NOTICE OF A PROPOSED CHANGE TO AN APPROVED DEVELOPMENT

Transcription

1 NOTICE OF A PROPOSED CHANGE TO AN APPROVED DEVELOPMENT LEGACY PROJECT K+S Potash Canada GP November 30, 2012

2 TABLE OF CONTENTS 1. Introduction Description of Proposed Change Existing Environment Environmental Effects Summary and Conclusions...14 Page 2 of 14

3 1. INTRODUCTION BACKGROUND The Legacy Project (Project) is a greenfield potash solution mine and production facility located in south-central Saskatchewan, within the Rural Municipality of Dufferin and near the communities of Findlater and Bethune. The Legacy Project Environmental Impact Statement (EIS) received Ministerial Approval on November 8, 2010 by the Saskatchewan Minister of Environment. The EIS documents the Environmental Assessment findings for the Legacy Project including consideration of the main surface pipelines from the proposed processing plant to the wellfield production pads (pipelines). The purpose of this proposal is to notify the Ministry of Environment of a proposed change to the Project description contained in the original EIS and to seek an amendment to the approval to proceed with the Project development based on installing the pipelines below the ground surface as opposed to above the ground surface. This proposal presents information to demonstrate that the existing environmental assessment adequately assesses the potential environmental effects of the proposed change and that overall the environmental effects of buried pipelines do not significantly differ from the environmental effects of above ground pipelines. PROPOSED CHANGE The EIS described the main pipelines that will connect the processing plant to the mine well field and noted that the pipelines will be above ground. The proposed change involves replacing the plan to install the main pipelines on surface with a plan to bury these pipelines causing a short term land disturbance and facilitating a smaller pipeline footprint. The Pipeline footprint will be reduced as the large thermal expansion loops required for the surface pipeline are not required for the underground pipeline. The ground disturbance required to construct the buried pipelines will be commensurate with the progress of the pipeline installation and will be progressively reclaimed and remediated as the pipeline is installed, thus minimizing the time that the impacts from the disturbed ground remain unmitigated. The buried pipelines will be monitored for leaks using a proven buried digital leak monitoring system to ensure that the pipeline monitoring is equal to or better than the original routine visual monitoring that was proposed in the EIS. The digital monitoring system will be backed up by traditional pressure and flow monitoring reconciliation methods as presented in the EIS. Page 3 of 14

4 2. DESCRIPTION OF PROPOSED CHANGE ROUTING As stated in the EIS, the layout of the well field infrastructure will be refined over the life of the mine. The EIS presented a conceptual layout of the mine well field including pipelines aligned parallel to existing grid roads with a discrete footprint. The detailed mine plan and associated pipeline route has not been finalized, and is not considered part of this notification of change. The selected pipeline routing will be included in the application for approval to construct and operate the pipeline. Pipeline route selection will depend on a number of factors including: Environmental and heritage resource management considerations Long term operations considerations Engineering considerations Construction considerations Financial considerations To ensure that the selected route does not significantly impact the environment or heritage resources, an aquatic, terrestrial and heritage resource survey will be conducted by an external party to characterize the existing environmental conditions along proposed pipeline routes. The pipeline route selection will be strongly influenced by these findings which will be included in the application for approval to construct and operate the pipeline. The route will be adjusted to avoid wetlands wherever possible, while maintaining a relatively straight run to best serve the production pads of the well field. DESIGN The preliminary design of the buried pipelines includes a total of eight pipes to be installed within the first thirteen years of production and two additional pipes to be installed at a future date after the initial eight pipelines have been installed. The eight initial pipelines include the following: Two 18 (OD) pipes that are required to convey raw water and brine to and from the well field for initial cavern development. Two 24 (OD) pipes required to convey brine during primary mining. Four 24 (OD) pipes required for secondary mining. Page 4 of 14

5 Table 1: Main Pipeline Description on Main Services Piping Corridor Pipeline Start Destination Wellfield development injection Raw water pond Production well cavern development Fluid Type Design Flow (m 3 /hr) Raw water 880 Early brine return Primary mining injection Production well cavern development Raw water pond, refinery process condensate Disposal well Brine 880 Production wells Heated Raw water 1950 Primary mining return Production wells Processing plant Brine 1950 Secondary mining injection(1) 1 Brine cooling pond Production wells Heated Brine 2500 Secondary mining return(1) 2 Production wells Processing plant Brine 2500 Secondary mining injection(2) 1 Brine cooling pond Production wells Heated Brine 2500 Secondary mining return(2) 2 Production wells Processing plant Brine 2500 Notes: 1 The two secondary mining injection pipelines are connected by a branch line to the production pads and operate in parallel. 2 The two secondary mining return pipelines are connected by a branch line to the production pads and operate in parallel. The design of the pipelines is similar to the design of the above ground pipelines that was described in the approved Application for Approval to Construct and Operate Pad 2. The proposed piping sizes, purpose and flow rates remain unchanged. A comparison of the design features between buried pipelines and surface pipelines is provided in Table 2. Figure 1 shows a cross section of the proposed buried pipelines. The pipelines will be designed in accordance with appropriate standards (e.g. ASME B31.3 for Process Piping). Page 5 of 14

