20230815PAC to Staff 13 Attachment.pdf

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Transmission & Distribution
Vegetation Management Program
Standard Operating Procedures

Mission Statement:
Manage trees and vegetation around PacifiCorp's transmission and distribution facilities in a
professional, cost effective and environmentally conscientious manner to provide safe, reliable and
outstanding service to our customers.

Approval: Chris Spencer, Managing Director, T&D Support Services Date: 06/19/2019
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TABLE OF CONTENTS

1. PROGRAM OVERVIEW ...................................................................................................... 1
1.1 Applicable References .......................................................................................................... 1
1.2 Professionalism ..................................................................................................................... 2
1.2.1 Required Qualifications for Independent Contractors ................................................... 2
1.3 Tree Line USA ...................................................................................................................... 3
2. GENERAL PROCEDURES ................................................................................................... 4
2.1 Safety .................................................................................................................................... 4
2.1.1 Holds and Clearances ..................................................................................................... 4
2.1.2 Emergencies ................................................................................................................... 5
2.1.2.1 Whistles................................................................................................................... 5
2.1.2.2 Tree on Line ............................................................................................................ 6
2.1.3 Readily Climbable Trees................................................................................................ 8
2.1.4 Tree Houses ................................................................................................................... 8
2.1.5 Fire Protection ................................................................................................................ 8
2.1.6 At-Fault Tree Crew Caused Outages ............................................................................. 9
2.2 Environment .......................................................................................................................... 9
2.2.1 Species of Concern ........................................................................................................ 9
2.2.2 Wetlands ...................................................................................................................... 10
2.2.3 Stream Protection ......................................................................................................... 10
2.2.4 Bird Protection ............................................................................................................. 10
2.2.5 Spills ............................................................................................................................ 12
2.3 Archaeological Sites ........................................................................................................... 13
2.4 Communication ................................................................................................................... 13
2.4.1 Internal Communication .............................................................................................. 13
2.4.1.1 Communication of Vegetation Conditions That Are Imminently Likely to Cause
an Outage .......................................................................................................................... 13
2.4.1.2 Media .................................................................................................................... 14
2.4.1.3 Legal ..................................................................................................................... 14
2.4.2 Communication with External Stakeholders ............................................................... 14
2.5 Tree Growth Rate Definitions ............................................................................................. 14
2.6 Tree Removal ...................................................................................................................... 15
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2.7 Mechanized Vegetation Control ......................................................................................... 15
2.8 Slash Disposal ..................................................................................................................... 16
2.9 Emergency Response .......................................................................................................... 16
2.10 Pronounced Facility Conditions ........................................................................................ 17
2.11 Property Damage .............................................................................................................. 17
2.12 Freelance Work ................................................................................................................. 17
2.13 Fences and Gates............................................................................................................... 18
2.14 Climbing Spurs ................................................................................................................. 18
2.15 Winching Vehicles ............................................................................................................ 18
3. TREE BIOLOGY AND PRUNING ..................................................................................... 19
3.1 Tree Biology ....................................................................................................................... 19
3.1.1 Foliage.......................................................................................................................... 19
3.1.2 Stems ............................................................................................................................ 19
3.1.2.1 Xylem .................................................................................................................... 19
3.1.2.2 Cambium ............................................................................................................... 19
3.1.2.3 Branch Collars ...................................................................................................... 20
3.1.2.4 Codominant Stems ................................................................................................ 21
3.2 Utility Line Clearance Pruning ........................................................................................... 21
3.2.1. Natural Target Pruning ............................................................................................... 22
3.2.2 Directional Pruning ...................................................................................................... 22
3.2.3 Collar Cuts ................................................................................................................... 23
3.2.4 Reduction Cuts ............................................................................................................. 24
3.2.5 Large Branches ............................................................................................................ 25
3.2.6 Heading Cuts ................................................................................................................ 26
3.2.7 Deciduous Trees........................................................................................................... 27
3.2.8 Conifers ........................................................................................................................ 28
4. PLANNING, SCHEDULING AND REPORTING WORK ................................................ 29
4.1 Process Checklist ................................................................................................................ 29
4.1.1 Authorize Project Work ............................................................................................... 29
4.1.2 Project Planning ........................................................................................................... 30
4.1.3 Work Identification ...................................................................................................... 33
4.1.4 Work Assignments to Project Crews ........................................................................... 33
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4.2 Reporting Work .................................................................................................................. 33
4.2.1 Daily Report ................................................................................................................. 33
4.2.2 Weekly Report ............................................................................................................. 33
4.3 Tree Crew Audits ................................................................................................................ 34
4.3.1 Extreme Exceptions ..................................................................................................... 34
4.4 Worksite Inspection ............................................................................................................ 35
4.5 Contractor Project Completion ....................................................................................... 35
4.6 Project Closure ................................................................................................................ 35
5. DISTRIBUTION PROCEDURES........................................................................................ 36
5.1 Distribution New Construction Clearing ............................................................................ 36
5.2 Distribution Cycle Maintenance ......................................................................................... 36
5.2.1 Specified Vegetation Clearance Distances – Primary ................................................. 37
5.2.2 Specified Vegetation Clearance Distances – Secondary ............................................. 39
5.2.3 Other Facility Clearances ............................................................................................. 40
5.3 Distribution Interim Maintenance ....................................................................................... 41
5.4 Distribution Annual Maintenance ....................................................................................... 41
5.5 Distribution Ticket Maintenance ........................................................................................ 42
5.6 Side Clearance Exception ................................................................................................... 44
5.7 Increased Overhang Clearance Alternative ........................................................................ 44
5.8 Pole-Clearing ...................................................................................................................... 44
5.9 Padmount Transformers ...................................................................................................... 45
6. TRANSMISSION PROCEDURES ...................................................................................... 46
6.1 Initial Clearing and Construction ........................................................................................ 46
6.2 Transmission Clearances .................................................................................................... 46
6.2.1 MVCD Violations ........................................................................................................ 48
6.2.1.1 MVCD Calculation ............................................................................................... 48
6.2.2 Structure Clearances .................................................................................................... 48
6.2.3 Guy Wires .................................................................................................................... 48
6.3 Inspections ...................................................................................................................... 48
6.3.1 Inspection Frequency ................................................................................................... 49
6.3.2 Line Patrolmen Responsibilities Under FAC-003 ....................................................... 49
6.3.3 Additional Inspection ................................................................................................... 49
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6.4 Work Planning .................................................................................................................... 50
6.4.1 Annual Work Plan........................................................................................................ 50
6.5 Integrated Vegetation Management .................................................................................... 51
6.5.1 IVM Control Methods.................................................................................................. 51
6.5.2 Wire Zone—Border Zone ............................................................................................ 52
6.6 Tree Removals in Transmission Rights-of-Way ................................................................. 55
6.7 Tree Removals Outside Transmission Rights-of-Way ....................................................... 55
6.8 Post-Work Assessment ....................................................................................................... 55
6.9 Mitigation Measures ........................................................................................................... 55
6.10 Vegetation Screens............................................................................................................ 56
6.11 Merchantable Timber ........................................................................................................ 56
6.12 Transmission Safety Procedures ....................................................................................... 56
6.12.1 Pre-work Communication with Control Center ......................................................... 56
6.12.2 Post-Work Communication with the Control Center................................................. 57
6.12.3 Safe Working Procedure ............................................................................................ 57
6.13 Monthly Progress Tracking............................................................................................... 57
6.14 Quarterly WECC Audit Report ......................................................................................... 58
7. CHEMICAL PROCEDURES ............................................................................................... 59
7.1 Notification ......................................................................................................................... 59
7.2 Licensed Applicators .......................................................................................................... 59
7.3 Closed Chain of Custody .................................................................................................... 59
7.4 Chemical Reporting ............................................................................................................ 59
7.5 Herbicide Applications ....................................................................................................... 59
7.5.1 Herbicide Best Management Practices ........................................................................ 60
7.5.2 Wetlands and Waterbodies .......................................................................................... 60
7.5.3 Spills ............................................................................................................................ 60
7.5.4 Inappropriate Applications ........................................................................................... 61
7.6 Approved Herbicides ...................................................................................................... 62
7.7 Approved Tree Growth Regulators (TGR) ......................................................................... 62
8. CUSTOMER RELATIONS.................................................................................................. 63
8.1 Educational Information ..................................................................................................... 63
8.2 Notification for Tree Work ................................................................................................. 63
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8.2.1 Door Hangers ............................................................................................................... 64
8.2.2 Personal Notification ................................................................................................... 64
8.3 Affirmative Customer Consent ....................................................................................... 64
8.4 Property Owner Refusal Procedure .................................................................................... 64
8.5 Work Completed Without Property Owner Consent .......................................................... 65
REFERENCES ............................................................................................................................. 67
APPENDIX A Vegetation Management work scheduling and reporting forms. ........................ 70
APPENDIX B Revision History .................................................................................................. 84

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TABLE OF FIGURES

Figure 2.1. Emergency procedure for tree-on-line incident. .......................................................... 7

Figure 2.2. Bird nest procedure .................................................................................................... 12

Figure 3.1. The Cambium creates a barrier zone that contains discoloration and decay in the old
wood. ............................................................................................................................................. 20

Figure 3.2. Branch collars form at the base of branches. ............................................................. 21

Figure 3.3 "V" or "L" shapes can develop from crown reductions on trees growing in close
proximity to power lines. The ultimate objective is to train the tree up and away from the
conductor whenever possible, so the facility is cleared while minimizing health risks to the tree.
....................................................................................................................................................... 23

Figure 3.4. A proper collar cut, on a tree with and without a visible branch collar (Gillman 2015)
....................................................................................................................................................... 24

Figure 3.5. A proper crown reduction cut. ................................................................................... 25

Figure 3.6. Old Heading Cut. Shoots that proliferate from these cuts often dominate the tree's
crown, and gaps result when branches containing these shoot clusters are removed. .................. 26

Figure 3.7. On return visits to "V-Outs", under pruning should leave the smaller, suppressed
shoots to retain foliage and soften the visual effect of crown reduction. ..................................... 27

Figure 3.8. Crown reduction on a conifer. ................................................................................... 28

Figure 5.1. Distribution ticket maintenance procedure. ............................................................... 43

Figure 5.2. Illustration of pole-clearing requirements (California Department of Forestry & Fire
Protection 2008, Figure 3, PRC 4292, 14 CCR 1254, Fire Break Clearance Requirement Around
Poles and Towers) ......................................................................................................................... 45

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Figure 6.1. In densely vegetated areas, rights-of-way usually have to be completely cleared
initially to establish a wire-border zone. ....................................................................................... 47

Figure 6.2. Bramble and Byrnes Wire Zone-Border Zone (adapted from Yahner, Bramble, and
Byrnes 2001) ................................................................................................................................. 53

Figure 6.3. The border zone is condensed on up-slopes, where wire sag and sway could bring it
into contact with trees, and is extended on down-slopes. ............................................................. 53

Figure 6.4. Transmission under-clearance regions ...................................................................... 54

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TABLE OF TABLES

Table 2.1. Minimum approach distances for qualified line-clearance arborists and line-clearance
arborist trainees. .............................................................................................................................. 5

Table 2.2. Control center numbers ................................................................................................. 6

Table 2.3. Tree house clearances ................................................................................................... 9

Table 2.4. Work buffers around active nests of eagles, hawks, and herons. ................................ 11

Table 5.1. Normal primary specified vegetation clearance distances. ......................................... 37

Table 5.2. Primary specified vegetation clearance distances for work in California and areas of
elevated risk, as specifically designated on a particular Release or Scope of Work. ................... 38

Table 5.3 Non-primary wire vegetation clearance distances ....................................................... 39

Table 5.4. Normal distribution interim work thresholds. ............................................................. 41

Table 5.5. Distribution interim work thresholds for work in California and areas of elevated
wildfire risk, as specifically designated on a particular Release or Scope of Work. .................... 41

Table 6.1. Transmission clearance requirements (in feet). .......................................................... 48

Table 6.2. Typical transmission right-of-way widths. ................................................................. 50

Table 7.1. Buffer widths to minimize impacts on non-target resources (adapted from Childs
2005). ............................................................................................................................................ 61

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1. PROGRAM OVERVIEW
PacifiCorp has an extensive vegetation management program, for both its transmission and
distribution systems. Trees growing into or near power lines can create safety and service
reliability risks, and PacifiCorp’s vegetation management program seeks to minimize such risks,
primarily by pruning trees, Scientifically-based arboricultural practice of removing tree parts, or
removing trees which could grow into power lines.
The risks of unchecked vegetation growth are well known. Close growing branches can provide
access for children and others to high-voltage lines, exposing them to the potential danger of
serious injury or death due to electric contact. Branches touching power lines can spark and start
fires and cause interruptions in electric supply. Trees whipped by winds or weighed down by rain
or snow can interrupt power, which disrupts businesses, homes, and compromises critical
community infrastructure, such as hospitals and emergency services. Three major electric grid
failures, including the catastrophic blackout on August 14, 2003, were initiated by tree-caused
outages on transmission lines (Cieslewicz and Novembri 2004). For these reasons and others, the
National Electrical Safety Code (American National Standards Institute 2016). Section 2l8-A-l,
states:
Trees which may damage ungrounded supply conductors should be pruned or removed. Normal
tree growth, the combined movement of trees and conductors under adverse weather conditions,
voltage and sagging of conductors at elevated temperatures are among the factors considered in
determining clearance specifications.
Particularly in the case of transmission lines, PacifiCorp favors the removal of tall-growing trees
in favor of low-growing species that will never interfere with the high-voltage lines. In giving
consideration to the interests of property owners and other land use objectives, however, it is not
always possible to remove conflicting trees. Thus, tall-growing trees that cannot be removed
must be pruned to keep power lines clear. To this end, PacifiCorp uses modern, arboriculturally-
sound pruning practices.
PacifiCorp’s vegetation management program is modeled on the industry’s best practices,
including systematic maintenance, scientifically-based pruning, tree removal, tree replacement,
cover type conversion, herbicide use and tree growth regulator applications, and the use of
specialized tools and equipment. PacifiCorp is progressive in trying innovative methods,
products, and equipment to improve safety and productivity. These standard operating
procedures cover the vegetation management program for both distribution and transmission
facilities. These procedures also include program descriptions, specifications and protocols for
customer relations. In addition to providing direction for PacifiCorp’s professional Foresters,
these standard operating procedures are binding on all contractors performing vegetation
management on PacifiCorp’s system.
1.1 Applicable References
The following standards and best practices should be followed:

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 American National Standard for Tree Care Operations: ANSI A300 (Part 1) Pruning
 American National Standard for Tree Care Operations: ANSI A300 (Part 7) Integrated
Vegetation Management
 American National Standard for Tree Care Operations: ANSI A300 (Part 9) Tree Risk
Assessment.
 American National Standard for Arboricultural Operations ANSI Z133 Safety
Requirements
The following best practices should be followed:
 International Society of Arboriculture: Best Management Practices, Utility Pruning of
Trees
 International Society of Arboriculture: Best Management Practices, Integrated
Vegetation Management
 International Society of Arboriculture: Best Management Practices, Tree Risk Assessment
 Utility Arborist Association Best Management Practices: Field Guide to Closed Chain of
Custody for Herbicides in the Utility
1.2 Professionalism
PacifiCorp employs a staff of professional Foresters (“Foresters”) to manage its vegetation
program. All Foresters on PacifiCorp’s system are to be International Society of Arboriculture
(ISA). Certified Arborists and Certified Utility Specialists. PacifiCorp also encourages ISA
Board Certified Master Arborist credentials among its staff Foresters.
1.2.1 Required Qualifications for Independent Contractors
PacifiCorp also has required certifications for the independent contractors who perform
vegetation management services for PacifiCorp.
Front line managers for the independent contractors retained by PacifiCorp must be ISA
Certified Arborists and ISA Certified Utility Specialists. These front line managers are often
called supervisors or general foremen in the field and are referred to as “Supervisors” in these
standard operating procedures.
Forest technicians working on PacifiCorp projects are required to have certain levels of
experience, certifications, and professional qualifications. On a temporary basis for no more than
90 days, PacifiCorp will allow a forest technician with Forest Technician I classification. In all
other circumstances, a forest technician must have a Forest Technician II classification or higher.
 Forest Technician I —No certifications, qualifications or experience required.
 Forest Technician II—Minimum of 3 years arboriculture-related experience. ISA
Arborist certification and certified pesticide applicator license required.
 Forest Technician III—Minimum of 5 years arborculture-related experience or 3 years
plus an associate’s degree in a related field. ISA Arborist and Utility Specialist
certifications and certified pesticide applicator license required.

