Appendix B Transmission Line and Substation Components Prepared by: Idaho Power Company 1221 W Idaho Street Boise, ID 83702

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1 Transmission Line and Substation Components Prepared by: Idaho Power Company W Idaho Street Boise, ID 0 November 0

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3 TABLE OF CONTENTS.0 PROJECT FACILITIES.... Transmission Structures..... Types of Transmission Line Support Structures..... Structure and Conductor Clearances..... Structure Foundations.... Conductors.... Other Hardware Insulators Grounding Systems Minor Additional Hardware.... Communication Systems..... Optical Ground Wire..... Communications Stations.... Access Roads.... Substations..... Substation Components..... Distribution Supply Lines....0 SYSTEM CONSTRUCTION.... Land Requirements and Disturbance..... Right-of-Way Width..... Right-of-Way Acquisition..... Land Disturbance.... Transmission Line Construction..... Transmission Line System Roads..... Soil Borings..... Staging Areas..... Site Preparation..... Install Structure Foundations..... Erect Support Structures..... String Conductors, Shield Wire, and Fiber Optic Ground Wire..... Cleanup and Site Reclamation.... Communication System..... Communication Sites..... Access Road.... Substation Construction..... Substation Roads Soil Borings Clearing and Grading Storage and Staging Yards Grounding Fencing Foundation Installation..... Oil Containment..... Structure and Equipment Installation Conduit and Control Cable Installation..... Construction Cleanup and Landscaping.... Special Construction Techniques... November 0 iii

4 0 0.. Blasting..... Helicopter Use..... Water Use.... Construction Elements..... Construction Workforce..... Construction Equipment and Traffic..... Removal of Facilities and Waste Disposal Construction Schedule SYSTEM OPERATIONS AND MAINTENANCE.... Routine System Operations and Maintenance..... Routine System Inspection, Maintenance, and Repair..... Transmission Line Maintenance..... Hardware Maintenance and Repairs..... Access Road and Work Area Repair Vegetation Management Noxious Weed Control..... Substation and Communication Site Maintenance.... Emergency Response..... Fire Protection....0 DECOMMISSIONING Table -. Table -. Table -. Table -. Table -. Table -. Table -. Table -. Table -. Table -. Table -. Table -. Table -. Table -0. Table -. Table -. LIST OF TABLES Proposed Structure Characteristics... Foundation Excavation Dimensions... Proposed Communications Station Locations... Access Road Requirements for Transmission Line System... Summary of Land Required for Construction and Operations... Summary of Land Disturbed during Construction and Used during Permanent Operations... Miles of New and Improved off-row Access Roads... Miles of New and Improved Access Roads... Construction Staging Areas and Helicopter Fly Yards... Summary of Shallow Bedrock... Estimated Water Usage for Construction by County... Projected Workers and Population Change during Peak Construction... Transmission Line Construction Equipment Requirements... Equipment Requirements for Grassland and Hemingway Substations... Average and Peak Construction Traffic (per spread)... Solid Waste Generation from Construction Activities... 0 November 0 iv

5 0 0 Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -0. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. Figure -. LIST OF FIGURES Proposed 00-kV Single Circuit Lattice Steel Structure... Proposed 00-kV Single Circuit Tubular Steel Pole H-frame Structure... Proposed /-kv Double Circuit Structure with Distribution Underbuild... Proposed ROW Designs... Alternative 00-kV Single Shaft Steel Pole Structure... Alternative ROW Design... Typical Communication Site... Typical Road Sections for Different Terrains... Type Drive Through Stream Crossing Methods... Type and Type Crossing Methods... Type Channel Spanning Structures Including Fish Passage... Typical 00-kV Substation... Disturbance Area for Tower Structures... Typical Disturbance Area... 0 Example Access Roads and Tower Locations... Transmission Line Construction Sequence... Conductor Installation... Project Construction Schedule... Live-line Maintenance Space Requirements, Single-Circuit 00-kV Lattice Tower... Right-of-Way Vegetation Management... November 0 v

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7 0 0 This appendix contains detailed information provided by Idaho Power Company (IPC) regarding the components of the transmission system including the transmission structures, the communications system, and the substations. It provides details regarding construction of the system (Section.0), goes on to provide information regarding the operations and maintenance of the system (Section.0), and finally details the proposed abandonment and restoration techniques (Section.0)..0 PROJECT FACILITIES This section describes the various components of the transmission system for the Boardman to Hemingway Transmission Line Project (Boardman to Hemingway or Project), including the structures themselves, the conductors used, other hardware needed, the communication system, the access roads, and finally the substations. Both the proposed and alternative structures are described herein. Transmission Structures.. Types of Transmission Line Support Structures The majority of the proposed transmission line circuits will be supported by steel single-circuit steel lattice towers. Figure - illustrates the typical tangent lattice tower structure configuration. In some instances, single-circuit tubular steel H-frame structures will be used where required to mitigate sensitive environmental resources or where land use requires shorter structure heights. Figure - illustrates a tangent tubular steel H-frame structure. Figure - provides an illustration of a typical /-kilovolt (kv) structure with.-kv underbuild distribution that would be used for approximately. miles. Tangent structures are primarily used in straight line segments and are the most common type of structure. Running angles are used when a transmission line changes direction up to a specified threshold line angle. Dead-end structures are needed for extremely long spans, when the line angle exceeds the threshold of a running angle tower, in highly varied terrain which can create uplift conditions, or when there is a need for a failure containment structure. Angle and dead-end structures are heavier and require larger foundations. Figure - illustrates the right-of-way (ROW) design configurations for proposed structures. Of the. miles, 0. miles would be a -kv single-circuit which because of its limited extent, is not further discussed in this document. November 0