6 Table 2: Comparison of Design Features of the Buried and Surface Pipelines: SURFACE PIPELINES External thermal insulation required to maintain fluid temperatures in the pipelines. The pipeline would be supported above ground and anchored to control the movement of pipe due to thermal expansion and contraction and operations. A Number of 20 metre X 20 metre (approx.) expansion loops would be installed to accommodate the longitudinal thermal expansion and contraction of the steel pipe. Pipeline crossings would provide access for operational traffic. Pipeline crossings would provide access for wild life. BURIED PIPELINES Eliminates the thermal insulation that would have been required by surface pipelines at the site. Do not require the special anchoring that is required for surface pipelines. Burying the pipelines would provide the necessary anchoring. No expansion loops are required to accommodate longitudinal thermal expansion. No crossings are required as there are no physical surface barriers to operational traffic. No crossings are required as there are no physical surface barriers to wildlife. Page 6 of 14

7 Figure 1: Buried Pipeline Cross Section Page 7 of 14

8 CONSTRUCTION The construction of the buried pipeline will occur as a staged process over a period of years. The first stage of construction will involve excavating a trench for the first pair of steel pipes. The electronic leak detection system sensing system will be installed in close proximity to the pipeline in compliance with the manufacturer s recommendations. An example of the installation from a potential manufacturer is shown in Figure 2. In this case, the pipes will be installed above the electronic leak detection system sensing cables and then buried as the pipeline installation advances. The filled trench will be compacted and contoured to match the surrounding topography and local vegetation replanted or encouraged to fill in naturally. It is expected that this stage of construction will occur during the summer months prior to the first year of planned production. The leak detection system will be connected to the control system and undergo full commissioning including component testing, loop testing, calibration, operational and performance testing prior to becoming fully operational. The second stage of construction is expected to occur approximately two years later, in the third year of production. This stage will involve installing a pair of pipes adjacent to the previously installed pipes. A similar construction process will be followed including the installation of the leak detection system sensor cables below the pipes to be installed. The commissioning process will be repeated for this pair of pipes. Rehabilitation of the area will also be undertaken as in the first stage. The third stage of construction is expected to occur approximately four years later following a similar construction, commissioning and rehabilitation process. This stage involves the installation of four pipes. Although not clearly defined yet, two additional pipes may be installed at a future date using the same approach. The total width of the temporary land disturbance over time (after all the pipelines have been installed) is expected to be approximately 30 metres and extend the length of the wellfield. As described above, the disturbance will be sequential - corresponding to the development of the mine well field and the installation of the pipeline. Details of the proposed installations will be included in the applications for Approval to Construct and Operate Pollutant Control Facilities within the wellfield. After each stage of construction, the spoil piles and construction waste material will be removed and used as fill where appropriate or disposed of in an approved manner. Page 8 of 14

9 Figure 2: An Example of Leak Sensing Cable Installation OPERATION, MONITORING, AND LEAK RESPONSE During operations, the underground cavities are developed in stages starting with cavern development between two boreholes, then primary mining followed by secondary mining. It is this mining sequence that allows the construction of the pipelines to be staged over a period of seven years or more. The pipelines installed during the first stage of construction are required for cavern development, the second stage of construction is necessary to provide pipelines for primary mining and the final stage of construction is to provide the pipeline capacity to accommodate secondary mining and primary mining. A wellfield buried pipeline maintenance program will be developed and will include routine cleaning and inspections, including smart pigging technology whenever possible. This program will be refined over time as we gain insight into the pipeline corrosion modes that will be active within the wellfield. During all stages of operation, brine will be handled within most of the buried pipes. It is therefore important to have a reliable leak detection system that provides at least the same level of protection as visual routine monitoring of surface pipelines would provide. Electronic leak detection systems employ a number of techniques including unexpected acoustic emissions monitoring, surrounding ground temperature monitoring, vapour detection and fibre-optics to monitor temperature profiles along the fibre. These systems have been successfully used in municipal applications, petrochemical industry applications and general pipeline transport applications. The leak detection system that best suits the application and the environmental and operating conditions will be selected. The sensitivity of the system in terms of identifying the location and size of the leak will be considerations in the selection of the leak detection system. To ensure the required level of protection is maintained, the electronic leak detection system (ELDS) will be installed with the following: redundancy built directly into the system; routine verification of the monitoring results; and a management system that responds to alarms in an appropriate and timely manner. Page 9 of 14