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 Forest Technician IV—Minimum of 8 years arboriculture related experience or 4 years
plus a Bachelor of Science degree in a related field. ISA Arborist and Utility Specialist
certifications, certified pesticide applicator license, and ISA Tree Risk Qualification
required.
For additional certifications related to safety, for all personnel including forest technicians see
Section 2.1 below.
1.3 Tree Line USA
PacifiCorp has been a Tree Line USA recipient utility every year since 2002. Tree Line USA is
an award from the National Arbor Day Foundation, which recognizes utilities for utilizing
practices that protect America's urban forests. To qualify, utilities must apply scientifically-based
tree care, conduct annual worker training, plant trees, and conduct public education, including
participating in Arbor Day celebrations. Contract employees should participate in annual worker
training to cooperate with and help PacifiCorp continue to merit this award.

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2. GENERAL PROCEDURES
This chapter sets forth many general procedures for vegetation management work, whether on
distribution lines (see Chapter 5) or on transmission lines (see Chapter 6).
2.1 Safety
Federal and state OSHA requirements governing vegetation management activities shall be
followed at all times. ANSI Z133 (American National Standards Institute 2017) and OSHA
1910.269, are examples of these requirements. Activities shall be conducted in a manner that
minimizes both tree crew and public safety risks. Crews shall have functional radio or telephone
communication on the job site at all times.
PacifiCorp’s electrical system will continue in normal operations during routine vegetation
management work. Contract employees shall be aware of the potential dangers and qualified to
work in the vicinity of energized facilities. Contract personnel performing line clearance work
shall hold one of the following designations as defined by ANSI Z133:
 Qualified Line Clearance Arborist
 Qualified Line Clearance Arborist Trainee
2.1.1 Holds and Clearances
Minimum approach distances for qualified line clearance arborists specified in ANSI Z133 or
PacifiCorp's Accident Prevention Manual (Joint APM Safety Committee 2017) should not be
compromised. If there is a difference in the distances required in the two standards, the greater of
the two is operative. If work requires violating minimum approach distances, or if a crew leader
determines conditions to be unsafe, crew leaders should contact their Supervisor before
proceeding. The Supervisor should determine whether or not a clearance or Hold is necessary at
that work site.
A “Hold” means deactivating automatic line reclosers on a circuit. A Hold is intended to protect
PacifiCorp facilities and should not be considered a safety measure. If, in the judgment of the
crew leader, an energized line cannot be worked safely, the Supervisor should arrange a
Clearance. A “Clearance” is de-energizing a line for safety purposes. (Note: a Clearance, as
defined here and capitalized as a defined term should not be confused with the use of the word
clearance in describing vegetation management work designed to maintain clearances between
vegetation and conductors.)
PacifiCorp does not issue Holds or Clearances to tree crews. Rather, if warranted, PacifiCorp
will issue Holds or Clearances to a journeyman lineman, who shall be present at the site during
work. Holds require at least 48 hours’ notice to the Control Center, vegetation management and
the district operations manager. Customers who will be affected by planned power outages
associated with Clearances must also receive 48 hours notice, except during emergency
situations such as storm restoration work. In some cases, a Clearances on transmission lines must

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be requested weeks or even months in advance. Customers do not need to be notified if a
Clearances is necessary to safely work trees from lines in an emergency.
De-energized lines, whether due to a planned outage, wind or storm damage, or some other
reason, must be worked as if they are energized. If an energized line cannot be worked safely, it
must be grounded. Linemen must set the grounds and be present during work and give approval
prior to tree crew members breaching minimum approach distances to ensure safety.
Unless a lineman has given approval to tree crew members to breach minimum approach
distances, the following minimum approach distances much be maintained by qualified line-
clearance arborists and line-clearance arborist trainees at all time.

Table 2.1. Minimum approach distances for qualified line-clearance arborists and line-clearance
arborist trainees.
Voltage (kV)
(Phase-to-Phase)
Minimum Approach Distance
Source Sea Level to 5000 ft. 5000 to 10000 ft 10000 to 14000
’ 6”1’ 7”1’ 7”
’6”2’ 7”2’ 10
3’ 6”3’ 7”3’ 8”
3’ 6”4’ 0”4’ 4”
3’ 11”4’ 6”4’ 10”
4’ 6”5’ 2”5’ 7”
5’ 1”5’ 9”6’ 3”
’ 0”7’ 11”8’ 7”
1’ 9”13’ 6”14’ 7”
14’ 8”16’ 9”18” 2”
17’ 6”20’ 0”21’ 8”
23’ 9”27’ 2”29’ 5”
ificorp’s Accident Prevention Manual
2.1.2 Emergencies
An emergency is major storm (as declared by PacifiCorp), or situation where vegetation has
either caused or presents a clear, imminent threat of causing an outage, fire or public electric
contact.
2.1.2.1 Whistles
Every crew member, Supervisor and Forester shall carry a whistle at all times while on work
sites. A whistle shall be used as an alarm, commanding all crew members to immediately stop
work and respond to the emergency. Whistle blasts should also be used to initiate aerial rescue
drills. Whistles are not to be used for non-emergency situations, such as getting another crew
member’s attention.

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2.1.2.2 Tree on Line
If a tree or tree part accidentally falls onto an energized line, work shall stop immediately. If
emergency services are required, 911 should be called. The incident should also be reported to
the applicable PacifiCorp Control Center (Table 2.2).

Table 2.2. Control center numbers
Control Center Phone Number Service Areas
PP North [phone] Astoria/Clatsop, OR; Bend, OR; Hood River,
OR; Pendleton, OR; Portland, OR; Walla
Walla, WA; Yakima, WA

PP Central [phone] Albany, OR; Lincoln City, OR; Casper, WY;
Cody, WY; Douglas, WY; Laramie, WY;
Rawlins, WY; Riverton, WY; Rock Springs,
WY; Worland, WY

PP South [phone] Coos Bay, OR; Crescent City, OR; Grants
Pass, OR; Kalamath Falls, OR; Medford, OR;
Mount Shasta, CA; Roseburg, OR; Yreka, CA

RMP North [phone] Entire service territory

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Figure 2.1

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2.1.3 Readily Climbable Trees
Readily climbable trees have low limbs that are accessible from the ground and sufficiently
strong and close together to support a child or average person and can be accessed by climbing
from the ground (without using a ladder, vehicle, or special equipment). Readily climbable trees
are typically located near homes, schools, parks, businesses or other locations where people
(particularly children) frequent.
Readily climbable trees pose an extremely high risk when a trunk or main stem would allow a
child or average person to climb within arm’s reach of an uninsulated, energized electric line. If a
readily climbable tree has grown within such an area, the tree shall be immediately removed or
pruned consistent with the process set forth in Chapter 8. If possible, branches should also be
removed to at least 8 feet above the ground (to discourage climbing on the tree generally).
2.1.4 Tree Houses
Tree houses built in trees growing near power lines present possible electric safety risks.
Children or others may contact the line, either directly or indirectly, if a tree house is built too
close to conductors. Indirect contact may occur through any conductive object, including a tree
or tree parts that are contacting power lines. Minimum tree house distances are set at twice the
minimum approach distance to energized conductors for arborists not qualified by training and
experience to work within 10 feet of electrical conductors (ANSI Z133, Table 1).
Tree houses built in trees growing in proximity to power lines must meet two criteria in order to
remain where they are located. First, no part of the structure may be any closer than the distance
specified in Table 2.3. Second, the tree must be pruned sufficiently to maintain the clearance
distances specified in Table 2.3 throughout the time period prior to the next scheduled work.
Maximum line sag and sway must also be taken into consideration. If these conditions cannot be
met, tree houses shall be removed promptly, consistent with the process set forth in Chapter 8.
As an alternative to removal, facility reconfiguration may be done at a property owner’s request
and expense.
2.1.5 Fire Protection
Federal, state and local fire protection laws and regulations shall be followed, and the contractor
performing the work must obtain necessary work permits. Crews shall have all firefighting tools
and equipment required by the responsible governmental agency. Contractors shall also adhere
to fire restrictions concerning work hours, fire watch following work and other policies of the
pertinent jurisdiction. Contractors with crews working in fire-prone rural areas are expected to
provide basic fire prevention and suppression training to their crews.

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Table 2.3
Voltage Minimum Tree House Distance
Phase to Phase From Conductors Tree Clearance
(kV) (Ft-In) (Ft-In)
2.1.6 At-Fault Tree Crew Caused Outages
Primary distribution and transmission outages caused by tree crews shall be assessed by a
committee made up of the managing director of distribution and transmission support, director of
vegetation management, business analyst and two contract representatives. The conduct of the
subject crew during the incident will be compared to requirements in ANSI Z133, OSHA
1610.269, contractor safety rules and the PacifiCorp Accident Prevention Manual. Outages
determined to be “at fault” by the majority of committee members will result in a credit to
PacifiCorp from the contractor in an amount specified contractually.
2.2 Environment
Environmental respect is a core value of PacifiCorp, as well as Berkshire Hathaway Energy, the
parent company of PacifiCorp. Contractors are required to strictly adhere to all environmental rules
and regulations. Moreover, contractors are also required to conform to the additional
environmental protections contained in these standard operating procedures.
2.2.1 Species of Concern
Tree work should not disturb or harm any rare, threatened, endangered, or protected plant or
animal species. Nesting season work restrictions are examples of important scheduling
considerations necessary to accommodate protected species. Prior to beginning projects on

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federal and state lands, PacifiCorp Foresters will contact the responsible agency to determine
whether or not such species are present on the right-of-way. If there are such species present,
Foresters should contact PacifiCorp environmental services for support.
All tree and brush work shall conform to guidelines of the responsible governing agency. Field
data inventories of threatened or endangered species may be on file in PacifiCorp district offices.
PacifiCorp environmental services should be contacted whenever threatened and endangered
species are identified.
2.2.2 Wetlands
Wetlands are lands where water saturation is the dominant factor determining the nature of soil
development and the types of plant and animal communities present living in and on the soil (US
EPA 2015). Wetlands shall be worked by hand. Federal, State and local laws and regulations
concerning wetlands shall be followed.
2.2.3 Stream Protection
Work shall not pollute water. Trees shall not be felled into streams or drainage ditches in a way
that could obstruct or impair the flow of water, unless instructed otherwise by the responsible
governing agency. Machine work shall not be performed within fifty feet of a stream. Soil or
debris shall not be placed below the high water mark of streams, unless instructed otherwise by a
responsible authority. Equipment shall use existing or designated stream crossings. State
forestry or fish and wildlife agencies shall be contacted if tree removal in and around streams
could cause erosion or if resulting exposure could increase water temperature. Federal and state
laws and regulations shall be followed concerning stream protection.
2.2.4 Bird Protection
Migratory birds are protected by the Migratory Bird Treaty Act of 1918 (16 USC 703-712). Most
bird species are protected under the Act; therefore, in an abundance of caution, all bird species
should be considered subject to the law’s provisions. Contractors are expected to provide
whatever training is necessary to ensure that their crews comply with the Act and adhere to these
standard operating procedures.
The Migratory Bird Treaty Act prohibits removal of bird nests that have eggs or chicks and
killing any birds which are members of any protected species. Active nests may be disturbed
only in rare cases of urgent fire or electrical safety risk (in the judgment of the responsible
Forester). If tree crews identify a possible immediate risk, they should contact the regional
Forester for authorization. Foresters should consult PacifiCorp environmental services regarding
whether or not work may be approved. If it may not, work should be postponed until after young
have left the nest.
The nests of eagles, threatened and endangered species, and colonial water bird nests (such as
those of cormorants and herons) may not be disturbed regardless of whether or not they are
active. Eagles are subject to additional protection insofar as it is illegal to disturb them near their
nests or winter roosting sites.

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Raptors (birds of prey) and herons require buffers (Table 2.4) around active nests to prevent
them from being disturbed, unless instructed otherwise by competent environmental or fish and
wildlife authorities.

Table 2.4

Species Work Buffer

In general, if a bird leaves a nest and does not return within an hour, it is being disturbed and the
buffer should be increased. In these cases, environmental services should be contacted within 24
hours to monitor the nest and respond appropriately if the adults fail to return.
Active bird nests and inactive eagle nests should be reported to the appropriate Forester and
environmental services using the procedure outlined in Figure 2.2.
Anyone working in vegetation management encountering a dead bird should report it to
environmental services

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Figure 2.2

2.2.5 Spills
To prepare for accidental spills, absorptive material shall be available. Mixing, loading and
cleaning equipment are critical activities that present the greatest exposure to accidents or spills.
In the event of a spill or herbicide misapplication:
 STOP, CONTAIN, ISOLATE
o Stop the source of the spill
o Contain the spill (it is especially important to prevent the spill from entering
waterways)
o Isolate the area – prevent people or vehicles from passing through the area.
 Report the spill to the Spill Hotline: 800.94.SPILL and provide:
o Caller and manager’s name
o Date and time spill was discovered
o Location (address or longitude and latitude)
o Manufacturer name and serial number
o Cause of spill
o Amount of spill
o Types of surfaces contaminated

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o Containment and/or clean-up activities performed so far
 Request the help of and notify Supervisor and PacifiCorp Forester and environmental
services.
 Remediate the spill
o Clean up the spill or have it cleaned up, following directives from the Spill
Hotline
o Wash equipment and vehicles.
o Properly dispose of cleanup materials
o Follow up with appropriate cleanup documentation.
 Clean-up at or near PacifiCorp generating sites or substations must comply with site
specific spill prevention and remediation plans.
2.3 Archaeological Sites
Vegetation management activities shall not disturb archeological sites. Known archaeological
sites shall be identified on the process checklist described in Chapter 4. If a forest technician or
tree crew identifies something that might have archeological significance, they should move off
site and contact the appropriate Forester. The Forester should contact environmental services for
advice on whether or not to continue. Work should not proceed without authorization from
environmental services.
2.4 Communication
Communication should be open and interactive. It should include everyone involved:
management, planners, vegetation management crews, property owners, public land managers,
appropriate governmental officials, members of organizations dedicated to related causes and
others.
2.4.1 Internal Communication
Communication within the vegetation management department needs to be clear and concise to
ensure everyone involved understands the desired outcome. Decision making authority should be
delegated throughout the organization, as appropriate.
2.4.1.1 Communication of Vegetation Conditions That Are Imminently Likely to Cause an
Outage
Members of the vegetation management team must comply with Transmission Grid Operations
Operating Procedure PCC-215, which is designed to meet Requirement 4 of the NERC
Transmission Vegetation Management Program standard FAC-003-4. Requirement 4 instructs
utilities to notify Control center with switching authority for the applicable line of vegetation
conditions that is likely to cause a fault at any moment. PacifiCorp may implement temporary
action, such as rating reductions or taking transmission lines out of service until vegetation can
be cleared. Inspectors should report the exact location of the subject trees (providing longitude
and latitude if possible) as part of the process.

