Utility Vegetation Management in North America

Utility Vegetation Management in North America:

Results from a 2019 Utility Forestry Census of Tree Activities and Operations

Photo Credit: John Evins-Schroder

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Photo Credit: Karen Jenkins

TABLE OF CONTENTS List of Figures

ii

List of Tables

iii

Executive Summary

iv

Introduction 1 Section I – Company Profile

3

Section II – Safety

5

Section III – Program Management

8

Section IV – Pruning

15

Section V – Integrated Vegetation Management

20

Section VI – Electrical Operations

25

Section VII – Storm Response

28

Section VIII – Communications

32

Conclusions 34 References 35 Appendix A

36

Suggested Citation: Hauer, R.J. and Miller, R.H. 2021. Utilities & Vegetation Management in North America: Results from a 2019 Utility Forestry Census of Tree Activities & Operations. Special Publication 21-1. College of Natural Resources.

University of Wisconsin Stevens – Point. 69 pp.

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LIST OF FIGURES Figure 1-1. Utility ownership structure

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Figure 1-2. The combined business ownership of utilities

3

Figure 1-3. The combined business structure of utilities

4

Figure 2-1. The safety communication approaches taken and how lessons learned are communicated to others within an organization

5

Figure 2-2. The importance of safety subject areas to the safety committee

6

Figure 2-3. Annual DART rate per 100 employees was significantly higher in contracting staff

7

Figure 2-4. Annual tree related events over the past three years with public electrical contacts

(n=43) and fires involving trees (n=54)

7

Figure 3-1. Education levels and other credentials held by the UVM department head

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Figure 3-2. The department that the UVM department resides

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Figure 3-3. The levels of management that are involved in directing the UVM program

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Figure 3-4. The workers who conduct UVM pre-planning or inspection, ahead of tree crews

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Figure 3-5. Devices used to collect vegetation management data

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Figure 3-6. Work locations used to identify vegetation management data

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Figure 3-7. Importance of the following credentials to the UVM program

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Figure 3-8. Importance of the following considerations to the UVM program

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Figure 3-9. The UVM program budget (left axis) for all responding utilities and the percent below identified need (right axis) for the 53% of utilities who indicated their budget was

in-adequate for their identified needs

13

Figure 3-10. The percent of time that is allocated for the following quality assurance and quality control methods

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Figure 4-1. Pruning clearances by electric distribution line type

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Figure 4-2. Pruning factors used to determine overhang clearance distances of trees from electrical distribution lines

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Figure 4-3. Pruning considerations used to determine clearance distances of trees from electrical utility lines

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Figure 4-4. The importance of pruning objectives to a UVM program

17

Figure 4-5. The importance of pruning standards, best practices, and resources to a UVM program

18

Figure 4-6. The importance of locations with developing a pruning program

19

Figure 5-1. Information collected by utilities for the IVM program

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Figure 5-2. The importance of incorporation of standards and best management practices into IVM programs

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Figure 5-3. The importance of IVM considerations with setting IVM objectives

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Figure 5-4. Site evaluations that were part of IVM programs

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Figure 5-5. Action thresholds used in decision making

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Figure 5-6. The importance of treatment options to IVM programs

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Figure 5-7. The importance of cultural control options to IVM programs

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Figure 5-8. The importance of engineering solutions to IVM programs

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Figure 6-1. The percent of outages caused by vegetation by line type

25

Figure 6-2. The importance of protective strategies to electrical operations

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Figure 6-3. The importance of protective strategies on three-phase lines compared to single-phase lines to electrical operations

26

Figure 6-4. The percent of vegetation-related outages caused by outage type

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Figure 7-1. What strategy do you use to cap hours for the following time periods

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Figure 7-2. The importance of storm response factors

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Figure 7-3. Criteria used to declare a storm emergency

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Figure 7-4. How important are the following storm preparation factors in your vegetation management storm response

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Figure 7-5. Production data collected during storms

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Figure 7-6. How is your communication department involved in storm response

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Figure 8-1. How do you conduct customer satisfaction surveys

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Figure 8-2. The importance of the following groups for UVM-related communications of utility operations (outside of UVM)

33

Figure 8-3. The importance of the following types of communication you use for UVM

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LIST OF TABLES Table 1. Examples of regulations to which utilities are required to comply

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Table 2. Response rate for the questionnaire by location and overall

2

Table 1-1. Line distance (mi) of overhead lines type reported by utilities

4

Table 3-1. Measurements collected to track utility vegetation management

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Table 3-2. Average salary or hourly pay rate by UVM position

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Photo Credit: Lorenzo Villanueva

EXECUTIVE SUMMARY The Utility Vegetation Management in North America: Results from a 2019 Utility Forestry Census of Tree Activities & Operations report© describes the current state of utility forestry tree activities and operations. The intent was to enable industry professionals to compare and contrast their program with their peer North American utilities.

The ultimate objective of this benchmark study was to further develop an understanding of utility arboriculture, advance the profession, and help utility vegetation managers improve their programs. Further, the study was designed to describe results from the 2019 base year – what utilities are undertaking and accomplishing in the management of vegetation in and near utility corridors. 71 of 210 utilities responded to a request to participate.

Participants were determined using a combined list from CNUC and the Arbor Day Foundation Tree Line USA® database. From that list, 16 addresses were not deliverable, duplicates from merged companies with separate addresses or companies returning a non-completed survey. Thus, a total 194 valid utilities could potentially participate for a 36.6% response with participation.

Questions were designed to quantify the following: • Company Profile • Safety • Program Management • Pruning • Integrated Vegetation Management • Electrical Operations • Storm Response • Communications Appendix A details summary statistics from a 34-page questionnaire received between November 10, 2019 and March 9, 2020. Results were tabulated descriptively through mean values, associated variability through the standard error of the mean (SE) statistic, and tests of statistical significance. Respondent perceptions to some questions were ascertained using a five point Likert scale (e.g. 1 = very unimportant, 2 = unimportant, 3 = neither unimportant or important, 4 = important, and 5 = very important).

Key findings from this report include: Company Profile • The average customer base of responding utilities was 756,000 with a range of 3,500 to 7.8 million (out of 69 utilities that provided data).

• Most (97.2%) of responding utilities had distribution systems. Fewer (28.2%) were distribution only and nearly 41% were distribution, transmission and generation companies.

• Study participants drew from a cross section of ownerships. Nearly 38.0% are investor-owned, 31.0% are municipal or public utility districts and 20.0% cooperative, comprising nearly 90.0% of respondents. The remaining 10.0% responded state/provincial, federal or other.

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Safety • Nearly all UVM programs (97.0%) sought to learn from safety incidents. Moreover, 97.1% of UVM programs reported close calls.

• Most responding UVM programs did not discipline employees for unintentional safety errors (55.6%). On the other hand, nearly all (95.2%) subjected intentional safety misconduct to progressive discipline.

• Utility Arborist Association (UAA) Safety Summits were rated of neutral importance in a safety program with a mean response of 3.1 out of 5. That was also true for investor owned utilities (IOUs), who responded at 3.2.

• Safety committees were commonly used by two-thirds of utilities, most meeting once a month.

• Several safety subject areas were highlighted as important or very important (4.2 or higher, 1 to 5 scale).

Identifying tree risk was ranked highest (4.54). Evaluating safety training and education was lowest (4.17) while still indicating high importance.

Program Management • UVM programs were overwhelmingly centralized, 79.7% of respondents organized into a single department and another 17.4% centralized by program (i.e., distribution or transmission).

• Nearly all responding UVM programs (92.9%) had a department head. 56% of those department heads hold degrees in natural resources or a related field, 49.2% hold a B.S. and another 6.3% with a M.S. degree. Utility department heads hold the following industry credentials:

>> 82.5% ISA Certified Arborists

>> 52.4% Certified Utility Specialists

>> 20.6% ISA Tree Risk Assessment Qualified (TRAQ) • Most utilities used multiple contracting strategies for UVM. Time and material contracts were used by 88.6% of respondents, although only 25.7% used it solely. Unit contracts were used by 50.0% of utilities, but only 5.7% solely. Hard price was used by 31.4% of respondents, but only 1.4% used it exclusively.

• UVM programs are most likely housed in the operations (43.9%) or vegetation management (33.3%) department.

• A mean 215.1 (101.8 SE) workers are in a UVM program with a range of 1 to 5,320 people reported.

Pruning • Respondents reported that an average of 21.3% of trees were in contact with distribution lines at the time of work.

• Overall, 58.5% of responding utilities indicted they perform ground to sky pruning at least some of the time, and 38.5% did so on all locations where trees were off to the side of conductors.

• Mean clearance distances for distribution varied by type of line and aspect. Side and under clearance averaged 10.6 feet (3.2 meters) and 10.9 feet (3.3 meters) for single and three-phase lines respectively. Overhang was on average 3.0 feet (0.94 meters) greater than side clearance and under clearance.

• Pruning objectives are used to guide and prioritize work. Most respondents ranked reliability (4.86), risk reduction (4.73) and clearance distance (4.67) as very important for formulating pruning objectives. While not rated as high, maintaining tree structure (3.86) was ranked as important.

• Pruning Standards and Best Management Practices (BMPs) were ranked important or higher as resources for creating UVM pruning specifications. The ANSI A300 Part 1 Pruning Standard (4.52) and ISA Utility Pruning BMPs (4.44) were rated as very important.

Integrated Vegetation Management (IVM) • ANSI A300 Part 7 was ranked as important with a 4.12 mean out of 5, followed by the ISA Integrated Vegetation Management Best Management Practices (3.99). The now obsolete UAA Tree Risk Assessment for Fire Prone Areas was lowest ranked with a 2.33 mean.

• Safety and service reliability were ranked equally as the most important reasons to conduct IVM (3.34 mean).

Environmental stewardship was ranked as unimportant (2.34 mean).

• Ground surveys were the most common method (4.69 mean) in conducting workload evaluations, followed by aerial photos (2.93), satellite imagery (2.69) LiDAR (2.62) and remote-controlled aerial systems (2.37 mean).

• Based on the previous results, it is not surprising that 85.5% of respondents conduct site evaluations as part of their IVM program.

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Electrical Operations • A mean 23.2% of outages and 21.7% of lost customer minutes were attributable to vegetation.

• Of responding utilities, 64.2% had the same UVM strategy for single and three-phase lines.

• Of various methods employed to decrease vegetation related outages, responding utilities favored greater action thresholds (4.13) and greater clearances at time of work (4.08) on three-phase lines.

Storm Response • 92.9% of utilities issued a storm response declaration in response to a significant storm event.

• Respondents ranked an emergency operations center (4.31) as the highest storm preparation strategy, followed by pre-storm communication checks (4.17), incident command system (4.16), pre-mobilization (3.86), coordination with local governments (3.73) and storm practice drills (3.66).

• Safety was a very important factor in storm response (4.96). Electric hazard communication protocol (4.57), supervision, (4.56), fatigue (4.55) and wood under tension (4.46) were highly important. Animals and insects (2.74), and equipment rental (2.88) were relatively unimportant.

Communications • Most UVM programs use multiple ways to communicate with customers. The majority of responding utilities use contract (55.7%) or in-house (57.1%) arborists to contact customers prior to work. 50% use tree crew members as a frontline communication approach. Indirect contacts were less common and included direct mail (14.3%), phone message (14.3%) or door hangers (8.6%).

• Respondents rated brochures (3.57) and social media (3.45) as the most important non-face-to-face communication method. Town hall meetings and email messages or blasts (2.51) were less important.

• Slightly more than half of utilities (54.3%) use customer satisfaction surveys to understand how operations are perceived.

Photo Credit: Joshua Salas

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INTRODUCTION Vegetation management is a major expense for utilities.

For many, it is the single greatest operational budgetary line item. Study respondent’s average outlay for vegetation management was over $27 million a year, and the cost is justified. Utilities must meet safety and service reliability challenges. The most pressing safety considerations are public electrical contact and fire. For example, in Oregon the most common incidents of people contacting power lines for the period 1996-2015 were tree related. The Oregon Public Commission observes, “If utility customers are going to get injured with high-voltage lines, chances are high that it will be connected to a tree in their yard” (Carter 2016). Fires caused by vegetation contacting power lines can be catastrophic. Recent examples include the autumn 2017 Sonoma, CA firestorm (Avalos 2018) and the 2018 Camp Fire which incinerated Paradise, CA (James and Ortiz 2018).

determined that vegetation is responsible for an average of 33% of power outages, resulting in 50% of interrupted customer minutes (Cieslewicz and Porter 2010).

Due to the serious consequences of vegetation conflicts with high voltage lines, utilities are subject to comply with laws and regulations requiring clearance between vegetation and electric facilities. FAC-003-4 is a standard developed by the North American Electric Reliability Corporation (Table 1). It consists of seven requirements intended to prevent cascading outages on the bulk transmission system. Most notably, trees are prohibited form encroaching within a minimum vegetation clearance distance (MVCD), which is a calculated maximum flash distance between transmission lines energized to specific voltages at various elevations. The standard has the force of law insofar as it been adopted by the Federal Energy Regulatory Commission (FERC) and carries possible fines of up to one million dollars per violation per day.

Trees are a significant source of power interruptions.

A 2010 CNUC survey of 68 North American utilities

Table 1. Examples of regulations to which utilities are required to comply.

• FAC-003-4: Transmission vegetation management standard. A North American standard developed by the North American Electric Reliability Corporation. The standard has the force of law insofar as it has been adopted by the Federal Energy Regulatory Commission. It has seven requirements intended to prevent cascading outages. Most notably trees are prohibited form encroaching within a minimum vegetation clearance distance (MVCD), which is a calculated maximum flash distance between transmission lines energized to specific voltages and trees. It carries potential penalties of a million dollars per day per violation.

• States and provinces such as California, Oregon and Alberta have clearance requirements between trees and power lines. They are promulgated by the state or provincial regulatory commissions. California also has a state law requiring clearances between trees and power lines in areas of the state that are fire prone.

• International Wildland-Urban Interface Code, which is adopted by many states and local jurisdictions, includes clearances between trees and power lines.

• Some states such as Illinois, require specific cycles on distribution lines.

Study Design and Methods The project was conducted jointly between the University of Wisconsin – Stevens Point (UWSP) and CNUC. Funding came from CNUC and the UWSP College of Natural Resources. A questionnaire was developed in conjunction with CNUC staff to gather required data. The 2018 “Utility Vegetation Management: The Utility Specialist Certification Study Guide” by Miller and Kempter (2018) was used as an outline for the survey as were past surveys conducted

by CNUC (Cieslewicz and Porter 2010, Porter and Cohn 2014, and Porter and Cohn 2016). Prior to delivery of the questionnaire, approval for a human subject study was sought and granted by the Institutional Review Board at UWSP to comply with federal regulations.

The results presented in this report depict the 2019 baseline. They are drawn from a 34-page questionnaire mailed to 210 utilities and received between Nov. 10, 2019

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and Mar. 9, 2020 (Appendix A). Six utilities from Canada and 65 from the United States are included (Table 2).

The mailing list was developed from two lists, one obtained from CNUC and another from the 2019 Arbor Day Foundation Tree Line USA® program. Duplicate records between the two were combined resulting in a distribution list of 210 potential utilities. This sample is from a population of approximately 3,300 electrical North American utilities. A reported 2,938 utilities in the United States are represented by 168 investor-owned, 812 cooperatives and 1,958 publicly owned utilities (EIA 2019). A reported 380 utilities, 16 major and 364 smaller are located in Canada (Lee and Humphrys 2014). A total 16 utilities were invalid for inclusion due to nondeliverable mail, utilities that merged into one company or companies that did not want to participate. That left 194 possible sample utilities, out of which 36.6% (71) responded to the request.

All statistical analysis used SPSS version 25 (IBM 2017).

Within this report we define mean as the arithmetic mean which is the sum of values divided by the total responses. The range is the value from the lowest to highest reported values for a question. The standard error of the mean (SE) was used to denote an estimate of how far the sample mean is likely to be from the population mean. For example, if the current length of the vegetation management cycle is a mean 4.5 (0.18 SE) years, this means the expected population mean is between 4.32 and 4.68. Within the report all error bars in a figure are standard error bars. In many cases we use a five-point Likert scale to ascertain a respondents’ ordered opinion of importance (e.g., 1 to 5 scale where 1=very little and 5=very much). The frequency of these responses is reported along with a mean index scale that provides a central tendency of responses. Finally, for some questions we provided the opportunity to expand answers through an open-ended other option, reflecting self-reported information. Overall, the findings in this report provide baseline information for utilities in North America for comparison.

Questions were designed to quantify Company Profile, Safety, Program Management, Pruning, Integrated Vegetation Management, Electrical Operations, Storm Response, and Communications. Topics for inquiry corresponded to chapters of the aforementioned 2018 utility specialist study guide (Miller and Kempter 2018).

Summary descriptive statistics are reported in the 34page questionnaire as Appendix A. As many as seven contacts were made using the total design method of Dillman et al. (2014).

Results

This report documents results from the most recent assessment of Utilities & Vegetation Management (UVM) in North America. Findings in this report document utility baselines from 2019, and are organized by themed sections from the questionnaire. For example, Section I was used to describe attributes of utility companies such as number of customers, business type, ownership structure and line distance under management. Key outcomes from the questionnaire are presented in each section. Not all findings from the questionnaire are reported. Appendix A provides a more complete description of findings.