10 An ELDS is a permanent monitoring solution that continuously monitors at all points along the pipeline at all times providing superior monitoring coverage to the traditional visual periodic inspection. Monitoring is done in real time and reported almost instantly to the central data monitoring unit. In the case of fibre optic sensors, the fibre optic cable is made up of many fibre filaments used to convey the data. If one fibre filament fails, the adjacent filaments will still be active and convey the data. In addition, the data acquisition unit provides an immediate indication of loss of signal if a sensor were to stop providing data. If the entire system were to fail this would be immediately apparent by the lack of data on the display screens. In addition to the ELDS, routine pressure and volume measurements at intervals along the pipe will be manually reconciled to verify the performance of the ELDS and confirm potential alarms. A management system will be in place with specific procedures to follow in the event of an alarm. The procedures will include methods for verifying the leak size and location, the appropriate response to stop and repair a leak, and the required remediation standard for the surrounding environment. With this technology, rapid location identification minimises response time, and any potential excavation expenses in order to find and repair the leak. Spill response can be initiated before significant environmental damage occurs through early detection; once a leak is detected the damaged pipeline can be isolated by closing valves at the processing plant and the valve houses on the production pads to prevent further uncontrolled leakage. Leak detection sensitivities depend on the circumstance and external conditions. Although the leak detection system and manufacturer has yet to be selected, KSPC is committed to installing best practice technology. Details will be included in the application to construct and operate the pipelines. PROGRESSIVE RECLAMATION Lands disturbed by pipeline installation will be returned to a condition that is physically stable, safe, and environmentally sustaining in keeping with the land use and landscape of the day. Progressive reclamation of the disturbed surface area will occur as the pipelines are installed to minimize the delay between disturbance and reclamation. Progressive reclamation will include: Filling in the pipe trench with soil from the excavation spoil piles. Placing a layer of local topsoil on top of the filled trench. Compacting and contouring the fill and topsoil to meet the land use and landscape requirements of the day. Implementing erosion control measures until the area has naturally vegetated or is cultivated for agricultural purposes. Page 10 of 14

11 DECOMMISSIONING An approved preliminary decommissioning plan will be developed while the pipelines are in operation and updated to reflect the current technology and acceptable practice. Once the decision is made to decommission the pipelines, an approved detailed decommissioning plan will be developed in consultation with the Saskatchewan Ministry or Environment and other stakeholders. Currently, the decommissioning concept for the pipelines involves isolating the pipeline and removing the standpipes to surface from the buried pipeline, capping the ends, and filling in the excavations used to access the ends of the pipeline. The pipe would remain in place, thereby avoiding a second ground disturbance along the entire pipeline. 3. EXISTING ENVIRONMENT The buried pipeline corridor is within the bounds of the Local Study Area (LSA) discussed in the Project EIS and is located on predominantly cultivated land with narrow fringes of vegetation along the field margins and wetlands. Occasional small bluffs of trees and tall shrubs remain along the field fringes and fence lines. The pipeline corridor may encounter native vegetation communities and modified grassland planted with oil seed and grain crops. As part of the Project EIA, field surveys were completed to classify wetlands within the anticipated solution mine well field area. Wetlands were classified based on a collaboration of classification systems described by Stewart and Kantrud (1971) and Ducks Unlimited (2000). Seasonal wetlands were the most dominant wetland identified, followed by temporary, semipermanent, ephemeral and permanent wetlands. As previously mentioned, an aquatic, terrestrial and heritage resource survey will be conducted by an external party to characterize the existing environmental conditions along proposed pipeline routes. The pipeline route selection will be strongly influenced by these findings, which will be included in the application for approval to construct and operate the pipeline. Page 11 of 14