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2.4.1.2 Media
Requests from media (print, electronic, radio or television) shall be referred to PacifiCorp Media
Relations and the community relations manager responsible for the area in which the request was
made. Media Relations can be reached for each business unit at:
 Pacific Power: 800.570.5838
 Rocky Mountain Power: 800.775.7950
Vegetation management personnel and contractors shall not speak to media representatives
without prior authorization from PacifiCorp Media Relations.
2.4.1.3 Legal
No response shall be made to an attorney unless through PacifiCorp’s General Counsel’s office.
2.4.2 Communication with External Stakeholders
Public land managers, property owners, regulators, and civic organizations have interests in
utility vegetation management activities. Educating potentially affected parties about the need
for, benefits of and science behind vegetation management can clarify expectations. Members of
the vegetation management team, including crewmembers, should know the facts about the
program, be prepared to answer basic questions and refer more complex issues through to their
Supervisor.
Communication should begin well in advance of work and involve listening to and
understanding people’s concerns. Work on governmentally-managed property can involve
administrative procedures that take months of advance work, including navigating through
permit processes and the concerns of specialists who have responsibility for stewardship over
public lands. It is not always clear to lands specialists how vegetation management helps
balance their (the land manager’s) responsibilities against the public’s need for a safe and
reliable electric grid. A memorandum of understanding among Edison Electric Institute (EEI)
member utilities and federal land management agencies (Edison Electric Institute et al. 2016)
established a framework for developing cooperative rights-of-way integrated vegetation
management (IVM) practices among EEI shareholder-owned electric companies, federal land
management agencies and the Environmental protection agencies.
2.5 Tree Growth Rate Definitions
Slow-growing trees grow vertically less than one-foot a year. Moderate growing trees grow
vertically between one and three feet a year. Fast-growing trees grow vertically more than three
feet a year. While trees exhibit species-specific growth rates, they can also be affected by short
term weather events and local site conditions. Professional judgement and experience should be
exercised when classifying tree growth by species.

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2.6 Tree Removal
In certain circumstances, it is necessary or appropriate to remove trees. Recognizing the special
interests of property owners in maintaining trees on their properties, PacifiCorp goes to great
lengths to make sure these interests are balanced against the need to maintain safe and reliable
service. When a tree is removed, the stumps shall be cut to within six inches of the ground or as
close to it as practical (for example, at the top of a barbed wire fence that has become imbedded
in the trunk). Stumps of all deciduous trees, brush and vines that are removed shall be treated
with an approved herbicide, where permitted. When trees are removed, work shall be performed
in a manner that neither damages trunks nor disturbs root systems of adjacent trees. Federal and
state agencies sometimes request that trees subject to removal be topped to create “wildlife
trees.” PacifiCorp may honor such requests, provided the safety of the tree workers or the
integrity of facilities are not compromised. Any trees which are removed along these lines should
be topped at a height so that the topped tree would never contact any PacifiCorp facilities should
it fall.
High Risk Trees. High risk trees are structurally unsound and could strike electric
facilities when they fail. “High Risk Trees” are defined as dead, dying, diseased,
deformed, or unstable trees which have a high probability of falling and contacting a
substation, distribution conductor, transmission conductor, structure, guys, or other
electric facility. High Risk Trees pose a safety and reliability risk and must be removed.
Discretionary Tree Removal. Discretionary tree removal is also an important component
of PacifiCorp’s vegetation management program. Tree removal can reduce safety risks;
improve access to facilities, clear lines of sight, and moderate future workloads. Tree
conditions are site and tree specific. In general, removals are encouraged in a distribution
right of way when trees are not part of landscaping. On a transmission right of way,
removal is encouraged and often mandated for all trees which could grow tall enough to
strike the subject transmission line. The specific scope of discretionary tree removals is
discussed in Chapter 5 (Distribution) and Chapter 6 (Transmission) and may be further
defined in a particular work release.
2.7 Mechanized Vegetation Control
Slashbusters, mowers, jarraffs, helicopter cutters, etc. have the potential to increase productivity
and reduce costs in rural, densely vegetated areas and should be used wherever practical.
Mowers and Slashbusters. Mowers and slashbusters are often more cost effective than
manual methods of tree removal and should be used where terrain and vegetation
conditions warrant. Mowing should be limited to fifteen feet either side of distribution
primary wires, within transmission rights-of-way and along access roads serving
PacifiCorp facilities.
Helicopter and Other Mechanized Cutters. Helicopter and other mechanized cutters can
improve productivity in rural, densely vegetated areas. Mechanical cutting shall comply
with ANSI A300 (Part 1) section 8.5. Mechanical cutting is typically limited to rural or

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remote locations, and contractors may use mechanical cutting only upon specific written
instruction from PacifiCorp. When mechanical cutting is employed, cuts should be made
close to the main stem, outside of the Branch Bark Ridge and branch collar. Precautions
are taken to avoid stripping or tearing of bark or excessive wounding.
2.8 Slash Disposal
Tree stems and tree limbs greater than six-inches in diameter should be left on site. Other
materials require disposal. “Slash” is brush, and tree limbs or shrubs less than six inches in
diameter, removed during tree operations. At the end of the work day or upon leaving a
particular worksite all Slash must be brought to ground and no severed limbs are to be left in the
tree canopy (hangers). Work locations shall be left in a safe and orderly condition.
Developed Areas. In developed areas, Slash should be chipped and removed from the site
unless an agreement has been reached with the property owner to leave it. Slash may be
left temporarily, provided the crew has notified the property owner or tenant, and
arrangements made to clean it up to the property owner’s reasonable satisfaction within
two business days.
Rural Areas. In rural, off-road areas, Slash can be disposed of on-site. All Slash should be
lopped into maximum lengths of three feet and scattered in piles no more than two-feet
high. Limbs greater than six-inches in diameter and brush should be piled separately.
Piles should be made at the sides of distribution rights-of-way and outside the wire zone
of transmission rights-of-way, unless specified otherwise by the regional Forester. If
brush is chipped, it may be broadcast on site, provided that resulting chip piles are no
higher than two-feet. Debris piles should not limit or block access to the right-of-way or
create fire risk.
2.9 Emergency Response
Tree work will be required from time to time on emergency storm restoration. Crews shall be
properly equipped to perform the work. PacifiCorp will be the sole determiner of equipment
appropriateness. Travel and lodging during the storm is billable. Double occupancy is expected
for crew members.
Contractor should provide a designated contact person for each region. Requests for crews
should be routed through that contact. Contractor shall be responsible for dispatching crews
whenever emergency restoration services are needed.
Crew rosters shall be provided by the contractor and maintained during restoration efforts. At a
minimum, rosters shall include: crew member names and position, location, contact information,
equipment and identification number.
Debris from storm work is left on site and not chipped or cleaned up, so chippers should not be
taken into the field during restoration work. Notification is not required during emergency
restoration work, but crews should conduct themselves respectfully.

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Emergency work shall be reported on a Weekly Time and Vegetation Report (Figure A.1).
Emergency work is done under the authority of the district operations managers in cooperation
with PacifiCorp Foresters. Tree crews and forest technicians assigned to storms should work
under the direction of circuit captains assigned by operations. Tree crews should report their
progress at least daily to both the circuit captain and their Supervisor. The supervisor should
report crew progress to the appropriate Forester. All storm work must be conducted as if the line
is energized. If the line cannot be worked safely under the assumption it is energized, it must be
grounded in accordance with section 2.1.1. In general, PacifiCorp does not dispose of Slash or
debris resulting from storm damage. Trees that fall during storms would do so regardless of
whether or not the lines are present. It should not be PacifiCorp’s responsibility to clear the
debris simply because the tree or trees from which it originated damaged PacifiCorp facilities on
the way down. However, if an outage is preventable, Slash may be cleaned-up and removed
from a property at the Forester's discretion.
2.10 Pronounced Facility Conditions
While tree crew members are not facility inspectors, they can be helpful in identifying
pronounced conditions, such as cracked poles, broken cross arms or insulators, loose guy wires,
and other problems. Tree crew members should report the condition on the Maintenance
Condition Report Form, (Figure A.2) and the Supervisor or forest technician should promptly
forward the completed Maintenance Condition Report Form.
2.11 Property Damage
Contractor shall be responsible for property damage arising out of or related to work.
Restoration of surfaces and repair of property damage in the execution of the Contract shall be
part of the work. Such restoration shall include, but is not limited to, ruts, disturbed drainage
ditches, broken drain tiles, cut fences and damaged fence posts.
Contractor shall inform PacifiCorp of claims within 24 hours of damaging the property.
Contractor has 15 business days to resolve any damages or PacifiCorp will settle the claim and
bill the contractor. Contractor must inform PacifiCorp personnel and get permission for an
extension if the time frame cannot be met.
Contractor shall be responsible for any damage or claims against PacifiCorp resulting in
violations of conservation measures as a consequence of Contractors actions.
2.12 Freelance Work
No one employed in PacifiCorp’s vegetation management department may solicit or perform
arboricultural-consulting or tree work (pruning, removal, insect or disease control, fertilization
etc.) for interests outside of officially authorized PacifiCorp projects on open feeders, grids,
transmission projects, tickets, storm orders, work orders or other PacifiCorp assigned project.
Outside projects may include side jobs for cash, work for private arboricultural firms (whether or
not they are owned by the tree crew members doing the work), consulting or any other enterprise
engaged arboricultural work.

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2.13 Fences and Gates
Gates should be left open or closed as they were found, or as the property owner instructs.
Damage to fences or gates shall be reported to the property owner and repaired as soon as
possible.
2.14 Climbing Spurs
Climbing spurs shall not be used when climbing to prune trees.
Exceptions:
 when limbs are more than throw line distance apart and there is no other safe means of
climbing the tree.
 when the bark is sufficiently thick to prevent spur damage to the Cambium.
 when working High Risk Trees that are to be reduced in height and left for wildlife.
2.15 Winching Vehicles
Winch cables or ropes should not be wrapped directly around anchor trees. Doing so damages a
tree’s bark and Cambium and cannot only reduce its health and value, but also eventually create
high risk to overhead lines. If the need arises to winch a vehicle (including an all-terrain
vehicle), a nylon strap (or equivalent) at least 2-inches wide shall be used around the tree, and
cables or ropes attached to the strap. Utility poles or towers shall not be used as winch anchors.

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3. TREE BIOLOGY AND PRUNING
Understanding fundamental tree biology is essential to understanding the impacts of pruning on
tree health and growth (Gilman 2012). Trees in proximity to electrical conductors should be
pruned for clearance in a manner that minimizes residual harm to the tree and directs future
growth away from the conductors.
3.1 Tree Biology
Understanding fundamental tree biology is essential to understanding the impacts of pruning on
tree health and growth (Gilman 2012; Lilly 2010). Trees in proximity to electrical conductors
should be pruned for clearance in a manner that minimizes residual harm to the tree and directs
future growth away from the conductors.
3.1.1 Foliage
Tree survival depends on an adequate supply of carbohydrates produced by the leaves. If a tree
abruptly loses a large portion of its foliage, as can happen with over-pruning, it could lack the
energy resources to meet its needs. Trees with insufficient foliage could be weakened to the point
where they become subject to attack by opportunistic insect and disease pests and sun damage
(Shigo 1986; Gilman 2012).
3.1.2 Stems
Trunks and branches are tree stems. Stems make up the bulk of the mass of a tree. Their
function is support, energy storage, and water, mineral, carbohydrate and growth regulator
transport. A developmental process unique to tree stems is their ability to compartmentalize or
“wall off” injury and decay (Harris, Clark, and Matheny 2004). Understanding the anatomy of
tree stems is critical in achieving the pruning objective while minimizing damage to the tree.
3.1.2.1 Xylem
Xylem is wood tissue. Sapwood is young, living xylem that stores carbohydrates, provides
support, and conducts water and essential elements. Heartwood is older, dead xylem that
provides support, and often contains anti-microbial compounds.
Long, hollow conducting cells (trachieds or vessels) predominate xylem structure. While trees
need this vascular structure to conduct water and essential elements, it can be exploited by
pathogens to spread up and down the stem. Trees attempt to block or “wall” off disease spread
by plugging cells in the xylem in a process known as tylosis (Shigo 1986).
3.1.2.2 Cambium
The tree’s “Cambium” consists of a thin layer of rapidly dividing cells around the outside of the
sapwood. Its primary function is to produce wood to its inside, creating diameter growth. This is

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the only source of wood production in the tree system, and the tree has no ability to replace
damaged or decayed wood.
Pathogens gain access to wood through wounds. In response to wounding, the Cambium
generates a "barrier zone” containing antimicrobial compounds. It protects new wood by
separating it from potentially infected wood that existed at the time of wounding (Figure 3.1).

Figure 3.1. The Cambium creates a barrier zone that contains discoloration and decay in the old
wood.
3.1.2.3 Branch Collars
Branch collars are a combination of parent stem and branch tissue generated through coordinated
growth around the branch attachment (Figure 3.2). In the spring of the year, diameter growth
begins at branch tips, and works toward the base. When new branch wood meets the branch base,
it grows around the juncture. Later in the growing season, wood from the parent stem envelops
branch wood laid down earlier. The “Branch Bark Ridge” is area of raised bark where branch
wood meets stem wood, pushing the bark outward, forming a layer of raised bark which is often
a sign of a strong branch attachment. The abundance of metabolically active tissue at the branch
collar can be made to produce antimicrobial compounds in response to infection. (Shigo1986).
This area is known as the “Branch Protection Zone,” which is an area of chemically and
physically modified tissue within the base of the branch that retards the spread of decay from the
branch to the parent stem.

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Figure 3.2. Branch collars form at the base of branches.

3.1.2.4 Codominant Stems
Codominant stems are stems that are at least half the diameter of their parent stem and compete
for dominance in the tree crown (Gilman 2012). They are similar to branches but have no branch
collars or Branch Protection Zones making them more prone to decay if one of the stems is
removed. Codominant stems are often problematic because as the two crowded branches grow
in diameter, they push against each other and undermine the structural integrity of the union,
making them prone to stem failure (Lilly 2010).
3.2 Utility Line Clearance Pruning
The primary purpose of utility line clearance work is to minimize safety and service reliability risks
caused by tree-power line conflicts. Pruning is primarily performed on distribution facilities,
although it can have application to transmission lines in some cases.

Pruning to clear conductors shall adhere to the principles of modern arboriculture. The American
National Standard for Tree Care Operations A300 (American National Standards Institute 2006,
2008), International Society of Arboriculture (ISA) Best Management Practices: Tree Pruning
(Gilman and Lilly 2002), Best Management Practices: Utility Pruning of Trees (Kempter 2004)
and An Illustrated Guide to Pruning (Gilman 2012), among other references, convey those
principles.

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While proper utility line clearance work should be consistent with practices that promote tree
health, utilities cannot place tree health over public welfare. Sometimes, there is no way to obtain
proper clearance in a manner that ensures the health of a tree (Lilly 2010). This is particularly true
regarding foliage retention. In cases were the tree cannot be pruned without harming its health, tree
removal is often best for the tree, tree owner and utility. If a property owner does not allow tree
removal, the tree should be pruned to specification clearances in all circumstances, even if that
pruning work is against a customer’s wishes or could harm the tree.
3.2.1. Natural Target Pruning
Natural targets are proper final pruning cut locations at strong points in the tree’s disease defense
system. Natural targets are branch collars and proper laterals. Removing branches at natural
targets rarely damages the joining trunk or limb (Gilman 2012). The ISA Best Management
Practices: Tree Pruning (Gilman and Lilly 2002) and ANSI A300 (American National Standards
Institute 2008) describe the technique. Targets vary depending on whether a branch is removed
or reduced.
3.2.2 Directional Pruning
Directional pruning is natural target pruning applied to redirect tree growth away from utility
lines (Gilman 2012). ANSI A300 and ISA’s Best Management Practices (Kempter 2004) instruct
that pruning to clear the utility space involves thinning cuts: removing at natural targets entire
branches that are growing toward (or once cut will produce sprouts that will grow toward) the
power lines.
While Heading Cuts produce sprouts that grow quickly back into the power lines, branch
removal and reduction promotes growth away from conductors. Since the point of utility
pruning is to train trees away from power lines wherever practical, branches growing away from
the electric facility should not be pruned. Instead, these stems should be allowed to develop to
their natural height or length, provided that growth does not create unreasonable safety risks.
This cannot be accomplished with strongly excurrent trees trapped directly beneath conductors.
Topping, round-overs, flush cuts, branch tipping and rip cuts are improper because they damage
trees. Directional pruning is consistent with natural tree structure. Remaining branches retain
their taper, strong attachments, growth regulators and spacing. They continue to grow and
function normally, allowing the tree to reach to its natural height.
"V" shapes often result on properly pruned trees growing under power lines particularly on
decurrent, deciduous trees (Gilman 2012; Kempter 2004; Miller 1998; Shigo 1990). Limbs
growing upward and toward the facility should be cut back to the trunk or to limbs growing away
from the conductors (Figure 3.3). Remaining branches should have sufficient clearance so they
do not damage the conductors in inclement weather common for the locality (high wind, freezing
rain, snow or other conditions). Excurrent trees (such as many conifers) are more problematic but
should be reduced to appropriate laterals or whorls. "L" or one-sided shapes often result on
properly pruned trees to the side of conductors (Shigo 1990; Gilman 2012). Limbs on the wire

23

side of trees located adjacent to facilities should be cut back to the trunk; or to limbs growing
vertically, sideways or downward; depending on the distance to the line or available natural
target.