• A pre-letter mailed on Oct. 14, 2019 explained the purpose of the project and a request to respond by October 23, 2019.

• A postcard reminder was sent Nov. 14, 2019.

• A second survey was sent to non-respondents on Dec. 12, 2019.

• On Jan. 6, 2020 an e-mail reminder was sent.

• A third, short version survey was sent Jan. 22, 2020.

• The final e-mail reminder was sent Feb. 21, 2020 that completed the request to participate.

Table 2. Response rate for the questionnaire by location and overall.

Location

Total Number Mailed

Total Valid Surveys1

Number Not Returned

Total Number Returned

% Returned Within Location

% of Total Returns

Canada

15

14

8

6

42.9

3.1

United States

195

180

115

65

36.1

33.5

Totals

210

194

123

71

36.6

36.6

1 Total number of valid locations after accounting for 16 addresses that were not deliverable, duplicates from merged companies with separate addresses, or companies returning a non-completed survey.

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SECTION 1 - COMPANY PROFILE Section I reports on attributes of responding utilities.

Questions were created to ascertain customer base, utility structure, and distance of utility line. The total of customers served was asked, which provides a basis to understand the scope of a utility’s responsibility to generate or supply electricity through safe and reliable transmission or distribution systems. A utilities business type, which characterizes a utility as having electrical generation, transmission or distribution capability, was ascertained. Ownership structure was used to identify if they are publicly owned, a cooperative, investor-owned utility, or other. Finally, line distance under management, like customers served, was determined as it provides a metric of the size and scope of vegetation management.

100

97.2

80

69.0

60

45.1

40 20 0

Distribution

Transmission

Generation

Ownership Structure

Key findings include: • The total customer base varied among the responding utilities with a mean of 756,600 (162,725 standard error of the mean, SE throughout report) served. The customers of a utility ranged from 3,500 to 7,752,009 (n=69). The results indicate the survey included a broad spectrum of utilities from largescale organizations to the smallest cooperatives.

Figure 1-1. Utility ownership structure (n=71).

1.4

Federal

2.7

Other

6.8

State/Provincial

• Most utilities (97.2%) provided electric distribution (Figure 1-1). At 69.0%, electrical transmission was common, while less than half (45.1%) were in the generation business.

20.3

Cooperative Municipal/Public Utility District

• Of all respondents, investor-owned comprised 37.8% of the sample (Figure 1-2). Municipal/public utility districts accounted for 31.1% and cooperatives at 20.3% were third most common.

31.1 37.8

Investor-owned utility 0

20

40 60 Percent

80

100

Figure 1-2. The combined business ownership of utilities (n=74).

Photo Credit: Todd Walker

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• State/provincial (6.8%), other (2.7%), and federal (1.4%) collectively represented approximately 10.0% of the sample.

Distribution lines were most common and 16,523 miles (3,514 SE) was the mean amount under management by a utility (Table 1-1). Single-phase (13,429 mean, 3,415 SE) was more common than three-phase (8,104 mean, 1,961 SE).

• Most utilities (70.4%) have a business structure with more than one operation, including generation, transmission, and distribution of electricity (Figure 1-3). Many, (40.8%) were in the business of all three.

A total 54.9% had a transmission and distribution or distribution only operational model. None of the responding utilities were solely in the electricity generation business.

Generation Only

0.0

Transmission and Generation

1.4

Transmission Only

1.4

• Two-thirds (66.8% mean, 3.0 SE) of primary lines were assessable by aerial lift.

2.8

Distribution and Generation

25.4

Distribution and Transmission

28.2

Distribution Only

40.8

Distribution, Transmission, and Generation 0

20

40

60

80

Percent Figure 1-3. The combined business structure of utilities overall (n=71).

Table 1-1. Line distance (mi) of overhead lines type reported by utilities.

Line Type

Mean (mi)

SE1 (mi)

Range (mi)

Transmission 2,999 963

9 to 31,000

Sub-transmission 1,936 401

6 to 11,127

(e.g., 200K line, subject to FAC-003-4)

(e.g., local, not subject to FAC-003-4)

Distribution 16,523 3,514

5 to 130,120

Secondary 3,322 1,702

25 to 32,000

Primary2 18,778 4,478

5 to 130,120

Three-phase2 8,104 1,961

5 to 48,000

0 to 83,292

1 2

Single-phase2 13,429 3,415 SE=Standard Error of the Mean throughout report Primary = Three-phase and Single-phase, means do not equal due to non-reporting of data.

4

100

SECTION 11 - SAFETY Section II investigated UVM approaches to safety. Safety is rightly a priority in UVM, and a commitment to fewer injuries to people and property damage incidents carry both humanitarian and economic imperatives (Miller and Kempter 2018). Respondents described their approach to incident response with an eye toward improving safety performance. Finally, we determined the occurrence of safety violations and incidents.

self-reporting that communication methods such as email (15.6%) and safety bulletins (6.3%) were common.

It is possible these methods would rank higher if they had been directly asked for in the questionnaire.

• 65.0% of respondents report that safety stand-downs are another important way they communicate safety (Figure 2-1). By OSHA definition, “a safety stand-down is a voluntary event for employers to talk directly to employees about safety.”

Key findings include: • Learning from safety incidents to improve operations was nearly unanimous, 97.0% communicate lessons learned to others in the organization. Likewise, 97.1% of respondents reported close calls. These results do not mean that every case is reported or communicated, rather, utilities have a system in place to learn and improve safety.

• Most (70.6%) did not use a third-party safety administrator (e.g., ISNetworld). However, 60% of utilities with more than 10,000 miles of distribution line and 71% of Investor Owned Utilities (IOUs) reported using a third-party safety administrator.

• It was determined employee discipline may result from a safety violation. Fewer than half (44.4%) of utilities reported unintentional safety errors were subject to progressive discipline, however, intentional safety misconduct was likely (95.2%) to result in progressive discipline.

• While not unimportant, the integration of external safety summits and external safety administration appeared to be less common than an internally developed program. For example, respondents on average were neutral (3.1 mean, 1 to 5 scale) to the importance of the Utility Arborist Association (UAA) Safety Summits. Investor owned utilities responded similarly regarding UAA Safety Summits, rating on average 3.2.

The 95.2% of utilities who reported intentional violations were subject to progressive discipline overwhelmingly agreed that intentional safety violations cannot be tolerated. From that perspective, it is surprising that intentional misconduct is not subject to discipline 100% of the time. On the other hand, the level of respondents who report relying on discipline in response to unintentional safety errors exposes a potential problem in the industry.

In their 2010 book “Safe by Accident”, Agnew and

• Many approaches are used to communicate safety with utilities, typically in combination (Figure 2-1).

A safety meeting was most common (89.1%). Job briefings (56.3%) or department-wide conference calls (28.1%) were also used. Several utilities indicated via

25.0

Other

Department-Wide Conference Call

28.1 56.3

Job Briefing

65.6

Safety Stand-Down

89.1

Safety Meeting 0

20

40

60

80

Percent

Figure 2-1. The safety communication approaches taken and how lessons learned are communicated to others within an organization (n=64).

5

100

Daniels caution that care must be taken in meting out punishment for safety incidents as over-reliance on it can be counterproductive. They observe that safety incidents have multiple causes and it is rare that an individual’s behavior is the sole cause of any event. Employees recognize that there is more to any incident than individual fault, and punishment without acknowledging contributing factors, positive reinforcement and a mitigation plan can lower morale, productivity and trust, increase turnover, provoke retaliation and suppress reporting of incidents and close calls. Of these negative, unintended consequences stifling incident and close call reporting is the most serious because it hampers safety culture development.

important, having all (100.0%) employees empowered to contribute to the departmental safety policy.

Ideally, safety committee members and management representatives should be drawn from every level in an organization, that means involving front line workers.

Front line workers are invariably willing to make tough decisions on how to make the workplace safer. Further, if they are consulted, employees are more willing to accept procedures than if not (Nutter 2012).

• A wide variety of subject areas are considered all important or very important (4.2 or higher, 1 to 5 scale) by safety committees (Figure 2-2). Identifying tree risk was ranked highest (4.54). While still of high importance, evaluating safety training and education was lowest ranked with a 4.17 index score.

Learning from safety incidents and close calls is essential in developing a safety culture. Collecting information on incidents and close calls can be applied to a risk matrix as described by McClenahan (2012). The matrix, similar to that used in tree risk assessment, categorizes unsafe acts and conditions on the likelihood they could cause an incident and the potential severity of the consequent event. The information can be used to target training programs to strengthen employee development, establish an earlywarning system and objective metrics for employee performance beyond monetary considerations.

• Two-thirds or 67.6% of utilities allow contractors to undertake safety training during billed working hours.

A mean 10.1 (2.6 SE) times a year billing is allowed for safety training. Utilities stress safety and a willingness to be partners with contractors indicates they are serious about that commitment.

• External safety authorities (e.g., ANSI Z133, OSHA/ OHS Canada, state/provincial requirements, utility company safety policy and contractor safety policy) were important to the program (4.2 or higher, 1 to 5 scale). The ANSI Z133 American National Standard for Arboricultural Operations – Safety Requirements were the highest ranked (4.54), interestingly higher rated than utility company safety policies, at 4.28 (lowest

• Safety committees were common in two-thirds (67.6%) of utilities. They met a mean 10.6 (1.2 SE) times annually and most (65.9%) met 12 times per year.

A company utility representative most commonly (92.9%) chaired the committee. And their purpose was

Very Unimportant (1)

Unimportant (2)

Safety Subject Area

Neither Important or Unimportant (3)

Important (4) Very Important (5)

INDEX SCORE

Evaluating Safety Training

4.17

Developing Training

4.22

Tracking Progress

4.26

Establishing Procedures

4.28

Evaluating Procedures

4.35

Assisting in Incident Investigations

4.35

Monitoring Safety Performance

4.39

Identifying High-Risk Tasks

4.54 0

20

40

60 Percent

Figure 2-2. The importance of safety subject areas to the safety committee (n=46).

6

80

100

Photo Credit: Tammy Nguyen

ranked). The results indicate that ANSI Z133 has a strong positive influence on safety in UVM.

per 1000-line miles, 0.0328 (0.0186 SE, range 0 to 0.6398) contacts occurred. Reducing the risk of electric contact involving trees is a prominent responsibility of UVM.

• The OSHA Days Away, Restricted or Transferred (DART) metric was calculated by 56.9% of responding utilities. The in-house staff rate (0.23 mean, 0.11 SE) was approximately half the rate reported for vegetation management contractors (0.51 mean, 0.11 SE). This was significantly lower (p=0.023, paired t-test) for the inhouse staff (Figure 2-3).

• On average a mean 0.76 (0.47 SE, 0 to 25 range) fires involving trees occurred annually over the past three years per utility (Figure 2-4). Normalized per 1000line miles, 0.0825 (0.0427 SE, range 0 to 2.0284) fires occurred. Fire has been prominent lately, as power line-caused fires in western North America have cost loss of life and billions of dollars of damage.

• On average a mean 0.50 (0.19 SE, 0 to 5 range) public utility contacts involving trees occurred annually over the past three years per utility (Figure 2-4). Normalized

1.2 1.0

1.0

0.8

0.8

0.6

0.6

0.4

0.4

0.2

0.2

0.0

0.23

0.51

In-house Staff

Contractor

0.0

Vegetation Management Staff

Figure 2-3. Annual DART rate per 100 employees was significantly higher in contracting staff (p=0.023, paired t-test, n=16, error bars are standard error bars).

0.50

0.76

Public Electrical Contacts

Fires Involving Trees

Tree Related Events

7

Figure 2-4. Annual tree related events over the past three years with public electrical contacts (n=43) and fires involving trees (n=54) (error bars are standard error bars).

SECTION 111 - PROGRAM MANAGEMENT • Most UVM programs had a department head (92.9%). Utilities

Section III reports on the many UVM tactics utilized by utility companies. Inquiry focused on UVM reporting structures, the title(s) of department heads, the number of people employed and various pay levels, among other variables. Metrics used to track production, where work occurs and devices used to collect information were also reviewed.

reported the department head title was most commonly manager (28.1%), director (14.1%) or supervisor (14.1%) of vegetation management. The “other” option was selected by 28.1% of respondents who reported some variation of manager (10.9%), supervisor (4.7%) or superintendent (4.7%).

This is consistent with results from 2002 and 2006 when 91% and 90% of responding programs had “system forester or equivalent” respectively (Cieslewicz and Porter 2010).

Moreover, this section reports on the importance of credentials, industry affiliations and how well management understands UVM. This report discusses budgets, inspection of work, allocation of time and money by utility line type, timebased work cycles and if work is done differently based on utility line type.

• A variety of credentials were held by UVM department

heads (Figure 3-1). Many (56.0%) hold a B.S. (49.2%) or M.S. (6.3%) in a natural resources or related field (e.g., agronomy, arboriculture, forestry, horticulture, urban forestry, wildlife biology). Other self-reported forms of education (e.g., A.A.S. forestry, engineer, environmental science, MBA) were provided by 21.9% of respondents. Credentials such as the International Society of Arboriculture (ISA) Certified Arborist (82.5%), ISA Certified Arborist Utility Specialist (52.4%), or ISA Tree Risk Assessment Qualification (20.6%) were commonly held.

Key findings include:

• None of the responding utilities indicated their UVM

program was decentralized. Most were centralized as a single department (79.7%), others centralized by program (17.4%). Two utilities (2.9%) self-reported other structures with one specifying under contract and the other saying centralized at the state office level.

In 2002, 71.0% of utilities responding to a CNUC industry survey indicated the “person in charge” had a green industry educational background in natural resources, but that fell to 46.0% in 2006. Further, 50.0% of programs were led by a certified arborist in 2006, and 33.0% by ISA Utility Specialists. 80.0% of 2002 and 90.0% of 2006 respondents considered ISA Certified Arborist credentials to be important. 45.0% of 2002 and 57.0% of 2006 respondents considered ISA Utility Specialist certifications to be important (Cieslewicz and Porter 2010).

In contrast, 89.0% of programs responding to CNUC’s 2002 industry survey and 77.0% of respondents to the 2006 survey were centralized in a single department. In 2002, 7% of respondents reported they were centralized by program and in 2006 that number rose to 13% (Cieslewicz and Porter 2010).

Four percent of responding programs in both 2002 and 2006 were decentralized. It is clear that over the past 18 years UVM programs have been overwhelmingly centralized, with most organized in a dedicated department and a few centralized by program (e.g., distribution and transmission).

Ph.D. Natural Resources/Related Field

0.0

ISA Board Certified Master Arborist

1.5 6.3

M.S. Natural Resources/Related Field

20.6

ISA Tree Risk Assessment Qualification

39.7

Other

49.2

B.S. Natural Resources/Related Field

52.4

ISA Certified Arborist Utility Specialist

82.5

ISA Certified Arborist 0

20

40

60 Percent

Figure 3-1. Education levels and other credentials held by the UVM department head (n=64).

8

80

100

The results suggest that ISA credentials are increasingly valued in utility vegetation management.

in directing the UVM program. This includes both utility employees and contractors (Figure 3-3).

• UVM programs were most likely housed in the operations

• UVM work for responding utilities is pre-planned or

(43.9%) or vegetation management (33.3%) department (Figure 3-2).

inspected ahead of tree crews 89.9% of the time. Both contract workers (52.3%) and company employees (39.1%) who were not tree crew members performed this task (Figure 3-4). Tree crew members uncommonly (5.3%) performed pre-planning or inspection.

• A mean 215.1 (101.8 SE) workers are in a UVM program with a range of 1 to 5,320 people reported.

• A mean 39.5% (5.5 SE) of total FTE’s are directly

responsible for managing the UVM program with a range of 0 to 100 reported.

The results suggest the overwhelming majority of UVM programs consider pre-planning and inspection, whether by in-house or contractor employees, to be important.

Pre-planning is widely used for a number of reasons.

• A mean 4.8 (0.3 SE) levels of management are involved

Technical Services

0.0

Finances

0.0

System Reliability and Maintenance

1.5

Contract Administration

1.5 6.1

Engineering

13.6

Other

33.3

Vegetation Management

43.9

Operations 0

20

40

60

80

100

Percent

Figure 3-2. The department that the UVM department resides (n=66).

30

27.0

25

Other

3.3

Tree crew members

5.3

19.0

20 15

11.1

12.7 9.5

7.9

10

4.8

1.6 0 1

1.6 2

3

4

5

6

7

8

39.1

Company employees 3.2

5 0

0.0

Combinations

9

10

0.0 11

Contract work planners

1.6

0

12

20

40

60

80

100

Percent

Number of Levels Figure 3-3. The levels of management that are involved in directing the UVM program (n=63).

52.3

9

Figure 3-4. The workers who conduct UVM work pre-planning or inspection, ahead of tree crews (n=61).

First, a single individual identifying work and planning the quickest route is more efficient than a tree crew with multiple members doing so. Second, many property owners and other stakeholders expect and deserve time to discuss what is planned on their property. If that discussion waits until a tree crew arrives, workers may be idle while the conversation is underway. Finally, vegetation management often interfaces with more customers than any other utility department. That interaction represents the company for better or worse. Communicating is outside of the skill set of many tree crew members and it is unrealistic to expect successful communication as a secondary assignment performed in addition to tree work.