8 Figure -. Proposed 00-kV Single Circuit Lattice Steel Structure November 0

9 Figure -. Proposed 00-kV Single Circuit Tubular Steel Pole H-frame Structure November 0

10 Figure -. Proposed /-kv Double Circuit Structure with Distribution Underbuild November 0

11 Figure -. Proposed ROW Designs November 0

12 Figure - presents the configuration of the alternative 00-kV monopole structure which could be used in active agricultural areas where location is critical to farming operations. Figure - illustrates the alternative ROW design configuration. Figure -. Alternative 00-kV Single Shaft Steel Pole Structure November 0

13 Figure -. Alternative ROW Design Proposed 00-kV Single Circuit Galvanized Lattice Steel Structures Lattice steel towers will be fabricated with galvanized steel members treated to produce a dulled galvanized finish. The average distance between 00-kV towers will be,00 to,00 feet. Structure heights will vary depending on terrain and the requirement to maintain minimum conductor clearances from ground. The 00-kV single-circuit towers will vary in height from 0 to feet.... Proposed 00-kV Single Circuit Tubular Steel H-Frame Structures The 00-kV H-frame structures will be fabricated with self-weathering tubular steel treated to produce a rust-like finish. The average distance between 00-kV H-frames will be,00 to,00 feet. Structure heights will vary depending on terrain and the requirement to maintain minimum conductor clearances from ground. The 00-kV H-frame structures will vary in height from 00 to feet.... Proposed /-kv Double Circuit Galvanized Monopole Structures Monopole structures will be fabricated with self-weathering steel treated to produce a rust-like finish. The average distance between /-kv towers will be 0 feet. Structure heights will vary depending on terrain and the requirement to maintain minimum conductor clearances from ground. The /-kv double-circuit towers will vary in height from to 00 feet.... Alternative 00-kV Single Circuit Monopole Structures The alternative 00-kV Monopole structures if use would be fabricated with self-weathering tubular steel treated to produce a rust-like finish. The average distance between 00-kV Monopoles would be 00 to,000 feet. Structure heights would vary depending on terrain and the requirement to maintain minimum conductor clearances from ground. The 00-kV Monopole structures would vary in height from 0 to 0 feet. Table - describes the number and type of structures by typical height, typical distances between structures, and temporary and permanent disturbance areas by structure. 0 November 0

14 0 0 0 Table -. Structure Type 00-kV Single Circuit Lattice Structure 00-kV Single Circuit H- Frame Structure /-kv Double Circuit Monopole Structure Proposed Structure Characteristics Typical Height (feet) Reasonable estimate from preliminary engineering. Average Distance Between Structures (feet) Short Term Disturbance Area per structure (sq. feet.) No. of Structures / 0-,,00-,00 ROW Width 0 feet x 0 feet =. acre ,00 ROW Width 0 feet x 0 feet =. acre ROW Width 00 feet x 00 feet = 0. acre Long Term Disturbance Area per structure (sq. feet.) ROW Width 0 feet x 0 feet = 0.0 acre ROW Width 0 feet x 0 feet = 0.0 acre ROW Width 0 feet x 0 feet = <0.0 acre.. Structure and Conductor Clearances Conductor phase-to-phase and phase-to-ground clearance parameters are determined in accordance with IPC Company Standards and the National Electrical Safety Code (NESC), ANSI C, produced by the American National Standards Institute (ANSI). These documents provide minimum distances between the conductors and ground, crossing points of other lines and the transmission support structure, and other conductors, and minimum working clearances for personnel during energized operation and maintenance activities (IEEE 00). Typically, the clearance of conductors above ground is feet for 00-kV, but where the line crosses land used for agricultural purposes a minimum clearance of 0 feet will be used. For the /-kv double-circuit section, the.-kv underbuild distribution conductor clearance is feet above grade. During detailed design, clearances may be increased to account for localized conditions... Structure Foundations The 00-kV single-circuit lattice steel structures each require four foundations with one on each of the four corners of the lattice towers. The foundation diameter and depth will be determined during final design and are dependent on structure loading conditions and the type of soil or rock present at each specific site. Typically, the foundations for the single-circuit tangent lattice towers will be composed of steel-reinforced concrete drilled piers with a typical diameter of feet and a depth of approximately feet. For the 00-kV H-frame structures each structure will require two foundations, one for each pole that comprises the H-frame structure. At angle and dead-end structures the H-frames will be replaced with three poles each with its own foundation. They will be steel-reinforced drilled piers with a typical diameter of feet and a depth of approximately feet. The /-kv monopole structures will be a combination of directembedded steel poles and self-supported poles on drilled pier foundations. Tangent structures will be direct-embedded in a single drilled boring, typically feet in diameter and feet deep. Angle and dead-end structures will be on steel-reinforced drilled pier foundations with a typical diameter of feet and a depth of approximately 0 feet. Typical foundation diameters and depths for the proposed structure families are shown in Table -. November 0