Figure 3.3 "V" or "L" shapes can develop from crown reductions on trees growing in close
proximity to power lines. The ultimate objective is to train the tree up and away from the
conductor whenever possible, so the facility is cleared while minimizing health risks to the tree.
3.2.3 Collar Cuts
Branches should be removed at the collar (Figure 3.4). Cutting into the collar, known as flush
cutting, compromises the Branch Protection Zone and creates a direct port of disease entry into
the parent stem. Flush cuts are damaging and inappropriate.
Disease can weaken stems, potentially creating safety risks. On the other hand, proper branch
removal does not leave stubs that pathogens can use as an energy source to overcome the tree's
defense system and spread into the trunk. If the branch is removed correctly, only the Branch
Protection Zone is exposed, giving an advantage to trees in keeping out disease. As a result,
collar cuts virtually prevent decay from entering the parent stem (Gilman 2012).
Occasionally, branch collars are not readily evident and the collar must be approximated using
the Branch Bark Ridge. The cut should start in the branch crotch, just outside the Branch Bark

24

Ridge, and follow an outward angle that mirrors the inward angle the Branch Bark Ridge makes
with the trunk or parent stem. The cut should end roughly opposite the bottom of the Branch
Bark Ridge (Figure 3.4).

Figure 3.4. A proper collar cut, on a tree with and without a visible branch collar (Gillman 2015)

3.2.4 Reduction Cuts
Reduction is selective pruning applied to reduce the top or side of a tree or individual limb
(American National Standards Institute 2008). In a utility context, the goal of reduction is to
promote future tree growth away from the conductors, at least on decurrent trees. Reduction cuts
shorten leads to appropriate laterals (Figure 3.5). An appropriate lateral is no less than one-third
the diameter of the original limb and retains at least three-quarters of the lead's foliage
(American National Standards Institute 2008). Individual branches are autonomous in their
energy requirements. Removing too much foliage from a limb could deprive it of sufficient
energy to establish apical dominance, maintain its taper, close the wound, and compartmentalize
disease which will enter the wound.
A lateral that is too small will not develop into a structurally viable leader. Moreover, shortening
a lead removes apical meristems and other points of growth regulator production, which can
disrupt orderly growth. If, for example, auxin concentrations are insufficient, on some species a
crowded mass of upright, rapidly growing, poorly attached shoots can sprout from the cut and
grow directly back into the lines.

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Removing more than 25% of foliage from a limb has the same damaging result as internodal
topping cut, regardless of whether or not the cut is made to a proper-sized lateral. Even under the
best circumstances, reduction cuts are potentially harmful, acting more like a heading than a
thinning cut (Gilman 2012). Consequently, if a lead cannot be shortened to a limb at least one-
third the diameter of the original lead, or if a cut removes more than 25% of the foliage, that limb
should be either targeted for removal, or not pruned.

Figure 3.5. A proper crown reduction cut.

3.2.5 Large Branches
Large branches (those 3-inches in diameter or greater) can seldom, if ever, be removed without
harming the tree, particularly if they are codominant stems. Yet, large branches must be
prevented from growing toward the utility space, and that can mean heading or removing them
entirely. Both options can be harmful to the tree, and heading large branches often fails in
effectively clearing the conductors (Figure 3.6).
Removal of large branches should be done based on a measured approach. For example, one or
two large limbs might be removed out of three that are growing toward the conductors, and the
remaining limb(s) subordinated and targeted for removal on subsequent cycles, so long as the
required specification clearances are accomplished.

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Figure 3.6. Old Heading Cut. Shoots that proliferate from these cuts often dominate the tree's
crown, and gaps result when branches containing these shoot clusters are removed.

Large branches selected for later removal can be subordinated or removed gradually over
subsequent cycles (either interim or cycle). Subordination thins a portion of a limb's foliage.
Reducing a fraction of the foliage in this way suppresses the stem's growth and allows the
remaining tree parts to adjust and develop. In some cases, subordination can allow a codominant
stem to develop into a branch over time, enabling a Branch Protection Zone to form so a limb
can be removed without unnecessarily subjecting a tree to disease (Gilman 2012). Using
subordination over multiple cycles to remove large branches can reduce the effect of structural
limb removal on tree health, while ultimately circumventing the permanent problems Heading
Cuts can cause, even if that means temporarily heading the branch.
3.2.6 Heading Cuts
A heading cut is an internodal cut on a stem, or a cut made to a lateral too small to assume
dominance and should be considered a “cut of last resort”. Removing large stems that have been
headed often leaves wide gaps in the tree, because shoots that proliferate from the old Heading
Cuts often dominate the crown, and gaps result when branches containing these shoot clusters
are removed. Moreover, previously headed branches usually lack natural targets. When such
branches are growing toward the conductors, there might be no alternative but to remove them
entirely. However, in some cases, headed limbs may be left as a temporary measure. Such
headed branches should be removed on subsequent cycles.
Headed branches growing away from the facility space should not be pruned as a matter of
standard practice. However, shoots growing from the old Heading Cuts should be inspected for
structural integrity during subsequent visits. Corrective action, such as crown restoration
(Gilman 2012), could be necessary if these sprouts are found to be structurally weak. Crown
restoration involves restoring a previously headed stem’s natural structure by thinning sprouts
emanating from the old wound. Crown restoration should be done incrementally over the course
of several cycles. In some cases, structural defects resulting from heading cuts are so severe that

27

they cannot be corrected (Dahle et al. 2006). In these cases, the customer should be contacted
about removing the entire tree, or at least the subject branch or branches. If tree or branch
removal is not possible, there could be no choice but to remove the weak growth with a new
Heading Cut. This should be done only when extensive decay or hollow exists in the remaining
branch, with the approval of the Forester or Supervisor, for safety (not aesthetic) purposes.
3.2.7 Deciduous Trees
The "V" in many crown-reduced deciduous trees quickly fills in with shoots. These shoots
eventually require pruning to prevent them from interfering with the lines. In subsequent cycles,
it is important not to strip all these sprouts away, since that practice contributes to lion’s tailing
and can stimulate resurgent growth in many species. Rather, about half of the shoots should be
removed, and the other half retained providing adequate clearance is maintained (Figure 3.7).

Figure 3.7. On return visits to "V-Outs", under pruning should leave the smaller, suppressed
shoots to retain foliage and soften the visual effect of crown reduction.
Shoots selected for removal should be the largest and most vigorous, leaving smaller sprouts
behind. Growth selected for retention should be pencil-thin at the point of attachment. If need
be, these remaining shoots may be headed back to obtain specification clearances. In this way, a
rotation can be established where the largest, most vigorous shoots are removed each cycle, but
smaller, suppressed shoots are left to soften the negative visual effect that many customers find
objectionable.
Leaving shoots in the interior of a "V" provides shade and retains auxin production, both of
which suppress vigorous sprouting, and helps the trees hold clearance. Eventually the sides of the
tree will exceed wire height, resulting in more of a "U," and shade the interior of the tree,

28

suppressing shoot growth even more. In time, this top growth decreases the proportion of the
crown occupied by the cleared utility space and softens the negative aesthetics.

Figure 3.8. Crown reduction on a conifer.
3.2.8 Conifers
Many conifers; such as pine (Pinus spp.), spruce (Picea spp.) and Douglas-fir (Pseudotsuga
menziesii) have strong central leaders (excurrent form). When these types of trees grow directly
under the lines, they should be reduced to the whorl or largest available lateral that provides
specification clearance. Cuts made to conifer whorls are typically flat-topped in order not to
damage any branches in the whorl (Figure 3.8). Laterals should be tipped on conifers, which
prevents them from bending up toward the conductor.

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4. PLANNING, SCHEDULING AND REPORTING WORK
Scheduled work involves systematic cycle or interim projects on both distribution and
transmission lines. Transmission overbuilt on distribution lines should be worked in conjunction
with distribution feeder or grid projects. Schedules should be based on the time elapsed since the
last scheduled work, compliance, voltage (particularly for transmission lines), the frequency of
tree-caused outages, customer count, the existence of important accounts (hospitals, factories,
mines or other high demand facilities), tree conditions, the number of customer complaints, the
growth rate of predominant tree species, geography, customer density, rainfall and other
environmental factors.
4.1 Process Checklist
For all scheduled distribution and transmission work, Foresters and Supervisors utilize the
PacifiCorp Vegetation Management Process Checklist (Figure A.3) to facilitate systematic
project management.
4.1.1 Authorize Project Work
No work may begin on any project until a Forester has authorized such work in writing. The
contract with an independent contractor specifies the specific manner by which work is
authorized; typically work is authorized through issuance of a Work Release (Figure A.4). A
work release authorizes a contractor to proceed with a specific project and provides additional
written instructions for the completion of the work. Contractors will not be compensated for any
work performed on projects that have not been authorized through a work release or similar
written instruction, if contemplated in the contract.
For internal tracking purposes, the Forester should also forward a copy of any issued work
release to the PacifiCorp business specialist and director of vegetation management. The Forester
should also notify internal stakeholders of a project prior to beginning work. Internal
stakeholders include operations managers, customer-community managers, line patrolmen, hydro
facility site managers and other personnel. PacifiCorp tariff policy should be notified if work will
be conducted in a location where either past or current state public utility commission complaints
have been received. PacifiCorp communications department should be informed if work will be
conducted in the vicinity where public relations issues have surfaced in the past or could be
reasonably expected to arise during currently planned work.
The work release specifies the project type and provides instructions on discretionary tree
removals, tree replacements, use of chemical treatments, and other particulars. It also assigns
required completion dates. Before work begins, the Supervisor shall distribute copies of the work
release to each crew assigned to the project, and review instructions for proceeding.
After the project is finished, the Supervisor shall sign the work release to certify the project is
completed and closed. The signed work release shall specify the actual starting and completion
dates and any pertinent comments, including notation of any work that is either incomplete or
has been excused from meeting specifications by the Forester. By signing off on a project, the
contractor guarantees that the work required under the work release has been completed to

30

PacifiCorp's specifications, and assumes responsibility for any failures to meet PacifiCorp
requirements, outside of exceptions noted in the comments.
PacifiCorp maintains a database of historic data on work performed by vegetation management
contractors, including information on the type of work performed, and the person-hours charged
to complete these tasks. Historic information about a location may be provided to independent
contractors released to perform work at such a location.
4.1.2 Project Planning
The contractor performing the work is responsible for developing the project plan and deciding
how work will be completed. In developing the project plan, the supervisor and forest technician
typically coordinate with each other and should factor certain issues that may be implicated in
the project plan and performance of work.
 Federal Lands. PacifiCorp facilities that cross federally-managed lands are in place under
the authority of special use permits. Supervisors and forest technicians must ensure the
conditions in the pertinent special use permits are satisfied. Any concerns about the
potential of not complying with provisions in special use permits shall be communicated
to the Forester.

 Chemical Permits. Herbicide or pesticide use permits are required in certain jurisdictions,
particularly on federally-managed land. If a permit is required, Supervisors and forest
technicians must confirm that the permit has been acquired before herbicide application
may proceed.

 Other Permits. Other permits may also be required. Examples may include projects along
state road rights-of-way, in some communities, county or state forests or riparian areas.
All required permits shall be obtained by the contractor before work may proceed.

 Ticket Work. PacifiCorp will provide a contractor with past ticket work requests
associated with a feeder or grid, representing instances that customers had called in work
requests which were not an immediate threat to safety or electric service and could wait
until regularly scheduled work. Forest technicians shall ensure that such work is
performed or explain to the customer the reasons why the work does not need be done.

 Flagging. Many areas require flaggers and traffic control. Supervisors and forest
technicians shall identify areas where flagging support is necessary, on both the Activity
Report and a map.

 Uniground Construction. The overwhelming majority of PacifiCorp distribution circuits
are built with wye configuration, which includes a neutral wire. However, uniground
construction, which does not have a neutral wire, is found in some areas. The difference
is of little consequence on wires attached to cross arms, as all cross arm-mounted wires
should be cleared to primary specifications (see section 5.6.5). However, there is a

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significant distinction on lines without cross arms. Wye construction has a low neutral,
while the low wire on uniground construction carries primary voltage. This could lead to
safety and clearance risks if the low primary is mistakenly identified as a neutral.
Contractors are responsible to protect the safety of their employees. If a circuit is
uniground construction, Supervisors and forest technicians are responsible to alert tree
crews of the potential of a low-mounted primary, so safe work practices can be conducted
and proper clearances obtained.

 Special Request Property Owners. PacifiCorp provides contractors with notes identifying
customers who previously requested that the contractor (i) make personal contact prior to
performing work , (ii) comply with special access restrictions (i.e., property owners who
have requested tree crews not use a particular gate or drive), or perform work consistent
with time sensitive instructions (i.e. to refrain from work prior to a hay harvest).

 Hostile Property Owners. Certain property owners may be hostile to vegetation work on
or near their property. PacifiCorp often provides contractors with some historical notes
related to property owners who have exhibited opposition to work in the past, but
PacifiCorp cannot guarantee that every hostile property is identified in such notes. Forest
technicians are responsible to be proactive in working with all property owners,
especially those who have been identified as hostile in the past. Supervisor and forest
technicians should develop a strategy for working with hostile customers which
minimizes any direct adversarial exchanges.

 Hydroelectric Facilities. PacifiCorp hydroelectric facilities and adjacent rights-of-way
could have restrictions on vegetation management activities. PacifiCorp’s hydro
operations and implementation (compliance group), PacifiCorp right-of-way services, or
PacifiCorp environmental services shall be contacted before activities on or adjacent to
hydroelectric facilities begin. Herbicide use on or adjacent to PacifiCorp hydroelectric
facilities shall be reported to the plant manager weekly. Tree crews working on property
that is part of a hydroelectric project site should check in with the plant office before
beginning work and check out after work each day.

 Schools. School main or administrative offices should be notified of work to be done
within school grounds or on property adjacent to schools. An effort should be made to
schedule work without children present or specific accommodations made for pupils’
safety. Particular effort should be made to identify targets within drop zones, climbable
trees, access issues and other safety matters on site.

 Mobile Home Parks and Apartment Complexes. Mobile home park and apartment
complex managers should be notified in advance of planned work. Managers could be
aware of tenants with specific concerns. Mobile home park and apartment managers
should be encouraged to communicate with affected renters. Individual units may still
need notification of impending work.

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 Archeological Sites. Archeological sites should be located and marked. Work must
conform to guidelines of the responsible governing agency. If archaeological artifacts are
located on private lands, the finding shall be reported to PacifiCorp environmental
services. Field data inventories of sites known to PacifiCorp are on file in PacifiCorp
district offices.

 Environmentally or Culturally Sensitive Areas. Governmental, tribal and environmentally
sensitive lands present particular demands. Lands under governmental or tribal
management and environmentally sensitive areas should be identified early to allow time
to work through the required processes. The contractor will identify federal, state, county,
city and pertinent non-governmental organizations potentially affected by the project.
The appropriate entity should be notified of the impending project and asked whether or
not they have any concerns.

Before any field work begins, a meeting should be conducted with appropriate
governmental agencies that have interest in the project. This is especially important for
federal land managers and tribal leaders. In particular, no work may begin on Bureau of
Land Management or Forest Service managed lands without a pre-work coordination
among federal officials and vegetation management. Multiple projects and multiple
agencies may be covered by a single meeting. The meeting(s) should be organized by the
Forester, and PacifiCorp’s environmental services should be notified and invited to
attend. The meeting may be held either in person or through a conference call. Work shall
not begin until vegetation management receives written notice to proceed from the
appropriate agency.

If environmentally or culturally sensitive areas are identified on governmentally-managed
lands, a contractor with appropriate expertise should be retained to delineate subject sites
or areas. Target locations should be marked on maps and on site. Care should be taken
with field marking to ensure it is sufficiently clear to alert crews, while at the same time
being sufficiently discreet to avoid casual detection.