0.0

Other

36.9

Desktop Computer

38.5

Mobile Phones

46.2

Laptop

55.4

Paper

58.5

Tablet (PCs/iPad)

• Most participating UVM programs reported leveraging

0

technology as vegetation management data is collected through a variety of electronic technologies including tablet or iPad (58.5%), laptop (46.2%), mobile phones (38.5%) or desktop computers (36.9%).

Surprisingly, paper is also commonly used (55.4%) to collect vegetation management data (Figure 3-5).

20

40

60

80

100

Percent Figure 3-5. Devices used to collect vegetation management data (n=65).

• GIS-based software is regularly used (72.1%) to spatially

relate vegetation data. A variety of attributes (e.g., address, circuit, pole number, tree/brush unit) are used to identify work locations (Figure 3-6).

29.2

Grid or Polygon

• Nearly all utilities (91.1%) reported they track the amount of accomplished work.

• Table 3-1 summarizes production measurements

collected to track UVM. The number of trees removed was the most common production measurement with over 70% of utilities reporting this for distribution (75.4%) and transmission lines (70.5%). Line distance (75.4%) and trees pruned (60.7%) were also common metrics collected for distribution lines. Areas treated with herbicide (68.2%) or saplings/brush removed (59.1%), along with trees pruned (56.8%), were common transmission line metrics collected.

Span

41.5

GIS Location

41.5 43.1

Tree/bush Units Worked

56.9

Pole Number

70.8

Address

75.4

Circuit 0

20

40

60

80

100

Percent

• UVM programs maintain a variety of industry affiliations.

Figure 3-6. Work locations used to identify vegetation management data (n=65).

The International Society of Arboriculture (83.1%), Utility Arborist Association (81.5%), and Arbor Day Foundation Tree Line USA (80.0%) were very common affiliations. All other cited affiliations were 15% or below (Appendix A, Section 3 Question 19).

their budget was met at least 95.0% of the time, 14.0% responded their budget was significantly lower, and 10.0% that their budget is usually nowhere close to meeting the UVM program needs (Porter and Cohn 2014).

• ISA credentials were important to responding utilities.

The ISA Certified Arborist (4.27, 1 to 5 scale), ISA Certified Utility Specialist (3.99), and Tree Risk Assessment Qualification (3.51) were important. Board Certified Master Arborist (2.70) and Certified Municipal Specialist (2.48) credentials were relatively unimportant to responding utilities (Figure 3-7).

• Respondents provided their total annual UVM budget

6.2

Other

• In 2016, 52.0% of utilities indicated their budget met at

least 98.0% of their UVM schedules. 24.0% indicated their UVM budget was significantly lower than needed, 6.0% that their budget was nowhere close to UVM needs, and another 6.0% indicated their budget is usually less than UVM needs.

(Figure 3-9). A mean $27,182,769 (7,021,420 SE) was spent in 2018. The amount spent ranged from $50K to $320M. Approximately half (53.7%) indicated their budget was stable over the past five years. Nearly half (52.9%) indicated their budget was not adequate. Of these utilities, the budget was a mean 28.9% (4.3 SE) below the identified need.

• Most utilities use line item (49.3%) or program (23.9%) based budgeting. None used performance. Entrepreneurial (17.9%) and zero-based (9.0%) were also used. See Appendix A Section 3 Question 27 for definitions.

• An array of contracting types were used for UVM, with a

In 2014, 31.0% of 29 responding utilities responded

10

mean of 2.0 (0.1 SE). Time and material were most reported, with 88.6% using this structure and 25.0% solely using this system. Unit based contracting was used by 50.0% but only 5.7% used it exclusively. Hard price contracts were used by

Table 3-1. Measurements collected to track utility vegetation management.

Production Measurements Collected N-size

%

Distribution Line

61

-

Area (ft2 / m2) of saplings (brush) pruned

11

18.0

Area (ft2 / m2) of saplings (brush) removed

24

39.3

Area (ft2 / m2) of saplings (brush) treated with herbicide

23

37.7

Distance (km or mi) of line cleared

46

75.4

Trees in contact with the line at the time of maintenance

5

8.2

Trees per mile / km worked

19

31.1

Trees pruned

37

60.7

Trees removed

46

75.4

Other

6

9.8

Transmission Line

44

-

Area (Acres or ft2 / hectare or m2) of saplings (brush) pruned

12

27.3

Area (Acres or ft2 / hectare or m2) of saplings (brush) removed

26

59.1

Area (Acres or ft2 / hectare or m2) of saplings (brush) treated with herbicide

30

68.2

Trees pruned

25

56.8

Trees removed

31

70.5

Other

11

25.0

Very Unimportant (1)

ISA Credential

Important (4)

Unimportant (2)

Neither Important or Unimportant (3)

Very Important (5)

INDEX SCORE

ISA Certified Municipal Specialist

2.48

ISA Board Certified Master Arborist

2.70

ISA Certified Tree Worker Climber Specialist

2.97

ISA Certified Tree Worker Aerial Lift Specialist

3.00

ISA Tree Risk Assessment Qualification

3.51

ISA Certified Utility Specialist

3.99

ISA Certified Arborist

4.27 0

20

40

60 Percent

Figure 3-7. Importance of the following credentials to the UVM program (n=64 to 70).

11

80

100

• Quality assurance (QA) and quality control (QC) methods

31.4% but only 1.4% use it as their only contracting strategy.

While we collected percentages on types of contracting used, we did not collect the budget percentage allocated to contracting types. The results suggest that many UVM programs use a variety of contracting strategies on their system, depending on what works best under particular circumstances.

were commonly used (Figure 3-10). 100.0% field auditing was most common (69.0%) for transmission lines but only used by 39.0% of respondents for secondary distribution lines. A 100.0% drive-by assessment was second most common. Sampling was used approximately 20.0% of the time. Finally, it was uncommon for respondents to have no QA or QC program, and only absent on distribution lines (i.e., all respondents had some QA or QC on subtransmission and transmission lines).

• Respondents were asked how well management

understands UVM, rating from very little (1 scale) to very much (5 scale). Overall, most factors were rated above neither little nor much (3 scale) or above much (4 scale) (Figure 3-8). Variability of natural systems was rated lowest with a 3.33 index score. The highest rated were the effect of UVM on reliability (4.57), compliance (4.45), benefits of tree removal (4.36), need for professionalism in UVM (4.27), and liability (4.26).

• Conducting UVM work on a time-based cycle was most

common (88.7%). A reactive, just in time, or reliabilitybased system was uncommon, each used by 3.1% of utilities. A total 9.2% of respondents used a variable work cycle. A regular work cycle was most common as 81.5% of responding utilities used this approach. On average a 3.8 (0.2 SE) year cycle was desired, while utilities were currently on a 4.5 (0.2 SE) year cycle to complete all work.

Thus, utilities on average were 0.7 (0.2 SE) years or 19.3% behind their desired cycle.

Anecdotally, many utility arborists have expressed frustration in the level of understanding their management has about UVM. These responses suggest this is a misperception and utility management actually have good command of the UVM issues, or at least those investigated in this study.

• The average rate of pay increased from ground worker

• Post-work inspection was very common with 94.4% of

($17.10) to planner QA specialist ($32.94) (Table 3-2). In most cases pay level was higher for contractors, with the one exception of planner QA specialist position.

Rate of pay does not include fringe rates, thus total compensation was not ascertained. The average department head (in-house employee) salary was $116,288 (Table 3-2). An in-house utility arborist/manager

respondents indicating their program does such. A mean 81.3% (4.3 SE) of work is audited. Results indicate the overwhelming number of responding utilities recognize the importance of quality control. Many utilities postinspect 100.0% of their work.

UVM Consideration

Very Little (1)

Little (2)

Neither Little or Much (3)

Much (4)

Very Much (5)

INDEX SCORE

Variability of Natural Systems

3.33

Problems Related to Underfunding UVM

3.94

Cost of Deferring Maintenance

3.97

Long-term Cost Effectiveness of a Proactive

4.06

Need for Consistent Funding

4.19

Liability (e.g., Consequence of Tree Causes)

4.26

Need for Professionalism in UVM

4.27

Benefits of Tree Removals

4.36

Compliance

4.45

Effect of UVM on Reliability

4.57 0

20

40

60 Percent

Figure 3-8. Importance of the following considerations to the UVM program (n=64 to 70).

12

80

100

40,000,000 35,000,000

30,348,253

Budget % Below Need

100

25,428,476 80

30,000,000 25,000,000

60

20,000,000 40

15,000,000 10,000,000 5,000,000 0

6,927,258 4.0 Transmission

10.9 4,912,886

10.6 20

2.1 Sub-transmission

Distribution

Total

0

UVM Budget and % Below Identified Need by Line Type

Figure 3-9. The UVM program budget (left axis) for all responding utilities and the below identified need (right axis) for the 53.0% of utilities who indicated their budget was inadequate for their identified needs (n=4 to 59).

one level below the department head on average made $86,877. An in-house utility arborist/manager two levels below the department head on average made $71,813.

Management positions in-house paid a higher salary than contracted positions.

Browing and Wiant (1997) found the cost of working trees beyond the time they reach conductors increased by 20.0% a year before inflation. Recent work by CNUC (Chen and Vanderhoof 2020) indicated that at a project level, there is no correlation between time since last worked and cost. They concluded that while the cost of working trees increased in correlation with time, other factors such as weather, growth rates and pruning methodology seemed to affect project level cost. Condition-based scheduling using pre-established work thresholds is considered best practice rather than strict time intervals (Miller 2014) and Chen and Vanderhoof’s results affirm that best management practice. Evidence suggests that UVM might de-emphasize cycle work in favor of evidencebased scheduling.

and allows for a direct correlation to be made between vegetation management and electric system reliability.

The disadvantage is the amount of line in a circuit can vary as load is shifted, particularly in urban or other areas of high demand. Shifted line segments can be stranded and missed between cycles resulting in unacceptable safety and service reliability risks. Further, potential variable line distances mean that data from one time a circuit is worked cannot always be compared to that of another time worked. While working on polygons or grids enables consistent data collection from one treatment to another, line on a particular circuit is often divided between grid boundaries, meaning reliability correlation can be compromised (Miller and Kempter 2018). Responding utilities have evidently found the consistency of working grids or polygons is preferable to the reliability correlation attendant to circuit scheduling.

• The vast majority (78.8%) of respondents used a grid

(polygon) basis for UVM work. Whether a line was threephase or single-phase had little effect on cycle length with most (90.6%) using the same cycle length for both line types.

The proportion of responding utilities that schedule by grid has markedly increased in recent years. 32.0% scheduled by grid in 2002 and 11% of responding utilities scheduled by grid in 2006 (Cieslewicz and Porter 2010).

The advantage of scheduling on a circuit basis is that it systematically completes all the line on a circuit as part of a project. It is the best way to maximize reliability

13

Distribution primary

Distribution secondary

Subtransmission

Transmission

100

80

60

40

20 7 0

4 0

23 18

0

None

21

31

13

31

39 47 58 69

20 18

100% Drive-by

Sample

100% Field Audit

Quality Assurance and Quality Control Methods

Figure 3-10. The percent of time that is allocated for the following quality assurance and quality control methods (n=32 to 58).

Table 3-2. Average salary or hourly pay rate by UVM position.

In-House Position Categories

Pay Level $c

SE N-size

Contractor

Pay Level $c

SE

N-size

Management Annual Salary Department Head

116,288

5,461

37

82,500

7,500

2

Utility Arborist/Managera

86,877

3,353

36

64,556

6,702

5

71,813

3,857

25

63,775

5,223

14

Utility Arborist/General Foremenb

Field Utility Arborist/Forester Hourly Pay Ground Worker

17.10

2.10

6

19.94

1.58

29

Chemical Applicator

19.57

3.81

5

26.69

2.73

15

Qualified Utility Arborist Trainee

19.61

4.01

4

21.58

1.10

23

Qualified Utility Arborist

26.47

2.12

10

24.85

1.46

28

Crew Leader

29.27

2.41

11

30.14

1.86

Planner QA Specialist

32.94

3.35

7

27.53

2.78

19

Other

31.25

---

1

33.28

11.73

2

a 1 level below department head b 2 levels below department head c Pay does not include fringe benefits

14

32

SECTION 1V - PRUNING When done correctly, tree pruning is effective in reducing conflict between trees and utility lines where removal is not possible or appropriate. The science and application of tree pruning has advanced in the past few decades. Knowledge on how to properly prune trees, the limited use of wound coverings, where to prune, tree biomechanics and standards have progressed markedly.

Questions in this section established the state of trees at time of pruning. Examples of inquiry include whether a utility uses a ground to sky approach and where this work is done. The various considerations (e.g., line location, reliability, risk reduction, pruning cycle length) for tree pruning and their importance were given. The target pruning distance from tree to distribution line type (clearance) was established. The importance of pruning factors, pruning objectives and standards was determined.

Finally, how utility line location affects decision making was ascertained (Figure 4-1) along with pruning factors, objectives, and considerations (Figures 4-2, 4-3, 4-4).

Key findings include:

• The tree canopy positions relative to lines at time of

pruning was determined. A mean 21.3 % (3.5 SE) of trees were in contact with the line at time of pruning. A mean 24.6 % (3.7 SE) of trees were over-hanging the line.

A high percentage of trees in contact with the line at time of work raises costs (Browning and Wiant 1997) and is an indicator of inadequate financial resources (Miller and Kempter 2018). Recall 16 that nearly half (52.9%) of respondents indicated 14 their budget was not adequate. Of these 12 utilities, the budget was 28.9% (4.3 SE) below the 10 identified need. Being behind in cycles and a high percentage of trees 8 growing in the lines at the time of work contribute 6 to a spiral of decline that could result in 4 unacceptable safety and service reliability risks.

• Chemical pruning

programs were uncommon, only 13.4% of responding utilities state it is part of their operation. Chemical

Photo Credit: Bill Spencer

Side

Under

Overhang

2

0

10.9 10.7 13.9

10.6 10.3 13.6

Three-phase

Single-phase

6.8

6.3

6.1

Open wire

Line Type Figure 4-1. Pruning clearances by electric distribution line type (n=17 to 46).

15

4.0

3.8 Triplex

4.9

pruning involves spraying branches with fosamin amomonium herbicide. Fosamin ammonium has limited translocation within plants and it inhibits bud development in many species (Senseman 2007). When properly applied it kills target stems without harming the rest of the plant. While it has efficacy in some cases, it is evidently not in widespread use in UVM.

• A mean 58.5% of responding utilities indicated they

perform some aspect of ground to sky pruning. Over one-third (38.5%) practiced ground to sky pruning in all locations. Nearly half (48.7%) did so around three-phase lines and one-quarter (25.6%) applied this approach to rural locations. If you apply all locations (e.g., 58.5% said all locations), then 82.1% of three-phase lines and 59.0% of rural locations used ground to sky pruning.

(James 2003). Removing all the side and sub-branches from the tree system effectively lion tails trees, which could result in whole tree or major limb failure. The results in this questionnaire show mass damping was the lowest rated factor in obtaining clearances (Figure 4-2), suggesting that compromising this tree characteristic is either not a problem or utility specialists are unaware the technique may be counterproductive. Given that the majority of utilities prune ground to sky, research is needed to determine the efficacy of the practice.

• The pruning distance from electrical distribution lines

Ground to sky pruning clears all stems of the subject trees growing toward conductors, including those above the lines, in an effort to eliminate branches that might expose power lines to mechanical breakage or cross phasing resulting in outages. The authors are unaware of any research conducted to determine the efficacy of the practice. On one hand it’s a matter of common sense. On the other, ground to sky pruning may circumvent mass damping properties in trees. Mass damping is a tree adaptation to withstand dynamic loading due to winds. It involves a complex structure including the trunk, side branches and sub-branches of all sizes, including twigs. When subject to wind, each stem absorbs the dynamic force asynchronously, often preventing the tree system from devolving into damaging large sway motions that could result in tree failure

Very Unimportant (1)

Pruning Factors

Important (4)

Unimportant (2)

Neither Important or Unimportant (3)

was dependent upon the line type (Figure 4-1). Triplex lines were commonly not maintained (11.0%) or pruned to relieve strain and abrasion (52.0%). A mean 4.0 ft. (0.5 SE) or 1.2 m (0.2 SE) of side clearance and 4.9 ft. (1.1 SE) or 1.5 m (0.3 SE) of overhang clearance was reported. In contrast, approximately 95% of distribution lines (single and threephase) were pruned to a set distance rather than no maintenance (2-3%) and cleared only to relieve abrasion (~3%). The mean side distance of 10.6 ft. (0.5 SE) or 3.2 m (0.2 SE) for single-phase and 10.9 ft. (0.6 SE) or 3.3 m (0.2 SE) were reported for single-phase and three-phase lines, respectively. The overhang distance was reported to be approximately 3 ft. (0.9 m) greater than the side distance for single- and three-phase lines. Side and under line distance were similar in all cases. Several utilities did not specify an exact distance, rather they self-reported that distance was dependent upon tree species (e.g., growth rate, conifer versus deciduous), and line location (e.g., urban versus rural, all overhang is cleared ground to sky, all under branches removed).