15 0 0 Table -. Foundation Excavation Dimensions Proposed Structures Number of Structures Holes Per Structure Depth (feet) Diameter (feet) Concrete (cubic yards) 00-kV Single Circuit - Light Tangent Lattice Tower 00-kV Single Circuit - Heavy Tangent Lattice Tower 00-kV Single Circuit - Small Angle Lattice Tower 00-kV Single Circuit - Medium Angle Lattice Tower kV Single Circuit - Medium Dead-End Lattice 0 0 Tower 00-kV Single Circuit - Heavy Dead-End Lattice 0 0 Tower 00-kV Single Circuit Tangent H-Frame Structure 00-kV Single Circuit Angle H-Frame Structure 0 00-kV Single Circuit Dead-end H-Frame Structure 0 /-kv Double Circuit - Monopole Tangent N/A Structure /-kv Double Circuit - Monopole Angle Structure 0 /-kv Double Circuit - Monopole Dead-end 0 Structure Dead-end structure typically refers to a structure that is placed at a point where the transmission line turns direction.. Conductors The proposed conductor for the 00-kV lattice structure lines is, KCM / ACSR Bittern /. Each phase of a 00-kV three-phase circuit will be composed of three subconductors in a triple bundle configuration. The individual, KCM conductors will be bundled in a triangular configuration with spacing of inches between horizontal subconductors and inches of diagonal separation between the top two conductors and the lower conductor (see Figure -). The triple-bundled configuration is proposed to provide adequate current carrying capacity and to provide for a reduction in audible noise and radio interference as compared to a single large-diameter conductor. Each 00-kV subconductor will have a / aluminum/steel stranding, with an overall conductor diameter of. inches and a weight of. pounds per foot and a non-specular finish. The proposed conductor for the /-kv monopole structure lines is KCM / ACSR Ibis (KV, one conductor per phase), /0 / ACSR Penguin ( KV, one conductor per phase), No. Copper Conductor (.-kv Distribution, one conductor per phase plus neutral wire), and a / EHS -strand shield wire. Conductors will be aligned with typical vertical spacing of feet between shield wire and or KV phase wires, feet between phase wires, and a minimum of feet between or KV phase wires and distribution wires. Where multiple conductors are utilized in a bundle for each phase, the bundle spacing will be maintained through the use of conductor spacers at intermediate points along the conductor bundle between each structure. The spacers serve a dual purpose: in addition to maintaining KCM (,000 cmils) is a quantity of measure for the size of a conductor; kcmil wire size is the equivalent cross-sectional area in thousands of circular mils. A circular mil (cmil) is the area of a circle with a diameter of one thousandth (0.00) of an inch. Aluminum/steel refers to the conductor material composition. The preceding numbers indicate the number of strands of each material type present in the conductor (i.e., / aluminum/steel stranding has aluminum strands wound around steel strands). For AC transmission lines, a circuit consists of three phases. A phase may consist of one conductor or multiple conductors (i.e., subconductors) bundled together. Non-specular finish refers to a dull finish rather than a shiny finish. November 0

16 the correct bundle configuration and spacing, the spacers are also designed to damp out windinduced vibration in the conductors. The number of spacers required in each span between towers will be determined during the final design of the transmission line.. Other Hardware.. Insulators As shown in Figure - and Figure -, the typical insulator assemblies for 00-kV steel lattice tangent structures and H-frame structures will consist of two insulators hung in the form of a V. As shown in Figure -, insulator assemblies for /-kv tangent structures will consist of supported insulators which extend horizontally away from the monopole. Insulators are used to suspend each conductor bundle (phase) from the structure, maintaining the appropriate electrical clearance between the conductors, the ground, and the structure. The V-shaped configuration of the 00-kV insulators also restrains the conductor so that it will not swing into the structure in high winds. Dead-end insulator assemblies for the transmission lines will use an I-shaped configuration, which consists of insulators hung from either a tower dead-end arm or a dead-end pole in the form of an I. Insulators will be composed of grey porcelain or green-tinted toughened glass... Grounding Systems Alternating current (AC) transmission lines such as the Project transmission lines have the potential to induce currents on adjacent metallic structures such as transmission lines, railroads, pipelines, fences, or structures that are parallel to, cross, or are adjacent to the transmission line. Induced currents on these facilities will occur to some degree during steady-state operating conditions and during a fault condition on the transmission line. For example, during a lightning strike on the line, the insulators may flash over, causing a fault condition on the line and current will flow down the structure through the grounding system (i.e., ground rod or counterpoise) and into the ground. The magnitude of the effects of the AC induced currents on adjacent facilities is highly dependent on the magnitude of the current flows in the transmission line, the proximity of the adjacent facility to the line, and the distance (length) for which the two facilities parallel one another in proximity. The methods and equipment needed to mitigate these conditions will be determined through electrical studies of the specific situation. As standard practice and as part of the design of the Project, electrical equipment and fencing at the substation will be grounded. All fences, metal gates, pipelines, metal buildings, and other metal structures adjacent to the ROW that cross or are within the transmission line ROW will be grounded as determined necessary. If applicable, grounding of metallic objects outside of the ROW may also occur, depending on the distance from the transmission line as determined through the electrical studies. These actions take care of the majority of induced current effects on metallic facilities adjacent to the line by shunting the induced currents to ground through ground rods, ground mats, and other grounding systems, thus reducing the effect that a person may experience when touching a metallic object near the line (i.e., reduce electric shock potential). In the case of a longer parallel facility, such as a pipeline parallel to the Project over many miles, additional electrical studies will be undertaken to identify any additional mitigation measures (more than the standard grounding practices) that will need to be implemented to prevent damaging currents from flowing onto the parallel facility, and to prevent electrical shock to a person that may come in contact with the parallel facility. Some of the typical measures that could be considered for implementation, depending on the degree of mitigation needed, could include: Fault Shields shallow grounding conductors connected to the affected structure adjacent to overhead electrical transmission towers, poles, substations, etc. They are November 0 0