Foresters maintain the single master version of any PacifiCorp mapping resources. Effort
should be made to work off of digitized maps wherever possible. Forest technicians
should work with the GIS department to secure digital maps and communicate with the
PacifiCorp Forester responsible for the region. Foresters should ensure that there is a
digital master with all pertinent information. If paper map copies are necessary, the
Forester will check out copies of the master version, which should include sensitive
environmental or cultural sites.

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4.1.3 Work Identification
Prior to any tree crew work, forest technicians should attempt to contact the property owner or
tenant on whose property the work will occur, consistent with the procedures outlined in Section
8.2. Forest technicians shall document their contact with property owners or land managers, and
organize work for tree crews on an Activity Report (Figure A.5).
The Activity Report should identify the district in which work is to be conducted, the project
number (the discrete number assigned to the district), the contractor assigned to the job and the
feeder or grid number for distribution or plant locality number for transmission.
4.1.4 Work Assignments to Project Crews
Work assignments are the responsibility of the contractor performing the work. Tree crew
members should be supplied with copies of work releases and permits, so that crew members are
able to produce required documentation to the appropriate authorities on demand.
4.2 Reporting Work
After completing work, the contractor (i.e., the crew leader) shall document tree work on weekly
and daily reports.
4.2.1 Daily Report
The Vegetation Management Daily Report (Figure A.6) shall be used by an independent
contractor to keep detailed records of productivity, tree location, and chemical use.
4.2.2 Weekly Report
Tree work shall be reported accurately on the Weekly Time & Vegetation Report (Figure A.1).
The back of the report provides instructions and definitions for each cell. Weekly Reports, along
with the corresponding invoice should be submitted to the Forester responsible for the area in
which the report was completed.
Most of the items on the Weekly Report are self-explanatory. A few cells warrant clarification:
 Item 27. General Work Location: The general location should be the approximate
address. For example, the 4000 block of Dead Elm Memorial Road. Note that for audit
purposes, crew leaders will be responsible to find and identify all the trees they worked
over the course of a week. Consequently, more detailed information should be kept in
the daily report (Figure A.6).
 Items 32, 33. Woody plants (including vines) less than 6-inches in diameter at breast
height are classified as saplings. The actual square footage occupied by the above ground
portion of the plant should be measured and recorded, with a 100 ft2 maximum per plant
for both pruned and removed vegetation. Note that multi-stemmed woody plants where
no single stem is over 6-inches in diameter are classified as saplings, with a maximum of
100 square feet per plant.

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 Item 37. Stump Spraying: Document the time spent treating stumps of trees and Brush
feet that have been removed during the day. Use quarter-hour increments.
 Items 43-45. To obtain the diameters of multi-stemmed trees, add the diameters at breast
height of individual stems. For example, if a tree has three stems of 8, 4 and 3- inches in
diameter, the tree would be 15 inches in diameter and reported as a 12 to 24-inch
removal. An exception would be if no stems on the plant are over 6 inches in diameter at
breast height, in which case the plant should be classified as a sapling.
 Item 47 and 48. Saplings pruned and removed. Saplings are trees under six-inches in
diameter at breast height. Report area covered by the crown of the plant, with a 100 ft2
maximum for each plant. There must be six inches of soil between stems of the same
species to count as multiple plants.
 Items 54 and 55. For transmission cycle work, capture the number of acres cleared or
sprayed respectively using linear feet.

4.3 Tree Crew Audits
A PacifiCorp will occasionally perform a tree crew audit. The primary purpose is to provide a
quick assessment of quality assurance. Crew audits benefit both PacifiCorp and the Contractor
and are considered a best management practice (American National Standards Institute 2006).
Completion of an audit does not constitute acceptance of work, which must still be validated by
the submission of a complete work release. But catching exceptions and identifying the crew
behaviors that produce such exceptions early will very likely reduce the number of exceptions
found on post-audit. Exceptions found during post-audits after crews have left the area can be
costly for the contractor to remedy and can incur additional PacifiCorp staff time to follow-up
and ensure their correction.
Crew audits will be done at the Forester’s discretion. All work including work identification,
transmission, TGR, post-inspection, and pole-clearing will be subject to audit at any time.
Each audit should include the Forester, the crew-leader, and optionally, the Supervisor. The tree
crew shall be allowed to bill their time at time & equipment (T&E) rates for the duration of the
audit.
During an audit when an exception is noted it will be recorded on the Tree Crew Field Audit
Form (Figure A.7) along with the location, comments on the nature of the exception, and if
correction is required. Contractor shall remedy any exceptions noted on the Tree Crew Audit
Form.
4.3.1 Extreme Exceptions
If during the course of an audit the Forester identifies an exception that is in violation of federal
or state law, or witnesses an egregious safety violation, the crew may be shut down (at the
Forester’s discretion) until the exception is corrected.

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4.4 Worksite Inspection
PacifiCorp Foresters will also conduct worksite inspections, at the Forester’s discretion. The
Forester should use the Worksite Inspection Form (Figure A.8), to record the findings of these
inspections. The form provides a general checklist of inspection items like use of personal
protective equipment, tailboard, equipment condition, vehicle set up, herbicide labeling, and
other safety items.
4.5 Contractor Project Completion
Contractors performing work are always responsible for ensuring that all work on a project is
completed to PacifiCorp specifications, consistent with these standard operating procedures.
Supervisors (or a delegate) should inspect all work for compliance with these specifications and
any additional instructions provided in the work release. Any exceptions to specifications, for
any reason, must be noted on the work release.
Contractors are responsible to collect and submit to the Forester:
 PDF copies of all maps that have been marked by tree crews;
 PDF copies of Vegetation Management Daily Reports (Figure A.6);
 PDF copies of Weekly Time & Vegetation Reports (Figure A.1);
 PDF copies of any signed Property Owner Refusal Complaint forms (Figure A.9)
 customer information that might require follow-up the next time a project is worked,
including customers who refuse to allow work or access, customers who express
concerns about work, or customers or property owners who threaten vegetation
management employees;
 PDF copies of tree replacement vouchers issued
 a PDF copy of the signed work release.
4.6 Project Closure
Foresters should inventory maps and collect daily logs, tree replacement vouchers, hazard forms
as well as concerned customer, dangerous customer and refusal information received from the
Supervisor. Foresters should file this information digitally, so it can be retrieved when work is
conducted the next time through.
Foresters must confirm receipt and filing of a signed work release from the contractor for each
job. Foresters must examine the comment section for any work that was not completed to
specification, and if necessary, make provisions to correct those outstanding conditions.
The Forester should close the work release and inform the business specialist and director of
vegetation management of the closure by electronic mail.

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5. DISTRIBUTION PROCEDURES
Distribution lines are overhead facilities that are energized less at below 46 kV (except that there
are some legacy 34.5 kV transmission lines in certain areas). Distribution primary voltage
ranges from 600 to 45,000 volts, while lines energized below 600 volts are secondary.
5.1 Distribution New Construction Clearing
Every effort should be made by the PacifiCorp not to build new line over or through trees that
will need to be cleared from the facilities in the future. New distribution rights-of-way should be
cleared to specification before the lines are energized. Initial clearing is important because it
reduces the need for future planned outages to clear the line after conductors are installed and
sets customer expectations for future work.
5.2 Distribution Cycle Maintenance
Trees and vegetation shall be cleared from distribution facilities on scheduled cycles. Facilities
shall be worked systematically, either by feeder or grid map. The duration of a cycle is
dependent on local conditions, as determined by PacifiCorp. Cycles at PacifiCorp are typically 4
years in California, Oregon, and Wyoming, and 3 years in Idaho, Utah, and Washington.
In performing vegetation management distribution cycle work, contractors are required to:
 Systematically clear trees and other vegetation a specified distance from all primary
conductors, consistent with Sections 5.2 through 5.5 depending on the type of project
specified in any particular work release;
 Remove dead wood from crowns at risk of falling or being blown into the conductors;
Identify and correct readily climbable trees which are too close to power lines, consistent
with Section 2.1.3;
 Identify and remedy or remove tree houses violating the criteria specified in Section
2.1.4;
 Identify and remove High Risk Trees, consistent with Section 2.6;
 Remove or apply herbicide (presuming the property owner has not expressed objection to
herbicide application) to all volunteer trees (naturally seeded non-landscaped trees) which
are 6-inch or less diameter at breast height (DBH) and have potential to grow into the
conductors;
 Maintain compliance with state regulatory rules, laws or regulations.

Other work requirements may be specified in a work release for a particular project. For
example, a work release may have specific instructions regarding the application of tree growth
regulator (“TGR”) to fast-growing tree species.

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5.2.1 Specified Vegetation Clearance Distances – Primary
Each work cycle, trees and other vegetation are cleared to a specified clearance distance from
conductors, as set forth in Table 5.1 and
. Specified clearance distances are absolute minimums which dictate when pruning work must be
performed. Because of the application of natural target pruning techniques described in Section
3.2.1, the actual distances achieved after work is performed will almost always exceed the
distances specified. Specified vegetation clearance distances from primary conductors in the
distribution system are designed to allow sufficient space to prevent any contact with primary
conductors throughout the entire pruning cycle. Any trees or vegetation identified within the
specified clearance distance to a primary distribution conductor must be pruned (if not otherwise
removed). Neutral conductors in a raised (primary) position are treated as primary conductors for
purposes of this section.

Table 5.1 Three-year Cycle Four-year Cycle
Slow
Growing
(< 1ft./yr.)
Moderate
Growing
(1-3 ft./yr.)
Fast
Growing
(>3ft./yr.)
Slow
Growing
(< 1ft./yr.)
Moderate
Growing
(1-3 ft./yr.)
Fast
Growing
(>3ft./yr.)

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Table 5.2.

Slow
Growing
(< 1ft./yr.)
Moderate
Growing
(1-3 ft./yr.)
Fast
Growing
(>3ft./yr.)

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5.2.2 Specified Vegetation Clearance Distances – Secondary
A secondary line is a line energized to less than 600 volts. A service line is a secondary line that
runs between the electric supply and the customer. Specified distances from secondary
conductors in the distribution system are designed to allow sufficient space to prevent limbs
deflecting secondary or service conductors through the entire pruning cycle. Any trees or
vegetation within the specified distance (Table 5.3) to a secondary or service conductor must be
pruned (if not otherwise removed); provided, however, that if a work threshold is specified, then
pruning need not be completed unless the work threshold requirement is met.
Table 5.3
Line Type Work Threshold Specification Clearance
–

In addition to the specification clearances (Table 5.3), the following requirements also apply.
 Non-Insulated Wire Pole-to-Pole Secondary: any tree limbs between a primary
conductor and a non-insulated wire pole-to-pole secondary conductor shall be removed or
pruned. Side clearances may be reduced to one foot for structurally sound limbs greater
than 6-inches in diameter at wire height.

 Any Neutral: any tree limbs between a primary conductor and a neutral or insulated
secondary conductor should be removed or pruned.

 Insulated Pole-to-Pole Secondary Clearance: any tree limbs between a primary
conductor and an insulated pole-to-pole secondary conductor should be removed or
pruned.

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 Non-Insulated Service or Street Light: If the customer desires to remove other limbs
or trees around these lines, in addition to the minimum one foot clearance, forest
technicians or crew leaders should inform the customer to call the customer service line
to arrange for a temporary disconnection of the facilities to allow safe completion of the
desired tree work, as required by law.

 Insulated Service Streetlight: Limbs that are causing strain to the point of deflection or
that are abrading the insulation to the extent they could cause an outage before the next
scheduled cycle should be pruned to relieve the pressure. If pruning or removal is not
practical, arrangements should be made with operations to have the facility re-routed or
have suitable material or devices installed to avoid insulation damage by abrasion. If the
customer desires to remove other limbs or trees around these lines, they must arrange for
a temporary disconnection to allow the desired work to be done safely. PacifiCorp does
not clear trees for street light illumination, unless required to by specific language in a
franchise agreement.
5.2.3 Other Facility Clearances
Trees or branches two-inches or more in diameter applying direct pressure to or threatening to
fall on or through poles or guy wires shall be removed or pruned on cycle (Table 5.3).
One-third of the circumference around poles shall be cleared of vegetation to a distance of 5-feet
to allow linemen a climbing path. The remaining two-thirds of the pole circumference should be
cleared of all vegetation to a distance of one foot from the pole.
Vines shall be removed on cycle from poles and guys, cut at ground level, and treated with an
approved herbicide. They shall be reported as brush (< 6-in. dbh) or tree (>6-in. dbh) removed.
Vines clearly part of a landscape and rooted well away from the pole may be pruned and
reported as saplings pruned. Vines shall be pulled off the bottom 5-ft. of poles after they have
been cut. The facility point shall be documented by the tree crew and given to their supervisor,
who shall report it to operations to clear the remainder of the pole.
Trees should not be pruned or removed expressly to provide clearance for television cable,
telephone lines or private electrical facilities unless authorized in advance by the appropriate
forester.

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5.3 Distribution Interim Maintenance
In certain locations, where and when circumstances warrant, interim work may be performed
half way through a four-year cycle period, to address any trees which are likely to exceed
minimum clearance requirements prior to the next scheduled work. Interim work is focused on
the fastest growing trees, referred to as “cycle-busters”, which may not hold for an entire cycle.
When an interim project is performed, the distances in Table 5.4 and dictate if a tree must be
pruned. Whenever a tree is pruned, pruning should always accomplish the specified vegetation
clearance distances set forth in Section 5.2 (using Table 5.1 or Table 5.2 as applicable.

Table 5.4
Slow
Growing
(< 1ft./yr.)
Moderate
Growing
(1-3 ft./yr.)
Fast
Growing
(>3ft./yr.)

5.4 Distribution Annual Maintenance
In certain locations, where and when circumstances warrant, annual work may be performed. All
general provisions of these standard operating procedures apply for distribution annual
maintenance, including the identification and removal of High Risk Trees under Section 2.6.
Similar to an interim project, annual work is designed to address clearances on any trees which
Table 5.5

Slow
Growing
(< 1ft./yr.)
Moderate
Growing
(1-3 ft./yr.)
Fast
Growing
(>3ft./yr.)

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are likely to exceed minimum clearance requirements prior to the next scheduled work. Annual
maintenance focuses not only on extremely fast growing trees but also on identifying and
remediating rapidly developing hazard situations like storm, fire, and construction damage to
trees near the line. Trees reaching the threshold distances outlined in Table 5.5 will be removed
or pruned to specification clearances as set forth in Section 5.3.
5.5 Distribution Ticket Maintenance
Customers, district operations staff, governmental bodies, regulatory agencies or others alert
vegetation management to real or perceived conflicts between trees and power lines from time to
time. All regular work is performed as part of the scheduled cycle maintenance (including
interim and annual) described above. The intent of ticket maintenance is to correct immediate
and unreasonable safety or electrical service risks. Foresters are responsible to determine
whether a reported condition presents an immediate and unreasonable safety or electrical service
risk.
Condition which present an immediate and unreasonable safety or electrical service risk include:
 Trees representing an unreasonable safety risk as determined by the responsible forest
technician;
 Trees that have caused an outage;
 Trees violating specific state regulatory regulations;
 Limbs that are deflecting secondary conductors to the extent they present a high
probability of tearing down the wire before the next scheduled cycle work;
 Trees that are likely to start a fire;
 Readily climbable trees;
 Trees where the property owner requires clearance so non-utility line clearance workers
may work the tree (which complies with various state line safety laws and may be billed
to the requesting party).
If a report of a vegetation condition is readily discernable as an emergency situation, the Forester
should arrange for correction within 24 hours. Critical conditions reported by regulatory agencies
and other urgent situations should be inspected within 48 hours and corrected within 7 days.
Other tickets should be inspected within 10 business days from the date of request, and a
determination made regarding whether or not the reported condition warrants work.
All ticket maintenance work should be completed consistent with these standard operating
procedures. Non-critical conditions should be monitored and corrected on the next scheduled
maintenance work. The concerned party shall be contacted regarding the inspection
determination. This contact may be face to face if the customer is present, or by door hanger,
letter, or telephone if they are not present.