Very Important (5)

INDEX SCORE

Mass Damping

2.89

Expected Weather in the Vicinity

3.25

Community Expectations

3.27

Storm Exposure

3.62

Branch Size

3.78

Line Priority

3.87

Tree Biomechanics

3.94

Tree Species

4.43

Branch Defect

4.47 0

20

40

60

80

100

Percent Figure 4-2. Pruning factors used to determine overhang clearance distances of trees from electrical distribution lines (n=54 and 64).

16

Very Unimportant (1)

Neither Important or Unimportant (3)

Pruning Consideration

Important (4)

Unimportant (2)

INDEX SCORE

Very Important (5)

Expected Weather in the Vicinity

3.24

Maintaining Tree Structure

3.32

Line Location (e.g., Urban, Suburban, Rural)

3.53

Number of Customers Served

3.59

Facility Construction (e.g., Single Pole)

3.76

Site Factors (e.g., # and Type of Trees, Terrain)

3.78

Three or Single-Phase Lines

4.03

Planned Cycle Length

4.08

Facility Priority (e.g., Voltage, overcurrent)

4.09

Tree Positions Relative to the Line

4.11

Risk Reduction (Safety)

4.45

Reliability

4.47 0

20

40

60

80

100

Percent Figure 4-3. Pruning considerations used to determine clearance distances of trees from electrical utility lines (n=63 to 64).

Very Unimportant (1)

Important (4)

Unimportant (2)

Neither Important or Unimportant (3)

Very Important (5)

Pruning Objectives

INDEX SCORE Maintaining Tree Structure

3.86

Clearance

4.67

Risk Reduction (Safety)

4.73

Reliability

4.86 0

20

40

60 Percent

Figure 4-4. The importance of pruning objectives to a UVM program (n=64 to 66).

17

80

100

It is not surprising that triplex lines are either not pruned or minimally cleared to relieve abrasion or tension.

Triplex are insulated distribution secondary lines that carry 110/220V in North America. Since they often serve only a single or a few customers at most outages carry less urgency or consequences. Secondly, due to their low voltage and insulation, vegetation caused outages are usually mechanical. With that in mind, the strictest clearance requirements for triplex lines in the United States can be found in the California Public resource code section 4293 and Oregon Administrative Rule 860-0240016, which require clearing only to relieve deflection or abrasion of lines energized below 750 and 600 volts respectively. The mean of 4.0 ft. (1.2 m) of side and 4.9 ft.

(1.5 m) of overhang distance for triplex indicate responding utilities that clear triplex go far beyond what is minimally expected.

The 2004 ISA Best Management Practices for Utility Pruning of Trees (Kempter 2004) advises that preestablished clearances between electric facilities and tree stems take into consideration the following variables: • tree species characteristics • anticipated growth rate • natural tree structure • expected reaction to pruning • wood strength • tree health • anticipated time until next scheduled pruning • type of facility (construction type, voltage and other factors) • presence of other trees • buildings • terrain

Very Unimportant (1)

Unimportant (2)

Neither Important or Unimportant (3)

It also advises pruning cuts should be made at the next suitable natural target proximal to the specified clearance distance rather than at a strict clearance distance.

• Many pruning factors are used to prioritize distribution

overhang clearance (Figure 4-2). Branch defect (4.47) and tree species (4.43) were the most important (Figure 4-3). Mass damping of trees was ranked the lowest (2.89), near the important or unimportant ranking. Tree biomechanics (3.94), line priority (3.87), branch size (3.78) and storm exposure (3.62) were collectively ranked as important for guiding overhang pruning clearance.

• The importance of pruning considerations in the context

of clearance distance varied (Figure 4-3). Using a 1 to 5 scale (5 highest), reliability (4.47) and risk reduction (4.45) for safety were the highest rated considerations. Tree position relative to the line (4.11), facility priority (4.09), planned cycle length (4.08), and three- or single-phase lines (4.03) were rated as important. Expected weather in the vicinity (3.24) and maintaining tree structure (3.32) were the lowest ranked, however, still above a neutral 3 index score.

Mass damping was discussed in relation to ground to sky clearance earlier. The low importance of the concept as a consideration in overhang clearance might suggest a need for research on the topic.

• Pruning objectives are used to guide and prioritize work

(Figure 4-4). Most respondents ranked reliability (4.86), risk reduction (4.73) and clearance distance (4.67) as very important for formulating pruning objectives. While not rated as high, maintaining tree structure (3.86) was ranked as important. Respondents ranked Pruning Standards and Best Management Practices as important or higher as resources in creating UVM pruning

Important (4) Very Important (5) INDEX SCORE

Pruning Resources

Pruning of Trees Near Electric Utility Lines: A Field Pocket Guide for Qualififed Line-Clearance Tree

4.00

ISA Utility Pruning BMP’s

4.44

ANSI A300 - Part 1

4.52

Other

4.71 0

20

40

60 Percent

Figure 4-5. The importance of pruning standards, best practices, and resources to a UVM program (n=71).

18

80

100

specifications (Figure 4-5). Specifically, the ANSI A300 Part 1 Pruning Standard (4.52) and ISA Utility Pruning BMPs (4.44) were rated as very important.

• The location of electrical lines is important or very

important to developing a pruning program (Figure 4-6).

A rural (3.77) location was ranked lowest in importance to developing a program and the ranking increased in more populated urban (4.03), suburban (4.06), and urban-rural interface locations.

• Several other (4.71) considerations were self-reported for creating specifications including ANSI A 300 Part 7 IVM, UAA BMPs closed chain of custody, BMP of fire prone states and provinces, OSHA, FAC003-4 and company or program specifications.

Very Unimportant (1)

Pruning Locations

Important (4)

Unimportant (2)

Neither Important or Unimportant (3)

Very Important (5)

INDEX SCORE

Rural

3.77

Remote

3.82

Urban-Rural Interface

4.00

Urban

4.03

Suburban

4.06 0

20

40

60 Percent

Figure 4-6. The importance of pruning of locations with developing a pruning program (n=64 to 66).

Photo Credit: Steve Schwartz

19

80

100

SECTION V - Integrated Vegetation Management Section V describes different aspects within Integrated Vegetation Management (IVM). Respondents were asked to report the information they collect for their IVM program including data that depicts operations and methods for conducting workload evaluations.

The importance of objectives used to drive IVM was identified. Likewise, how well industry standards are incorporated into operations and action thresholds for decision making were reported. The use of tree growth regulators and mechanical pruning approaches were quantified. Finally, the use and importance of IVM methods (e.g., biological, chemical, cultural, engineering, physical) was reported.

Growth Rate

15.9

Tree Orientation

17.5 23.8

Branch Distance Tree Height

30.2

Tree Density

33.3

Tree Condition

34.9

GPS Coordinates

34.9 42.9

Tree Diameter

Key findings include: programs included address (71.4%), species (60.3%) and pole number (50.8%) (Figure 5-1). Growth rate (15.9%), tree orientation (17.5%) and tree risk assessment rating (19.0%) were least common.

71.4

Address 0

IVM program on a 1 (very unimportant) to 5 (very important) scale. Safety (3.34 mean, 0.17 SE) and service reliability (3.34 mean, 0.20 SE) were highest ranked. Compliance (3.04 mean, 0.18 SE) and costeffectiveness (2.95 mean, 0.16 SE) were similar and intermediate. Environmental stewardship (2.34 mean, 0.21 SE) was ranked lowest for importance.

20

40

60

80

100

Percent Figure 5-1. Information collected by utilities for the IVM program (n=63).

The low value given to environmental stewardship indicates more work needs to be done to raise awareness

Important (4)

Unimportant (2)

Neither Important or Unimportant (3)

60.3

Species

• Utilities ranked five reasons for conducting an

Very Unimportant (1)

50.8

Pole Number

• The most common information collected for IVM

Pruning Standards & Practices

19.0

Tree Risk

Very Important (5)

INDEX SCORE

UAA Tree Risk Assessment and Abatement for Fire-Prone States

2.33

Utility Arborist Association Best Management Practices

3.00

ISA BMPs - Tree Risk Assessment Qualification

3.04

ANSI A300 Part 9 - Tree Risk Assessment

3.39

ISA BMPs - Integrated Vegetation Management

3.99

ANSI A300 Part 7 - Integrated Vegetation Management

4.12 0

20

40

60

80

Percent Figure 5-2. The importance of incorporation of standards and best management practices into IVM programs (n=68 to 69).

20

100

• The development and use of IVM objectives are

of its importance. Environmental Stewardship is a core value of the UAA, whose website observes, “The UAA recognizes that excellence in the UVM industry can only be achieved when we treat our rights-of-way as ecosystems and take the best possible care of the natural resources we have been entrusted to manage”.

commonly done to manage utility lines (Figure 5-3).

Not surprising, service reliability (4.84) and safety (4.73) were the highest ranked. Facility protection (4.49), cost efficiency (4.45), and compliance (4.25) were also ranked important. Even the lowest ranked objective, cultural site protection (3.57) was leaning toward an important consideration.

• Standards are incorporated into IVM programs in a

variety of ways (Figure 5-2). Not surprising, the ANSI A300 Part 7 – Integrated Vegetation Management standard was ranked highest at a 4.12 mean index score (1=very little and 5=very much) followed by the companion ISA BMP – Integrated Vegetation Management (3.99), the ANSI A300 Part 9 Tree Risk Assessment (3.39) and companion ISA BMP – Tree Risk Assessment Qualification (3.04). The UAA tree risk assessment for fire prone areas was lowest ranked (2.33 mean index score), however, it was higher ranked for utilities in fire prone areas.

Since the questionnaire was distributed, the UAA and ISA published a utility tree risk assessment best management practice (Goodfellow 2020). This publication is not limited to fire prone areas and given its more wide application will likely receive broader acceptance in UVM.

Very Unimportant (1)

IVM Objective Setting Considerations

workload evaluations. Ground evaluations were rated by far the most important (4.69). The following methods, while not unimportant, were rated lower: aerial photos (2.93), satellite imagery (2.69), LiDAR (2.62) and unmanned aerial systems (2.37).

• The use of the ISA Tree Risk Assessment BMP was

uncommon, 79.4% said it was not part of their IVM program as a tree risk assessment system. This does not mean utilities are not conducting tree risk assessment, rather the ISA system is not commonly used.

It is surprising that the Tree Risk Assessment BMP was used by such a small number of utilities’ IVM programs.

Tree risk assessment should be an important part of any

Important (4)

Unimportant (2)

Neither Important or Unimportant (3)

• Respondents provided the methods they used to conduct

Very Important (5)

INDEX SCORE

Cultural Site Protection

3.57

Workload Evaluations

3.64

Environmental Stewardship

3.76

Access

3.87

Security

3.90

Compliance

4.25

Cost Efficiency

4.45

Facility Protection

4.49

Safety

4.73

Service Reliability

4.84 0

20

40

60 Percent

Figure 5-3. The importance of IVM considerations with setting IVM objectives. (n=60 to 64).

21

80

100

IVM program. Perhaps it is because the IVM BMP did not have a specific tree risk assessment dedicated exclusively to UVM for the period covered by the survey.

23.2

Soil Types

25.0

Fire Risk

Since this survey was conducted, that shortcoming has been remedied with the release of the 2020 ISA and UAA Utility Tree Risk Assessment BMP (Goodfellow 2020).

30.4

Archaeological and Cultural Waste Resources

46.4

Vulnerable or Protected Areas

46.4

Funding Availability

48.2

Workload

50.0

Topography

51.8

• Based on the previous results it is not surprising that 85.5% of respondents conduct site evaluations as part of their IVM program.

• Figure 5-4 details the variety of site evaluation

attributes. Safety was most common, and 85.7% of respondents said it was part of site evaluations.

Right-of-way width (78.6%), access routes (76.8%), line voltage and criticality (76.8%), and line location (73.2%) were also common. In contrast, soil types (23.2%), fire risk (25.0%), and archaeological and cultural issues (30.4%) were the least common site evaluations.

55.4

Presence of Species Concern

• 76.8% use action thresholds in decision making.

Minimum clearances were most common, applied by 86.8% of responding utilities (Figure 5-5). This was followed by length of time (69.8%), tree risk rating (52.8%), vegetation height (49.1%), and vegetation density (37.7%). Minimum vegetation clearance distance (MVCD) FAC-003-4 was the most common (67.2%) criteria used to develop tolerance levels. Compliance with state/provincial or federal regulations was used by 44.3% to set tolerance levels.

Anticipated Control Methods

62.5

Wire Height Off the Ground

64.3

Labor and Equipment

66.1

Line Construction

67.9

Land Ownership and Use

67.9 73.2

Line Location Line Voltage and Criticality

76.8

Access Routes

76.8 78.6

Right-of-way Width

85.7

Safety 0

20

40

60

80

100

Percent

Action thresholds rather than a set time period are an integrated vegetation management best management practice. Action thresholds are Figure 5-4. Site evaluations were part of IVM programs (n=56). vegetation height, density, location or condition targets that trigger control methods (Miller 2014). The the most recent ANSI A300 Part 7 has not yet established idea is that vegetation management schedules should be common use in the industry. determined by existing site and vegetative conditions rather than predetermined time intervals.

• Closed chain of custody was used by less than half (45.0%) of responding utilities. There is a closed chain of custody • IVM is based on a variety of methods. Physical (manual and BMP from the UAA, published by ISA (Goodfellow and mechanical) methods were most commonly used (4.75 Holt 2011). mean index score). All respondents said it was important or very important. Chemical control was also important (4.36 mean index), followed by engineering (3.45), cultural (3.30), and biological methods (3.03).

37.7

Vegetation Density

The relatively low score for biological control methods (while still neutral) is consistent with the low priority on environmental stewardship and reinforces the need for more work to be done to increase awareness in that regard.

Vegetation Height

ANSI A300 Part 7 (ANSI 2018) advises that the reason for integrated vegetation management is to create, cultivate and conserve sustainable plant communities compatible with the site. In the case of electric utility lines, that often means converting from a tall-growing plant community to one comprised of plants that do not have the genetic predisposition to grow into the facilities. This process is called cover type conversion and it ultimately matures into a biological control (Miller and Kempter 2018). The comparatively low rating for biological control indicates that

49.1 52.8

Tree Risk Rating

69.8

Time Length

86.8

Minimum Clearances 0

20

40 60 Percent

80

100

Figure 5-5. Action threshold used in decision making (n=53).

22

Very Unimportant (1)

Unimportant (2)

Neither Important or Unimportant (3)

Important (4) Very Important (5)

INDEX SCORE

Chemical Tree-Pruning

1.95

UVM Treatment Options

Aerial

2.07

Trunk Injection

2.17

Cut Stubble

3.13

High Volume Foliar

3.40

Bare Ground Treatment

3.47

Basal

3.64

Stump Treatment

4.41

Other

4.76 0

20

40

60

80

100

Percent

Figure 5-6. The importance of treatment options to IVM programs (n=59 to 61).

Closed chain of custody involves containers that are used, returned to the supplier for refilling in computerized facilities, and distributed for reuse. It requires closed connections when chemicals are transferred, creating a tracking system and auditable record. It is an advance that reduces the likelihood of errors in mixing, spills and the need for triple rinsing and container disposal.

(3.15), and planting of seed compatible plants (3.07) were highest ranked.

• Overall, responding utilities were neutral on engineering

solutions for their UVM program (Figure 5-8).

Underground construction (3.27) of lines and moving poles or lines (3.21) were ranked highest. Wire-border zone (3.06), rising poles (3.02) and alley arms (2.98) were options with intermediate importance.

• Relating to chemical treatment options, a significant

number of utilities self-reported that low volume foliar spray treatment (4.76 mean index score) rated as most important.

Stump treatment (4.41) was rated as very important (Figure 5-6). Chemical tree-pruning (1.95), aerial application (2.07) and trunk injection (2.17) were unimportant methods.

• Few utilities (25.7%) use tree growth regulators (TGRs). Of those that did, soil injection (57.1%) was most common followed by soil drench (8.1%). Trunk injection (9.5%) was uncommon. Only one utility (4.8%) used more than one option (soil injection and soil drench). The remainder of respondents indicated they only use one approach.

Overall, the importance of TGRs was mixed. 55.0% said they are somewhat important and no utility responded it was very important. 40.0% said they are unimportant, 30.0% stated somewhat unimportant and 10.0% said TGRs are very unimportant.

• Mechanical pruning using helicopters (equipped with

an array of circular saw heads slung underneath) and ground machines (that have a circular saw on a extending boom) were common, 64.3% used this approach. Of those respondents a mean 17.6% (2.8 SE) of the total UVM budget was used for mechanical pruning.

The advantage of mechanical pruning is that it is significantly less expensive than what can be achieved by traditional tree crews. The disadvantage is that it is difficult to hit natural pruning targets with ground machines and impossible with helicopters. Consequently, ANSI A300 Part 1 (ANSI 2017) requires that, outside of emergency situations, mechanical pruning shall only be performed in remote or rural locations away from homes.

• Most cultural control methods were unimportant or

recorded as neither important nor unimportant (Figure 5-7).

Wire-border zone management (3.39), cover type conversion

The chemical effect of TGRs results in retarding tree growth.

Responses suggest utilities are unenthusiastic about their use. Their history might provide insight into why. The first large scale use of TGRs in the 1970s involved methyl or isopropyl alcohol as carriers, which caused cracks, weeping from trunk injection sites and internal wood discoloration.

The resulting widespread tree damage discredited TGR use among utility arborists (Chaney 2005). Perhaps they have not recovered from their early failure. Yet, by reducing growth of some species, tree growth regulators have been demonstrated to increase safety and tree health and reduce cost for utilities (Watson 2018).

