Transmission Line and Substation Components

Appendix BTransmission Line and Substation Components

Prepared by: Idaho Power Company 1221 W Idaho Street Boise, ID 83702

November 2011

Transmission Line and Substation Components Appendix B

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TABLE OF CONTENTS 11.0 PROJECT FACILITIES ........................................................................................................ 12

1.1 Transmission Structures .............................................................................................. 131.1.1 Types of Transmission Line Support Structures .............................................. 141.1.2 Structure and Conductor Clearances .............................................................. 851.1.3 Structure Foundations ..................................................................................... 86

1.2 Conductors .................................................................................................................. 971.3 Other Hardware ......................................................................................................... 108

1.3.1 Insulators ....................................................................................................... 1091.3.2 Grounding Systems ....................................................................................... 10101.3.3 Minor Additional Hardware ............................................................................ 1111

1.4 Communication Systems ........................................................................................... 12121.4.1 Optical Ground Wire ...................................................................................... 12131.4.2 Communications Stations .............................................................................. 1214

1.5 Access Roads ........................................................................................................... 13151.6 Substations................................................................................................................ 2116

1.6.1 Substation Components ................................................................................ 21171.6.2 Distribution Supply Lines ............................................................................... 2218

2.0 SYSTEM CONSTRUCTION .............................................................................................. 23192.1 Land Requirements and Disturbance ........................................................................ 2320

2.1.1 Right-of-Way Width ....................................................................................... 23212.1.2 Right-of-Way Acquisition ............................................................................... 25222.1.3 Land Disturbance .......................................................................................... 2623

2.2 Transmission Line Construction ................................................................................ 32242.2.1 Transmission Line System Roads ................................................................. 32252.2.2 Soil Borings ................................................................................................... 34262.2.3 Staging Areas ................................................................................................ 34272.2.4 Site Preparation ............................................................................................. 35282.2.5 Install Structure Foundations ......................................................................... 35292.2.6 Erect Support Structures ............................................................................... 36302.2.7 String Conductors, Shield Wire, and Fiber Optic Ground Wire ..................... 37312.2.8 Cleanup and Site Reclamation ...................................................................... 3932

2.3 Communication System ............................................................................................ 39332.3.1 Communication Sites ..................................................................................... 39342.3.2 Access Road ................................................................................................. 3935

2.4 Substation Construction ............................................................................................ 39362.4.1 Substation Roads .......................................................................................... 40372.4.2 Soil Borings ................................................................................................... 40382.4.3 Clearing and Grading .................................................................................... 40392.4.4 Storage and Staging Yards ........................................................................... 40402.4.5 Grounding ...................................................................................................... 40412.4.6 Fencing .......................................................................................................... 40422.4.7 Foundation Installation .................................................................................. 41432.4.8 Oil Containment ............................................................................................. 41442.4.9 Structure and Equipment Installation ............................................................. 41452.4.10 Conduit and Control Cable Installation .......................................................... 42462.4.11 Construction Cleanup and Landscaping ........................................................ 4247

2.5 Special Construction Techniques .............................................................................. 4248


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2.5.1 Blasting .......................................................................................................... 4212.5.2 Helicopter Use ............................................................................................... 4422.5.3 Water Use ...................................................................................................... 453

2.6 Construction Elements .............................................................................................. 4542.6.1 Construction Workforce ................................................................................. 4652.6.2 Construction Equipment and Traffic .............................................................. 4762.6.3 Removal of Facilities and Waste Disposal .................................................... 5072.6.4 Construction Schedule .................................................................................. 508

3.0 SYSTEM OPERATIONS AND MAINTENANCE ................................................................ 5493.1 Routine System Operations and Maintenance .......................................................... 5410

3.1.1 Routine System Inspection, Maintenance, and Repair .................................. 54113.1.2 Transmission Line Maintenance .................................................................... 55123.1.3 Hardware Maintenance and Repairs ............................................................. 57133.1.4 Access Road and Work Area Repair ............................................................. 60143.1.5 Vegetation Management ............................................................................... 60153.1.6 Noxious Weed Control ................................................................................... 62163.1.7 Substation and Communication Site Maintenance ........................................ 6217

3.2 Emergency Response ............................................................................................... 63183.2.1 Fire Protection ............................................................................................... 6319

4.0 DECOMMISSIONING ........................................................................................................ 6520

21

LIST OF TABLES 22Table 1-1. Proposed Structure Characteristics .................................................................. 823Table 1-2. Foundation Excavation Dimensions ................................................................. 924Table 1-3. Proposed Communications Station Locations ................................................ 1225Table 1-4. Access Road Requirements for Transmission Line System ........................... 1426Table 2-1. Summary of Land Required for Construction and Operations ........................ 2327Table 2-2. Summary of Land Disturbed during Construction and Used during Permanent 28

Operations ...................................................................................................... 2629Table 2-3. Miles of New and Improved off-ROW Access Roads ..................................... 3330Table 2-4. Miles of New and Improved Access Roads1 ................................................... 3431Table 2-5. Construction Staging Areas and Helicopter Fly Yards .................................... 3532Table 2-6. Summary of Shallow Bedrock ......................................................................... 4333Table 2-7. Estimated Water Usage for Construction by County ...................................... 4534Table 2-8. Projected Workers and Population Change during Peak Construction .......... 4635Table 2-9. Transmission Line Construction Equipment Requirements ............................ 4736Table 2-10. Equipment Requirements for Grassland and Hemingway Substations .......... 4837Table 2-11. Average and Peak Construction Traffic (per spread) ..................................... 4938Table 2-12. Solid Waste Generation from Construction Activities ..................................... 5039

40


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LIST OF FIGURES 1Figure 1-1. Proposed 500-kV Single Circuit Lattice Steel Structure ................................... 22Figure 1-2. Proposed 500-kV Single Circuit Tubular Steel Pole H-frame Structure ............ 33Figure 1-3. Proposed 138/69-kV Double Circuit Structure with Distribution Underbuild ..... 44Figure 1-4. Proposed ROW Designs ................................................................................... 55Figure 1-5. Alternative 500-kV Single Shaft Steel Pole Structure ....................................... 66Figure 1-6. Alternative ROW Design ................................................................................... 77Figure 1-7. Typical Communication Site ........................................................................... 138Figure 1-8. Typical Road Sections for Different Terrains .................................................. 159Figure 1-9. Type 1 Drive Through Stream Crossing Methods .......................................... 1610Figure 1-10. Type 2 and Type 3 Crossing Methods ............................................................ 1811Figure 1-11. Type 4 Channel Spanning Structures Including Fish Passage .................... 1912Figure 1-12. Typical 500-kV Substation .............................................................................. 2213Figure 2-1. Disturbance Area for Tower Structures .......................................................... 2914Figure 2-2. Typical Disturbance Area ................................................................................ 3015Figure 2-3. Example Access Roads and Tower Locations ............................................... 3116Figure 2-4. Transmission Line Construction Sequence .................................................... 3217Figure 2-5. Conductor Installation ..................................................................................... 3718Figure 2-6. Project Construction Schedule ....................................................................... 5219Figure 3-1. Live-line Maintenance Space Requirements, Single-Circuit 500-kV Lattice 20

Tower .............................................................................................................. 5921Figure 3-2. Right-of-Way Vegetation Management ........................................................... 6122

23


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This appendix contains detailed information provided by Idaho Power Company (IPC) regarding 1the components of the transmission system including the transmission structures, the 2communications system, and the substations. It provides details regarding construction of the 3system (Section 2.0), goes on to provide information regarding the operations and maintenance 4of the system (Section 3.0), and finally details the proposed abandonment and restoration 5techniques (Section 4.0). 6

1.0 PROJECT FACILITIES 7

This section describes the various components of the transmission system for the Boardman to 8Hemingway Transmission Line Project (Boardman to Hemingway or Project), including the 9structures themselves, the conductors used, other hardware needed, the communication 10system, the access roads, and finally the substations. Both the proposed and alternative 11structures are described herein 12

1.1 Transmission Structures 131.1.1 Types of Transmission Line Support Structures 14The majority of the proposed transmission line circuits will be supported by steel single-circuit 15steel lattice towers. Figure 1-1 illustrates the typical tangent lattice tower structure configuration. 16In some instances, single-circuit tubular steel H-frame structures will be used where required to 17mitigate sensitive environmental resources or where land use requires shorter structure heights. 18Figure 1-2 illustrates a tangent tubular steel H-frame structure. Figure 1-3 provides an 19illustration of a typical 138/68-kilovolt (kV) structure with 12.5-kV underbuild distribution that 20would be used for approximately 5.3 miles.121

Tangent structures are primarily used in straight line segments and are the most common type 22of structure. Running angles are used when a transmission line changes direction up to a 23specified threshold line angle. Dead-end structures are needed for extremely long spans, when 24the line angle exceeds the threshold of a running angle tower, in highly varied terrain which can 25create uplift conditions, or when there is a need for a failure containment structure. Angle and 26dead-end structures are heavier and require larger foundations. 27

Figure 1-4 illustrates the right-of-way (ROW) design configurations for proposed structures. 28

29

1 Of the 5.3 miles, 0.3 miles would be a 138-kV single-circuit which because of its limited extent, is not further discussed in thisdocument.