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Figure 5.1. Distribution ticket maintenance procedure.

44

5.6 Side Clearance Exception
Side clearances from conductors may be reduced to 18-inches for structurally sound limbs
greater than 6-inches in diameter at wire height, provided the tree is not readily climbable and
the tree shows no evidence of conductor contact due to wire or tree sway. High Risk Trees
should be removed or pruned to reduce the potential threat they pose.
5.7 Increased Overhang Clearance Alternative
Increased overhang clearance, in excess of the minimum distances specified in Table 5.1 and
Table 5.2, may be implemented by the contract supervisor or may be required by the responsible
forester. Increased overhang clearance should be considered by the forester or supervisor under
the following types of circumstances: three-phase lines (particularly to the first protective
device), rural or difficult to access areas, weak-wooded or fast-growing tree species, poorly-
structured trees, and/or foreseeable weather conditions, such as frequent high wind, heavy rains,
ice and snow. In some cases, such as three phase lines or remote areas, all overhanging branches
may be removed. Overhang may be tapered, with the greatest side clearance at minimum
clearance height, with gradually more overhang higher in the tree.
5.8 Pole-Clearing
PacifiCorp performs pole clearing in areas of elevated wildfire risk. (Figure 5.2). After removing
herbaceous and volunteer woody vegetation to bare ground for a 10-foot radius around subject
poles, herbicides, including soil sterilants, should be applied, unless expressly prohibited or it is
against the customer’s wishes. When pole-clearing is performed, trees or saplings with trunks
within the clearance zone should have eight feet of vertical clearance from the ground to the
highest limb. In California and consistent with California Resource Code 4292, Pole Clearing is
performed around subject poles in delineated resource areas during designated fire season.
Subject poles have fuses, air switches, clamps or other devices that could create sparks and start
fires (Nichols et al. 1995). This cleared space should be established and maintained by pruning
and removing above ground branches and plant parts. In other states, PacifiCorp performs pole
clearing on identified equipment poles in areas of elevated wildfire risk.

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Figure 5.2. Illustration of pole-clearing requirements (California Department of Forestry & Fire
Protection 2008, Figure 3, PRC 4292, 14 CCR 1254, Fire Break Clearance Requirement Around
Poles and Towers)
5.9 Padmount Transformers
Padmount transformers should not be cleared as part of normal distribution cycle or interim
maintenance. They may be cleared in response to facility point inspection requests should
operations require access and a work order is provided. Qualified line clearance tree workers are
not required to clear padmount transformers, so contractors responsible for landscape
maintenance around substations may be assigned to remove shrubs and other low-growing
vegetation that is interfering with padmount transformers.

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6. TRANSMISSION PROCEDURES
Transmission facilities are overhead lines energized to greater than 34.5kV. Typical
transmission voltages on PacifiCorp's system are 46kV, 69kV, 115kV, 138kV, 161kV, 230kV,
345kV and 500kV. Facility voltage and type determine the amount of transmission clearance
needed. Table 6.1 provides specification clearances for transmission rights-of-way.
Transmission work shall comply with the ANSI A300 American National Standard for Tree Care
Operations (American National Standards Institute 2006, 2011) and should follow Best
Management Practices (Miller 2014; Smiley, Matheny, and Lilly 2011)
Transmission work on lines at or above 200 kV and those designated by the Western Electricity
Coordinating Council as an element of the major transfer path in the bulk electric system,
including those that extend greater than one mile beyond the fenced area of the generating station
switchyard to the point of interconnection with a PacifiCorp facility or do not have a clear line of
site form the generating station switchyard fence to the point of interconnection with a
PacifiCorp facility shall also conform to the North American Electric Reliability Corporation’s
(NERC) Reliability Standard FAC-003(North American Electric Reliability Corporation 2009).
PacifiCorp’s vegetation management philosophy for transmission lines is to utilize integrated
vegetation management best practices wherever possible to conduct cover type conversion and to
cultivate stable, low-growing plant communities comprised of plants that will never interfere
with transmission lines in their lifetime. Reliability and safety are most effectively protected
through establishing and maintaining a right-of-way consistent with the wire-border zone
concept (W C Bramble et al. 1991). When the line is less than 50 feet off the ground, the wire-
border zone should be cleared of all incompatible vegetation unless an easement fails to provide
appropriate authority or there are legal impediments preventing it.
6.1 Initial Clearing and Construction
Newly constructed transmission lines should be cleared to full specifications prior to being
energized. In densely vegetated areas, rights-of-way usually have to be completely cleared,
(ground to sky) to the full width of the right-of-way as the initial stage in establishing a wire-
border zone (Figure 6.1).
6.2 Transmission Clearances
The objective of systematic transmission work is to safeguard the reliability of PacifiCorp’s
transmission system by preventing outages from contact with vegetation. Clearance work on a
transmission line is guided by three concepts: Minimum Vegetation Clearance Distances, Action
Thresholds, and Minimum Clearances Following Work (Table 6.1)

47

Figure 6.1. In densely vegetated areas, rights-of-way usually have to be completely cleared
initially to establish a wire-border zone.
Minimum Vegetation Clearance Distance (MVCD) represent radial distances from the
conductors inside of which trees shall not encroach. These distances are established in FAC-003-
4 (National Electric Reliability Corporation 2016) and must be maintained at all times.
Action Thresholds are designed to trigger vegetation management action and provide roughly a
ten-foot buffer from the MVCD. Clearance work is performed, anytime vegetation is located
within the Action Threshold distance from the conductor.
Minimum Clearances Following Work are designed to maintain the MVCD at all times. Trees
are removed or pruned so as to establish clearance distances well in excess of Action Thresholds.
Consistent with the general approach to maximize clearances on all transmission rights-of-way,
however, a PacifiCorp Forester may also increase the Minimum Clearances Following Work,
depending upon local conditions and the legal parameters of the right-of-way. Local conditions
may include appropriate vegetation management techniques, fire risk, reasonably anticipated tree
and conductor movement, species types and growth rates, species failure characteristics, local
climate and rainfall patterns, line terrain and elevation, location of the vegetation within the span,
worker approach distance requirements and other factors.

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Table 6.1. Transmission clearance requirements (in feet).
Line Voltage
500 kV 345 kV 230 kV 161 kV 138 kV 115 kV 69 kV 45 kV
8.5 5.3 5.0 3.4 2.9 2.4 1.4 N/A
18.5 15.5 15.0 13.5 13.0 12.5 10.5 5

50

40

30

30

30

30

25

20

6.2.1 MVCD Violations
Because of the buffers built into the Actions Thresholds and the Minimum Clearances Following
Work, a violation of MVCD is extremely rare. If a violation is ever identified, trees that violate
MVCD shall be corrected within 24 hrs., consistent with PacifiCorp Transmission Grid
Operations Operating Procedure No. PCC-215 Guidelines for Communication of Vegetation
Conditions that Present an Imminent Threat of Transmission Line Outage.
6.2.1.1 MVCD Calculation
The Minimum Vegetation Clearance Distance represents minimum clearances that should be
maintained from conductors at all times, considering the effects of ambient temperature on
conductor sag under maximum design loading, and the effects of wind velocities on conductor
sway. MVCDs in Table 6.1 are for 10,000-11,000 feet above sea level (Table 2 of FAC-003-04)
and apply across PacifiCorp’s service territory regardless of elevation.
6.2.2 Structure Clearances
Trees and Brush should be cleared within a twenty-five-foot radius of transmission "H" or metal
structures, a ten-foot radius of single pole construction and a five-foot radius of guy anchors.
Clearing activities shall not damage poles, structures, guys or anchors. Grasses, forbs, ferns and
other herbaceous species may be left around structures and guys.
6.2.3 Guy Wires
Trees or branches two-inches or more in diameter applying direct pressure to or threatening to
fall on or through poles or guy wires shall be removed or pruned.
6.3 Inspections
Vegetation management work on transmission lines is scheduled as needed, depending on the
results of regular inspections.

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6.3.1 Inspection Frequency
Main Grid Transmission. Transmission lines defined as “applicable lines” in FAC-003 are
inspected at least annually, by ground or air, by Line Patrolmen who have responsibility for
inspecting transmission lines subject to FAC-003 and reporting conditions to vegetation
management. PacifiCorp Foresters coordinate with Line Patrolman to discuss vegetation
conditions.
Local Transmission. Local transmission (non-FAC-003 lines) shall be inspected by the
contractor in conjunction with distribution cycle work.
6.3.2 Line Patrolmen Responsibilities Under FAC-003
Line Patrolmen are responsible to comply with Requirement R4 of NERC Standard FAC-003
and shall do so by following the procedures set forth in PacifiCorp Transmission Grid Operations
Operating Procedure No. PCC-215 Guidelines for Communication of Vegetation Conditions that
Present an Imminent Threat of Transmission Line Outage. Line Patrolmen encountering a tree
that poses a threat of causing a transmission outage at any moment must:
 Immediately notify the grid operator by phone and describe the nature and extent of the
threat.
 Complete and process the Emergency Tree Action Form.
 Communicate the vegetation conditions to vegetation management for urgent attention.
Examples of tree conditions that pose a threat of causing a transmission outage at any moment
include (but are not limited to) trees that violate or pose a risk within 72 hours of violating
NERC Minimum Vegetation Clearance Distance (MVCD), uprooted trees that are leaning
toward the line and pose a risk of immediate failure, and trees with structural failures that may
cause them to break in part or whole onto the transmission facilities (Smiley, Matheny, and Lilly
2011).
6.3.3 Additional Inspection
In addition to the inspection performed by Line Patrolmen, Foresters may select lines among
those subject to FAC-003 for additional inspection. These inspections supplement, rather than
substitute for, those conducted by line patrolmen. Foresters should assign contract
representatives to complete these inspections, using Level 1 assessments (American National
Standards Institute 2011).
Such inspection should identify trees that pose a threat of causing an outage at any moment, and
trees that could possibly violate work thresholds within the next year. PacifiCorp plan and
profiles should be used in the field itemizing maximize sag and sway along with range finders to
confirm the MVCD has not been violated. Locations should be noted on an activity report, and
assigned to a tree crew for work, with the appropriate Forester’s approval.
If the inspections discover a tree that poses a high likelihood of causing an outage at any
moment, the inspector shall contact the appropriate Forester within three hours. Foresters shall

50

immediately request the appropriate line patrolman to inspect the line, consistent with the
procedures set forth in Section 6.3.2.
6.4 Work Planning
The Vegetation Management A300 standard (American National Standards Institute 2006) and
best management practice (Miller 2014) recommend against cycle-based transmission work
thresholds. Rather, such standards recommend that work be scheduled based on a number of
factors, including line voltage, line importance, vegetation conditions that violate the action
thresholds in Table 6.1, location, predominant species’ growth rates, threatened and endangered
species, archeological sites, topography and other factors. Accordingly, PacifiCorp Foresters
may consider any or all of these factors in scheduling work on transmission lines. A
comprehensive approach that exercises the full extent of legal rights is superior to incremental
management in the long term because it reduces overall encroachments, and it ensures that future
planned work is sufficient at all locations on the right-of-way. In planning work, Foresters
should consult with PacifiCorp Right-of-Way Services to determine the width of a right-of-way
and the scope of the easement rights associated with a right-of-way. Foresters should generally
plan work for the full extent of the easement; in all cases, except as otherwise directed by Right-
of-Way Services, the width of planned work should be at least as wide as the typical widths for
transmission rights-of-way, which are listed in Table 6.2.
Table 6.2. Typical transmission right-of-way widths.

6.4.1 Annual Work Plan
PacifiCorp performs vegetation management work in accordance with annual work plans
prepared by a Forester, which details the circuits and facilities to be managed during a calendar
year. Plans should include:

51

 a list of facilities subject to scheduled work (if only a portion of a line is scheduled, the
line segment must be identified)
 dates when work is anticipated to start and end on each project (Gantt charts are
recommended)
 a description of the type of control methods (cycle, herbicide, mowing, aerial, etc.).
The annual work plan may be adjusted during the year to account for changes in conditions that
require a circuit, line segment or project to be moved into or out of the work plan. Examples of
reasons for adjustments include, but are not limited to, vegetation growth in excess of anticipated
levels, vegetation inspection results, new construction projects or removal of existing facilities.
Adjustments to the annual work plan shall be documented as they occur and shall be authorized
by the director of vegetation management.
6.5 Integrated Vegetation Management
Integrated vegetation management is a system of managing vegetation in which undesirable
vegetation is identified, action thresholds are considered, all possible control options are
evaluated, and selected control(s) are implemented (American National Standards Institute
2006). The purpose of vegetation management on utility rights-of-way is to establish sustainable
plant communities that are compatible with the electric facilities, wherever possible. These
communities are stable, low-growing, compatible with conductors, diverse, and establish a
sustainable supply of forage, escape and nesting cover, movement corridors for wildlife, reduced
fire risk, and more open access to the line (Yanner and Hutnik 2004). Ground disturbance shall
also be minimized on all rights-of-way during vegetation management activities. By establishing
and maintaining native vegetation the invasion of noxious weeds into the corridor will be
minimized (Bonneville Power Administration 2000).
6.5.1 IVM Control Methods
Control methods are the processes used to achieve objectives. Control methods selection should
be based on pre-control evaluations, expected growth rates, line priority, economics, regulations
and specified objectives. Control method types include manual, mechanical, chemical,
biological, and cultural.
Manual Control Methods. Manual methods involve workers using hand-carried tools, such as
chainsaws, handsaws, pruning shears. Manual techniques are selective and can be used where
others may not be appropriate, including urban or developed areas, environmentally sensitive
locations (such as wetlands or places inhabited by sensitive species), in the vicinity of
archeological sites and on steep terrain.
Mechanical Control Methods. Mechanical control may be efficient and cost effective,
particularly for clearing dense vegetation during initial establishment, or reclaiming neglected or
overgrown rights-of-way. Mechanical control methods, however, can also be non-selective and
disturb sensitive sites, such as wetlands and culturally sensitive sites. Many machines are also
not suitable for use on steep terrain.

52

Chemical Control Methods. Chemical control methods like herbicides are key to the success of
IVM because they provide for cost-efficient cover type conversion (Yahner and Hutnik 2004).
Herbicides must be used according to directives on their labels. Applicators are not only
required to comply with label instructions, but also all other laws and regulations pertaining to
their use (see Chapter 7).
Biological Control Methods. Biological control methods use plants, animals, insects or
pathogens to control undesirable vegetation. Some plants, including certain grasses, release
chemicals that suppress other species growing around them. Known as allelopathy, this
characteristic can serve as a type of biological control against incompatible species. Promoting
wildlife populations is also a form of biological control. Birds, rodents and other animals can
encourage compatible plant communities by eating seeds or shoots of undesirable plants.
Cultural Control Methods. Cultural controls employ establishment of compatible stable plant
communities or agricultural crops, pastures, mulching, or other managed landscapes to control
undesirable vegetation. The wire zone—border zone concept is an example of a cultural control
(Miller 2014).
6.5.2 Wire Zone—Border Zone
Properly managed, wire zone—border zone linear corridors not only effectively protect the
electric facilities, but also can become an asset for forest ecology and forest management. (W C
Bramble et al. 1991; Yahner and Hutnik 2004)
Flat Terrain. On flat terrain, the wire zone is the right-of-way portion directly under the wires
and including roughly ten additional feet to the field side of the outside phases. (W C Bramble et
al. 1991) The border zone is the area, on both sides of the line, from the edge of the wire zone to
the edge of the right-of-way (Figure 6.2). Species of trees that could grow into the wires at any
time in their lives should not be allowed in either the wire zone or the border zone.
Sloped Terrain. On slopes and adjacent to slopes, the wire zone and border must be adjusted
according to the degree of the slope(s). The wire zone should be extended on the up-slope (and
the border zone to the up-slope side should be reduced or eliminated), because of wire sag and
sway. Consequently, the border zone on the down-slope side may be extended proportionately
(Figure 6.3).

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Figure 6.2. Bramble and Byrnes Wire Zone-Border Zone (adapted from Yahner, Bramble, and
Byrnes 2001)

Figure 6.3. The border zone is condensed on up-slopes, where wire sag and sway could bring it
into contact with trees, and is extended on down-slopes.