23

Very Unimportant (1)

Important (4)

Unimportant (2)

Very Important (5)

Cultural Control Methods

Neither Important or Unimportant (3)

INDEX SCORE

Fertilizing

1.88

Hydroseeding

2.04

Prairie Restoration

2.38

Growing Agricultural Crops

2.40

Landscaping

2.90

Planting or Seed Compatible Plants

3.07

Cover Type Conversion

3.15

Wire-Border Zone

3.39 0

20

40

60

80

100

Percent Figure 5-7. The importance of cultural control options to IVM programs (n=66 to 68).

Very Unimportant (1)

Important (4)

Unimportant (2)

Very Important (5)

Engineering Solutions

Neither Important or Unimportant (3)

INDEX SCORE

Prairie Restoration

2.34

Covered Overhead Construction

2.49

Hendrix Spacers

2.53

Alley Arms

2.98

Rising Poles

3.02

Wire-Border Zone

3.06

Moving Poles for the Lines to Avoid Trees

3.21

Underground Construction

3.27 0

20

40

60 Percent

Figure 5-8. The importance of engineering solutions to IVM programs (n=59 to 62).

24

80

100

SECTION VI - Electrical Operations This section covers electrical operations.

Metrics used to describe system reliability was collected. The total percent of outages and total customer minutes of outages was reported. Respondents also described protective strategies to reduce vegetation-caused outages. Lastly, respondents reported on the percentage of outages caused by vegetation.

Key findings include: • Responding utilities reported on their

% of Total Outages

30 25

23.2

% of Total Customer Minutes

21.7

20 15 10

3.8 vegetation caused outages (Figure 6-1).

5 2.0 The percentage of outages was lowest 1.2 1.1 for transmission lines. A mean 1.1% (0.5 0 SE) of total outages and a mean 1.2% Transmission Distribution Subtransmission (0.7 SE) of total customer minutes Utility Line Type were identified as vegetation related.

Subtransmission lines were slightly higher with a mean 2.0% (0.9 SE) of Figure 6-1. The percentage of outages caused by vegetation by line type (n=61). total outages and mean 3.8% (1.7 SE) of total customer minutes identified as vegetation related. Distribution outages Subtransmission vegetation-related outages are twice the were a magnitude higher. A mean 23.2% (2.6 SE) of total outages and 21.7% (3.1 SE) of total customer minutes were proportion they are on transmission lines, but still far fewer than on the distribution system of responding utilities— identified as vegetation related. subtransmission outages were reported at one-tenth of distribution system outages. While subtransmission is Vegetation related outages are typically significantly not subject to FAC-003, successful control of vegetationlower for transmission than distribution lines for a number related outages likely resulted from lessons learned from of reasons. First, many transmission lines are subject to the transmission standard compliance. Secondly, utilities FAC-003 under the auspices of FERC with the intent of are aware an outage on a subtransmission or transmission preventing cascading outages of the transmission grid line can have consequences a magnitude of order greater initiated by vegetation. It carries potential fines of $1 million than that on distribution, so they have a vested interest in a day for each violation. The standard has had a dramatic proactively managing those lines. effect in improving reliability on the transmission grid.

Photo Credit: Joshua Salas

Photo Credit: Russel Evans

25

Finally, transmission rights-of-way are often much wider than those for distribution lines, which lends itself to cover type conversion and compatible, low-growing plant communities.

Index (CAIDI) were important reliability metrics and had mean index scores 4.37, 4.36 and 4.21 respectively.

• Expanding pruning clearances at time of work was the

highest ranked protective strategy with a mean 3.95 index score (Figure 6-2). Greater action thresholds (3.87) and greater tolerance levels (3.27) for three-phase lines were used. Shorter cycles for three-phase lines (3.20) was the lowest ranked protective strategy.

• Reliability is an aspect of UVM strategy for most (95.8%) responding utilities.

• Distribution fuse coordination is a strategy for mitigating vegetation-caused reliability with nearly half (47.6%) of responding utilities.

• The System Average Interruption Frequency Index

(SAIFI), System Average Interruption Duration Index (SAIDI) and Customer Average Interruption Duration

Very Unimportant (1)

Unimportant (2)

Neither Important or Unimportant (3)

Note that this result is consistent with those presented earlier indicating that only one-third of responding utilities have different strategies for single and three-phase lines.

Important (4) Very Important (5)

Protective Strategies

INDEX SCORE Shorter Cycles on 3-Phase Lines

3.20

Greater Tolerance levels on 3-Phase Lines

3.27

Greater Action Thresholds on 3-phase Lines

3.87

Expanded Clearances at the Time of Work

3.95 0

20

40

60

80

100

Percent Figure 6-2. The importance of protective strategies to electrical operations (n=63 to 64).

Very Unimportant (1)

Unimportant (2)

Neither Important or Unimportant (3)

Important (4) Very Important (5)

Protective Strategies

INDEX SCORE Broader Tolerance Thresholds

2.95

Shorter Cyles

3.04

Greater Clearances at Time of Work

4.08

Greater Action Thresholds

4.13 0

20

40

60

80

100

Percent

Figure 6-3. The importance of protective strategies to three-phase lines compared to single-phase lines to electrical operations (n=22 to 23).

26

• Utilities tend to have the same strategies for single and

which is inadequate to generate a short circuit. This explains why some utilities that emphasize reliability (perhaps at the expense of safety) have different strategies for single and three-phase distribution lines.

three-phase lines. Only 35.8% reported having different strategies for each.

A significant minority of utilities have adopted separate maintenance strategies for single and three-phase distribution lines. Their justification is that three-phase lines are more vulnerable to outages than single-phase lines (Reese et al., 2010). Electrical vegetation-caused outages occur due to either mechanical tear-down or short circuit. Mechanical tear-down is caused by tree parts or whole trees failing and damaging electrical facilities and is the most common cause of outage. Vegetationcaused short circuits occur when branches contact two phases, a phase and a neutral, or a phase and another conductive object.

• Each UVM strategy provides a method to decrease

vegetation related outages. Responding utilities favored the importance of greater action thresholds (4.13) and clearances on three-phase than single-phase lines.

Shorter cycles (3.04) and broader tolerance thresholds (2.95) were less important (Figure 6-3).

• Knowing how vegetation causes an outage provides

valuable data to implement management methods to minimize future conflicts (Figure 6-4). The two most frequent vegetation-related outages, explaining over 60.0% of all causes, were off right-of-way trees (34.4%, 4.1 SE) and whole tree failure (27.2%, 3.7 SE). Broken branches explained 19.4% (2.6 SE) of vegetation related outages. Grow-ins (11.4%, 2.4 SE) and overhang (6.0%, 1.4 SE), while not unimportant, were the lowest identified reasons. Vines were identified as a self-reported other cause and collectively account for 0.26% of outages.

Experimental work by Russell in 2011 established that a voltage gradient of roughly 2 kV per foot (6.6 kV per meter) is necessary for vegetation to cause an outage.

Single-phase distribution lines are seldom sufficiently close to the neutral to build to the gradient threshold necessary to cause an outage. However, three-phase lines are often spaced sufficiently close and energized to a level that will develop a 2 kV per foot voltage gradient.

For example, common spacing on three-phase lines is four feet (1.2 m), and they are often energized at 12.7 kV phase-to-phase. A branch laying across two such phases can result in a voltage gradient of more than 3 kV per foot (9.84 kV per meter), making an outage likely. By contrast, single-phase lines can be energized at 7.6 kV and have 6 feet (1.8 m) to a neutral. A branch contacting such a single-phase line and the neutral would have a voltage gradient of only 1.3 kV per foot (4.2 kV per meter),

These results are consistent with observations by Russell (2011) and others that most outages are caused by off right-of-way trees. It emphasizes the importance of tree risk assessment programs in UVM.

40 35 30 25 20 15 10 5 0

19.4

11.4

34.4

6.0

27.2

Broken Branches

Grow-ins

Off Right-ofway Trees

Overhang

Whole Tree Failures

Outages Type

Figure 6-4. The percentage of vegetation-related outages caused by outage types (n=53).

27

1.6 Other

Section VII – Storm Response Section VII covers storm response by utilities. The survey investigated how utilities respond to storms and storm debris. It inquired whether utilities have a storm response protocol that triggers a response and if so, what criteria is used to initiate. The survey asked utilities if a storm declaration affects overtime pay and if storm response work is capped.

20 16

Consecutive # of Hours

Total # of Hours

24 18.5

15.9

15.9 13.2

12

15.4

14.9 10.7

10.4

8

Utilities explained who declares 4 a storm emergency and the criteria used to declare the 0 storm emergency. The survey First 24 Hours Daily Weekly Monthly determined whether the Time Period communications department staff are involved in the storm response and how important Figure 7-1. What strategy do you use to cap hours for the following time periods (n=5 to 26)? pre-approved messages are for tree crews. Finally, respondents • A storm response declaration affects how storm reported which production data they collect during storms. responders are paid (e.g., trigger overtime) in approximately half (52.5%) of utilities.

Key findings include: • 63.3% of utilities capped hours worked during storms.

• The use of a storm response declaration protocol is very Capping of time varied with length of storm response common, implemented by 92.9% of responding utilities.

(Figure 7-1). Responders were allowed to work longer

28

(total time and consecutive hours) during the first 24 hours versus over a longer period (weekly or monthly).

During the first 24 hours a mean 18.5 (0.7 SE) total hours with 15.9 (1.4 SE) hours allowed consecutively. During storm events that last several days or longer (e.g., week, months), total hours worked in a day were capped at 15 to 16. The consecutive amount of time worked was capped at approximately 10 to 11 hours for events lasting a week or longer.

• Many factors were identified as important to very

important in storm response (Figure 7-2). By far, safety was nearly unanimously rated (4.96) as a very important factor. Electrical hazard communication protocol (4.57), supervision (4.56), fatigue (4.55) and wood under tension (4.46) were also rated as important and very important factors. Animals and insects (2.74) and equipment rental (2.88), while not considered unimportant, were rated lowest.

declare a storm emergency (Figure 7-3). The number of customers out of power was the most common (92.2%) criteria cited. Extent of infrastructure damage (81.3%), percent of customers without power (56.3%), duration of storm (43.8%) and number of interruptions (42.2%) were also important.

Storm preparedness involves developing a set of processes and operations prior to a storm so the response goes as well as can be expected (Miller and Kempter 2018).

• Respondents ranked having an emergency response

center (4.31) as the highest storm preparation strategy (Figure 7-4). Also important was having prestorm communication checks (4.17) and an incident command system (4.16) in place. In advance of storms developing, pre-mobilization systems or agreements (3.86), coordination with local government (3.73) and storm practice drills (3.66) were important for storm preparedness.

• Utilities provided insight into the criteria they used to

Amount of Precipitation

2.74

Animals and Insects

2.88

Equipment Rental

3.72

Rerouting

3.88

Communication

18.8

Type of Precipitation ( e.g., Freezing Rain)

28.1 28.1

Housing

4.09

Geographic Area Covered by Storm

Rosters

4.17

34.4

Mutual Assistance

4.21

Wind Speed Type of Storm

34.4

Percent of Area Out of Power

39.1

Contracts

4.25

Driving

4.26

Fuel

4.29

Incident Command

4.31

Extended Hours

4.35

Number of Interruptions

42.2

Equipment

4.35 4.36

Duration of Storm

43.8

Food Wood Under Tension

4.46

Fatigue

4.55

Supervision

4.56

Electrical Hazard

4.57

Percent of Customers Out of Power Extent of Infrastructure Damage

0

1

2 3 4 Index Score

92.2 0

5

Figure 7-2. The importance of storm response factors (n=65 to 69).

81.3

Number of Customers Out of Power

4.96

Safety

56.3

20

40

60

80

100

Percent Figure 7-3. Criteria used to declare a storm emergency (n=64).

29

Very Unimportant (1)

Unimportant (2)

Storm Preparation Factors

Neither Important or Unimportant (3)

Important (4) INDEX SCORE

Very Important (5)

Storm Practice Drills

3.66

Coordination With Local Government

3.73

Pre-mobilization

3.86

Incident Command System (ICS)

4.16

Pre-storm Communication Checks

4.17

Emergency Operations Center

4.31 0

20

40

60

80

100

Percent Figure 7-4. How important are the following storm preparation factors in your vegetation management storm response (n=65 to 68)?

• Appointing an official who declares a storm emergency

common as media approaches. 59.7% said media relations control 100.0% of storm messaging. Further, 37.1% place restrictions on front line employee communications and 30.6% use a pre-approved message for tree crews (e.g., “we are working hard to get things back to normal”). Respondents were mixed with the importance of a pre-approved message with a mean 2.86 (0.15 SE) index score.

is standard practice. More than one person may be part of this process, however, 64.6% of utilities indicated one person made the declaration. An operations leader is part of appointing the decision nearly 80.0% of the time, as either the operations manager (40.0%) or operations director (38.5%). A storm response committee was part of the decision 26.2% of the time. The president (20.0%) or vice-president (20.0%) were involved, but to a lesser degree. These senior level positions were likely to be part of the decision-making group 62.5% of the time.

Loads or Volume (ft3 or m3) Collected

• Collecting production data during a storm response

is one of many important functions. Only half of responding utilities (50.7%) reported collecting production data during storm response, compared to nearly all (97.1%) doing so during normal operations. Data collected during storms most included hours worked (94.3%) and locations worked (71.4%) (Figure 7-5). Data collection pertaining to production was uncommon and reported as number of trees removed (25.7%), square area (11.4%), and loads or cubic volume (8.6%) of debris.

Area (ft2 or m2) Worked

11.4

Number of Trees Worked

25.7

Locations Worked

• A plan for storm debris, whether left on site, removed,

or a combination approach is important to develop prior to storm response. Debris is left on site for 70.1% of responding utilities. A total 25.4% never leave debris from storms on site. Few (4.5%) utilities occasionally leave debris on site and for these utilities a mean 74.6% (7.3 SE) of debris is left on site.

8.6

71.4 94.3

Hours Worked 0

20

40

60

80

100

Percent Figure 7-5. Production data collected during storms (n=35).

• Involving communications departments may provide for timely and appropriate messages to customers (Miller and Kempter 2018) (Figure 7-6). Press releases on the extent of outages (77.4%) and communicating estimated time of restoration (71.0%) were most

30

6.5

Other Pre-approved Message For Tree Crews (e.g., “We are working hard to get...”)

30.6 37.1

Restrictions on Front Line Employee Communications

59.7

Media Relations Control 100% of the Messaging For Storms

71.0

Communicating Estimated Time of Restoration Press Releases on the Extent of Outages

77.4 0

20

40

60

Percent Figure 7-6. How is your communication department involved in storm response (n=62)?

Photo Credit: Dennis Cueva

31

80

100

Section VIII – COMMUNICATIONS Communication in advance of an action and keeping customers informed are best management strategies to increase service satisfaction. Respondents provided information on how they communicate to customers before work. For example, the questionnaire inquired whether utilities used customer satisfaction surveys to evaluate work. Respondents ranked the importance of outside groups as well as the importance of a variety of communication types.

Follow-up Personal Visit

8.1

Other

16.2 27.0

Door Hanger

• Utilities use a variety of ways to communicate with

customers before work occurs. Most (71.4%) use two or more methods. Utilities may use contract (55.7%) or inhouse (57.1%) utility foresters/arborists to communicate with customers prior to work occurring. Most often (82.9%), a person was involved with communicating with customers (in-person or providing materials) and this contact was mixed with approximately one-third using contract, in-house, or both to do such. Tree crews were an important f rontline communication approach, used by 50.0% of utilities. Other self-reported (35.7%) methods used include indirect contact. Direct mail (14.3%), phone message (14.3%) or door hangers (8.6%) were used. These percentages are reflective of the total response.

Website Directed Survey

40.5

Phone Call

43.2 0

20

40

60

80

100

Percent

Figure 8-1. How do you conduct customer satisfaction surveys (n=37)?

• Customer satisfaction surveys provide information

to reflect how well operations are occurring and if changes are needed. Over half (54.3%) of respondents said they use customer satisfaction surveys. Phone call (43.2%) and website directed surveys (40.5%) were most common (Figure 8-1). Door hangers (27.0%) or followup visits (8.1%) were less commonly used.

• Groups external to a UVM program can provide

communication messages about utility operations (Figure 8-2). Residential customers (4.48), property owners (4.42) and UVM contractors (4.41) were the three most important groups. They are most closely tied to where work occurs, so their importance is not surprising. Interestingly, the media (3.77) was considered of intermediate importance.

• Respondents were asked to rank the importance

of five types of communication. Using a scale of 1 (least important) to 5 (most important), town hall meetings (2.30) and e-mail messages/blasts (2.51) were considered least important for UVM communication.

Brochures (3.57) and social media (3.45) were ranked highest and press releases (2.86) of intermediate importance. A take home message is that although a variety of approaches are used, some rank higher than others, but in general, communication plans are highly individual and what works best for some operations might not work best for another utility.

