EnCana’s Reply to Intervenor Submissions Appendix T: Evaluation of Arthropod Species at Risk in the Suffield National Wildlife Area Appendix T Evaluation of Arthropod Species at Risk in the Suffield National Wildlife Area EnCana Corporation August 2008 Page T-1 EnCana’s Reply to Intervenor Submissions Appendix T: Evaluation of Arthropod Species at Risk in the Suffield National Wildlife Area August 2008 EnCana Corporation Page T-2 EnCana’s Reply to Intervenor Submissions Appendix T: Evaluation of Arthropod Species at Risk in the Suffield National Wildlife Area T.1 Introduction Canadian Forces Base Suffield (CFB Suffield) contains the largest contiguous area of surviving native grassland (more than 50 percent native vegetation remaining) in western Canada (Patriquin and Skinner 1992). The area acts as a refuge for native grassland species and is a valuable resource of national significance (Finnamore and Buckle 1999). Five environmentally significant areas are located within CFB Suffield (Table T-1) with four of these areas considered to be of national significance. In 2003 the Department of National Defence created the CFB Suffield National Wildlife Area (NWA), which included 458.7 km2 encompassing the Middle Sand Hills, some mixed grassland and the riparian zone along the South Saskatchewan River. Shallow gas wells were first drilled in the NWA in 1973. EnCana and its predecessor companies have engaged in oil and gas activities on CFB Suffield and shallow natural gas activities within the NWA since 1975. With the present Project, EnCana is proposing to extract sweet shallow gas from the NWA via shallow gas infill well development (drilling that occurs within boundaries of an existing developed gas or oil field). Current well density in the NWA varies from 4 wells per section (wps) to a maximum of 16 wps. The intention of this Project is to develop to an average of 16 wps. Well density has already been increased to 16 wps in several areas. Associated with these wells will be pipelines connecting wells into existing and new infrastructure. To minimize impact on flora and fauna, construction activities will occur between October and April over three-years. Minimal impact techniques developed by EnCana will be used to drill these existing wells and include: • use of existing roads; no new roads will be constructed • minimal disturbance shallow gas well sites, and no levelling • suspension of drilling and other activities during unfavourable (e.g., wet) conditions • removal of all fluids (for drilling and completions) from the NWA; and • use of dormant-season low-impact spider ploughing techniques for pipeline construction It is expected that an average of 16 wps will be drilled. Wells will be tied-in to existing and new pipeline infrastructure by 50.8 mm (2 in.) inside diameter, high-density polyethylene plastic (HDPE) pipe. The pipelines will normally be ploughed into the ground (using a spider plough to a depth of 1.5 m), resulting in minimal surface disturbance (no topsoil will be stripped and the width of the pipeline right of way will be kept as narrow as possible). Conventional techniques (chain ditcher) will only be used if ploughing is not feasible or if it is determined that ploughing in will result in excessive damage to soils and vegetation (e.g., stony/rocky soils or frozen ground). Approximately 40 km of new 101.6 mm, 152.4 mm, and 203.2 mm (4, 6, and 8-in.) steel pipe will be required to effectively transport the additional gas volumes to compressor stations outside the NWA. Working areas during construction of pipeline will typically be 15 m wide, however, the width of the linear disturbance (i.e., topsoil stripping for ditching installation of steel pipe) will be limited to 2 to 4 m. (see EnCana EIS May 2007 Volume 1 Project Description). The four phases of the proposed Project include: i) preconstruction activities; (ii) construction; (iii) operations; and (iv) decommissioning and abandonment. The Project will cause some temporary disturbance of habitats; disturbance of over-wintering habitats; changes to vegetation (both species diversity and vegetation height); some minor loss of habitat at points occupied by Project infrastructure (wells, gathering pipelines, etc.); some changes to drainage and soil compaction; alteration of original soil structure and quality. Changes in the habitat may influence some arthropod species assemblages and community structure in the disturbed areas and may influence the presence or absence of other species, which could affect food resources, pollination activity, predation rates, parasites, disease suppression and control and other ecosystem functions. EnCana Corporation August 2008 Page T-3 EnCana’s Reply to Intervenor Submissions Appendix T: Evaluation of Arthropod