54

Varying Terrain. When the terrain varies, the wire zone—border zone concept adapts to the
changes in elevation. The type of vegetation allowed in either the wire zone or the border zone is
dependent on the height of the conductors, at maximum engineered sag and sway, relative to the
ground, with attention to side slope. When a transmission line crosses areas of variable elevation
between structures, there are additional clearance considerations. The right-of-way in each of
Region A, B, and C, (Figure 6.4) should be cleared as follows:

Figure 6.4. Transmission under-clearance regions

 Region A (Under 50 Feet). Region A is the area where lines are less than 50 feet off the
ground. The 50-foot height should be from maximum engineered sag and sway. After
clearing, the Region A wire zone should consist only of grasses, legumes, herbs, ferns
and low-growing shrubs (under 5-feet at maturity). The Region A border zone should
consist of tall shrubs or short trees (up to 25 feet in height at maturity), grasses and forbs.
These cover types benefit the right-of-way by competing with and excluding undesirable
woody species.

 Region B (50-100 Feet). Region B occurs where the lines are between 50 and 100 feet off
the ground from maximum engineered sag and sway. In Region B, tall shrubs or short
trees (up to 25 feet in height at maturity), grasses and forbs may be established
throughout the right-of-way, including the Region B wire zone. Note that many
transmission structures are tall enough that conductors are at over 50 feet high on and
near the structures. In such cases, a border zone community may be maintained near
structures, but care should be taken to maintain access to the structure as specified in
Section 6.1.5.

55

 Region C (Over 100 Feet). Region C is where the lines are 100 feet or more off the
ground. Tall-growing trees may be allowed in any zone in Region C, provided they have
at least 50 feet of clearance. Trees with less than 50 feet of clearance in the Region C
wire zone should be removed.
6.6 Tree Removals in Transmission Rights-of-Way
In performing vegetation management on transmission rights-of-way, removal of trees is
generally superior to pruning. Removal minimizes the possibility of conflicts between energized
conductors and vegetation. Contractors performing work in a transmission right-of-way must
obtain specific permission from the responsible Forester to leave a tree within the widths
described in the work plan, as follows: (i) all trees in Regions A wire zones should be removed;
(ii) any trees species which would grow into the MVCD, in any border zone and in Region B
wire zone, should be removed; and (iii) any tall-growing trees which have grown within 50 feet
of the line in Region C should be removed.
Foresters may establish generalized exceptions to the requirement for tree removal in a work
plan. For example, transmission lines may be constructed on the edge of dedicated road right-of-
way where there may or may not be an easement or permit on the adjoining property allowing
full tree removal.
6.7 Tree Removals Outside Transmission Rights-of-Way
Whenever vegetation management work is scheduled on transmission lines, High Risk Trees
shall be identified and removed, consistent with Section 2.6.
6.8 Post-Work Assessment
Foresters should audit transmission work following procedures outlined in Section 4.3. The
audits should document adherence to specifications. Moreover, audits should provide the tree
crew leader with feedback on production, professionalism, equipment, safety and crew
efficiency. Results shall be documented on an Audit Report (Figure A.7). Following systematic
work, the entire length of completed line should be inspected to verify work complies with
PacifiCorp specifications.
6.9 Mitigation Measures
NERC Requirement R5 directs transmission owners to develop mitigation measures to achieve
sufficient clearances for protection of the transmission facilities when it identifies locations on
the right-of-way where the transmission owner is restricted from performing work that may lead
to a vegetation encroachment into the MVCD. Prior to the implementation of the next annual
work plan, the owner shall take corrective action to ensure continued vegetation management to
prevent encroachments.
Whenever the restriction is caused by a landowner, the refusal process in Chapter 8 shall be
followed. If the refusal process has been completed without attaining clearances that would
prevent encroachment into the MVCD before the next scheduled work, such locations must be

56

documented on the Work Release (Figure A.4). These sites should be reported in writing to the
appropriate line patrolmen within 30 days. The line patrolmen should report annually on these
site’s status. In addition, Foresters shall arrange to have the site inspected at least biannually.
6.10 Vegetation Screens
Vegetation screens may be required by federal or local authorities in some locations at high
visibility areas such as major road crossings. Where these mandates exist, vegetation screens
should consist of border zone communities and be located near structures (where the line is
unlikely to sag), if possible. If no border zone species are present, tall-growing trees may be left
provided they have at least the minimum clearances in Table 6.1 following scheduled work.
Leaving tall-growing trees in transmission rights-of-way should be discouraged because they
impede cover type conversion. Vegetation screens should be no more than twenty-five feet from
frequented vantage points into the right-of-way. Areas where tall-growing species are retained
as screens shall be documented and monitored annually by line patrolmen. If remaining trees
violate work thresholds specified in Table 6.1, line patrolmen should report them to Vegetation
Management within 30 days for correction.
6.11 Merchantable Timber
Rights-of-way could contain merchantable timber. Merchantable timber is defined as trees with
at least six-inch diameter at breast height (DBH) that are recoverable and have a market in the
local area. Merchantable timber belongs to the property owner unless the easement or permit
states otherwise. If merchantable timber needs to be felled, the property owner should be
contacted regarding timber recovery.
After the merchantable timber is felled, it should be de-limbed and left in total tree length on the
right-of-way for recovery by the owner. In limited cases, PacifiCorp may decide to purchase
merchantable timber from the property owner and retain or transfer ownership to another party.
A forest practice permit from the appropriate state department of forestry may be required for
timber recovery.
6.12 Transmission Safety Procedures
The following safety procedures shall be followed by all tree crews on PacifiCorp transmission
facilities.
6.12.1 Pre-work Communication with Control Center
Operative communication capability is mandatory at all times on transmission rights-of-way
Communication with the Control Center is critical for tree crew safety. Every morning before
starting transmission work, tree crews shall call the Control Center from the right-of-way by
radio or telephone and provide the following information to comply with Power Delivery System
Operations System policy SOP-152:
 Name of crew leader
 Name of company

57

 Contact information (radio or cell number)
 Name of transmission line
 Line section (substation names between which work is to occur, such as "Alvey to
Dixonville," or "Ben Lomond to Terminal")
 Location of work (structure number, address or both)
 How long the crew will be working at that location
 Radio or cellular telephone number of the crew
 Name of Supervisor and their cellular telephone number
If radio or telephone contact cannot be made with the Control Center from the right-of-way, non-
emergency work shall not be performed at that site. The crew should relocate to work where
they can communicate with the Control Center. Satellite phones might be necessary in remote
locations to provide the required communication.
6.12.2 Post-Work Communication with the Control Center
Each afternoon after completing transmission work for the day, tree crews shall call the Control
Center and provide the following information:
 Name of crew foreman
 Name of company
 Contact information (radio or cell number)
 Name of transmission line
 Line section (substation names between which work occurred, such as "Alvey to
Dixonville," or Ben Lomond to Terminal")
 Location where work was performed
 Notice that crew members and equipment are off the right-of-way or in the clear.
6.12.3 Safe Working Procedure
If a tree cannot be felled or pruned safely, work shall not proceed. If a tree or limb falls into the
conductors, work shall stop immediately and emergency procedures followed (Figure 2.1).
Minimum approach distances (Table 2.1) shall not be violated. Transmission conductors can sag
considerably at mid-span during hot weather, ice buildup and heavy electrical loads. Trees that
have safe clearance in the morning may not have safe clearance in the afternoon. Conditions
could require a Hold or Clearances. Clearances on some transmission lines can take weeks or
months to schedule. See Section 2.1.1 for Hold and Clearances instructions.
6.13 Monthly Progress Tracking
Progress on the annual work plan for NERC Transmission Lines shall be tracked on the
PacifiCorp Main Grid Transmission Progress Report (Figure A.10) for lines under the auspices
of NERC Standard FAC-003. Progress on the annual work plan for other transmission lines shall
be tracked on the monthly Local Transmission Progress Report. Both reports track miles
achieved against plan on a monthly basis (Figure A.11).

58

6.14 Quarterly WECC Audit Report
PacifiCorp is required to report outages on transmission lines subject to FAC-003.

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7. CHEMICAL PROCEDURES
Herbicides and tree growth regulators are an integral part of PacifiCorp’s Vegetation
Management program. Tree Growth Regulators (“TGR”) refers to chemicals that slow growth of
some tree species. Chemical applications shall be performed according to federal, state and local
regulations. Chemical use must comply with labeling. PacifiCorp’s director of vegetation
management shall approve all products and mixes.
7.1 Notification
Property owners shall be notified at least five days, but no more than six weeks in advance,
whenever chemicals are to be used on their property. Property owner objection to herbicide use
shall be honored.
7.2 Licensed Applicators
Crew leaders in all states except California shall hold a valid applicator’s license. Applicators
shall either hold that license, or work under the direct supervision of a certified applicator as
required in the state in which they are working. Tree crews found working without a crew leader
or applicator without a valid applicators license for the state in which they are working may be
shut down at the Forester’s discretion. Supervisors of qualified applicators shall hold a certified
applicator’s license in the state or states in which they supervise crews.
7.3 Closed Chain of Custody
The company making the application is responsible for chemical purchase and storage, record
keeping as well as container disposal. Closed chain of custody best practices are encouraged
(Goodfellow and Holt 2011). Closed chain of custody is a concept in which ready-to-use, diluted
concentrate formulations are utilized in closed delivery systems. Closed chain of custody
includes herbicide shipping, distribution, storage, and mixing, which includes returning empty
containers for refilling and reuse.
7.4 Chemical Reporting
All chemical applications shall be documented in the Daily Report (Figure A.6), unless a
different method is specifically approved in writing by the regional Forester. The company
making the application shall be responsible for maintaining reports for review by the state
departments of agriculture.
When chemical work is done on or adjacent to PacifiCorp Hydro properties, copies of chemical
reports shall be provided to the plant manager weekly.
7.5 Herbicide Applications
Herbicides prevent sprouting from stumps of deciduous trees and should be used on saplings of
tall-growing species to reduce future inventories. Herbicides are essential in cover type
conversion necessary in establishing the wire zone-border zone method on transmission lines.

60

When properly used, herbicides are effective and efficient, minimize soil disturbance, and
enhance plant and wildlife diversity. Herbicide application can benefit wildlife by improving
forage as well as escape and nesting cover. In some instances, noxious weed control is a
desirable objective on utility rights-of-way that can be accomplished through herbicide
treatment.
Herbicide use can control individual plants that are prone to re-sprout or sucker after removal.
When trees that re-sprout or sucker are removed without herbicide treatment, dense thickets
develop, impeding access, swelling workloads, increasing costs, blocking lines-of-site, and
deteriorating wildlife habitat (Yahner and Hutnik 2004). Treating suckering plants allows early
successional, compatible species to dominate the right-of-way and out-compete incompatible
species, ultimately reducing work.
Treatments include individual stem, broadcast and aerial treatments. Ninety-five percent control
shall be assumed on all herbicide applications to be considered effective. Treatments exhibiting
less than 95% control may need to be retreated at the contractor’s expense.
7.5.1 Herbicide Best Management Practices
PacifiCorp is dedicated to ensuring proper application of approved herbicides to minimize the
effects on non-target vegetation, human health, fish and wildlife species, and water quality
(Childs 2005).
Herbicide applications shall:
 follow all product label mandatory provisions such as registered uses, maximum use
rates, application restrictions, worker safety standards, restricted entry levels,
environmental hazards, weather restrictions, and equipment cleansing.
 follow all product label advisory provisions such as mixing instructions, protective
clothing and others matters.
 have on site a copy of the label and Safety Data Sheets (SDS); and
 be made in the presence of a licensed applicator valid for the state in which work is
performed.
7.5.2 Wetlands and Waterbodies
Climate, geology and soil types should be considered when selecting the herbicide mix with the
lowest relative risk of migrating to water resources (Childs 2005). The effects of herbicides on
wetland and water resources should be minimized by utilizing buffer zones. Buffer zones reduce
the movement of herbicides from the application site into adjoining water bodies. Buffer zones
must be followed unless instructed otherwise by competent authorities.
7.5.3 Spills
Mixing, loading and cleaning equipment are critical activities that present the greatest exposure
to accidents or spills. Spills can be avoided by using closed chain of custody best management
practices. If any spill occurs, the procedures in Section 2.2.5 must be followed.

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Table 7.1.
Herbicide
Ecological Toxicities
and Characteristics
Buffer Width From Water Resource per Application Method

Spot

Localized

Broadcast
Mixing,
Loading,
Cleaning

7.5.4 Inappropriate Applications
There are situations where herbicide applications are inappropriate. If any applicator is uncertain
whether or not an application is appropriate, the applicator shall consult the regional Forester.
Inappropriate applications include (but are not limited to) situations involving:
 areas where the property owner expresses objections to herbicide use
 areas where herbicide could drift or leach into organic farms
 governmental lands where herbicides are prohibited
 conditions of heavy precipitation or strong winds
 periods of high temperatures, which can cause product volatility and damage off-target
plants
 trees that could be root grafted to desirable trees
 trees that are near desirable plants where the herbicide could move into contact with off
target foliage or roots
 trees close to agricultural crops or harvestable, edible plants
Note that caution during periods of high temperatures can be particularly important for foliar
applications and that vineyards can be especially sensitive to synthetic auxins. During periods of
high temperatures, treatment can be deferred until weather cools. If there is any uncertainty
regarding whether or not an application is appropriate, contact the regional Forester.

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7.6 Approved Herbicides
A list of approved products appears in the following sections. PacifiCorp’s director of
vegetation management must authorize other chemicals.
 Stump Application
o 2, 4-D
o Glyphosate
o Picloram
o Triclopyr

 Low Volume Basal Application
o Imazapyr
o Triclopyr

 Foliar Application
o 2, 4-D
o Aminopyralid
o Fosamine ammonium
o Glyphosate
o Imazapyr
o Metasulfuron methyl
o Picloram
o Sulfometuron methyl
o Triclopyr

 Soil Application
o Diuron
o Imazapyr
o Picloram
o Sulfentrazone
o Tebuthiuron
7.7 Approved Tree Growth Regulators (TGR)
Tree Growth Regulator applications are intended to retard fast-growing trees so that they will not
interfere with facilities or violate state regulatory agency tree policy before the next scheduled
maintenance.
 Fluprimidol
 Paclobutrazol

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8. CUSTOMER RELATIONS
Representatives of vegetation management interact with a significant number of customers. As a
result, customers often develop an impression of PacifiCorp based on their experience with
vegetation management. Particularly because vegetation management work is often
controversial, excellent customer service is imperative for a successful program. PacifiCorp
personnel must be professional, prompt, fair and courteous to customers. Contractor personnel
are also required to be professional, prompt, fair and courteous to the property owners with
whom they interact while performing work for PacifiCorp.
Independent contractors are responsible for managing communications with property owners in a
manner consistent with this Chapter 8. Communications with customers should accurately
describe the work to be performed, and any jargon should be avoided in the conversation.
8.1 Educational Information
PacifiCorp has a variety of educational materials about tree-power line conflicts and planting the
right tree in the right place.
The Trees and Power Lines brochure explains the need for line clearance work, as well as natural
target pruning. It also provides color pictures of how properly pruned trees could look following
line clearance. (This brochure is used a companion to the “yellow door card” described in
Section 8.2.1 below.)
The Small Trees for Small Places is a publication in PDF format available at
www.PacificPower.net or www.RockyMountainPower.net. It provides tree selection tree
planting and electrical safety information. It offers an easy-to-use chart on ornamental and
adaptive characteristics of 100 different species that can be used adjacent to power lines. Not all
these trees can be used everywhere in PacifiCorp’s service territory. By providing a choice of
100 small-statured trees, however, there are several options appropriate for use in any given
location around PacifiCorp’s system.
The Right Tree in the Right Place poster provides illustrations and descriptions of small trees
that are suitable across PacifiCorp’s service territory. It also relates information about proper
utility tree pruning and tree planting.
8.2 Notification for Tree Work
As a customer courtesy, prior to vegetation management work a reasonable attempt shall be
made using the techniques specified in this Section 8.2, to notify the property owners (or tenants)
of residential properties occupied year-round and occupied business properties. Forester
authorization is required prior to performing work on such properties without such notice to
owners and tenants. Some circumstances, such as work on historic, unique or unusual trees,
could warrant personal contact with the customer.
School main or administrative offices should be notified of work to be done within school
grounds or on property adjacent to schools. An effort should be made to schedule work without
children present or specific accommodations made for pupils’ safety. Particular effort should be

64

made to identify targets within drop zones, climbable trees, access issues and other safety matters
on site.
In cases of municipal, county, state or federal properties, the proper agency representative shall
be notified by the Forester or the contractor. The appropriate customer and community relations
manager should be notified prior to meeting with governmental officials.
Notification should be given at least five business days, but no more than six weeks, prior to the
crew arriving. Notification shall be documented on an Activity Report (Figure A.5).
8.2.1 Door Hangers
PacifiCorp employs a variety of door hangers. Pacific Power door hangers shall be used in
California, Oregon and Washington, and Rocky Mountain Power door hangers shall be used in
Idaho, Utah and Wyoming. Door hangers shall not be placed in U.S. Mail boxes but shall be
placed at the entry way of a dwelling or business structure.
8.2.2 Personal Notification
When crews arrive for work at a residential site, a member of the crew should make a courtesy
knock on the door to let the homeowner or tenant know that work is about to begin. So long as
the homeowner or tenant does not articulate a protest or otherwise indicate that the owner refuses
to allow work, the crew may proceed with the planned work. If no one is home, the crew may
proceed with the planned work. On business property sites, prior notification is all that is
necessary for crews to begin work.
8.3 Affirmative Customer Consent
As a courtesy and to avoid unnecessary disputes, PacifiCorp sometimes requires that an
independent contractor make reasonable attempts to obtain and document “Affirmative Customer
Consent” for:
 tree removal
 tree and Brush disposal
 mowing
 herbicide application
 TGR application
Affirmative Customer Consent is documented with a property owner’s signature on the
Property Owner Permission Form (Figure A.12)
8.4 Property Owner Refusal Procedure
If a property owner refuses to allow work, the crew may not proceed with work, except as
expressly allowed under the “Property Owner Refusal Process” described in this section.
Detailed records should be kept of every conversation, including the date and time it occurred,
and summary of the matters discussed.