32

Photo Credit: larn McCulley

Very Unimportant (1)

Unimportant (2)

Important (4) Very Important (5)

Neither Important or Unimportant (3)

INDEX SCORE

3.28

Non-utility Arborists (Municipal Government)

3.36

Environmental Organizations

3.41

Neighborhood Associations

3.50

Owners and Investors

3.56

State Department of Natural Resources

3.64

Federal Land Management Agencies

3.65

Media

3.77

County Goverement

3.83

Regulatory Agencies

3.98

Commerical Customers

3.99

Municipal Goverment

4.09

UVM Contractors

4.41

Property Owners

4.42

Residential Customers

4.48

Groups Involved with UVM-related Communications

Suppliers

0

20

40

60

80

100

Percent

Figure 8-2. The importance of the following groups for UVM-related communications of utility operations (outside of UVM, n=63 to 68).

Very Unimportant (1)

Unimportant (2)

Storm Preparation Factors

Important (4) Very Important (5)

Neither Important or Unimportant (3)

INDEX SCORE

2.30

Town Hall Meetings

2.51

E-mail Messages (Blasts) Press Releases

2.86

Social Media

3.45

Brochures

3.57 0

20

40

60

Percent

80

Figure 8-3 The importance of the following types of communication you use for UVM (1 = very unimportant to 5= very important, n=63 to 67).

33

100

CONCLUSIONS The 2019 Utilities & Vegetation Management in North America report© describes the current state of utility forestry tree activities and operations. This study drew from a list of 210 utilities from a historical CNUC list and Tree Line USA® recipients from the Arbor Day Foundation.

71 responding utilities covered over 52 million customers, 107,000 miles of transmission, nearly 80,000 miles of subtransmission and 1.1 million miles of distribution lines.

It solicited answers to questions covering UVM programs that require command of safety, program management, pruning, IVM, electrical operations, storm response and communications.

Important findings show 97.0% of responding UVM programs learn from safety incidents, but they were not enthusiastic on UAA Safety Summits.

Nearly 80.0% of responding utilities had centralized UVM programs, the majority of which had a department head with a natural resource degree. Over 21.0% of trees were in contact with distribution lines at the time of work. Safety and service reliability were the prominent

reasons responding utilities used for UVM, while 23.2% of outages and 21.7% of lost customer minutes were attributable to vegetation. Emergency response centers were a prominent storm response strategy and safety was the most important consideration. UVM programs use contract, or in-house arborists to communicate with customers, commonly via brochures and social media for non-face-to-face communication. Follow-up surveys might focus on utility forest population and workload, productivity, and research and development.

We sincerely thank the many people vital to completing this project. We thank the initial group who reviewed the research instruments prior to its release. Ian Vierck and Emily Cleaver for the survey layout and database management.

Questionnaire and final report editors Shannon BussoneRue and Katie Moehn and final report designer Megan Taylor. The UWSP Print Design staff were vital to the quality printing of the questionnaire and final report. And lastly, we thank all utilities that participated and provided their valuable time to share their current UVM programs.

34

REFERENCES Arbor Day Foundation. 2019. Tree Line USA Utilities. Arbor Day Foundation. <https://www.arborday.org/programs/treelineusa/ directory.cfm> Accessed November 21, 2020.

Goodfellow, J.W. and H. Holt. 2011. Utility Arborist Association Best Management Practices: Field Guide to Closed Chain of Custody for Herbicides in the Utility Vegetation Management Industry.

International Society of Arboriculture. Champaign, IL. 20 pp.

Agnew J. and A. Daniels. 2010. Safe by Accident: Take the LUCK out of SAFETY. Performance Management Publications. Atlanta, GA. 175 pp.

IBM Corp. 2017. IBM SPSS Statistics for Windows, Version 25.0.

Armonk, NY: IBM Corp.

ANSI. 2017. American National Tree, Shrub, and Other Woody Plant Management – Standard Practices (Pruning). ANSI A300 (Part 1).

Tree Care Industry Association, Inc. Londonderry, NH. 31 pp.

James, K. 2003. Dynamic Loading of Trees. Journal of Arboriculture. 29(3): 165-171.

James, M and J.L. Ortiz. 2018. Class Action Lawsuit Alleges Deadly Wildfire Was Caused By Pacific Gas And Electric. <https://www. usatoday.com/story/news/nation/2018/12/05/lawsuit-utility-campwildfire-pacific-gas-electric-unsafe-negligent/2221260002/>.

Accessed November 21, 2020.

ANSI. 2018. American National Tree, Shrub, and Other Woody Plant Management – Standard Practices (Integrated Vegetation Management). ANSI A300 (Part 7). Tree Care Industry Association, Inc. Londonderry, NH. 19 pp.

Avalos, G. 2018. Cal Fire blames PG&E for North Bay Wildfires.

San Jose Mercury News. June 82018. <https://www.mercurynews. com/2018/06/08/pge-blamed-for-multiple-north-bay-wildfires/> Accessed November 21, 2020.

Lee, P. and E.W. Humphrys. 2014. Electric Utilities. The Canadian Encyclopedia. <https://www.thecanadianencyclopedia.ca/en/ article/electric-utilities#:~:text=There%20are%2016%20major%20 electric%20utilities%20in%20Canada.> Accessed November 21, 2020.

Browning, D.M. and H.V. Wiant.1997. The Economic Impacts of Deferring Electric Utility Tree Maintenance. Journal of Arboriculture. 23:106-112.

Carter, R. 2019. 2015 Electric Utility Contact Report (From Electrical Contact Injury Incidents Reported to the OR-PUC Through 2015).

Oregon Public Utility Commission, Salem, OR. Chaney, W.R. 2005. Growth Regardant: A Promising Tools for Managing Urban Trees. Purdue Extension publication FNR-252-W. <https://www.extension.purdue.edu/extmedia/fnr/fnr-252-w.pdf> Accessed November 21, 2020.

Chen, P. and R. Vanderhoof. 2020. Correlation Between Cost and Time Since Last Worked. Unpublished.

Miller, R.W., Hauer, R.J. and Werner, L.P. 2015. Urban Forestry Planning and Managing Urban Greenspaces (3rd Edition).

Waveland Press. Long Grove, IL. 560 pp.

Porter, W. and N. Cohn. 2014. Utility Vegetation Management Benchmark & Industry Intelligence: 2014 Distribution Update CN Utility Benchmark Survey Report. CNUC, Des Moines, IA. 59 p.

Dillman, D.A., J.D. Smyth, and L.M. Christian. 2014. Internet, Phone, Mail, and Mixed Mode Surveys: The Tailored Design Method (4th ed.). John Wiley & Sons Inc. 528 pp. .

EIA. 2019. Investor-Owned Utilities Served 72% of U.S. Electricity Customers in 2017. U.S. Energy Information Administration. <https://www.eia.gov/todayinenergy/detail.php?id=40913> Accessed November 21, 2020.

Goodfellow, J.W. 2020. Utility Tree Risk Assessment: Best Management Companion publication to ANSI A300 Part 9: Tree, Shrub, and Other Woody Plant Management – Standards Practices (Tree Risk Assessment a. Tree Failure). International Society of Arboriculture. Atlanta, GA. 95 pp.

Miller, R.H. and G. Kempter. 2018. Utility Arboriculture: The Utility Specialist Certification Study Guide. International Society of Arboriculture. Champaign, IL 266 pp.

Nutter, W. 2012. Safety Culture. Utility Arborist Newsline. 3:26-28.

Cieslewicz, S. and W. Porter. 2010. CN Utility Consulting: Utility Vegetation Management Benchmark & Industry Intelligence.

CN Utility Consulting. Sebastopol. CA. 478. pp.

Watson, B.G. 2018. Five Things to Know About Tree Growth Regulators. T&D World. <https://www.tdworld.com/vegetationmanagement/article/20971444/five-things-to-know-about-treegrowth-regulators> Accessed November 21, 2020.

McClenahan, J. 2012. Risk Management: Utilization of Leading Indicators in the Continuous Improvement Cycle. Tree Care Industry, XXIII(11):68-72.

Porter W. and N. Cohn. 2016. Distribution Vegetation Management Benchmark Survey Results 2016. CNUC, Des Moines, IA. 95 pp.

Russell, B.D. 2011. Best Practices in Vegetation Management for Enhancing Electric Service in Texas. PUCT Project 38257. Texas Engineering Experiment Station, Texas A&M University System.

College Station, TX. 90 pp.

Reese, W.T. Jr., T.C. Birx, D.L. Neal, C.J. Summersn, F.L. Tiburzi, J.A. Thurber. 2010. Priority Trimming to Improve Reliability. T&D World. <https://www.tdworld.com/vegetation-management/reliabilitysafety/article/20958816/priority-trimming-to-improve-reliability.> Accessed November 21, 2020.

Senseman, S.A. (Ed.). 2007 Herbicide Handbook. (9the Ed.).

Lawrence, Kansas: Weed Science Society of America. 458 p.

UAA. 2020. Environmental Stewardship. <https://www.gotouaa. org/environmental-stewardship2/>. Accessed November 21, 2020.

35

APPENDIX A: QUESTIONNAIRE & RESULTS Thank you for participating in the 2019 utility vegetation management survey jointly conducted by CNUC and the University of Wisconsin – Stevens Point (UWSP). It is the latest iteration of benchmarking surveys CNUC has conducted since 2002. This survey is intended for the person(s) who can best tell us about your utility operation and utility vegetation management (UVM). Ideally, the person directly responsible for your program will respond, however, any utility employee who can best respond, to any question, should do so. Answer each question the best you can.

If multiple departments/groups are involved with your utility, we ask that the entire program be formulated as one response using this questionnaire. It is important to answer as many applicable questions as possible.

Please read each question carefully: Respond to each question with the answer that best fits your utility. An example follows below.

1. Does your utility conduct utility vegetation management?

(CHECK ONE)

□ Yes □ No

Please try to answer every question that applies to you. If none of the answers provided seem exactly right, choose the one that best reflects what occurs in your utility. If you are unable to answer any question, leaving it blank is acceptable.

The data from each participating utility is pooled together and shared, without identifying any responding utility.

The intent is to enable industry professionals to compare and contrast their program with their peer North American utilities. The ultimate objective of this benchmark study is to further develop an understanding of utility arboriculture, advance the profession, and help utility vegetation managers improve their programs. The results of the survey will be submitted for publication in Arboriculture and Urban Forestry, the Utility Arborist Newsline, and other periodicals.

Each participating utility will be randomly assigned a discreet three-character numeric identifier, to which responses will be exclusively attributed. Codes are changed for each survey to enhance security. Participating utilities will be informed of their individual code. Only the subject utility and the CNUC director of research and development and the cooperating University of Wisconsin – Stevens Point research team will know the codes assigned to specific respondents. Exceptions will only be made at a participating utility’s written permission or request.

Abbreviations/Definitions n= number of respondents for a question SE= standard error of the mean

36

Section I – Company Profile 1. How many total customers does your company serve? n=69 756,600 (mean), 3500 to 7,752,009 (range) # of total customers 2. What type of business is your utility? n=71 (CHECK ALL THAT APPLY)

97.2% Distribution

69.0% Transmission

45.1% Generation

3. What is your ownership structure? n=74 (note 1 was both Federal and municipal owned and 1 was both investor owned and state/provincial owned) (CHECK ALL THAT APPLY)

20.3% Cooperative

1.4% Federal

37.8% Investor-owned utility

31.1% Municipal/public utility district

6.8% State/provincial

2.7% Other: (2 responses: Authority; Owned by the states DU’s)

4. What distance (km or mi) of overhead lines do you have on your system and specify the unit metric used to measure line distance? n=71

Units are in: (CHECK ONE)

□ km (kilometers) □ mi (miles)

Line Distance (all units below expressed in miles)

(Please enter “0” if none.)

Mean (mi)

Range (mi)

SE1 (mi)

Line Type

2,999

9 to 31,000

963

Transmission (e.g., 200K line, subject to FAC-003-4)

1,936

6 to 11,127

401

Sub-transmission (e.g., local, not subject to FAC-003-4)

16,523

5 to 130,120

3,514

Distribution

3,322

25 to 32,000

1,702

Secondary

18,778

5 to 130,120

4,478

Primary

8,104

5 to 48,000

1,961

Three-phase2

13,429

0 to 83,292

3,415

Single-phase2

66.8 (mean, 3.0 SE), 6 to 100 (range) % of primary lines accessible by aerial lift (e.g., truck, backyard, skidder)

1

SE = Standard Error of the Mean throughout report

2

Primary = Three-phase and Single-phase

37

Section II – Safety 1. How important are the results of Utility Arborist Association (UAA) Safety Summits to your program? n=65

13.8% Very unimportant

16.9% Somewhat unimportant

30.8% Neither unimportant or important

23.1% Somewhat important

15.4% Very important

3.09 (mean, 0.16 SE, 1= very unimportant and 5= very important)

2. Does your company use a third-party safety administrator (such as ISNetworld)? n=68 (CHECK ONE)

29.4% Yes

70.6% No

3. Are unintentional safety errors subject to progressive discipline? n=63

(CHECK ONE)

44.4% Yes

55.6% No

4. Is intentional safety misconduct subject to progressive discipline? n=63

(CHECK ONE)

95.2% Yes

4.8% No

5. Are close calls (near misses) reported? n=70 (CHECK ONE)

97.1% Yes

2.9% No

6. Are lessons learned communicated to others in the organization? n=66 (CHECK ONE)

97.0% Yes

3.0% No → (PLEASE GO TO QUESTION 8)

If yes, please explain:

38

7. How are lessons learned communicated to others in the organization? n=64 (CHECK ALL THAT APPLY)

28.1% Department-wide conference call

56.3% Job briefing

89.1% Safety meeting

65.6% Safety stand-down

25.0% Other: (16 responses)

e-mail (10 responses, 15.6%)

Safety bulletin/report (4 responses, 6.3%)

8. Does your department have a safety committee(s)? n=71

(CHECK ONE) 67.6% Yes

32.4% No → (PLEASE GO TO QUESTION 13)

9. How many times a year does your safety committee meet? n=41

10.61 (mean)

1 to 52 (range)

12 (65.9%) most common # of times

0.0

13.0

Mean Index Score

Neither Important or Unimportant (3)

2.2

Very Important (5)

Unimportant (2)

Assisting in incident investigations

Important (4)

Subject Area (% of total & mean)

Very Unimportant (1)

10. Please rate the importance of each subject area to your safety committee. n=46

30.4

54.3

4.35

Developing training 2.2 0.0 13.0 43.5 41.3 4.22

Establishing procedures 2.2 0.0 10.9 41.3 45.7 4.28

Evaluating procedures 2.2 0.0 6.5 43.5 47.8 4.35 Evaluating safety training and educational material

2.2

0.0

17.4

39.1

41.3

4.17

Identifying high-risk tasks 2.2 0.0 6.5 23.9 67.4 4.54

Monitoring safety performance 2.2 2.2 0.0 45.7 50.0 4.39

Tracking progress 2.2 2.2 13.0 32.6 50.0 4.26 Other: 1 response, committee identifies issues work to address - - - - - -

39

11. Who currently chairs the safety committee? n=42

(CHECK ONE)

92.9% Company utility representative

0.0% Contract manager

0.0% Contract general foreperson/supervisor

0.0% Tree crew leader

0.0% Tree crew member

7.1% Other: (3 responses: Combination of people)

12. Is the safety committee(s) empowered to contribute to departmental safety policy? n=42

(CHECK ONE)

100.0% Yes

0.0% No

13. Is contractor safety training allowed during billed working hours? n=68

(CHECK ONE) 67.6% Yes

32.4% No → (PLEASE GO TO QUESTION 15)

14. How many times per year is contractor safety training allowed during billed working hours? n=26

10.12 (mean), 1 to 52 (range), 12 (26.9%) most common # of times

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Subject Area (% of total & mean)

Unimportant (2)

Very Unimportant (1)

15. What is the importance of the following safety authorities to your program? n=69 to 70

ANSI Z133 (2017 version) 7.1 1.4 1.4 15.7 74.3 4.54

Contractor safety policy 4.3 0.0 4.3 18.8 72.5 4.39

OSHA/OHS Canada 7.2 0.0 4.3 21.7 66.7 4.35

State/provincial requirements 2.9 0.0 13.0 24.6 59.4 4.35

Utility company safety policy

2.9

40

0.0

5.8

10.1

81.2

4.28

16. How many OSHA/OHS Canada recordable safety incidents have occurred by working group in the past three years (enter “0” if no incident)? n=43 to 52, (mean value and (SE) reported in table)

Working Group 2016 2017 2018

In-house staff

0.77 (0.71)

0.92 (0.86)

0.90 (0.75)

Vegetation management contractor

2.65 (0.83)

2.72 (0.76)

3.15 (1.08)

Consulting arborist

0.002 (0.02)

0.0 (0)

0.02 (0.02)

17. Do you calculate OSHA accident rates (DART: Days Away, Restricted or Transferred, per 100 employees per year)? n=58

(CHECK ONE)

56.9% Yes

43.1% No → (PLEASE GO TO QUESTION 19)

If yes, please explain how you apply it to your safety program:

18. On average, what is your annual DART rate (per 100 employees per year) over the past 3 years? n=18 to 23 (Please enter “0” if none)

0.23 (mean), 0 to 2.06 (range) In-house staff

0.51 (mean), 0 to 1.60 (range) Vegetation management contractor

0.00 (mean), 0 to 0 Consulting arborist (planning and quality assur.)

19. On average, how many public electrical contacts involving trees have occurred annually on your system over the past 3 years?