Species at Risk in the Suffield National Wildlife Area T.2 Selection of Valued Ecosystem Components (VECs) The term “arthropods” refers to a large phylum of animals with jointed legs and segmented bodies, such as insects, crustaceans and spiders. Arthropods influence soil capability and quality, vegetation growth and development, are a dominant part of species level biodiversity and serve as a significant food resource for other animals. Even though arthropod species represent more than half of the described species on the planet, the diversity and distribution of vertebrate species are usually better known. This familiarity has resulted in the routine discussion and assessment of vertebrate fauna in environmental assessments, while arthropod fauna have not been commonly considered in environmental assessments until recently. Problems with using arthropod fauna include their small size and cryptic natures; limited ecological and life history data for most species; labour intensive and time-consuming sampling and identification processes; and limited number of taxonomic keys making species-level identification problematic for many taxonomic groups. In the past, there were few formal guidelines for the use of insects in environmental impact assessments (e.g., Rosenberg et al. 1986). However, some guidance is provided by Canadian Wildlife Service (2004) for species at risk. Some taxonomic groups such as Lepidoptera (butterflies and moths), dragonflies/damselflies and tiger beetles are sufficiently well studied that they have received attention to determine which species are of conservation concern. The Alberta Natural Heritage Information Centre has applied structured ranking criteria to the arthropod groups previously mentioned and thus identified those species of conservation concern based on best available information. The Committee on the Status of Endangered Wildlife in Canada has also assessed the conservation status of some arthropod species through a rigorous science-based process and the species for which status reports have been generated are considered by statutory decision makers for legal listing under the Species at Risk Act (SARA). The Project area is federal land and thus the provisions of SARA apply in full. High species diversity and wide distribution of arthropods coupled with their integration into ecosystems provides valuable information. Furthermore, arthropods can be useful indicators since their presence or absence reflects site conditions over a long time, not just the chemical and physical properties at the time of collection (Rosenberg et al. 1986). Arthropod species have specific physiological, behavioral and other traits that are fixed genetically. Thus, closely-related species can respond uniquely to environmental conditions and disturbances making them useful indicators of particular conditions. According to the Biological Survey of Canada (Fall 2006 Newsletter of the Biological Survey of Canada (Terrestrial Arthropods) Vol. 25, No.2), there is much interest in using insects because of the SARA. However, the paucity of data for many insect species with respect to density, distribution and life history makes it difficult to determine whether such species are endangered or not. The combination of inadequate systematics and limited biological knowledge restricts our understanding of the role arthropods have in terrestrial ecosystems. This fact, in combination with the large number of arthropod species, means that scarce resources must be directed to species that have been determined to be at risk and for which there is sufficient information to be reasonably included in development and regulatory decision. Such species are the focus of this report. August 2008 EnCana Corporation Page T-4 EnCana’s Reply to Intervenor Submissions Appendix T: Evaluation of Arthropod Species at Risk in the Suffield National Wildlife Area T.3 Overview Project Area Description The NWA is located within the Dry Mixedgrass Subregion. Topography is generally subdued with only a few minor uplands. The predominant landform is a low-relief ground moraine with significant areas of hummocky moraine, glaciofluvial outwash, glaciolacustrine sand plains, fine-textured glaciolacustrine lake deposits, and eroded plains. Elevations range from 600 m to more than 1300 m. The Subregion is drained by several major rivers that have exposed Cretaceous shales and sandstones, creating extensive badlands in some areas. Drainage is to the Missouri River system via the Milk River and to the Saskatchewan River system via all of the other rivers in the Subregion. The Dry Mixedgrass Subregion is the warmest and driest in Alberta. It has a typical continental climate with cold winters, warm summers and low precipitation. The rate of evaporation