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1

Figure 1-1. Proposed 500-kV Single Circuit Lattice Steel Structure 2

3


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1

Figure 1-2. Proposed 500-kV Single Circuit Tubular Steel Pole H-frame Structure2

3


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1

2

Figure 1-3. Proposed 138/69-kV Double Circuit Structure with Distribution 3Underbuild4


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1

Figure 1-4. Proposed ROW Designs 2

3


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Figure 1-5 presents the configuration of the alternative 500-kV monopole structure which could 1be used in active agricultural areas where location is critical to farming operations. Figure 1-6 2illustrates the alternative ROW design configuration. 3

4

Figure 1-5. Alternative 500-kV Single Shaft Steel Pole Structure 5


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1

Figure 1-6. Alternative ROW Design 2

3

1.1.1.1 Proposed 500-kV Single Circuit Galvanized Lattice Steel Structures 4Lattice steel towers will be fabricated with galvanized steel members treated to produce a dulled 5galvanized finish. The average distance between 500-kV towers will be 1,200 to 1,300 feet. 6Structure heights will vary depending on terrain and the requirement to maintain minimum 7conductor clearances from ground. The 500-kV single-circuit towers will vary in height from 110 8to 195 feet. 9

1.1.1.2 Proposed 500-kV Single Circuit Tubular Steel H-Frame Structures 10The 500-kV H-frame structures will be fabricated with self-weathering tubular steel treated to 11produce a rust-like finish. The average distance between 500-kV H-frames will be 1,200 to 121,300 feet. Structure heights will vary depending on terrain and the requirement to maintain 13minimum conductor clearances from ground. The 500-kV H-frame structures will vary in height 14from 100 to 165 feet. 15

1.1.1.3 Proposed 138/69-kV Double Circuit Galvanized Monopole Structures 16Monopole structures will be fabricated with self-weathering steel treated to produce a rust-like 17finish. The average distance between 138/69-kV towers will be 350 feet. Structure heights will 18vary depending on terrain and the requirement to maintain minimum conductor clearances from 19ground. The 138/69-kV double-circuit towers will vary in height from 55 to 100 feet. 20

1.1.1.4 Alternative 500-kV Single Circuit Monopole Structures 21The alternative 500-kV Monopole structures if use would be fabricated with self-weathering 22tubular steel treated to produce a rust-like finish. The average distance between 500-kV 23Monopoles would be 800 to 1,000 feet. Structure heights would vary depending on terrain and 24the requirement to maintain minimum conductor clearances from ground. The 500-kV Monopole 25structures would vary in height from 120 to 130 feet. 26

Table 1-1 describes the number and type of structures by typical height, typical distances 27between structures, and temporary and permanent disturbance areas by structure. 28

2930


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Table 1-1. Proposed Structure Characteristics 1

Structure Type

Typical Height (feet)

No. of Structures1/

Average Distance Between

Structures1(feet)

Short Term Disturbance

Area per structure (sq. feet.)

Long Term Disturbance

Area per structure (sq. feet.)

500-kV Single Circuit Lattice Structure

110-195 1,228 1,200-1,300 ROW Width 250 feet x 250 feet = 1.43 acre

ROW Width 50 feet x 50 feet = 0.06 acre

500-kV Single Circuit H-Frame Structure

100-165 75 900-1,300 ROW Width 250 feet x 250 feet = 1.43 acre

ROW Width 50 feet x 50 feet = 0.06 acre

138/69-kV Double Circuit Monopole Structure

55-100 72 350 ROW Width 100 feet x 100 feet = 0.23 acre

ROW Width 50 feet x 50 feet =


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Table 1-2. Foundation Excavation Dimensions 1

Proposed Structures Number of Structures

Holes Per Structure

Depth (feet)

Diameter(feet)

Concrete (cubicyards)

500-kV Single Circuit - Light Tangent Lattice Tower 964 4 15 4 28 500-kV Single Circuit - Heavy Tangent Lattice Tower 82 4 18 5 52 500-kV Single Circuit - Small Angle Lattice Tower 12 4 16 6 68 500-kV Single Circuit - Medium Angle Lattice Tower 27 4 21 6.5 104 500-kV Single Circuit - Medium Dead-End Lattice Tower1

103 4 28 7 160

500-kV Single Circuit - Heavy Dead-End Lattice Tower

40 4 30 7 172

500-kV Single Circuit Tangent H-Frame Structure 61 2 25 6 53 500-kV Single Circuit Angle H-Frame Structure 8 3 30 7 129 500-kV Single Circuit Dead-end H-Frame Structure 6 3 40 8 224 138/69-kV Double Circuit - Monopole Tangent Structure

37 1 15 5 N/A

138/69-kV Double Circuit - Monopole Angle Structure 5 1 20 5 15 138/69-kV Double Circuit - Monopole Dead-end Structure

30 1 25 6 27

1 Dead-end structure typically refers to a structure that is placed at a point where the transmission line turns direction. 2

1.2 Conductors 3The proposed conductor for the 500-kV lattice structure lines is 1,272 KCM2 45/7 ACSR Bittern 445/73. Each phase of a 500-kV three-phase circuit4 will be composed of three subconductors in 5a triple bundle configuration. The individual 1,272 KCM conductors will be bundled in a 6triangular configuration with spacing of 25 inches between horizontal subconductors and 18 7inches of diagonal separation between the top two conductors and the lower conductor (see 8Figure 1-1). The triple-bundled configuration is proposed to provide adequate current carrying 9capacity and to provide for a reduction in audible noise and radio interference as compared to a 10single large-diameter conductor. Each 500-kV subconductor will have a 45/7 aluminum/steel 11stranding, with an overall conductor diameter of 1.345 inches and a weight of 1.432 pounds per 12foot and a non-specular finish5.13

The proposed conductor for the 138/69-kV monopole structure lines is 397 KCM 26/7 ACSR 14Ibis (138KV, one conductor per phase), 4/0 6/1 ACSR Penguin (69 KV, one conductor per 15phase), No. 4 Copper Conductor (12.5-kV Distribution, one conductor per phase plus neutral 16wire), and a 3/8 EHS 7-strand shield wire. Conductors will be aligned with typical vertical 17spacing of 8 feet between shield wire and 69 or 138 KV phase wires, 6 feet between phase 18wires, and a minimum of 12 feet between 138 or 69 KV phase wires and distribution wires. 19

Where multiple conductors are utilized in a bundle for each phase, the bundle spacing will be 20maintained through the use of conductor spacers at intermediate points along the conductor 21bundle between each structure. The spacers serve a dual purpose: in addition to maintaining 22

2 KCM (1,000 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 (0.001) of an inch.

3 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., 45/7 aluminum/steel stranding has 45 aluminum strands wound around 7 steel strands).

4 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.

5 Non-specular finish refers to a dull finish rather than a shiny finish.


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the correct bundle configuration and spacing, the spacers are also designed to damp out wind-1induced vibration in the conductors. The number of spacers required in each span between 2towers will be determined during the final design of the transmission line. 3

1.3 Other Hardware 41.3.1 Insulators 5As shown in Figure 1-1 and Figure 1-2, the typical insulator assemblies for 500-kV steel lattice 6tangent structures and H-frame structures will consist of two insulators hung in the form of a V. 7As shown in Figure 1-3, insulator assemblies for 138/69-kV tangent structures will consist of 8supported insulators which extend horizontally away from the monopole. Insulators are used to 9suspend each conductor bundle (phase) from the structure, maintaining the appropriate 10electrical clearance between the conductors, the ground, and the structure. The V-shaped 11configuration of the 500-kV insulators also restrains the conductor so that it will not swing into 12the structure in high winds. Dead-end insulator assemblies for the transmission lines will use an 13I-shaped configuration, which consists of insulators hung from either a tower dead-end arm or a 14dead-end pole in the form of an I. Insulators will be composed of grey porcelain or green-tinted 15toughened glass. 16