17 intended to provide localized protection to the structure and pipeline coating during a fault event from a nearby electric transmission power system. Lumped Grounding localized conductor or conductors connected to the affected structure at strategic locations (e.g., at discontinuities). They are intended to protect the structure from both steady-state and fault AC conditions. Gradient Control Wires a continuous and long grounding conductor or conductors installed horizontally and parallel to a structure (e.g., pipeline section) at strategic lengths and connected at regular intervals. These are intended to provide protection to the structure and pipeline coating during steady-state and fault AC conditions from nearby electric transmission power systems. Gradient Control Mats typically used for aboveground components of a pipeline system, these are buried ground mats bonded to the structure, and are used to reduce electrical step and touch voltages in areas where people may come in contact with a structure subject to hazardous potentials. Permanent mats bonded to the structure may be used at valves, metallic vents, cathodic protection test stations, and other aboveground metallic and nonmetallic appurtenances where electrical contact with the affected structure is possible. In these cases there is no standard solution that will solve these issues every time. Instead, each case must be studied to determine the magnitude of the induced currents and the most appropriate mitigation given the ground resistivity, distance paralleled, steady-state and fault currents, fault clearing times expected on the transmission line, and distance between the line and the pipeline, to name a few of the parameters. If the electrical studies indicate a need to install cathodic protection devices on a parallel pipeline facility, a distribution supply line interconnection may be needed to provide power to the cathodic protection equipment. During final design of the transmission line, appropriate electrical studies will be conducted to identify the issues associated with paralleling other facilities and the types of equipment that will need to be installed (if any) to mitigate the effects of the induced currents... Minor Additional Hardware In addition to the conductors, insulators, and overhead shield wires, other associated hardware will be installed on the tower as part of the insulator assembly to support the conductors and shield wires. This hardware will include clamps, shackles, links, plates, and various other pieces composed of galvanized steel and aluminum. A grounding system will be installed at the base of each transmission structure that will consist of copper or galvanized ground rods embedded into the ground in immediate proximity to the structure foundation and connected to the structure by a buried copper lead. When the resistance to ground for a grounded transmission structure is greater than a specified impedance value with the use of ground rods, counterpoise will be installed to lower the resistance to below a specified impedance value. Counterpoise consists of a bare copper-clad or galvanized-steel cable buried a minimum of inches deep, extending from structures (from one or more legs of structure) for approximately 00 feet within the ROW. Other hardware that is not associated with the transmission of electricity may be installed as part of the Project. This hardware may include aerial marker spheres or aircraft warning lighting as required for the conductors or structures per Federal Aviation Administration (FAA) NACE International. 00. Grounding Systems. Houston, TX. Available online at November 0

18 0 0 0 regulations. Structure proximity to airports and structure height are the determinants of whether FAA regulations will apply based on an assessment of wire/tower strike risk. IPC does not anticipate that structure lighting will be required because proposed structures will be less than 00 feet tall and will not be near airports that require structure lighting.. Communication Systems.. Optical Ground Wire Reliable and secure communications for system control and monitoring is very important to maintain the operational integrity of the Project and of the overall interconnected system. Primary communications for relaying and control will be provided via the optical ground wire (OPGW) that will be installed on the transmission lines; this path is solely for IPC use and will not be used for commercial purposes. A secondary communication path may also be developed using a power line carrier. No new microwave sites are anticipated for the Project. Updated microwave equipment may be installed at the substations. Each structure will have two lightning protection shield wires installed on the structure peaks (see Figure - and Figure -). One of the shield wires will be composed of extra high strength steel wire with a diameter of 0. inch and a weight of 0. pound per foot. The second shield wire will be an OPGW constructed of aluminum and steel, which carries glass fibers within its core. The OPGW will have a diameter of 0. inch and a weight of 0.0 pound per foot. The glass fibers inside the OPGW shield wire will provide optical data transfer capability among IPC s facilities along the fiber path. The data transferred are required for system control and monitoring... Communications Sites As the data signal is passed through the optical fiber cable, the signal degrades with distance. Consequently, signal communications sites are required to amplify the signals if the distance between substations or communications sites exceeds approximately 0 miles. As summarized in Table -, a total of eight communications sites will be required. Communication sites will be located on private and public lands. Table -. Proposed Communications Site Locations Total Construction Total Operations County Number Acres Acres Ownership Morrow Private Umatilla Private Union BLM Baker Private, BLM Malheur BLM, Private Owyhee The typical site will be 00 feet by 00 feet, with a fenced area of feet by feet. A prefabricated concrete communications shelter with dimensions of approximately.-foot by -foot by -foot-tall will be placed on the site and access roads to the site and power from the local electric distribution circuits will be required. An emergency generator with a liquid petroleum gas fuel tank will be installed at the site inside the fenced area. Two diverse cable U.S. Department of Transportation, Federal Aviation Administration, Advisory Circular AC 0/0-K Obstruction Marking and Lighting, August, 000; and Advisory Circular AC 0/0-K Proposed Construction or Alteration of Objects that May Affect the Navigable Airspace, March, 000. November 0