0.50 (mean, (0.19 SE), 0 to 5 (range), n=43: # of electrical contacts/year

20. On average, how many fires involving trees have occurred annually on your system over the past 3 years?

0.76 (mean, (0.47 SE), 0 to 25 (range), n=54: # of fires per year

41

Section III – Program Management 1. Which structure best characterizes your UVM program? n=69 (CHECK THE BEST DESCRIPTION)

79.7% Centralized into a single department

17.4% Centralized by program (e.g., distribution, transmission)

0.0% Decentralized (e.g., operational units like regional district offices, each responsible for independent UVM programs)

2.9% Other: (2 responses: Contract, Centralized State Office)

2. Do you have a UVM department head? n=70

(CHECK ONE)

92.9% Yes

7.1% No → (PLEASE GO TO QUESTION 5)

3. What is your UVM department head’s title? n=64 (CHECK ONE)

1.6% Arborist

14.1% Director of Vegetation Management

6.3% Forester

28.1% Manager of Vegetation Management

1.6% Operations Manager

1.6% Senior Utility Arborist

14.1% Supervisor of Vegetation Management

4.7% System Forester

28.1% Other: (18 responses)

Manager (7 responses, 10.9%)

Supervisor (3 responses, 4.7%)

Superintendent (3 responses, 4.7%)

4. What credentials does the UVM department head have? n=64 (CHECK ALL THAT APPLY)

82.5% ISA Certified Arborist

52.4% ISA Certified Arborist Utility Specialist

1.6% ISA Board Certified Master Arborist

20.6% ISA Tree Risk Assessment Qualification

49.2% Bachelor of Science in a natural resources related field

6.3% Master of science in natural resource related field

0.0% PhD in natural resource related field

39.7% Other: (25 responses, no central theme, variety of answers)

(e.g., agronomy, arboriculture, forestry, horticulture, urban forestry, wildlife biology)

42

5. In what department does UVM reside? n=66 (CHECK ONE)

1.5% Contract administration

6.1% Engineering

0.0% Finance

43.9% Operations

1.5% System reliability and maintenance

0.0% Technical services

33.3% Vegetation management

13.6% Other: (9 responses, operations and/or management)

6. How many total people work for your UVM program? n=68

215.1 (mean, 215.1 SE), 1 to 5320 (range), # of People

7. How many in-house UVM personnel or contractors work in your UVM program? Fill in the number of positions and Full Time Equivalents – FTEs, 2080 hours base year, enter “0” if no position.

Position Categories (mean values)

Number of Positions

Number of FTEs

Example Answer 2 1.5

General foreperson(s)/supervisors 15.58 16.97

Crew leaders 40.52 44.35

Planners 9.60 10.10

Tree care workers 156.51 174.38

Other: (

) 33.83 29.59

8. How many UVM personnel are contractors in your UVM program? Fill in the number of positions and Full Time Equivalents – FTEs, 2080 hours base year, enter “0” if no position.

Position Categories

Number of Positions

Number of FTEs

Example Answer 2 1.5

General forepersons/supervisors

Crew leaders

Planners

Tree care workers

Other: (

)

43

9. What percentage of your total FTE’s are directly responsible managing your UVM program? n=58

39.5 (mean, 5.6 SE), 0 to 100 (range) # of People

10. How many levels of management are involved in directing the UVM program?

(i.e., Utility CEO → Director of Vegetation Management → System Forester → Foreperson/supervisor → Crew Worker =

4 steps) n=63

4.8 (mean, 0.3 SE), 1 to 12 (range) # of levels

11. Is your UVM work pre-planned or inspected ahead of tree crews? n=69 (CHECK ONE)

89.9% Yes

10.1% No → (PLEASE GO TO QUESTION 13)

12. Who conducts your UVM work, pre-planned or inspected, ahead of tree crews? (Please enter “0” if none.) n=61

Who Conducts UVM Work

% of total

Example Answer 32

Company employees 39.1

Contract work planners 52.3

Tree crew members 5.3

Combinations 0.02

Other: (3 responses: foreman, manager, supervisor)

3.3

Total = 100% 13. On what device(s) is vegetation management data collected? n=65

(CHECK ALL THAT APPLY)

36.9% Desktop computer

46.2% Laptop

38.5% Mobile phones

55.4% Paper

58.5% Tablets (PCs/iPad)

0.0% Other: (no responses)

14. Do you use GIS-based software for vegetation management planning? n=65 (CHECK ONE)

72.1% Yes

27.9% No

44

15. How is the work location identified? n=65

(CHECK ALL THAT APPLY)

70.8% Address

75.4% Circuit

41.5% GIS location

29.2% Grid or polygon

56.9% Pole number

41.5% Span

43.1% Tree/bush units to be worked on

6.2% Other: (4 responses: street name, service #, map, line name)

16. Do you keep track of the amount of work you accomplish? n=68 (CHECK ONE)

97.1% Yes

2.9% No → (PLEASE GO TO QUESTION 19)

17. Which distribution line production measurements do you track? n=61

(CHECK ALL THAT APPLY)

18.0% Area (ft2 / m2) of saplings (brush) pruned

39.3% Area (ft2 / m2) of saplings (brush) removed

37.7% Area (ft2 / m2) of saplings (brush) treated with herbicide

75.4% Distance (km or mi) of line cleared

8.2% Trees in contact with the line at the time of maintenance

31.1% Trees per mile / km worked

60.7% Trees pruned

75.4% Trees removed

9.8% Other: (6 responses: spans 6.6%)

18. Which transmission line production measurements do you track? n=44

(CHECK ALL THAT APPLY)

27.3% Area (Acres or ft2 / hectare or m2) of saplings (brush) pruned

59.1% Area (Acres or ft2 / hectare or m2) of saplings (brush) removed

68.2% Area (Acres or ft2 / hectare or m2) of saplings (brush) treated with herbicide

56.8% Trees pruned

70.5% Trees removed

25.0% Other: (11 responses: 7 described some distance)

45

19. Which industry affiliations does your UVM program have? n=65

(CHECK ALL THAT APPLY)

80.0% Arbor Day Foundation (Tree Line USA)

3.1% Energy for Wildlife

83.1% International Society of Arboriculture

6.2% The Nature Conservancy

1.5% Pesticide Environmental Stewardship Program

3.1% Pheasants Forever

15.4% Pollinator Partnership

7.7% Right-of-way as Habitat Working Group

6.2% Right-of-way Stewardship Council

81.5% Utility Arborist Association

1.5% Wildlife Habitat Council

6.2% Wild Turkey Federation

13.8% Other: (9 responses: no central theme)

20. How important are the following International Society of Arboriculture (ISA) credentials to your program?

Credential (% of total & mean)

Unimportant (2)

Neither Important or Unimportant (3)

Important (4)

Very Important (5)

Mean Index Score

n=64 to 70 Very Unimportant (1)

ISA Certified Tree Worker Climber Specialist®

5.8

15.9

59.4

13.0

5.8

2.97

ISA Certified Tree Worker Aerial Lift Specialist®

5.8

15.9

58.0

13.0

7.2

3.00

ISA Certified Arborist® 4.3 2.9 11.4 24.3 57.1 4.27

ISA Certified Municipal Specialist®

15.6

31.3

45.3

4.7

3.1

2.48

ISA Certified Utility Specialist™

4.3

2.9

18.8

37.7

36.2

3.99

ISA Board Certified Master Arborist®

13.4

20.9

52.2

9.0

4.5

2.70

ISA Tree Risk Assessment Qualification

4.4

7.4

39.7

29.4

19.1

3.51

46

Very Much (5)

Much (4)

Neither Little or Much (3)

UVM Consideration (% of total & mean)

Little (2)

Very Little (1)

Mean Index Score

21. How well does your management understand the following UVM considerations? n=66 to 67

Benefits of tree removals 0.0 3.0 16.4 22.4 58.2 4.36

Compliance 1.5 3.0 10.6 18.2 66.7 4.45

Cost of deferring maintenance 3.0 10.4 14.9 29.9 41.8 3.97

Effect of UVM on reliability

0.0

1.5

10.4

17.9

70.1

4.57

Liability 1.5 4.5 12.1 30.3 51.5 4.26

(e.g., consequence of tree causes electrical hazard or fire risks)

Long-term cost effectiveness of a proactive UVM program

3.0

6.0

14.9

34.3

41.8

4.06

Need for consistent funding 3.0 7.5 3.0 40.3 46.3 4.19

Need for professionalism in UVM

1.5

3.0

14.9

28.4

52.2

4.27

Problems related to underfunding UVM

4.5

13.4

9.0

29.9

43.3

3.94

Variability of natural systems 7.6 16.7 30.3 25.8 19.7 3.33

Other: (2 response: Labor scarcity, tree response to pruning) - - - - - -

22. Does your program conduct work audits post-work inspection? n=67 (Yes or No) n=61 (If yes)

(CHECK ONE)

94.4% Yes → If yes, % audited 81.3 (mean, 4.3 SE), 2 to 100

5.6% No

23. What was your total UVM Expenditure in 2018? n=66

27,182,769 (mean, 7.0M SE), 50K to 320M (range) $ Total Expenditures

24. Is your UVM budget adequate to meet current needs as defined in your work plan or your identified annual UVM budget needs? This includes planning, maintenance, removal, inventory, education, etc. n=70 (Yes or No)

47.1% Yes

n=33 (If no)

52.9% No → If no, % below need 28.9 (mean, 4.3 SE), 5 to 100

25. Has your UVM budget been stable over the past five years? n=67

(CHECK ONE)

53.7% Yes

46.3% No

47

26. What were your 2018 program expenditures? n=4 to 59 (Please enter “0” if none.)

UVM Expenditure Category Total Expenditures Unplanned Expenditures ($ by Category) (% of Category)

Example Answer $12,256,265 22%

Transmission 6,927,258 (2,390,504 SE) 4.02 (1.32 SE)

Sub-transmission

4,912,886 (2,218,245 SE)

2.08 (0.94 SE)

Distribution

25,428,476 (6,412,338 SE)

10.85 (2.17 SE)

Total

30,348,253 (8,008,007 SE)

10.63 (2.02 SE)

27. What budget format do you employ for planning (see definitions)? n=67

(CHECK ONE)

17.9% Entrepreneurial (Management sets based company goals)

49.3% Line-item (Itemized categories and accounts)

0.0% Performance (Based on performance measures)

23.9% Program (Items based on programs rather than accounts)

9.0% Zero-based (Annually creating a budget from scratch)

28. What contracting types do you use in your UVM program? n=70

(CHECK ALL THAT APPLY)

31.4% Hard Price

11.4% Performance-based

88.6% Time and Material

50.0% Unit

14.3% Other: (10 responses: 50% were lump sum)

29. What percent of time is allocated for the following quality assurance and quality control methods? (Please enter % of time by method used.) n=32 to 58

Utility Area

Example answer

Distribution secondary

N

None

Sample

100% Drive-by

100% Field Audit

Total (%)

0

12

72

16

100

45

4.56

23.22

31.89

40.33

100

Distribution primary

58

4.28

17.69

31.03

47.00

100

Subtransmission

34

0.00

21.12

20.44

58.44

100

Transmission

32

3.13

12.91

18.44

65.53

100

48

30. What is the average salary or hourly pay rate by UVM position?

Position Categories In-house Contractor

Example Answer (salary) $52,300 $59,750

Department head (salary) 116,288 82,500

Utility arborist/manager 86,877 64,556

(1 level below department head) (salary)

Utility arborist/general foremen

(2 levels below the department head) (salary)

Example Answer (hourly) $26.32 $19.54

71,813

63,775

Crew leader (hourly) 29.27 30.14

Qualified utility arborist (hourly)

26.47

24.85

Qualified utility arborist trainee (hourly)

19.61

21.58

Ground worker (hourly) 17.10 19.94

Chemical applicator (hourly) 19.57 26.69

Planner Q/A specialist (hourly)

32.94

27.53

Other: (3 responses) 31.25 33.28

31. Do you conduct work on time-based cycles? n=71

(CHECK ONE) 88.7% Yes

11.3% No → (PLEASE GO TO QUESTION 33)

32. What best describes your work approach for time-based cycles? n=65

(CHECK ONE)

3.1% Reactive

3.1% Just in time

3.1% Reliability based

81.5% Regular work cycle

If regular cycle, current cycle length (years) 4.5 (0.18 SE)

If regular cycle, desired cycle length (years) 3.8 (0.19 SE)

9.2% Variable work cycle: (not specified)

33. Do you work single and three-phase lines on different cycles? n=64

(CHECK ONE)

9.4% Yes

90.6% No

34. Do you work in a circuit or a grid (polygon) basis? n=66

(CHECK ONE)

78.8% Grid

21.2% Circuit

49

35. What were your 2018 program expenditures per UVM area? n=31 to 53

(Please enter “0” if none.)

30,819,334 (8,525,039 SE)

Total UVM expenditures

26,591,007 (7,129,611 SE)

Total UVM distribution expenditures

40.37 (4.09 SE)

Total UVM cost per customer

3,085 (482.3 SE)

Total UVM expenditures per mile

1,719,989 (419,293 SE)

Total UVM expenditures for unplanned work

Section IV – Pruning 1. What was the tree condition at the time of maintenance? n=50 to 54 (Please enter “0” if none.)

21.3 (3.5 SE) Percent of trees in contact with line (n=50)

24.6 (3.7 SE) Percent of trees over-hanging line (n=54)

2. Do you have a chemical pruning program? n=67 (CHECK ONE)

13.4% Yes

86.6% No

3. Do you clear “ground to sky” on the wire side of trees? n=65 (CHECK ONE)

58.5% Yes

41.5% No → (PLEASE GO TO QUESTION 5)

4. Where do you clear “ground to sky” on the wire side of trees? n=39 (CHECK ALL THAT APPLY)

25.6% Rural locations

48.7% Three-phase lines

10.3% To the first protective device

38.5% All locations

30.8% Other: (12 responses, depends on situation)

50

Pruning Considerations (% of total & mean)

Very Unimportant (1)

Unimportant (2)

Neither Important or Unimportant (3)

Important (4)

Very Important (5)

Mean Index Score

5. Rate the importance of the following pruning considerations in determining the clearances distances. n=63 to 64

Expected weather in the vicinity

9.5

15.9

28.6

33.3

12.7

3.24

Facility construction 7.9 4.8 22.2 33.3 31.7 3.76

(e.g., single pole, crossarms, bundled, secondary)

Facility priority 6.3 3.1 7.8 40.6 42.2 4.09

(e.g., voltage, overcurrent protection, customers served, high-value customers)

Line location 6.3 6.3 35.9 31.3 20.3 3.53

(e.g., urban, suburban, rural, remote)

Maintaining tree structure 8.1 8.1 37.8 35.1 10.8 3.32

Number of customers served

11.1

1.6

19.0

54.0

14.3

3.59

Planned cycle length 3.1 3.1 15.6 39.1 39.1 4.08

Reliability 3.1 0.0 9.4 21.9 65.6 4.47

Risk reduction (safety) 0.0 1.6 9.4 31.3 57.8 4.45

Site factors 6.3 4.7 17.2 48.4 23.4 3.78

(e.g., # and type of trees, terrain, cultural resources)

Tree positions relative to the line

4.8

3.2

4.8

50.8

36.5

4.11

Three or single-phase lines

7.9

0.0

11.1

42.9

38.1

4.03

51

6. Please specify your distribution primary clearances. (Check the NM box if no maintenance, check the CO box if clear only to relieve abrasion or deflection, or enter the applicable distance for side, under, and overhang clearances.) n=57 to 62 Units are in: ft (feet) (CHECK ONE)

□ ft (feet) □ m (meters)

Line Type

---------number--------NM1

-------------------- Distance (ft) --------------------

CO2 Side Under Overhang

Single-phase (n=61) 2(3%) 2(3%) 10.60 10.31 13.57

Three-phase (n=61) 1(2%) 2(3%) 10.93 10.65 13.88

Open wire (n=57) 5(9%) 10(18%) 6.78 6.32 6.08

Triplex (n=62) 7(11%) 32(52%) 3.99 3.80 4.92

1

NM = No maintenance

2

CO = Clear only to relieve abrasion or deflection

7. Rate the following factors for their importance regarding how much overhang clearance you specify on

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Pruning Factors (% of total & mean)

Unimportant (2)

Very Unimportant (1)

distribution primary lines. n=54 to 64

Branch defect 7.8 0.0 1.6 18.8 71.9 4.47

Branch size 7.8 3.1 15.6 50.0 23.4 3.78

Community expectations 17.7 3.2 25.8 40.3 12.9 3.27

Expected weather in the vicinity

15.6

9.4

26.6

31.3

17.2

3.25

Line priority 14.3 0.0 7.9 39.7 38.1 3.87

Mass damping 18.5 9.3 48.1 13.0 11.1 2.89

Storm exposure 14.3 0.0 22.2 36.5 27.0 3.62

Tree biomechanics 8.1 0.0 12.9 48.4 30.6 3.94

Tree species 4.8 0.0 3.2 31.7 60.3 4.43

52

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Pruning Objectives (% of total & mean)

Unimportant (2)

Very Unimportant (1)