1.3.2 Grounding Systems 17Alternating current (AC) transmission lines such as the Project transmission lines have the 18potential to induce currents on adjacent metallic structures such as transmission lines, railroads, 19pipelines, fences, or structures that are parallel to, cross, or are adjacent to the transmission 20line. Induced currents on these facilities will occur to some degree during steady-state operating 21conditions and during a fault condition on the transmission line. For example, during a lightning 22strike on the line, the insulators may flash over, causing a fault condition on the line and current 23will flow down the structure through the grounding system (i.e., ground rod or counterpoise) and 24into the ground. The magnitude of the effects of the AC induced currents on adjacent facilities is 25highly dependent on the magnitude of the current flows in the transmission line, the proximity of 26the adjacent facility to the line, and the distance (length) for which the two facilities parallel one 27another in proximity. 28

The methods and equipment needed to mitigate these conditions will be determined through 29electrical studies of the specific situation. As standard practice and as part of the design of the 30Project, electrical equipment and fencing at the substation will be grounded. All fences, metal 31gates, pipelines, metal buildings, and other metal structures adjacent to the ROW that cross or 32are within the transmission line ROW will be grounded as determined necessary. If applicable, 33grounding of metallic objects outside of the ROW may also occur, depending on the distance 34from the transmission line as determined through the electrical studies. These actions take care 35of the majority of induced current effects on metallic facilities adjacent to the line by shunting the 36induced currents to ground through ground rods, ground mats, and other grounding systems, 37thus reducing the effect that a person may experience when touching a metallic object near the 38line (i.e., reduce electric shock potential). In the case of a longer parallel facility, such as a 39pipeline parallel to the Project over many miles, additional electrical studies will be undertaken 40to identify any additional mitigation measures (more than the standard grounding practices) that 41will need to be implemented to prevent damaging currents from flowing onto the parallel facility, 42and to prevent electrical shock to a person that may come in contact with the parallel facility. 43Some of the typical measures that could be considered for implementation, depending on the 44degree of mitigation needed, could include: 45

x Fault Shields shallow grounding conductors connected to the affected structure 46adjacent to overhead electrical transmission towers, poles, substations, etc. They are 47


November 2011 11

intended to provide localized protection to the structure and pipeline coating during a 1fault event from a nearby electric transmission power system. 2

x Lumped Grounding localized conductor or conductors connected to the affected 3structure at strategic locations (e.g., at discontinuities). They are intended to protect 4the structure from both steady-state and fault AC conditions. 5

x Gradient Control Wires a continuous and long grounding conductor or conductors 6installed horizontally and parallel to a structure (e.g., pipeline section) at strategic 7lengths and connected at regular intervals. These are intended to provide protection 8to the structure and pipeline coating during steady-state and fault AC conditions from 9nearby electric transmission power systems. 10

x Gradient Control Mats typically used for aboveground components of a pipeline 11system, these are buried ground mats bonded to the structure, and are used to 12reduce electrical step and touch voltages in areas where people may come in 13contact with a structure subject to hazardous potentials. Permanent mats bonded to 14the structure may be used at valves, metallic vents, cathodic protection test stations, 15and other aboveground metallic and nonmetallic appurtenances where electrical 16contact with the affected structure is possible. In these cases there is no standard 17solution that will solve these issues every time. Instead, each case must be studied 18to determine the magnitude of the induced currents and the most appropriate 19mitigation given the ground resistivity, distance paralleled, steady-state and fault 20currents, fault clearing times expected on the transmission line, and distance 21between the line and the pipeline, to name a few of the parameters. If the electrical 22studies indicate a need to install cathodic protection devices on a parallel pipeline 23facility, a distribution supply line interconnection may be needed to provide power to 24the cathodic protection equipment.625

During final design of the transmission line, appropriate electrical studies will be conducted to 26identify the issues associated with paralleling other facilities and the types of equipment that will 27need to be installed (if any) to mitigate the effects of the induced currents. 28

1.3.3 Minor Additional Hardware 29In addition to the conductors, insulators, and overhead shield wires, other associated hardware 30will be installed on the tower as part of the insulator assembly to support the conductors and 31shield wires. This hardware will include clamps, shackles, links, plates, and various other pieces 32composed of galvanized steel and aluminum. 33

A grounding system will be installed at the base of each transmission structure that will consist 34of copper or galvanized ground rods embedded into the ground in immediate proximity to the 35structure foundation and connected to the structure by a buried copper lead. When the 36resistance to ground for a grounded transmission structure is greater than a specified 37impedance value with the use of ground rods, counterpoise will be installed to lower the 38resistance to below a specified impedance value. Counterpoise consists of a bare copper-clad 39or galvanized-steel cable buried a minimum of 12 inches deep, extending from structures (from 40one or more legs of structure) for approximately 200 feet within the ROW. 41

Other hardware that is not associated with the transmission of electricity may be installed as 42part of the Project. This hardware may include aerial marker spheres or aircraft warning lighting 43as required for the conductors or structures per Federal Aviation Administration (FAA) 44

6 NACE International. 2003. Grounding Systems. Houston, TX. Available online at http://www.nace.org/content.cfm?parentid=1001&currentID=1001


November 2011 12

regulations.7 Structure proximity to airports and structure height are the determinants of whether 1FAA regulations will apply based on an assessment of wire/tower strike risk. IPC does not 2anticipate that structure lighting will be required because proposed structures will be less than 3200 feet tall and will not be near airports that require structure lighting. 4

1.4 Communication Systems 51.4.1 Optical Ground Wire 6Reliable and secure communications for system control and monitoring is very important to 7maintain the operational integrity of the Project and of the overall interconnected system. 8Primary communications for relaying and control will be provided via the optical ground wire 9(OPGW) that will be installed on the transmission lines; this path is solely for IPC use and will 10not be used for commercial purposes. A secondary communication path may also be developed 11using a power line carrier. No new microwave sites are anticipated for the Project. Updated 12microwave equipment may be installed at the substations. 13

Each structure will have two lightning protection shield wires installed on the structure peaks 14(see Figure 1-1 and Figure 1-2). One of the shield wires will be composed of extra high strength 15steel wire with a diameter of 0. 495 inch and a weight of 0.517 pound per foot. The second 16shield wire will be an OPGW constructed of aluminum and steel, which carries 48 glass fibers 17within its core. The OPGW will have a diameter of 0.646 inch and a weight of 0.407 pound per 18foot. The glass fibers inside the OPGW shield wire will provide optical data transfer capability 19among IPCs facilities along the fiber path. The data transferred are required for system control 20and monitoring.21

1.4.2 Communications Sites 22As the data signal is passed through the optical fiber cable, the signal degrades with distance. 23Consequently, signal communications sites are required to amplify the signals if the distance 24between substations or communications sites exceeds approximately 40 miles. As summarized 25in Table 1-3, a total of eight communications sites will be required. Communication sites will be 26located on private and public lands. 27

Table 1-3. Proposed Communications Site Locations28

County Number Total Construction

Acres Total Operations

Acres Ownership Morrow 1 0.2 0.1 Private Umatilla 1 0.2 0.1 Private Union 1 0.2 0.1 BLM Baker 2 0.5 0.3 Private, BLMMalheur 3 0.7 0.4 2 BLM, 1 Private Owyhee 0 0 0 --

29The typical site will be 100 feet by 100 feet, with a fenced area of 75 feet by 75 feet. A 30prefabricated concrete communications shelter with dimensions of approximately 11.5-foot by 3132-foot by 12-foot-tall will be placed on the site and access roads to the site and power from the 32local electric distribution circuits will be required. An emergency generator with a liquid 33petroleum gas fuel tank will be installed at the site inside the fenced area. Two diverse cable 34

7 U.S. Department of Transportation, Federal Aviation Administration, Advisory Circular AC 70/7460-1K Obstruction Marking and Lighting, August 1, 2000; and Advisory Circular AC 70/7460-2K Proposed Construction or Alteration of Objects that May Affect the Navigable Airspace, March 1, 2000.