12 4. ENVIRONMENTAL EFFECTS Table 4: Environmental Aspects for the Development ENVIRONMENTAL ASPECTS Solid Waste (construction) Liquid Waste (construction) Top soil (construction) Vehicular traffic (construction) Ground Disturbance (construction) POTENTIAL ENVIRONMENTAL IMPACT Attracts wildlife Litter Contaminated soil Contaminated ground water Contaminated surface water Habitat destruction Loss of stockpile volume Erosion Silting surface water bodies Dust Noise Wild life impact Introduction of invasive species Loss of native species Subsidence ENVIRONMENTAL CONTROLS Routine housekeeping Temporary storage procedures Proper segregation of waste to facilitate disposal Removal for approved disposal Routine inspection Collection in purpose built ponds, sumps and holding tanks Removal by licensed operator for appropriate disposal Spill prevention Appropriate containment Routine inspection Routine inspection Erosion control as required Local silt protection for exposed water bodies Restrict traffic to approved roads Limit speed Educate drivers and operators Locate pipeline corridor on cultivated land where possible Use previously disturbed land where possible Compacting backfill Temporary disturbance with small footprint Contoured and re-vegetated after excavation is filled Page 12 of 14

13 ENVIRONMENTAL ASPECTS Brine (operations) Hydraulic fluid (operation) POTENTIAL ENVIRONMENTAL IMPACT Invisible leakage Contaminated soil Contaminated ground water Contaminated surface water Habitat destruction Contaminated soil Contaminated ground water Contaminated surface water Habitat disruption ENVIRONMENTAL CONTROLS Routine maintenance and inspections Electronic leak detection system and backup systems to verify data Fully welded pipelines that meet accepted welding quality standards Quality control of welding including visual inspections of all welds and radiography of selected welds Spill prevention and appropriate containment where aboveground pipe fittings are used Pre-determined spill response and spill management system Continuous monitoring along full length of buried pipeline Spill prevention Scheduled equipment maintenance Routine inspections Strategically placed spill kits Spill response The environmental aspects for the proposed buried pipeline are essentially no different from those environmental aspects associated with constructing a surface pipeline except that, for the buried pipeline, the ground disturbance is temporary and smaller in area. In the original EIS based on surface main brine pipelines, the impact from loss of containment resulting in soil contamination and short term decrease in air quality (e.g. dust from explosion and / or spray of pipeline contents) was classified as a negligible risk. For the buried pipeline the potential impact would be soil contamination and ground water contamination. The potential soil contamination on surface would be less as the pipeline would be buried underground. The probability of groundwater contamination is considered to be low due to the lack of pathways that may have a measurable residual effect on the hydro geologic system as stated in Section 7.5 of the EIS. Page 13 of 14

14 In the event of a leak in the buried pipeline, the potential impacts resulting from the additional time it may take to repair the leak will be mitigated by early electronic leak detection and as in the case of the surface pipelines, the ability to quickly isolate the buried pipeline by closing valves in the plant and the well field. The buried pipeline option has potentially less of an environmental impact than the surface option and presents some clear advantages over the surface pipeline option. These include: The buried pipeline has a smaller footprint than the surface pipeline as the surface pipeline requires large expansion loops to accommodate thermal expansion and contraction of the pipeline as it is exposed to the ambient weather conditions. Burying the pipeline will create short term temporary ground disturbance along the piping corridor, while the ground disturbance for the surface pipeline expansion loops will be for the life of the mine and will extend well beyond the already disturbed pipe bench. A buried pipeline does not create physical surface barriers to wildlife. The buried pipeline will not require thermal pipe insulation, whereas the surface pipeline will require insulation along its entire exposed length. Burying the pipeline will inherently anchor the pipeline in place. The surface pipeline will require a specially designed and constructed pipe anchoring system. Installation of the buried pipeline will generate less construction waste than the surface pipeline. A number of options exist for decommissioning of the buried pipeline including leaving it buried in place. This approach would avoid disturbing the surface along the entire length of the pipeline once again to reclaim the pipe. Rehabilitation of the piping corridor surface will have been completed shortly after initial installation and burial of the pipe. The cost of a buried pipeline is less than the cost of installing a surface pipeline. A buried pipeline does not create physical surface barriers to operational traffic. 5. SUMMARY AND CONCLUSIONS For the buried pipeline option, the key environmental interactions that were not assessed in the current environmental assessment were the potentially increased risk associated with spills and the increased environmental risk from land disturbance along the proposed buried pipeline corridor. The overall environmental risk from the project is reduced by the buried pipeline option, especially when considering the smaller footprint, temporary land disturbance, substantial reduction in material used in construction, and subsequent waste reduction during decommissioning. Leak monitoring will be enhanced electronically by providing continuous monitoring along the full length of the buried pipeline. The leak detection system is able to detect leaks in a localized area with a real time alarm response. Early leak detection allows spill response to be initiated before significant environmental damage occurs. The environmental interactions from the buried pipeline option do not change the overall conclusions of the Environmental Impact Statement. Page 14 of 14