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Initial Refusal Stage. If a property owner refuses to give Affirmative Customer Consent and/or
sign a Property Owner Permission Form, the contractor shall complete a Property Owner
Refusal/Complaint Report and notify the Forester within two working days.
Intermediate Refusal Stage. After notifying the Forester, the contract Forest Technician shall
research PacifiCorp’s property rights for that location, in consultation with PacifiCorp right-of-
way services. After researching PacifiCorp’s property rights in the right-of-way, a representative
of the contractor other than the Supervisor (e.g. the Forest Technician) will then contact the
property owner, either by telephone or in-person, and re-attempt to obtain Affirmative Customer
Consent for the work referring to the property rights at issue, as appropriate. If the property
owner continues to refuse to allow the work to proceed, the Supervisor shall attempt to obtain
Affirmative Customer Consent. After at least 24 hours have passed since the prior attempt to
obtain consent, the Supervisor will contact the property owner, either by telephone or in-person,
and re-attempt to obtain Affirmative Customer Consent. If the property owner continues to
refuse to allow work to proceed, the Supervisor shall inform the Forester.
Final Refusal Stage. Within two weeks of being notified by the Supervisor that a property owner
continues to refuse to allow work to proceed, the Forester shall attempt to obtain Affirmative
Customer Consent for the work. If the Forester is unable to obtain Affirmative Customer
Consent, the Forester shall determine whether to (i) instruct contractor to proceed with the work
without affirmative consent or (ii) excuse contractor from performing the work to the
specifications required under these standard operating procedures.
8.5 Work Completed Without Property Owner Consent
If PacifiCorp holds property interests entitling it maintain its facilities, work may proceed over a
property owner’s unfounded refusal. If the Forester decides to proceed with work, the Forester
shall send the customer a letter by certified mail, notifying the property owner of (i) the work
which be performed and summary of reasons for the work and (ii) the date and time that the
tree(s) will be worked. If appropriate because of the nature of the property owner’s refusal, an
enclosure provided by PacifiCorp Right-of-Way Services (i.e. describing the legal authority
under which the PacifiCorp is acting) may also be included. The date of work shall be at least
five business days from the time the letter is postmarked. The Forester shall alert the director of
vegetation management, as well as the appropriate operations manager, customer and community
manager, wires director, and regulatory analyst about any work scheduled for completion after a
property owner refusal. The regulatory analyst will inform the proper regulatory agency about
the action. If it appears the media could become involved, the Media Hotline should be notified.
Once the letter to the property owner is sent, tree crews shall be dispatched to work the site to
specifications at the assigned date and time. The Forester or Supervisor should be on site during
work. Before and after photos of the site should be taken. The scheduled work should be
completed, regardless of any additional objection from the property owner, unless the property
owner threatens the safety of the crew or bystanders. As always, safety is the highest priority.
The Forester may contact local law enforcement to request a presence on the property while

66

work is performed. The Forester may seek assistance from PacifiCorp’s legal department. If
absolutely necessary to complete the work, PacifiCorp may obtain appropriate relief from a court
of law.

67

REFERENCES

American National Standards Institute. 2006. Tree, Shrub, and Other Woody Plant Maintenance-
Standard Practices (Integrated Vegetation Management a. Electric Utility Rights-of-
Way). ANSI A300 (Part 7). Manchester, NH 03103: Tree Care Industry Association, Inc.

———. 2008. Tree, Shrub, and Other Woody Plant Management-Standard Practices (Pruning).
ANSI A300 (Part 1). Londonderry, NH 03053: Tree Care Industry Association.

———. 2011. Tree, Shrub, and Other Woody Plant Management-Standard Practices (Tree Risk
Assessment a. Tree Structure Assessment). ANSI A300 (Part 9). Londonderry, NH
03053: Tree Care Industry Association.

———. 2016. National Electric Safety Code. 3 Park Avenue, New York, NY 10016-5997, USA:
Institute of Electrical and Electronics Engineers, Inc.

———. 2017. American National Standard for Arboricultural Operations-Safety Requirements.
ANSI Z133. Champaign, IL 61826-3129, USA: International Society of Arboriculture.

Bonneville Power Administration. 2000. “Transmission System Vegetation Management
Program: Record of Decision DOE/EIS-0285.” Bonneville Power Administration.
https://www.bpa.gov/efw/Analysis/NEPADocuments/nepa/Vegetation_Management/Veg
ROD.pdf.

Bramble, W C, W R Byrnes, RJ Hutnik, and S A Liscinsky. 1991. “Prediction Of Cover Type on
Rights-of-Way After Maintenance Treatments.” Journal of Arboriculture 17 (2): 38–43.

Bramble, William C., and William R. Byrnes. 1979. “Evaluation of the Wildlife Habitat Values
of Rights-of-Way.” The Journal of Wildlife Management 43 (3): 642.
https://doi.org/10.2307/3808742.

Childs, Shawn. 2005. Environmental Assessment: Pacificorp Vegetation Management in Power
Line Rights-of-Way. Salt Lake City, UT: United States Forest Service, Wasatch-Cache
National Forest.

Cieslewicz, Stephen R., and Robert R. Novembri. 2004. “Utility Vegetation Management Final
Report Commissioned to Support the Federal Investigation of the August 14, 2003
Northeast Blackout.” Des Moines, IA: Federal Energy Regulatory Commission.

68

Dahle, Gregory A, Harvey H Holt, William R Chaney, Timothy M Whalen, Daniel L Cassens,
Rado Gazo, and Rita L McKenzie. 2006. “Branch Strength Loss Implications for Silver
Maple (Acer Saccharinum) Converted from Round-over to V-Trim.” Journal of
Arboriculture 32 (4): 148–54.

Edison Electric Institute, Utility Arborists Association, U.S. National Park Service, U.S. Fish and
Wildlife Service, U.S. Bureau of Land Management, U.S. Forest Service, and U.S.
Environmental Protection Agency. 2016. “Memorandum of Understanding on Vegetation
Management For Powerline Rights-of-Way.”
https://www.epa.gov/sites/production/files/2016-
11/documents/signed_2016_vegetation_mou_between_industry_and_federal_land_mana
gement_agencies.pdf.

Gillman, Edward F. 2015. “Pruning Shade Trees--Pruning Cuts.” Landscape Plants (blog). 2015.
https://hort.ifas.ufl.edu/woody/pruning-cuts.shtml.

Gilman, Edward F. 2012. An Illustrated Guide to Pruning. Third Edition. Clifton Park, NY:
Delmar.

Gilman, Edward F., and Sharon J. Lilly. 2002. Best Management Practices: Tree Pruning.
Champaign, IL 61826-3129, USA: International Society of Arboriculture.

Goodfellow, John W., and Harvey A. Holt. 2011. Utility Arborist Association Best Management
Practices: Field Guide to Closed Chain of Custody for Herbicides in the Utility
Vegetation Management Industry. Champaign, IL 61826-3129, USA: International
Society of Arboriculture.

Harris, Richard W., James R. Clark, and Nelda P. Matheny. 2004. Arboriculture: Integrated
Management of Landscape Trees, Shrubs, and Vines. Fourth Edition. Upper Saddle
River, HJ: Prentice Hall.

Joint APM Safety Committee. 2017. “Accident Prevention Manual-Utah, Idaho and Southwest
Wyoming.” Ogden, UT 84401: Rocky Mountain Power.

Kempter, Geoff. 2004. Best Management Practices: Utility Pruning of Trees. Champaign, IL
61826-3129, USA: International Society of Arboriculture.

Lilly, Sharon J. 2010. Arborists’ Certification Study Guide. Champaign, IL 61826-3129, USA:
International Society of Arboriculture.

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Miller, Randall H. 1998. “Why Utilities V-out Trees.” Arborist News 7 (2): 9–16.
———. 2014. Best Management Practices: Integrated Vegetation Management For Electric
Utility Rights-of-Way. Champaign, IL 61826-3129, USA: International Society of
Arboriculture.

National Electric Reliability Corporation. 2016. “FAC-003-4 Transmission Vegetation
Management.” Federal Energy Regulatory Commission.
https://www.ferc.gov/industries/electric/indus-act/reliability/vegetation-mgt/fac-003-
4.pdf.

North American Electric Reliability Corporation. 2009. Transmission Vegetation Management
NERC Standard FAC-003-2 Technical Reference. Princeton, NJ 08540.

Shigo, Alex L. 1986. A New Tree Biology: Facts, Photos, and Philosophies on Trees and Their
Proper Care. Second Edition. Durham, NH: Shigo and Trees, Associates.

———. 1990. Pruning Trees Near Electric Utility Lines: A Field Pocket Guide for Qualified
Line-Clearance Tree Workers. Durham, NH: Shigo and Trees, Associates.

Smiley, Thomas, Nelda Matheny, and Sharon Lilly. 2011. Best Management Practices: Tree
Risk Assessment. Champaign, IL 61826-3129, USA: International Society of
Arboriculture.

US EPA, OW. 2015. “What Is a Wetland?” Overviews and Factsheets. US EPA. September 18,
2015. https://www.epa.gov/wetlands/what-wetland.

Yahner, Richard H, and Russell J Hutnik. 2004. “Integrated Vegetation Management on an
Electric Transmission Right-of-Way in Pennsylvania, U.S.” Journal of Arboriculture 5:
295–300.

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APPENDIX A
Vegetation Management work scheduling and reporting forms.

71

Figure A.1. Weekly Time and Vegetation Report form

72

Figure A.2. Maintenance Condition Report form

73

Figure A.3. Vegetation Management Process Checklist form (page 1of 2)

74

Figure A.3

75

Figure A.4. Vegetation Management Work Release

76

Figure A.5. Vegetation Management Activity Report

77

Figure A.6. Vegetation Management Daily Report

78

Figure A.7. Tree Crew Field Audit Form

79

Figure A.8. Worksite Inspection Form

80

Figure A.9. Property Owner Refusal/Complaint form

81

Figure A.10. Main Grid Transmission Report

82

Figure A.11. Local transmission progress report

83

Figure A.12. Property Owner Permission Form

84

APPENDIX B
Revision History

85

Revision Status Date Author Change Tracking
00 Issued for implementation 12/15/2008 R. H. Miller Manual created
01 Reviewed/Updated 06/15/2012 R. H. Miller 1. Clarified language throughout
2. Revised Chapter 4 to reflect a
process checklist used for project
management.
3. Modified Clearance 2 to strictly
reflect table 5 in IEEE 516-2003 Table 5.
4. Section 6.4.1 changed so that if
contract utility Foresters identify an
imminent threat, they contact the
appropriate line patrolmen to initiate the
imminent threat procedure.
02 Reviewed/Updated 09/06/2013 R.H. Miller 1.Clarified language throughout.
2. Revised distribution action thresholds
and clearance standards to
accommodate three and four year
cycles.
3. Modified transmission clearance
requirements to accommodate FAC-
003-02

03 Reviewed/Updated 06/24/2015 R.H. Miller 1. Clarified language
2. Brought specification manual into
line with FAC-003-03
04 Reviewed/Updated 07/01/2015 R.H. Miller 1. Corrected Table of Contents
2. Updated Figures 2.1 and 6.6 with
Rocky Mt. Power
3. Corrected reference to Table 2.2
4. Added substation inspection Section
(2.6 and 4.2.4.6)
5. Clarified definition of interim work.
6. Clarified side work.

05 Reviewed/Updated` 06/01/2016 R.H. Miller 1. Changed document to “Standard
Operating Procedures”
2. Clarified language
3. Chapter 2.
a. Added “At Fault” tree crew
caused outages language –
Section 2.1.6
b. Added language to contact
media – Section 2.4.2.1
c. Added language to contact legal
– Section 2.4.2.2
d. Added language that mechanical
cutting (Jarraff’s and
helicopters) to comply with
ANSI A300.
e. Added language for storm
emergency response 2.10.
f. Added language assigning
responsibility for property
damage to contractors 2.12.

86

Revision Status Date Author Change Tracking
4. Chapter 4
a. Added language to requiring
rules be followed on
hydroelectric facilities and
communicate with plant
manager – Section 4.2.4.7.
b. Added language requiring
limited visual hazard tree
inspections around substations
and transition stations – 4.2.4.8.
c. Added language on working
around schools – Section
4.2.7.1.
d. Added language regarding
working near mobile home
parks and apartment complexes
– Section 4.2.7.2.
e. Simplified language on
accounting for pruning in –
Section 4.3.1
5. Chapter 5
a. Updated interim maintenance
language – Section 5.3
b. Added a section on distribution
herbicide maintenance –
Section 5.5
c. Updated work thresholds and
clearances – Table 5.1
d. Added table on interim work
thresholds and clearances –
Table 5.2
e. Added section on padmount
transformers – Section 5.7.
6. Chapter 7
a. Added section on closed chain
of custody – Section 7.1

06 Reviewed/Updated` 06/01/2017 R.H. Miller 1. Made style consistent for all the
chapters
2. Changed figure presentation so they
followed first mention sequentially.
Updated section numbering
accordingly
3. Clarified language throughout
4. Updated Table 6.1 to comport with
FAC-003-4 MVCDs.
07 05/13/2019 R.E. Vanderhoof 1. Modified Forest Technician
qualification requirements
(Chapter 1)
2. Made style consistent across
tables and figures, and
eliminated extraneous figures
3. Eliminated two-column format
to facilitate future revisions
4. Moved standard form objects to
appendix.
5. Significantly condensed
chapters 3, 4 and 8

87

Revision Status Date Author Change Tracking
6. Modified Table 2.1 to reflect
new edition of Z133 safety
requirements
7. Removed threshold clearances
and increased specification
clearances for California
(Tables 5.2)
8. Increased interim clearances for
California (Table 5.5)
9. Increased transmission
clearances for 161, 138, and
115 kV lines to comply with
California Electric Tariff Rule
11(table 6.1)
10. Significantly simplified tree
crew audit process (Chapter 4)
11. Introduced new distribution
ticket maintenance procedure
(Chapter 5)
12. Reclassified brush as < 6 in.
dbh and trees as > 6in. dbh
13. Removed glossary and defined
terms in text.