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routes (aerial and/or buried) from the transmission ROW to the equipment shelter will be 1required. Figure 1-7 illustrates the plan arrangement of a typical communications sites. 2

3Figure 1-7. Typical Communication Site4

1.5 Access Roads 5The Project will require vehicular access to each structure for the life of the Project. For the 6purposes of calculating ground disturbance and operational needs, the Project has classified 7access roads into five categoriesfour of them permanent roads and one of them temporary. 8Table 1-4 summarizes the five categories of roads needed for accessing the transmission line 9structures for the Project. 10

The largest of the heavy equipment needed, which dictates the minimum needed road 11dimensions, is a truck-mounted aerial lift crane with 100,000 pounds gross vehicle weight, 8-by-128 drive, and a 210-foot telescoped boom. To accommodate this equipment, the road 13specifications require a 14-foot-wide travel surface and 16- to 20-foot-wide travel surface for 14horizontal curves (Figure 1-8). The required travel way in areas of rolling to hilly terrain will 15require a wider disturbance to account for cuts and fills. In addition, IPC plans to conduct 16maintenance using live-line maintenance techniques, thereby avoiding an outage to the critical 17transmission line infrastructure. High-reach bucket trucks along with other equipment will be 18used to conduct these activities. 19

20


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Table 1-4. Access Road Requirements for Transmission Line System 1

RoadCategory Construction Use Routine Operations Use

Non-Routine Operations

Use Existing roads requiring no improvement

No change No change No change

Existing roads requiring improvement

Surfaced and unsurfaced 14-foot-wide straight sections of road and 16- to 20-foot-wide sections at corners. Heavy machinery used as needed to ensure safe operation and access of vehicles.

For routine activities, an 8-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 non-

routine 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.

New roads - Bladed - Overland Travel

- Overland Travel with Clearing

New surfaced and un-surfaced, 14-foot-wide straight sections of road and 16- to 20-foot-wide sections at corners. Bladed Roads may be constructed to access structures in steep or uneven terrain. Used on sideslopes greater than 8%.

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.

For routine activities, an 8-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.

ATV Trails ATV access to helicopter sites

Unsurfaced 8-foot-wide straight sections of road and 8- to 10-foot-wide sections at corners.

For routine activities, an 8-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

Temporary roads Access to laydown and fly yards Access for construction,pulling and tension

14-foot-wide straight sections of road and 16- to 20-foot-wide sections at corners.

Nonecontours will be restored, and the road will be ripped and seeded.

None


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1

Figure 1-8. Typical Road Sections for Different Terrains 2


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Waterbody Crossings with Access Roads: Access roads will be constructed to minimize 1disruption of natural drainage patterns including perennial, intermittent and ephemeral streams. 2In order to estimate the impact on stream crossings, an assessment of stream crossing types 3was made based on preliminary engineering plans. These are conservative estimates using 4consistent quantitative descriptions for each crossing method. As the engineering plans are 5advanced for new access roads, site specific crossings will be designed and crossing 6disturbance will vary. On all federally managed lands, IPC will consult with the managing 7agency regarding relevant standards and guidelines pertaining to road crossing methods at 8waterbodies. Consultation will include site assessment, design, installation, maintenance, and 9decommissioning. New crossings of canals, ditches and perennial streams will be avoided to 10the extent practical by using existing crossings, but some new crossings are expected. The 11performance of stream crossings will be monitored for the life of the access road, and 12maintained or repaired as necessary to protect water quality. Four types of waterbody crossings 13are considered as part of the Project (Figure 1-9 through Figure 1-11). They are: 14

Type 1 Drive through with or without minor grading and/or minimal fill to match existing 15stream profile: Crossing of a seasonally dry channel with minimal grading and/or fill to 16repair surface ruts or re-contour minor surface erosion (Figure 1-9).17

18

Figure 1-9. Type 1 Drive Through Stream Crossing Methods 19Type 2 Drive through/ Ford: Crossing of a channel that includes grading and 20stabilization. Stream banks and approaches would be graded to allow vehicle passage 21and stabilized with rock, geotextile fabric or other erosion control devices. The stream 22bed would in some areas be reinforced with coarse rock material, where approved by 23the land-management agency, to support vehicle loads, prevent erosion and minimize 24sedimentation into the waterway. The rock would be installed in the stream bed such 25that it would not raise the level of the streambed, thus allowing continued movement of 26water, fish and debris. Fords may be constructed in small, shallow streams (less than 2 27


November 2011 17

stream depth and 20 active stream width) and rocky substrates. Fords may also be 1appropriate on wider streams when they have a poorly defined channel that often 2changes course from excessive bedload. A ford crossing results in an average 3disturbance profile of 25 feet wide (along the water body) and 50 feet long (along the 4roadway) for 1,000 square feet or 0.02 acre at each crossing. Disturbance amount is 5estimated based on need to get equipment into the riparian area to build the 14-foot-6wide travel way and protect it from erosion by adding armoring. Flowing streams may 7warrant temporary structures to maintain fish passage, hydrology and water quality to 8span active the channel during construction activities (Figure 1-10). 9

Type 3 Culvert: Crossing of a stream or seasonal drainage that includes installation 10of a culvert and a stable road surface established over the culvert for vehicle passage. 11Culverts would be designed and installed under the guidance of a qualified engineer 12who, in collaboration with a hydrologist and aquatic biologist where required by the land 13management agency, would recommend placement locations; culvert gradient, height, 14and sizing; and proper construction methods. Culvert design would consider bedload 15and debris size and volume. The disturbance footprint for culvert installation is estimated 16to be 50 feet wide (along the waterbody) and 150 feet long (along the road) for 7,500 17square feet or 0.17 acre at each crossing. Ground-disturbing activities would comply with 18Agency-approved BMPs. Construction would occur during periods of low flow. The use 19of equipment in streams would be minimized. All culverts would be designed and 20installed to meet desired riparian conditions, as identified in applicable unit management 21plans. Culvert slope would not exceed stream gradient. Typically, culverts would be 22partially buried in the streambed to maintain streambed material in the culvert. Sandbags 23or other non-erosive material would be placed around the culverts to prevent scour or 24water flow around the culvert. Adjacent sediment control structures such as silt fences, 25check dams, rock armoring, or riprap may be necessary to prevent erosion or 26sedimentation. Stream banks and approaches may be stabilized with rock or other 27erosion control devices (Figure 1-10). 28

29


November 2011 18

12

3Figure 1-10. Type 2 and Type 3 Crossing Methods4

Type 4 Channel spanning structures including fish passage: Crossing of a water 5body identifies as containing a sensitive fish species that includes installation of a large 6diameter culvert, arch culvert or short span bridge and a stable road surface established 7over the structure for vehicle passage. Channel spanning structures would be designed 8and installed under the guidance of a qualified engineer who, in collaboration with a 9hydrologist and aquatic biologist would recommend placement locations; structure 10gradient, height, and sizing; and proper construction methods. The disturbance footprint 11for channel spanning structure installation is estimated to be 60 feet wide (along the 12

TYPE 3 CULVERT


November 2011 19

water body) and 150 feet long (along the road) for 9,000 square feet or 0.2 acre at each 1crossing. (Figure 1-11). 2

34

Figure 1-11. Type 4 Channel Spanning Structures Including Fish Passage5


November 2011 20

Wetlands Crossings with Access Roads: During construction and for routine and emergency 1operations, access across wetlands to individual structure locations may be necessary. 2Selection of final wetland crossing techniques will be based on final access road alignment and 3wetland characteristics: 4

1. Constructing at grade roads with geotextiles and road materials which allow for water 5through-flow. This type of road will be below water during certain times of the year which 6will make locating the roads difficult, and the depth of the water over the drivable surface 7may make travel over the submerged road surface impractical or not feasible. 8

2. Limiting structure access across wetlands to dry or frozen conditions along with the use 9of low ground pressure tires or specialized tracked vehicles. This approach does not 10allow sufficient flexibility for emergency restoration and for operation and maintenance 11as the depth of water and/or soil conditions will not allow access to the structures during 12certain times of the year. Construction of ice roads in wetlands involves using lightweight 13equipment such as snowmobiles to tamp down existing snow cover and vegetation to 14allow penetration of frost into the wetland soils. This operation is followed by packing 15with heavier tracked equipment such as Bombardiers or wide tracked dozers. There is a 16relatively small window of time during the year where cold enough weather is present to 17allow for this technique thereby restricting the flexibility required for operation and 18maintenance in other seasons besides winter. 19

3. Installing temporary matting materials to allow access for heavy vehicles and equipment. 20The mats typically come in the form of heavy timbers bolted together or interlocking 21pierced-steel planks. Mats spread the concentrated axle loads from equipment over a 22much larger surface area thereby reducing the bearing pressure on fragile soils. 23However, mats are less effective when standing water is present. Matting has a limited 24service life before replacement is required and must be stored for maintenance and 25emergency restoration activities. 26

4. Constructing raised fill embankments for permanent above-grade access roads in 27wetlands such that the travel surface is higher in elevation than the ordinary high water 28level. The construction of above-grade access roads allows for the use of the types of 29equipment described above and the most flexibility for construction. All waterbody and 30wetland disturbances will be completed under the terms of a U.S. Army Corps of 31Engineers Clean Water Act Section 404 permit, the National Pollutant Discharge 32Elimination System Construction Stormwater Permit (Clean Water Act 402), and State 33401 water quality certification requirements that govern activities within any waters of the 34United States. In Idaho, there is an additional requirement for a stream channel 35alteration permit. 36