19 routes (aerial and/or buried) from the transmission ROW to the equipment shelter will be required. Figure - illustrates the plan arrangement of a typical communications sites. Figure -. Typical Communication Site 0. Access Roads The Project will require vehicular access to each structure for the life of the Project. For the purposes of calculating ground disturbance and operational needs, the Project has classified access roads into five categories four of them permanent roads and one of them temporary. Table - summarizes the five categories of roads needed for accessing the transmission line structures for the Project. The largest of the heavy equipment needed, which dictates the minimum needed road dimensions, is a truck-mounted aerial lift crane with 00,000 pounds gross vehicle weight, -by- drive, and a 0-foot telescoped boom. To accommodate this equipment, the road specifications require a -foot-wide travel surface and - to 0-foot-wide travel surface for horizontal curves (Figure -). The required travel way in areas of rolling to hilly terrain will require a wider disturbance to account for cuts and fills. In addition, IPC plans to conduct maintenance using live-line maintenance techniques, thereby avoiding an outage to the critical transmission line infrastructure. High-reach bucket trucks along with other equipment will be used to conduct these activities. 0 November 0

20 Table -. Access Road Requirements for Transmission Line System Non-Routine Road Operations Category Construction Use Routine Operations Use Use Existing roads requiring no No change No change No change improvement Existing roads requiring improvement New roads - Bladed - Overland Travel - Overland Travel with Clearing ATV Trails ATV access to helicopter sites Temporary roads Access to laydown and fly yards Access for construction, pulling and tension Surfaced and unsurfaced - foot-wide straight sections of road and - to 0-foot-wide sections at corners. Heavy machinery used as needed to ensure safe operation and access of vehicles. New surfaced and un-surfaced, -foot-wide straight sections of road and - to 0-foot-wide sections at corners. Bladed Roads may be constructed to access structures in steep or uneven terrain. Used on sideslopes greater than %. Overland Travel Routes created by direct vehicle travel over low growth vegetation ; or with minor clearing and grading using heavy machinery to remove larger vegetation or other obstructions as needed to ensure safe operation and access of vehicles. Unsurfaced -foot-wide straight sections of road and - to 0- foot-wide sections at corners. -foot-wide straight sections of road and - to 0-foot-wide sections at corners. For routine activities, an -foot portion of the authorized road will be used and vehicles will drive over the vegetation and brush where safe and practicable. Vegetation that may interfere with the safe operation of vehicles will be removed as necessary. For routine activities, an -foot portion of the road will be used and vehicles will drive over the vegetation where safe and practicable. Vegetation that may interfere with the safe operation of vehicles will be removed as necessary. For routine activities, an -foot portion of the road will be used and vehicles will drive over the vegetation where safe and practicable. Vegetation that may interfere with the safe operation of vehicles will be removed as necessary. None contours will be restored, and the road will be ripped and seeded. For nonroutine maintenance requiring access by larger vehicles the full width of the access road may be used. Access roads will be maintained, as necessary, but will not be routinely graded. None None November 0

21 Figure -. Typical Road Sections for Different Terrains November 0

22 0 Waterbody Crossings with Access Roads: Access roads will be constructed to minimize disruption of natural drainage patterns including perennial, intermittent and ephemeral streams. In order to estimate the impact on stream crossings, an assessment of stream crossing types was made based on preliminary engineering plans. These are conservative estimates using consistent quantitative descriptions for each crossing method. As the engineering plans are advanced for new access roads, site specific crossings will be designed and crossing disturbance will vary. On all federally managed lands, IPC will consult with the managing agency regarding relevant standards and guidelines pertaining to road crossing methods at waterbodies. Consultation will include site assessment, design, installation, maintenance, and decommissioning. New crossings of canals, ditches and perennial streams will be avoided to the extent practical by using existing crossings, but some new crossings are expected. The performance of stream crossings will be monitored for the life of the access road, and maintained or repaired as necessary to protect water quality. Four types of waterbody crossings are considered as part of the Project (Figure - through Figure -). They are: Type Drive through with or without minor grading and/or minimal fill to match existing stream profile: Crossing of a seasonally dry channel with minimal grading and/or fill to repair surface ruts or re-contour minor surface erosion (Figure -). 0 Figure -. Type Drive Through Stream Crossing Methods Type Drive through/ Ford: Crossing of a channel that includes grading and stabilization. Stream banks and approaches would be graded to allow vehicle passage and stabilized with rock, geotextile fabric or other erosion control devices. The stream bed would in some areas be reinforced with coarse rock material, where approved by the land-management agency, to support vehicle loads, prevent erosion and minimize sedimentation into the waterway. The rock would be installed in the stream bed such that it would not raise the level of the streambed, thus allowing continued movement of water, fish and debris. Fords may be constructed in small, shallow streams (less than November 0

