020 Private Water Supply Management Plan 7.6 Licences RUM SD EXT 0470 Groundwater Licences - Mine Dewatering - Bore Licence Renewal Certificate - 20BL RUM SD EXT 0471 Groundwater Licences - Mine Dewatering - Bore Licence Renewal Certificate - 20BL RUM SD EXT 0472 Surface Water Licence - Water Access - Certificate of Title WAL8964 RUM SD EXT 0473 Surface Water Licence - Water Access - Certificate of Title WAL8964 RUM SD EXT 0474 Surface Water Licence - Water Access - Certificate of Title WAL1046 RUM SD EXT 0475 Surface Water Licence - Water Access - Certificate of Title WAL1046 RUM SD EXT 0476 Surface Water Licence - Water Access - Certificate of Title WAL1325 RUM SD EXT 0477 Surface Water Licence - Water Access - Certificate of Title WAL1325 Page 30 of 33

31 8. APPENDICES 8.1 Appendix 1 Development Consent Conditions Extract taken from Development Application 104/96 under section 101 of the Environmental Planning and Assessment Act, 1979 Schedule 2 Conditions of Development Consent SITE WATER MANAGEMENT PLAN 8. The Applicant shall prepare and implement a Site for the development to the satisfaction of the Director-General. This plan must: a) be prepared in consultation with NOW, DECCW and I&I NSW; b) be submitted to the Director-General for approval by the end of December 2009; and c) include: a Site Water Balance; an Erosion and Sediment Control Plan; a Surface Water Monitoring Plan; a Groundwater Monitoring Program; and a Surface and Groundwater Response Plan. SITE WATER BALANCE 9. The Site Water Balance must: a) include details of: sources and security of water supply; water use and management on site; any off-site water transfers or discharges; and reporting procedures; and b) describe measures to minimise water use by the site. EROSION AND SEDIMENT CONTROL 10. The Erosion and Sediment Control Plan must: a) be consistent with the requirements of Landcom s Managing Urban Stormwater: Soils and Construction manual; b) identify activities that could cause soil erosion and generate sediment; c) describe measures to minimise soil erosion and the potential for transport of sediment downstream; d) describe the location, function and capacity of erosion and sediment control structures; and e) describe what measures would be implemented to maintain the structures over time. SURFACE WATER MONITORING 11. The Surface Water Monitoring Program must include: Page 31 of 33