5. Construction using helicopters in wetlands. Transmission tower structures proposed for 37the Project could be erected by helicopter, if needed. However, in each case, the use of 38ground based vehicles will still be required and will not eliminate the need for an access 39road to each structure to complete construction or during inspections and live-line 40maintenance activities. 41


November 2011 21

1.6 Substations 1The Project includes expansion at one planned (Grassland) and one existing (Hemingway) 2substation.3

1.6.1 Substation Components 4The following sections describe key components of substations.5

1.6.1.1 Bay 6A substation bay is the physical location within a substation fenced area where the high-7voltage circuit breakers and associated steel transmission line termination structures, high-8voltage switches, bus supports, controls, and other equipment are installed. For each 9transmission line, 500-kV circuit breakers, high-voltage switches, bus supports, and 10transmission line termination structures would typically be installed. The 500-kV transmission 11line termination structures are approximately 125 to 135 feet tall. 12

The tallest structures in the substations will be the 500-kV dead-end structures, from 125 to 135 13feet tall, and/or a microwave antenna tower, which will be in the range of 100 feet or more, 14depending on the height needed to maintain line of sight to the nearest microwave relay site. 15Figure 1-12 is a perspective sketch illustrating the appearance of a typical 500-kV substation 16with multiple line connections. 17

1.6.1.2 Access Road 18Permanent all-weather access roads are required at substation sites to provide access for 19personnel, material deliveries, vehicles, trucks, heavy equipment, low-boy tractor trailer rigs 20(used for moving large transformers), and ongoing maintenance activities at each site. 21Substation access roads are normally well-compacted, graded gravel roads approximately 2220 feet in width with a minimum 110-foot turning radius to accommodate the delivery of large 23transformers to the site. No new access roads are necessary for access to the Grassland and 24Hemingway substation locations. 25


November 2011 22

1Figure 1-12. Typical 500-kV Substation 2

1.6.1.3 Control Building 3One or more control buildings are required at each substation to house protective relays, control 4devices, battery banks for primary control power, and remote monitoring equipment. The size 5and construction of the building depends on individual substation requirements. Typically, the 6control building will be constructed of concrete block, pre-engineered metal sheathed, or 7composite surfaced materials. Special control buildings may be developed within the substation 8developments to house other control and protection equipment. 9

1.6.1.4 Fencing and Landscaping 10Security fencing will be installed around the entire perimeter of each new or expanded 11substation to protect sensitive equipment and prevent accidental contact with energized 12conductors by third parties. This 7-foot-high fence will be constructed of chain link with steel 13posts, with one foot of barbed wire above the chain link, and with locked gates. If required by 14the landowner or permitting agency, landscaping will be established using drought-resistant 15vegetation where allowed. The Hemingway Substation is already fenced. 16

1.6.2 Distribution Supply Lines 17Station service power will be required at each substation or communication sites. Typically, 18station service power is provided from a local electric distribution line, located in proximity to the 19substation or communication site. The voltage of the distribution supply line is typically 34.5-kV 20or lower and carried on wood poles. For the Grassland Substation, it will be necessary to extend 21the electric distribution line from a suitable take-off point on the existing distribution line to the 22new substation site. The location and routing of the existing distribution lines to the new 23


November 2011 23

substation will be determined during the final design process. The distance from Grassland 1Substation to the nearest existing distribution supply is approximately 4,000 feet. The 2Hemingway Substation exists and new distribution line extensions to provide station service 3power will not be required. However, modifications to the existing distribution facilities may be 4necessary to provide increased capacity to support the expansions at the existing Hemingway 5Substation. 6

2.0 SYSTEM CONSTRUCTION 7

The following section and subsections detail construction activities for the Project, including 8transmission line, substation communication, and associated ancillary features.9

2.1 Land Requirements and Disturbance 102.1.1 Right-of-Way Width 11IPC proposes to acquire a permanent 250-foot-wide ROW for the 500-kV single-circuit sections 12of the Project and a 100-foot-wide ROW for the 138/69-kV portions of the Project. Figure 1-413illustrates the ROW width requirements for the proposed structures. The determination of these 14widths is based on two criteria: 15

x Sufficient clearance must be maintained during a high wind event when the 16conductors are blown towards the ROW edge. 17

x Sufficient room must be provided within the ROW to perform transmission line 18maintenance. See Section 3.1 of this appendix for details of maintenance 19requirements. 20

Table 2-1 provides a breakdown of the amount of land needed temporarily for construction and 21for operation over the life of the Project. During construction, temporary permission will be 22required from landowners and land management agencies during construction for off-ROW 23access, staging areas, helicopter fly yards, and material storage. During operation, Project land 24requirements will be restricted to the ROW, substations, and communication facilities. Access to 25the ROW will be in accordance with the land rights obtained as part of the easement acquisition 26process. As further details of the final Project design are engineered, the amount of land 27required may change. 28

Table 2-1. Summary of Land Required for Construction and Operations29

Division by County Land Required for

Construction (acres) Land Required for Operations

(acres) Morrow County T-Line ROW 1,388.4 1,388.4 Off-ROW Staging Area 39.9 0 Off-ROW Fly Yards 15.3 0 Off ROW Wire Pulling/Splicing Sites 104.8 0 Off-ROW Access Roads 18.6 9.3 OPGW Communication Sites (1) 0.2 0.1 Grassland Substation 30.0 6.0 County Total Segment Subtotal 1,597.2 1,403.8

30


November 2011 24

Table 2-1. Summary of Land Required for Construction and Operations (continued) 1



(acres) Umatilla County T-Line ROW 1,498.2 1,498.2 Off-ROW Staging Area 41.2 0 Off-ROW Fly Yards 44.5 0 Off ROW Wire Pulling/Splicing Sites 140.5 0 Off-ROW Access Roads 71.8 35.9 OPGW Communication Sites (1) 0.2 0.1 County Total Segment Subtotal 1,796.4 1,534.2 Union County T-Line ROW 1,195.2 1,195.2 Off-ROW Staging Area 41.1 0 Off-ROW Fly Yards 103.8 0 Off ROW Wire Pulling/Splicing Sites 38.2 0 Off-ROW Access Roads 72.0 36.0 OPGW Communication Sites (1) 0.2 0.1 County Total Segment Subtotal 1,450.5 1,231.3 Baker County T-Line ROW 2,157.7 2,157.7 Off-ROW Staging Area 43.8 0 Off-ROW Fly Yards 116.1 0 Off ROW Wire Pulling/Splicing Sites 112.3 0 Off-ROW Access Roads 161.5 80.8 OPGW Communication Sites (2) 0.5 0.3 County Total Segment Subtotal 2,591.9 2,238.8 Malheur County T-Line ROW 2,184.3 2,184.3 Off-ROW Staging Area 63.9 0 Off-ROW Fly Yards 134.0 0 Off ROW Wire Pulling/Splicing Sites 120.2 0 Off-ROW Access Roads 163.0 81.5 OPGW Communication Sites (3) 0.7 0.4 County Total Segment Subtotal 2,666.1 2,266.2 Owyhee County T-Line ROW 720.9 720.9 Off-ROW Staging Area 42.5 0 Off-ROW Fly Yards 59.8 0 Off ROW Wire Pulling/Splicing Sites 41.9 0 Off-ROW Access Roads 55.6 27.8 Hemingway Substation 4.0 2.0 County Total Segment Subtotal 924.7 750.7

2


November 2011 25

Table 2-1. Summary of Land Required for Construction and Operations (continued) 1



(acres) Total Project Transmission line ROW 9,145.1 9,145.1 Off-ROW Staging Area 272.4 0 Off-ROW Fly Yards 473.5 0 Off ROW Wire Pulling/Splicing Sites 557.9 0 Off-ROW Access Roads 542.5 271.3 OPGW Communication Site(s) 1.8 1.0 Substations 34.0 8.0

Total Project 11,027.2 9,425.4 Assumptions/Notes: 21. The exact land requirements would depend on the final detailed design of the transmission line, which is influenced by the 3

terrain, land use, and economics. Alignment options may also slightly increase or decrease these values. 42. ROW width for 500-kV single circuit is 250 feet. 53. ROW width for 138/69-kV double-circuit is 100 feet. 64. The dimensions of the tower construction pads and area permanently occupied by towers after restoration are based on the 7

dimensions specified in Figure 1-1. 85. The staging areas would serve as field offices, reporting locations for workers, parking space for vehicles and equipment, 9

sites for material storage, fabrication assembly, equipment maintenance, and concrete batch plants. Staging/material storage 10yards/batch plants would be approximately 20 acres for 500-kV lines. They would be located every 20 to 30 miles along the 11line.12