23 0 0 stream depth and 0 active stream width) and rocky substrates. Fords may also be appropriate on wider streams when they have a poorly defined channel that often changes course from excessive bedload. A ford crossing results in an average disturbance profile of feet wide (along the water body) and 0 feet long (along the roadway) for,000 square feet or 0.0 acre at each crossing. Disturbance amount is estimated based on need to get equipment into the riparian area to build the -footwide travel way and protect it from erosion by adding armoring. Flowing streams may warrant temporary structures to maintain fish passage, hydrology and water quality to span active the channel during construction activities (Figure -0). Type Culvert: Crossing of a stream or seasonal drainage that includes installation of a culvert and a stable road surface established over the culvert for vehicle passage. Culverts would be designed and installed under the guidance of a qualified engineer who, in collaboration with a hydrologist and aquatic biologist where required by the land management agency, would recommend placement locations; culvert gradient, height, and sizing; and proper construction methods. Culvert design would consider bedload and debris size and volume. The disturbance footprint for culvert installation is estimated to be 0 feet wide (along the waterbody) and 0 feet long (along the road) for,00 square feet or 0. acre at each crossing. Ground-disturbing activities would comply with Agency-approved BMPs. Construction would occur during periods of low flow. The use of equipment in streams would be minimized. All culverts would be designed and installed to meet desired riparian conditions, as identified in applicable unit management plans. Culvert slope would not exceed stream gradient. Typically, culverts would be partially buried in the streambed to maintain streambed material in the culvert. Sandbags or other non-erosive material would be placed around the culverts to prevent scour or water flow around the culvert. Adjacent sediment control structures such as silt fences, check dams, rock armoring, or riprap may be necessary to prevent erosion or sedimentation. Stream banks and approaches may be stabilized with rock or other erosion control devices (Figure -0). November 0

24 TYPE CULVERT 0 Figure -0. Type and Type Crossing Methods Type Channel spanning structures including fish passage: Crossing of a water body identifies as containing a sensitive fish species that includes installation of a large diameter culvert, arch culvert or short span bridge and a stable road surface established over the structure for vehicle passage. Channel spanning structures would be designed and installed under the guidance of a qualified engineer who, in collaboration with a hydrologist and aquatic biologist would recommend placement locations; structure gradient, height, and sizing; and proper construction methods. The disturbance footprint for channel spanning structure installation is estimated to be 0 feet wide (along the November 0

25 water body) and 0 feet long (along the road) for,000 square feet or 0. acre at each crossing. (Figure -). Figure -. Type Channel Spanning Structures Including Fish Passage November 0

26 Wetlands Crossings with Access Roads: During construction and for routine and emergency operations, access across wetlands to individual structure locations may be necessary. Selection of final wetland crossing techniques will be based on final access road alignment and wetland characteristics:. Constructing at grade roads with geotextiles and road materials which allow for water through-flow. This type of road will be below water during certain times of the year which will make locating the roads difficult, and the depth of the water over the drivable surface may make travel over the submerged road surface impractical or not feasible.. Limiting structure access across wetlands to dry or frozen conditions along with the use of low ground pressure tires or specialized tracked vehicles. This approach does not allow sufficient flexibility for emergency restoration and for operation and maintenance as the depth of water and/or soil conditions will not allow access to the structures during certain times of the year. Construction of ice roads in wetlands involves using lightweight equipment such as snowmobiles to tamp down existing snow cover and vegetation to allow penetration of frost into the wetland soils. This operation is followed by packing with heavier tracked equipment such as Bombardiers or wide tracked dozers. There is a relatively small window of time during the year where cold enough weather is present to allow for this technique thereby restricting the flexibility required for operation and maintenance in other seasons besides winter.. Installing temporary matting materials to allow access for heavy vehicles and equipment. The mats typically come in the form of heavy timbers bolted together or interlocking pierced-steel planks. Mats spread the concentrated axle loads from equipment over a much larger surface area thereby reducing the bearing pressure on fragile soils. However, mats are less effective when standing water is present. Matting has a limited service life before replacement is required and must be stored for maintenance and emergency restoration activities.. Constructing raised fill embankments for permanent above-grade access roads in wetlands such that the travel surface is higher in elevation than the ordinary high water level. The construction of above-grade access roads allows for the use of the types of equipment described above and the most flexibility for construction. All waterbody and wetland disturbances will be completed under the terms of a U.S. Army Corps of Engineers Clean Water Act Section 0 permit, the National Pollutant Discharge Elimination System Construction Stormwater Permit (Clean Water Act 0), and State 0 water quality certification requirements that govern activities within any waters of the United States. In Idaho, there is an additional requirement for a stream channel alteration permit.. Construction using helicopters in wetlands. Transmission tower structures proposed for the Project could be erected by helicopter, if needed. However, in each case, the use of ground based vehicles will still be required and will not eliminate the need for an access road to each structure to complete construction or during inspections and live-line maintenance activities. November 0 0