6. Fly yards would be 10 to 15 acres located every 5 to 10 miles. Values in table assume helicopter construction throughout all13single-circuit 500-kV lines. The construction contractor may choose to construct using ground-based techniques, therefore, 14not utilizing fly yards. 15

7. Typical wiring pulling/splicing sites would be the ROW width x 600 to 900 feet located every 2 to 3 miles. Typically, the only 16sites 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 the17ROW. 18

8. Miles of access road are based on an indicative layout of access roads along the current preferred route as of the date of this19document.20

21

2.1.2 Right-of-Way Acquisition 22All portions of the route must obtain new ROWs through a combination of ROW grants and 23easements between IPC and various federal, state, and local governments; other companies 24(e.g., utilities and railroads), and private landowners. 25

Close coordination with all property owners and land agencies during initial surveys and the 26construction phase of the Project is essential for successful completion of the Project. In the 27early stages of the Project, landowners will be contacted to obtain right-of-entry for surveys and 28for geotechnical drilling at selected locations. Each landowner along the final centerline route 29will be contacted to explain the Project and to secure right-of-entry and access to the ROW. 30

All negotiations with landowners will be conducted in good faith, and the Projects effect on the 31parcel or any other concerns the landowner may have will be addressed. ROWs for 32transmission line facilities on private lands will be obtained as perpetual easements. Land for 33substation or communication sites will be obtained in fee simple where located on private land. 34Every effort will be made to purchase the land and/or obtain easements on private lands 35through reasonable negotiations with the landowners. 36

Section 2.2.4 of the POD describes North American Electricity Reliability Corporation (NERC) 37and Western Electricity Coordinating Council (WECC) reliability standards and capacity needs 38for the Project. To achieve the capacity needed to serve present and future loads within IPCs 39service areas, the WECC requires a minimum separation from existing transmission lines that 40serve substantially the same load as that served by the new Boardman to Hemingway 41transmission project. In these cases, the Project transmission lines must be located at least 42


November 2011 26

1,500 feet as a general rule from the nearest existing 230 kV or higher-voltage transmission 1lines or the length of the longest span where the two lines are adjacent to each other. Land 2between ROWs that are separated to meet reliability criteria will not be encumbered with an 3easement but could practically be limited in land uses due to the proximity of two or more large 4transmission lines. 5

2.1.3 Land Disturbance 6Land disturbance as described in Table 2-2 is the estimated amount of land that will be 7disturbed during construction or required to be permanently converted to operational uses. The 8areas are reported by county. These uses are less than the amount of land for which 9operational controls are required over the life of the Project as described in Table 2-1. 10

Table 2-2. Summary of Land Disturbed during Construction and Used during 11Permanent Operations12

Segment/Project ComponentLand Affected During Construction (acres)

Land Affected During Operations (acres)

Morrow CountySingle Circuit 500-kV Pad 304.0 12.2On ROW Pulling/Tensioning Sites 159.3 0ON ROW Construction Roads 59.4 29.6Off ROW Pulling/Tensioning Sites 104.8 0Off ROW Access Roads 18.6 9.3Staging Yards 39.9 0Fly Yards 15.3 0Communications Station (1) 0.2 0.1Grassland Substation 30.0 6.0County Total Segment Subtotal 731.5 57.2Umatilla CountySingle Circuit 500-kV Pad 294.7 11.9On ROW Pulling/Tensioning Sites 191.3 0ON ROW Construction Roads 53.8 26.9Off ROW Pulling/Tensioning Sites 140.5 0Off ROW Access Roads 71.8 35.9Staging Yards 41.2 0Fly Yards 44.5 0Communications Station (1) 0.2 0.1County Total Segment Subtotal 838.0 74.8

13


November 2011 27

Table 2-2. Summary of Land Disturbed during Construction and Used during 1Permanent Operations (continued) 2


Land Affected During Operation (acres)

Union CountySingle Circuit 500 kV Pad 248.1 10.0On ROW Pulling/Tensioning Sites 213.1 0ON ROW Construction Roads 42.7 21.3Off ROW Pulling/Tensioning Sites 38.2 0Off ROW Access Roads 72.0 36.0Staging Yards 41.1 0Fly Yards 103.8 0Communications Stations (1) 0.2 0.1County Total Segment Subtotal 759.2 67.4Baker CountySingle Circuit 500 kV Pad 418.9 16.8Double Circuit 138/69-kV Pad 16.5 4.1On ROW Pulling/Tensioning Sites 342.1 0ON ROW Construction Roads 78.2 39.1Off ROW Pulling/Tensioning Sites 112.3 0Off ROW Access Roads 161.5 80.8Staging Yards 43.8 0Fly Yards 116.1 0Communications Station (2) 0.5 0.3County Total Segment Subtotal 1,289.9 141.1Malheur CountySingle Circuit 500 KV Pad 456.7 18.4On ROW Pulling/Tensioning Sites 263.1 0ON ROW Construction Roads 80.1 40.0Off ROW Pulling/Tensioning Sites 120.2 0Off ROW Access Roads 163.0 81.5Staging Yards 63.9 0Fly Yards 134.0 0Communications Station (3) 0.7 0.4County Total Segment Subtotal 1,281.7 140.3Owyhee CountySingle Circuit 500 KV Pad 147.7 5.9On ROW Pulling/Tensioning Sites 121.1 0ON ROW Construction Roads 20.5 10.2Off ROW Pulling/Tensioning Sites 41.9 0Off ROW Access Roads 55.6 27.8Staging Yards 42.5 0Fly Yards 59.8 0Communications Station 0 0Hemingway Substation 4.0 2.0County Total Segment Subtotal 493.1 45.9

3


November 2011 28

Table 2-2. Summary of Land Disturbed during Construction and Used during 1Permanent Operations (continued) 2


Land Affected During Operations (acres)

Total Project Single Circuit 500 KV Pad 1,870.2 75.2Double Circuit 138/69-kV Pad 16.5 4.1On ROW Pulling/Tensioning Sites 1,290.0 0ON ROW Construction Roads 334.7 167.1Off ROW Pulling/Tensioning Sites 557.9 0Off ROW Access Roads 542.5 271.3Staging Yards 272.4 0Fly Yards 473.5 0Communications Station 1.8 1.0Substations 34.0 8.0Total Project 5,393.5 526.7

1 The exact land requirements would depend on the final detailed design of the transmission line, which is influenced 3by the terrain, land use, and economics. Alignment options may also slightly increase or decrease these values. 4

5Assumptions/Notes:61. ROW widths for 500-kV single circuit segments are 250 feet and 100 feet for 138/69-kV segments. 72. The staging areas would serve as field offices, reporting locations for workers, parking space for vehicles and equipment, sites8for material storage, fabrication assembly and stations for equipment maintenance, and concrete batch plants. 93. Staging/material storage yards/batch plants would be approximately 20 acres for 500 kV and located every 20 to 30 miles along10the line. 114. Fly yards would be 10 to 15 acres located every 5 miles. Values in table assume helicopter construction throughout all single-12circuit 500-kV segments. The construction contractor may choose to construct using ground-based techniques, therefore, not 13utilizing fly yards for those sections. 145. For 500 kV, wiring pulling/splicing sites would be the ROW width x 600 to 900 feet located every 2 to 3 miles. Typically, the only 15sites 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 the16ROW. 17

18

Estimates for construction disturbances are based on best professional judgment and 19experience with this type of project. Components estimated include transmission support 20structures; their associated construction pads; pulling sites for tensioning conductors; access 21roads to each structure, communications station, and substation; staging areas; fly yards where 22helicopter construction would be used; communications stations; and substations. As part of the 23conceptual design and in order to aid quantification of effects, preliminary indicative locations 24were assigned for all components of the Proposed Route and alternatives. Figure 2-1 through 25Figure 2-3 illustrate how disturbance was estimated for each of the components. Sections 2.2 26through 2.4 of this appendix describe typical disturbance areas for each construction activity. 27

28


November 2011 29

1

Figure 2-1. Disturbance Area for Tower Structures 2


November 2011 30

Figure 2-2. Typical Disturbance Area 1


November 2011 31

1

Figure 2-3. Example Access Roads and Tower Locations 2


November 2011 32

2.2 Transmission Line Construction 1The following sections detail the transmission line construction activities and procedures for the 2304 miles of transmission lines and associated support structures, including 5.3 miles to be 3rebuilt/relocated. Construction equipment and work force requirements are described in Section 42.6. Figure 2-4 illustrates the transmission line construction sequence. Substation construction 5is described in Section 2.4. Various construction activities will occur during the construction 6process, with several construction crews operating simultaneously at different locations. The 7proposed construction schedule is described in Section 2.6.4 of this appendix. 8

9

Figure 2-4. Transmission Line Construction Sequence 10

2.2.1 Transmission Line System Roads 11Construction of the new transmission lines would require vehicle, truck, and crane access to 12each new structure site for construction crews, materials, and equipment. Similarly, construction 13of other Project components such as staging areas and substation sites would require vehicle 14access. 15

Transmission line ROW access would be a combination of new access roads, improvements to 16existing roads, and use of existing roads as is. Unimproved, overland travel routes will be 17established in flat and moderate terrain where safe and practical. They may consist of existing 18or new roads with minor grading or clearing; two track roads created by construction vehicles 19driving directly over low growth vegetation and brush, leaving no defined roadway beyond 20crushed vegetation; or any combination along the route. In some cases stumps or large root 21


November 2011 33

wads will be removed with the aid of a bulldozer and surface restored with a grader. In steep 1terrain new bladed access roads would be constructed using a bulldozer or grader, followed by 2a roller to compact and smooth the ground. Front-end loaders will be used to move the soil 3locally or off-site as necessary. Typically, access to the transmission line ROW and tower sites 4requires a 14-foot-wide travel way for straight sections of road and a 16- to 20-foot-wide travel 5way at corners to facilitate safe movement of equipment and vehicles. In steep, rugged terrain, 68-foot-wide all-terrain vehicle (ATV) trails may be established to facilitate permanent access for 7off-road 4-wheel maintenance utility vehicles (UTVs).8

Wherever possible existing roads will be used and new access roads would be constructed 9within the proposed transmission line ROW. In other cases, new access roads would be 10required between the proposed transmission line and existing roads outside of the ROW, 11particularly in steep terrain where new bladed roads will often follow the contours to minimize 12grades. Erosion control and sedimentation measures such as at-grade water bars, culverts, 13sediment basins, or perimeter control would be installed as required to minimize erosion during 14and subsequent to construction of the Project. 15

After Project construction, existing and new permanent access roads would be used by 16maintenance crews and vehicles for inspection and maintenance activities. New roads created 17to access tower sites would be revegetated but not restored to original contours in the event that 18emergency access is needed to a tower location or for periodic inspection and maintenance 19activities. Temporary construction roads not required for future maintenance access will be 20restored after completion of Project construction. For example, access roads to staging areas 21will not be required once the staging area is restored. Depending on Agency or landowner 22preference, gates may be installed at fence crossings and other locations as requested to 23restrict unauthorized vehicular access to the ROW. Roads retained for operations would be 24seeded with an approved native grass mix and allowed to revegetate. For normal maintenance 25activities, an 8-foot portion of the road would be used and vehicles would drive over the 26vegetation. For non-routine maintenance requiring access by larger vehicles, the full width of the 27access road may be used. Access roads would be repaired, as necessary, but not be routinely 28graded. Vegetation (e.g., taller shrubs and trees) that may interfere with the safe operation of 29equipment would be managed on a cyclical basis. 30

Table 2-3 lists the estimated miles of proposed off ROW access roads by county. The table will 31be revised to show proposed locations of access roads once they are identified during the 32design phase. 33

Table 2-3. Miles of New and Improved off-ROW Access Roads 34

County New Access Roads

(miles)Existing Access Roads to be Improved (miles) Total Miles

Morrow 7.3 2.2 9.5 Umatilla 21.4 15.6 37.0 Union 9.1 28.1 37.2 Baker 38.1 44.8 82.9 Malheur 33.1 50.9 84.1 Owyhee 5.2 23.5 28.7 Total 114.8 165.1 279.9

35


November 2011 34

Table 2-4 lists the estimated miles of proposed on and off road access roads. The table will be 1revised to show any changes in the locations of access roads once they are identified during the 2design phase. 3

Table 2-4. Miles of New and Improved Access Roads14

County

New AccessRoads

Existing Access Roads to be Improved Totals

Miles Miles Miles Morrow 37.3 2.8 40.1 Umatilla 44.2 20.5 64.7 Union 27.4 31.6 59.0 Baker 72.6 50.4 123.0 Malheur 69.0 56.3 125.3 Owyhee 12.2 27.0 39.2 Total2 262.7 188.6 451.3 1 Includes on- and off-ROW access roads (including roads shown in Table 2-2). 2 Acreages in table are rounded to the nearest acre; column therefore may not sum exactly.

2.2.2 Soil Borings 5At the discretion of the Project engineer, soil borings will be completed along the route to 6determine depth to bedrock and the engineering properties of the soil. Based on the soil 7properties, foundation designs will be completed for transmission line towers and other 8structures. Borings would be made with truck- or track-mounted equipment. Access for 9exploration drilling will be primarily overland travel with possible crushing of vegetation under 10the vehicle; clearing/cutting of vegetation; temporary road building; road cuts or a combination 11of these four types. In steep rugged terrain where overland access is not feasible, access by a 12helicopter transported platform rig may be required. 13

The borings will be approximately 4 inches in diameter, range from 15 to over 60 feet deep, and 14will be backfilled in accordance with State Water Resources Department rules. 15

2.2.3 Staging Areas 16Construction of the Project will begin with the establishment of staging areas, or laydown yards. 17The staging areas will serve as field offices; reporting locations for workers; parking space for 18vehicles and equipment; and sites for material storage, fabrication assembly, concrete batch 19plants, and stations for equipment maintenance. Staging areas, about 20 acres each for 500-kV 20construction and 10 acres each for 138/69-kV construction, will be located approximately every 2125 miles along the route. Additionally, fly yards for helicopter operations will be located 22approximately every 10 miles along the route where helicopter construction is planned, and will 23occupy approximately 10 to 15 acres. 24

Staging areas and helicopter fly yards will be fenced and their gates locked. Security guards will 25be stationed where needed. Staging area locations will be finalized following discussion with the 26land management agency or negotiations with landowners. In some areas, the staging area 27may need to be scraped by a bulldozer and a temporary layer of rock laid to provide an all-28weather surface. Unless otherwise directed by the landowner, the rock will be removed from the 29staging area upon completion of construction and the area will be restored. 30

Table 2-5 lists the frequency and estimated acreage disturbance for proposed staging areas 31and helicopter fly yards by county. In locating yards, the preference is for relatively flat areas 32


November 2011 35

with easy existing access to minimize site grading and new road construction. The staging 1areas will be located in previously disturbed sites or in areas of minimal vegetative cover where 2possible.3

Table 2-5. Construction Staging Areas and Helicopter Fly Yards 4

CountyStaging Areas Fly Yards

Number Acres Number AcresMorrow 2 39.9 1 15.3Umatilla 2 41.2 3 44.5Union 2 41.1 7 103.8Baker 2 43.8 8 116.1Malheur 3 63.9 9 134.0Owyhee 2 42.5 4 59.8Total 13 272.4 32 473.5

5

2.2.4 Site Preparation 6Individual structure sites will be cleared to install the transmission line support structures and 7facilitate access for future transmission line and structure maintenance. Clearing individual 8structure sites will be done using a bulldozer to blade the required area. At each single-circuit 9500-kV structure location, an area approximately 250 feet by 250 feet will be needed for 10construction laydown, tower assembly, and erection at each tower site. This area will provide a 11safe working space for placing equipment, vehicles, and materials. The work area will be 12cleared of vegetation only to the extent necessary. For 138/69-kV structures the site prep area 13will be approximately 100 feet by 100 feet. After line construction, areas not needed for normal 14transmission line maintenance, including fire and personnel safety clearance areas, will be 15graded to blend as near as possible with the natural contours, then revegetated as required. 16

Additional equipment may be required if solid rock is encountered at a structure location. Rock-17hauling, hammering, or blasting may be required to remove the rock. Excess rock that is too 18large in size or volume to be spread at the individual structure sites will be hauled away and 19disposed of at approved landfills or at a location specified by the landowner. Table 2-2 provides 20the dimensions of each of the foundation holes required for each structure. See Section 1.1.1 of 21this appendix for a description of each structure type and Figure 1-1 through Figure 1-3 for 22structure illustrations. 23

2.2.5 Install Structure Foundations 24Table 1-1 lists the number of and type of support structures that will be installed. 25

2.2.5.1 Lattice Steel Tower Foundations 26Each 500-kV support structure will require the installation of foundations, which are typically 27drilled concrete piers. First, four holes will be excavated for each structure. The holes will be 28drilled using truck- or track-mounted augers of various sizes depending on the diameter and 29depth requirements of the hole to be drilled. Each foundation will extend approximately 1 to 2 30feet above the ground level.31