27 0 0. Substations The Project includes expansion at one planned (Grassland) and one existing (Hemingway) substation... Substation Components The following sections describe key components of substations.... Bay A substation bay is the physical location within a substation fenced area where the highvoltage circuit breakers and associated steel transmission line termination structures, highvoltage switches, bus supports, controls, and other equipment are installed. For each transmission line, 00-kV circuit breakers, high-voltage switches, bus supports, and transmission line termination structures would typically be installed. The 00-kV transmission line termination structures are approximately to feet tall. The tallest structures in the substations will be the 00-kV dead-end structures, from to feet tall, and/or a microwave antenna tower, which will be in the range of 00 feet or more, depending on the height needed to maintain line of sight to the nearest microwave relay site. Figure - is a perspective sketch illustrating the appearance of a typical 00-kV substation with multiple line connections.... Access Road Permanent all-weather access roads are required at substation sites to provide access for personnel, material deliveries, vehicles, trucks, heavy equipment, low-boy tractor trailer rigs (used for moving large transformers), and ongoing maintenance activities at each site. Substation access roads are normally well-compacted, graded gravel roads approximately 0 feet in width with a minimum 0-foot turning radius to accommodate the delivery of large transformers to the site. No new access roads are necessary for access to the Grassland and Hemingway substation locations. November 0

28 Figure -. Typical 00-kV Substation Control Building One or more control buildings are required at each substation to house protective relays, control devices, battery banks for primary control power, and remote monitoring equipment. The size and construction of the building depends on individual substation requirements. Typically, the control building will be constructed of concrete block, pre-engineered metal sheathed, or composite surfaced materials. Special control buildings may be developed within the substation developments to house other control and protection equipment.... Fencing and Landscaping Security fencing will be installed around the entire perimeter of each new or expanded substation to protect sensitive equipment and prevent accidental contact with energized conductors by third parties. This -foot-high fence will be constructed of chain link with steel posts, with one foot of barbed wire above the chain link, and with locked gates. If required by the landowner or permitting agency, landscaping will be established using drought-resistant vegetation where allowed. The Hemingway Substation is already fenced... Distribution Supply Lines Station service power will be required at each substation or communication sites. Typically, station service power is provided from a local electric distribution line, located in proximity to the substation or communication site. The voltage of the distribution supply line is typically.-kv or lower and carried on wood poles. For the Grassland Substation, it will be necessary to extend the electric distribution line from a suitable take-off point on the existing distribution line to the new substation site. The location and routing of the existing distribution lines to the new November 0

29 0 0 0 substation will be determined during the final design process. The distance from Grassland Substation to the nearest existing distribution supply is approximately,000 feet. The Hemingway Substation exists and new distribution line extensions to provide station service power will not be required. However, modifications to the existing distribution facilities may be necessary to provide increased capacity to support the expansions at the existing Hemingway Substation..0 SYSTEM CONSTRUCTION The following section and subsections detail construction activities for the Project, including transmission line, substation communication, and associated ancillary features.. Land Requirements and Disturbance.. Right-of-Way Width IPC proposes to acquire a permanent 0-foot-wide ROW for the 00-kV single-circuit sections of the Project and a 00-foot-wide ROW for the /-kv portions of the Project. Figure - illustrates the ROW width requirements for the proposed structures. The determination of these widths is based on two criteria: Sufficient clearance must be maintained during a high wind event when the conductors are blown towards the ROW edge. Sufficient room must be provided within the ROW to perform transmission line maintenance. See Section. of this appendix for details of maintenance requirements. Table - provides a breakdown of the amount of land needed temporarily for construction and for operation over the life of the Project. During construction, temporary permission will be required from landowners and land management agencies during construction for off-row access, staging areas, helicopter fly yards, and material storage. During operation, Project land requirements will be restricted to the ROW, substations, and communication facilities. Access to the ROW will be in accordance with the land rights obtained as part of the easement acquisition process. As further details of the final Project design are engineered, the amount of land required may change. Table -. Summary of Land Required for Construction and Operations Land Required for Construction (acres) Land Required for Operations (acres) Division by County Morrow County T-Line ROW,.,. Off-ROW Staging Area. 0 Off-ROW Fly Yards. 0 Off ROW Wire Pulling/Splicing Sites 0. 0 Off-ROW Access Roads.. OPGW Communication Sites () Grassland Substation County Total Segment Subtotal,.,0. November 0