2.2.5.2 H-Frame Installation 32Each 500-kV H-frame will require the installation of drilled pier foundations. Two or three 33foundations will be required per H-frame structures. The holes for each foundation will be drilled 34using truck- or track-mounted augers of various sizes depending on the diameter and depth 35


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requirements of the hole to be drilled. The diameter of each foundation will be approximately 7 1to 8 feet at a depth of 30 to 40 feet. Each foundation will extend approximately 1 to 2 feet above 2the ground level. 3

2.2.5.3 Monopole Installation 4Tangent 138/69-kV monopole structures will require the poles to be directly embedded in the 5ground. Holes will be drilled in the ground using a truck- or track-mounted auger. The diameter 6of the hole excavated for embedment is typically between 5 and 6 feet (see Table 1-2). Depths 7of the holes range from 15 to 25 feet deep. When the poles are placed in the holes, the hole will 8be backfilled with native or select backfill. When backfill must be imported, material must be 9obtained from commercial sources or from areas free of noxious weed species. See Section 101.1.1 of this appendix for a description a monopole structure and Figure 1-3 for an illustration.11

Angle and dead-end 138/69-kV monopole structures will require the installation of drilled pier 12foundations. The hole for each foundation will be drilled using a truck- or track-mounted auger of 13various sizes depending on the diameter and depth requirements of the hole to be drilled. The 14diameter of the foundation will be approximately 5 to 6 feet with at a depth of 20 to 25 feet deep. 15Each drilled pier foundation will extend approximately one to two feet above the ground level.16

Where solid rock is encountered, blasting (see Section 2.5.1 of this appendix), rock hauling, or 17the use of a rock anchoring or micro-pile system may be required. Micro-piles are high capacity, 18small diameter (5-inch to 12-inch) drilled and grouted in-place piles designed with steel 19reinforcement to primarily resist structural loading. The rock anchoring or micro-pile system will 20be used in areas where site access is limited or adjacent structures could be damaged as a 21result of blasting or rock hauling activities. 22

In environmentally sensitive areas with very soft soils, a HydroVac, which uses water pressure 23and a vacuum, may be used to excavate material into a storage tank. Alternatively, a temporary 24casing may be used during drilling to hold the excavation open, after which the casing is 25withdrawn as the concrete is placed in the hole. In areas where it is not possible to operate 26large drilling equipment due to access or environmental constraints, hand digging may be 27required. 28

Reinforced-steel anchor bolt cages will be installed after excavation and prior to structure 29installation. These cages are designed to strengthen the structural integrity of the foundations 30and will be assembled at the nearest Project laydown yard and delivered to the structure site via 31flatbed truck or helicopter. These cages will be inserted in the holes prior to pouring concrete. 32The excavated holes containing the reinforcing anchor bolt cages will be filled with concrete 33(Table 1-2). 34

Typically, and because of the remote location of much of the transmission line route, concrete 35will be provided from portable batch plants set up approximately every 25 miles along the line 36route in one of the staging areas. Concrete will be delivered directly to structure sites in 37concrete trucks with a capacity of up to 10 cubic yards. In the more developed areas along the 38route and in proximity to the substations, the construction contractor may use local concrete 39providers to deliver concrete to the site when economically feasible. 40

2.2.6 Erect Support Structures 41The steel support structures will be assembled on site, except where helicopter delivery is 42employed, as described in Section 2.5.2 of this appendix. Steel members for each structure will 43be delivered to the site by flatbed truck. Assembly will be facilitated on site by a truck-mounted 44crane. Subsequent to assembly, the structures will be lifted onto foundations using a large crane 45designed for erecting towers. Where possible, the crane will move along the ROW from 46


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structure to structure site erecting the towers, if access along the ROW is not possible the crane 1will leave the ROW and use the access road network to reach the next structure. 2

The H-frame and monopole structures will be framed on site. Two methods of assembly can be 3used to accomplish this, the first of which is to assemble the poles, braces, cross arms, 4hardware, and insulators on the ground. A crane is then used to set the fully framed structure by 5placing the poles in the excavated holes. Alternatively, aerial framing can be used by setting the 6poles in the ground first and assembling the braces, cross arms, hardware, and insulators in the 7air. Where possible, the crane will move along the ROW from structure to structure site setting 8the structures. 9

2.2.7 String Conductors, Shield Wire, and Fiber Optic Ground Wire 10Conductor, shield wire, and OPGW will be placed on the transmission line support structures by 11a process called stringing. The first step to wire stringing will be to install insulators (if not 12already installed on the structures during ground assembly) and stringing sheaves. Stringing 13sheaves are rollers that are temporarily attached to the lower portion of the insulators at each 14transmission line support structure to allow conductors to be pulled along the line. 15

Figure 2-5 illustrates the sequence of steps in installing conductors. 16

17

Figure 2-5. Conductor Installation 18

Additionally, temporary clearance structures (also called guard structures) will be erected where 19required prior to stringing any transmission lines. The temporary clearance structures are 20typically vertical wood poles with cross arms and are erected at road crossings or crossings with 21other energized electric and communication lines to prevent contact during stringing activities. 22Bucket trucks may also be used to provide temporary clearance. Bucket trucks are trucks fitted 23with a hinged arm ending in an enclosed platform called a bucket, which can be raised to let the 24


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worker in the bucket service portions of the transmission structure as well as the insulators and 1conductors without climbing the structure. 2

Once the stringing sheaves and temporary clearance structures are in place, the initial stringing 3operation will commence with the pulling of a lightweight sock line through the sheaves along 4the same path the transmission line will follow. Typically the sock line is pulled in via helicopter. 5The sock line is attached to the hard line, which follows the sock line as it is pulled through the 6sheaves. The hard line will then be attached to the conductor, shield wire, or OPGW to pull 7them through the sheaves into their final location. Pulling the lines may be accomplished by 8attaching them to a specialized wire stringing vehicle. Following the initial pulling of the wire into 9the sheaves, the wire will then be tensioned to achieve the correct sag between support 10structures. 11

Pulling and tensioning sites for 500-kV construction will be required approximately every 1.5 to 122 miles along the ROW and at angle points greater than 30 degrees and will require 13approximately 5 acres at each end of the wire section to accommodate required equipment. The 14138/69-kV pulling and tensioning sites will be required approximately every 1 to 2 miles along 15the ROW and will require approximately 1.2 acres each to accommodate required equipment. 16Equipment at sites required for pulling and tensioning activities will include tractors and trailers 17with spooled reels that hold the conductors and trucks with the tensioning equipment. To the 18extent practicable, pulling and tensioning sites will be located within the ROW. However, angle 19points typically necessitate pulling and tensioning sites outside of the ROW. Depending on 20topography, minor grading may be required at some sites to create level pads for equipment. 21Finally, the tension and sag of conductors and wires will be fine-tuned, stringing sheaves will be 22removed, and the conductors will be permanently attached to the insulators at the support 23structures. 24

At the tangent and small angle structures, the conductors will be attached to the insulators using 25clamps to suspend the conductors from the bottom of the insulators. At the larger angle dead-26end structures, the conductors cannot be pulled through and so they are cut and attached to the 27insulator assemblies at the structure which dead ends the conductors. There are two primary 28methods to attach the conductor to the insulator assembly at the dead-end structure. The first 29method, hydraulic compression fittings, uses a large press and pump that closes a metal clamp 30or sleeve onto the conductor. This method requires heavy equipment and is time consuming. 31The second method, implosive fittings, uses explosives to compress the metal together. 32Implosive fittings do not require heavy equipment, but do create noise similar to a loud 33explosion when the primer is struck. The implosive type sleeve is faster to install and results in a 34secure connection between the conductor and the sleeve. Implosive sleeves are planned for the 35Project.36

The 500-kV single-circuit line uses a three conductor bundle for each phase. At each single-37circuit 500-kV dead-end structure, 18 implosive dead-end sleeves (six per phase, one for each 38of the three subconductors on each of the three phases, and on each side of the structure) will 39be required. Additionally, 18 compression or implosive sleeves will be required to fabricate and 40install the jumpers that connect the conductors from one side of the dead-end structure to the 41other, for a total of 36 sleeves for each single-circuit dead-end structure. 42

The 138/69-kV double-circuit lines use a single-conductor bundle for each phase. Each of these 43dead-end structures will require 12 implosive or compression type sleeves to dead-end the 44conductors and 12 sleeves to fabricate the jumpers, for a total of 24 sleeves at each dead-end 45structure. For the overall Project, approximately 8,000 to 10,000 implosive fittings will be used. 46


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2.2.8 Cleanup and Site Reclamation 1Construction sites, staging areas, material st

Transmission Line and Substation Components

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