30 Table -. Summary of Land Required for Construction and Operations (continued) Land Required for Land Required for Operations Division by County Construction (acres) (acres) Umatilla County T-Line ROW,.,. Off-ROW Staging Area. 0 Off-ROW Fly Yards. 0 Off ROW Wire Pulling/Splicing Sites 0. 0 Off-ROW Access Roads.. OPGW Communication Sites () County Total Segment Subtotal,.,. Union County T-Line ROW,.,. Off-ROW Staging Area. 0 Off-ROW Fly Yards 0. 0 Off ROW Wire Pulling/Splicing Sites. 0 Off-ROW Access Roads.0.0 OPGW Communication Sites () County Total Segment Subtotal,0.,. Baker County T-Line ROW,.,. Off-ROW Staging Area. 0 Off-ROW Fly Yards. 0 Off ROW Wire Pulling/Splicing Sites. 0 Off-ROW Access Roads. 0. OPGW Communication Sites () County Total Segment Subtotal,.,. Malheur County T-Line ROW,.,. Off-ROW Staging Area. 0 Off-ROW Fly Yards.0 0 Off ROW Wire Pulling/Splicing Sites 0. 0 Off-ROW Access Roads.0. OPGW Communication Sites () County Total Segment Subtotal,.,. Owyhee County T-Line ROW Off-ROW Staging Area. 0 Off-ROW Fly Yards. 0 Off ROW Wire Pulling/Splicing Sites. 0 Off-ROW Access Roads.. Hemingway Substation.0.0 County Total Segment Subtotal. 0. November 0

31 Table -. Summary of Land Required for Construction and Operations (continued) Land Required for Land Required for Operations Division by County Construction (acres) (acres) Total Project Transmission line ROW,.,. Off-ROW Staging Area. 0 Off-ROW Fly Yards. 0 Off ROW Wire Pulling/Splicing Sites. 0 Off-ROW Access Roads.. OPGW Communication Site(s)..0 Substations.0.0 Total Project,0.,. Assumptions/Notes:. The exact land requirements would depend on the final detailed design of the transmission line, which is influenced by the terrain, land use, and economics. Alignment options may also slightly increase or decrease these values.. ROW width for 00-kV single circuit is 0 feet.. ROW width for /-kv double-circuit is 00 feet.. The dimensions of the tower construction pads and area permanently occupied by towers after restoration are based on the dimensions specified in Figure -.. The staging areas would serve as field offices, reporting locations for workers, parking space for vehicles and equipment, sites for material storage, fabrication assembly, equipment maintenance, and concrete batch plants. Staging/material storage yards/batch plants would be approximately 0 acres for 00-kV lines. They would be located every 0 to 0 miles along the line.. Fly yards would be 0 to acres located every to 0 miles. Values in table assume helicopter construction throughout all single-circuit 00-kV lines. The construction contractor may choose to construct using ground-based techniques, therefore, not utilizing fly yards.. Typical wiring pulling/splicing sites would be the ROW width x 00 to 00 feet located every to miles. Typically, the only sites that would be off of the ROW would be at large-angle dead-ends. It is estimated that one in four sites would be off of the ROW.. Miles of access road are based on an indicative layout of access roads along the current preferred route as of the date of this document... Right-of-Way Acquisition All portions of the route must obtain new ROWs through a combination of ROW grants and easements between IPC and various federal, state, and local governments; other companies (e.g., utilities and railroads), and private landowners. Close coordination with all property owners and land agencies during initial surveys and the construction phase of the Project is essential for successful completion of the Project. In the early stages of the Project, landowners will be contacted to obtain right-of-entry for surveys and for geotechnical drilling at selected locations. Each landowner along the final centerline route will be contacted to explain the Project and to secure right-of-entry and access to the ROW. All negotiations with landowners will be conducted in good faith, and the Project s effect on the parcel or any other concerns the landowner may have will be addressed. ROWs for transmission line facilities on private lands will be obtained as perpetual easements. Land for substation or communication sites will be obtained in fee simple where located on private land. Every effort will be made to purchase the land and/or obtain easements on private lands through reasonable negotiations with the landowners. Section.. of the POD describes North American Electricity Reliability Corporation (NERC) and Western Electricity Coordinating Council (WECC) reliability standards and capacity needs for the Project. To achieve the capacity needed to serve present and future loads within IPC s service areas, the WECC requires a minimum separation from existing transmission lines that serve substantially the same load as that served by the new Boardman to Hemingway transmission project. In these cases, the Project transmission lines must be located at least November 0

32 0,00 feet as a general rule from the nearest existing 0 kv or higher-voltage transmission lines or the length of the longest span where the two lines are adjacent to each other. Land between ROWs that are separated to meet reliability criteria will not be encumbered with an easement but could practically be limited in land uses due to the proximity of two or more large transmission lines... Land Disturbance Land disturbance as described in Table - is the estimated amount of land that will be disturbed during construction or required to be permanently converted to operational uses. The areas are reported by county. These uses are less than the amount of land for which operational controls are required over the life of the Project as described in Table -. Table -. Summary of Land Disturbed during Construction and Used during Permanent Operations Land Affected During Construction (acres) Land Affected During Operations (acres) Segment/Project Component Morrow County Single Circuit 00-kV Pad 0.0. On ROW Pulling/Tensioning Sites. 0 ON ROW Construction Roads.. Off ROW Pulling/Tensioning Sites 0. 0 Off ROW Access Roads.. Staging Yards. 0 Fly Yards. 0 Communications Station () Grassland Substation County Total Segment Subtotal.. Umatilla County Single Circuit 00-kV Pad.. On ROW Pulling/Tensioning Sites. 0 ON ROW Construction Roads.. Off ROW Pulling/Tensioning Sites 0. 0 Off ROW Access Roads.. Staging Yards. 0 Fly Yards. 0 Communications Station () County Total Segment Subtotal.0. November 0