8. Rate the importance of the following pruning objectives to your UVM program. n=64 to 66

Clearance 1.5 1.5 0.0 22.7 74.2 4.67

Maintaining tree structure 1.5 4.6 23.1 47.7 23.1 3.86

Reliability 1.5 0.0 0.0 7.6 90.9 4.86

Risk reduction (safety) 0.0 0.0 1.6 23.4 75.0 4.73

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Very Unimportant (1)

n=71

Unimportant (2)

9. How important are the following standards, best practices and resources to your UVM pruning specifications?

Standards (% of total & mean)

ANSI A300 - Part 1 1.4 1.4 9.9 18.3 69.0 4.52

ISA Utility Pruning of Trees Best Management Practices

2.8

1.4

4.2

32.4

59.2

4.44

Pruning of Trees Near Electric Utility Lines: A Field Pocket Guide for Qualified Line-Clearance Tree Workers

2.8

9.9

14.1

31.0

42.3

4.00

Other: (11 responses) 0.0 0.0 0.0 27.3 72.7 4.71

53

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Pruning Locations (% of total & mean)

Unimportant (2)

Very Unimportant (1)

10. How important are the following locations to your pruning program? n=64 to 66

Remote 4.6 1.5 27.7 40.0 26.2 3.82

Rural 4.6 1.5 30.8 38.5 24.6 3.77

Urban-rural interface 3.1 1.5 23.1 36.9 35.4 4.00

Suburban 3.0 1.5 24.2 28.8 42.4 4.06

Urban 3.1 3.1 23.4 28.1 42.2 4.03

Section V – Integrated Vegetation Management 1. What information do you collect for your IVM program? n=63 (CHECK ALL THAT APPLY)

71.4% Address

23.8% Branch distance from the line

34.9% GPS coordinates

15.9% Growth rate

50.8% Pole number

60.3% Species

34.9% Tree condition

33.3% Tree density

42.9% Tree diameter

30.2% Tree height

17.5% Tree orientation

19.0% Tree risk assessment rating

9.5% Other (6 responses) Number of trees/mile Keep track of circuits cut Miles of circuit/Area to be trimmed Monitor status Number pruned, Number removed Voltage, work prescription, line name, permit date, crew code, crew hours, crew work date, herbicide, lift or manual

54

2. Which treatment methods do you use for Tree Growth Regulators (TGRs)? n=21

(CHECK ALL THAT APPLY)

38.1% Soil drench

57.1% Soil injection

9.5% Trunk injection

3. Rank the importance of the following reasons for conducting IVM (1 = least to 5 = most important, use each # once only). n=56

3.04 (0.18 SE) Compliance

2.95 (0.16 SE) Cost-effectiveness

2.34 (0.21 SE) Environmental stewardship

3.34 (0.20 SE) Safety

3.34 (0.17 SE) Service reliability

Pruning Standards (% of total & mean)

Very Little (1)

Little (2)

Neither Little or Much (3)

Much (4)

Very Much (5)

Mean Index Score

4. How well are the following standards and best practices incorporated into your program? n=68 to 69

ANSI A300 Part 7 - Integrated Vegetation Management

5.8

2.9

14.5

27.5

49.3

4.12

ANSI A300 Part 9 - Tree Risk Assessment

7.2

11.6

31.9

33.3

15.9

3.39

ISA BMPs - Integrated Vegetation Management

4.3

2.9

15.9

43.5

33.3

3.99

ISA BMPs - Tree Risk Assessment Qualification

10.1

14.5

46.4

18.8

10.1

3.04

Utility Arborist Association Best Management Practices - Closed Chain of Custody

16.2

11.8

44.1

11.8

16.2

3.00

UAA Tree Risk Assessment and Abatement

37.7

8.7

42.0

5.8

5.8

2.33

for Fire-Prone States and Provinces

55

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

IVM Objective Considerations (% of total & mean)

Unimportant (2)

Very Unimportant (1)

5. How important are the following considerations in setting IVM objectives? n=60 to 64

Access 3.2 3.2 21.0 48.4 24.2 3.87

Compliance 1.6 1.6 13.1 37.7 45.9 4.25

Cost efficiency 0.0 0.0 6.5 41.9 51.6 4.45

Cultural site protection 0.0 5.0 48.3 31.7 15.0 3.57

Environmental stewardship 0.0 3.2 35.5 43.5 17.7 3.76

Facility protection 0.0 0.0 4.9 41.0 54.1 4.49

Safety 0.0 0.0 3.1 20.3 76.6 4.73

Security 0.0 1.6 38.7 27.4 32.3 3.90

Service reliability 0.0 0.0 3.1 9.4 87.5 4.84

Workload evaluations 0.0 4.9 36.1 49.2 9.8 3.64

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Assessment Methods (% of total & mean)

Unimportant (2)

Very Unimportant (1)

6. How important are the following methods in conducting workload evaluations? n=60 to 62 (3 for other)

Aerial photos 3.2 3.2 21.0 48.4 24.2 2.93

Ground evaluations 1.6 1.6 13.1 37.7 45.9 4.69

LiDAR 0.0 0.0 6.5 41.9 51.6 2.62

Satellite imagery 0.0 5.0 48.3 31.7 15.0 2.69

Unmanned aerial systems (UAS)

0.0

Other: (3 responses: Aerial/Helicopter)

56

3.2

35.5

43.5

17.7

2.37

0.0 0.0 0.0 0.0 100 5.00

7. Does your program have a dedicated tree risk assessment program based in the ISA tree risk assessment best management practices (Smiley, Matheny, and Lilly, 2011)? n=68 (CHECK ONE)

20.6% Yes

79.4% No

8. Are site evaluations part of your program? n=69 (CHECK ONE)

85.5% Yes

14.5% No → (PLEASE GO TO QUESTION 10)

9. Which site evaluations are part of your program? n=56 (CHECK ALL THAT APPLY)

76.8% Access routes

62.5% Anticipated control methods

30.4% Archeological and cultural issues

25.0% Fire risk

48.2% Funding availability

66.1% Labor and equipment resource availability

67.9% Land ownership and use

67.9% Line construction

73.2% Line location

76.8% Line voltage and criticality

55.4% Presence of species concern

78.6% Right-of-way width

85.7% Safety

23.2% Soil types

51.8% Topography

46.4% Vulnerable or protected areas

46.4% Water resources

64.3% Wire height off the ground

50.0% Workload

5.4% Other (3 responses) Biomes, climate, plant hardiness, clearance to conductor Insect damage Predominant mature edge species can dictate which herbicide mix is used

10. Do action thresholds apply to your decision making? n=69

(CHECK ONE) 76.8% Yes

23.2% No → (PLEASE GO TO QUESTION 12)

57

11. What are your action thresholds? n=53

(CHECK ALL THAT APPLY)

86.8% Minimum clearances

69.8% Time length

52.8% Tree risk rating

37.7% Vegetation density

49.1% Vegetation height

15.1% Other (8 responses: Species, Tree Health, Binary tree risk)

12. What criteria do you use to develop your tolerance levels? n=61

(CHECK ALL THAT APPLY)

44.3% Compliance with state/provincial or federal regulations

34.4% Density of vegetation

67.2% Minimum vegetation clearance distance (MVCD) FAC-003-4

13.1% Percent tree contact for distribution → Below Specify %

19.7% Other (12 various responses) 28.0 (Mean, 18.2 SE), 5 to 100% range

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

IVM Methods (% of total & mean)

Unimportant (2)

Very Unimportant (1)

13. How important are the following control methods to your IVM program? n=67 to 69

Biological 10.1 14.5 47.8 17.4 10.1 3.03

Chemical 2.9 2.9 7.1 30.0 57.1 4.36

Cultural 6.0 6.0 52.2 23.9 11.9 3.30

Engineering 4.5 10.4 35.8 34.3 14.9 3.45

Physical (manual and mechanical)

0.0

0.0

14. Do you use closed chain of custody in your program? n=60

(CHECK ONE)

45.0% Yes

55.0% No

58

0.0

24.6

75.4

4.75

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

IVM Treatment Options (% of total & mean)

Unimportant (2)

Very Unimportant (1)

15. Rate the importance of the following treatment options to your program (1 = lowest to 5 = highest). n=59 to 63

Aerial 42.4 27.1 16.9 8.5 5.1 2.07

Bare ground treatment 11.7 15.0 20.0 21.7 31.7 3.47

Basal 8.2 8.2 19.7 39.3 24.6 3.64

Chemical tree-pruning 49.2 14.8 29.5 4.9 1.6 1.95

Cut stubble 22.6 11.3 21.0 21.0 24.2 3.13

High volume foliar 16.1 9.7 21.0 24.2 29.0 3.40

Stump treatment 6.3 0.0 4.8 23.8 65.1 4.41

Trunk injection 39.0 18.6 32.2 6.8 3.4 2.17

Other: (17 responses: 16 were low volume foliar ~)

0.0 0.0 5.9 11.8 82.4 4.76

16. Does your program employ mechanical pruning (e.g., machines or helicopters) for line clearance? n=70, n=36 if yes response

(CHECK ONE)

64.3% Yes → If yes, 17.8 (2.8 SE) % of total UVM budget

35.7% No

17. Do you use tree growth regulators (TGRs)? n=70 (CHECK ONE)

25.7% Yes

74.3% No → (PLEASE GO TO QUESTION 19)

18. How important are TGRs to your program? n=20

10% Very unimportant

30% Somewhat unimportant

5% Neither unimportant or important

55% Somewhat important

0% Very important

3.05 (Mean, 0.26 SE)

59

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Cultural Control Methods (% of total & mean)

Unimportant (2)

Very Unimportant (1)

19. How important are the following cultural control methods to your program? n=66 to 68

Cover type conversion 14.7 13.2 29.4 27.9 14.7 3.15

Hydroseeding 38.2 22.1 36.8 2.9 0.0 2.04

Fertilizing 47.1 17.6 35.3 0.0 0.0 1.88

Growing agricultural crops 36.8 11.8 30.9 16.2 4.4 2.40

Landscaping 19.4 11.9 34.3 28.4 6.0 2.90

Planting or seed compatible plants

14.9

11.9

35.8

25.4

11.9

3.07

Prairie restoration 31.8 18.2 33.3 13.6 3.0 2.38

Wire-border zone 11.9 10.4 29.9 22.4 25.4 3.39 Other: (no responses) - - - - - -

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Engineering solutions (% of total & mean)

Unimportant (2)

Very Unimportant (1)

20. How important are the following engineering solutions to your UVM program? n=59 to 62

Alley arms 14.8 11.5 39.3 29.5 4.9 2.98

Covered overhead construction

29.5

13.1

39.3

14.8

3.3

2.49

Hendrix spacers 22.0 23.7 37.3 13.6 3.4 2.53

Moving poles for the lines to avoid trees

11.3

14.5

29.0

32.3

12.9

3.21

Rising poles 13.1 16.4 31.1 34.4 4.9 3.02

Underground construction 11.3 3.2 40.3 37.1 8.1 3.27

Prairie restoration 31.1 13.1 47.5 6.6 1.6 2.34

Wire-border zone 16.1 12.9 33.9 22.6 14.5 3.06 Other: (no responses) - - - - -

60

Section VI – Electrical Operations 1. What percent of total transmission outages and sub-transmission outages are vegetation related on your system? n=61

System

% of Total Outages

% of Total Customer Minutes

(Std Error) (Std Error)

Example Answer 61 16

Distribution outages caused by vegetation

23.19 (2.63 SE)

21.65 (3.12 SE)

Sub-transmission outages caused by vegetation

2.04 (SE 0.85)

3.84 (1.72 SE)

Transmission outages caused by vegetation

1.13 (0.47 SE)

1.21 (0.74 SE)

2. Is reliability part of your UVM strategy? n=71 (CHECK ONE)

95.8% Yes

4.2% No → (PLEASE GO TO QUESTION 4)

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Reliability Metrics (% of total & mean)

Unimportant (2)

Very Unimportant (1)

3. How important are the following reliability metrics to your program? n=54 to 59

ASAI 25.9 13.0 31.5 18.5 11.1 2.76

CAIDI 5.2 3.4 6.9 34.5 50.0 4.21

MAIFI 13.0 24.1 37.0 16.7 9.3 2.85

SAIDI 5.1 3.4 0.0 32.2 59.3 4.37

SAIFI 3.4 1.7 3.4 37.9 53.4 4.36

ASAI: Average System Availability Index

CAIDI: Customer Average Interruption Duration Index

MAIFI: Momentary Average Interruption Frequency Index

SAIDI: System Average Interruption Duration Index

SAIFI: System Average Interruption Frequency Index

61

4. Is distribution fuse coordination aligned with UVM on your system? n=63 (CHECK ONE)

47.6% Yes

52.4% No

Protective Strategies (% of total & mean)

Very Unimportant (1)

Unimportant (2)

Neither Important or Unimportant (3)

Important (4)

Very Important (5)

Mean Index Score

5. Please rate the importance of the following protective strategies. n=63 to 64

Expanded clearances at the time of work

1.6

6.3

14.3

50.8

27.0

3.95

Greater actions thresholds on three-phase lines

4.8

3.2

19.0

46.0

27.0

3.87

Greater tolerance levels on three-phase lines

12.5

6.3

39.1

26.6

15.6

3.27

Shorter cycles on three-phase lines

6.3

14.1

43.8

25.0

10.9

3.20

Other: (0 responses) - - - - - -

6. Does your program have different strategies on three- and single-phase lines? n=67 (CHECK ONE)

35.8% Yes

64.2% No → (PLEASE GO TO QUESTION 8)

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Strategies (% of total & mean)

Unimportant (2)

Very Unimportant (1)

7. How important are the following strategies on three-phase compared to single-phase lines? n=22 to 23

Broader tolerance thresholds 31.8 0.0 22.7 31.8 13.6 2.95

Greater action thresholds 8.7 0.0 13.0 26.1 52.2 4.13

Greater clearances at time of work

4.2

0.0

20.8

33.3

41.7

4.08

Shorter cycles 16.7 0.0 58.3 12.5 12.5 3.04

Other: (1 response, more tree removal)

-

62

-

-

-

-

-

8. What percent of vegetation-related outages are caused by the following outage types? n=53

Outage type

% of outages

Example Answer 35

Broken branches

19.4 (2.6 SE)

Grow-ins 11.4 (2.4 SE)

Off right-of-way trees

34.4 (4.1 SE)

Overhang 6.0 (1.4 SE)

Whole tree failure

27.2 (3.7 SE)

Other: (7 responses, beaver, public damage, vines)

1.6 (1.1 SE)

Total = 100%

Section VII – Storm Response 1. Do you leave storm debris on site? n=67 (CHECK ONE)

70.1% Always

25.4% Never

4.5% Occasionally → (If so, 74.6% (7.3 SE) percentage of time)

63

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Storm Response Factors (% of total & mean)

Unimportant (2)

Very Unimportant (1)

2. How important are the following factors to storm response? n=65 to 69

Animals and insects 19.7 15.2 40.9 19.7 4.5 2.74

Communication other than cell phones

1.5

10.4

19.4

35.8

32.8

3.88

Contracts with UVM companies to respond to difficult weather conditions

1.5

2.9

11.8

36.8

47.1

4.25

Driving 1.5 1.5 5.9 51.5 39.7 4.26

Electrical hazard communication protocol

1.5

0.0

4.5

28.4

65.7

4.57

Equipment availability, repair and maintenance

1.5

0.0

8.8

41.2

48.5

4.35

Equipment rental 10.4 16.4 52.2 16.4 4.5 2.88

Extended hours 0.0 0.0 8.8 47.1 44.1 4.35

Fatigue 0.0 0.0 0.0 44.9 55.1 4.55

Food 0.0 0.0 4.3 55.1 40.6 4.36

Fuel 1.5 1.5 5.9 48.5 42.6 4.29

Housing 3.0 3.0 11.9 46.3 35.8 4.09

Incident command 3.0 0.0 9.0 38.8 49.3 4.31

Mutual assistance agreements 1.5 3.0 17.9 28.4 49.3 4.21

Rerouting and navigations 1.5 1.5 38.5 40.0 18.5 3.72

Rosters 0.0 0.0 15.4 52.3 32.3 4.17

Supervision 0.0 0.0 2.9 38.2 58.8 4.56

Safety 0.0 0.0 0.0 4.3 95.7 4.96

Wood under tension 0.0 0.0 2.9 48.5 48.5 4.46

3. Does your company have storm emergency declaration protocols? n=70 (CHECK ONE)

92.9% Yes

7.1% No → (PLEASE GO TO QUESTION 5)

64

4. Does a declaration affect how UVM storm responders are paid (e.g., does it trigger overtime)? n=61

(CHECK ONE)

52.5% Yes

47.5% No

5. What criteria do you use in declaring a storm emergency? n=64

(CHECK ALL THAT APPLY)

18.8% Amount of precipitation

43.8% Duration of storm

81.3% Extent of infrastructure damage

28.1% Geographic area covered by storm

92.2% Number of customers out of power

42.2% Number of interruptions

56.3% Percent of customers out of power

39.1% Percent of area out of power

28.1% Type of precipitation (e.g., freezing rain, snow)

34.4% Type of storm

34.4% Wind speed

6. How important are the following storm preparation factors in your vegetation management storm response?

Protective Strategies (% of total & mean)

Neither Important or Unimportant (3)

Very Important (5)

Mean Index Score

Incident Command System (ICS)

2.9

2.9

19.1

25.0

50.0

4.16

Emergency operations center

0.0

1.5

16.2

32.4

50.0

4.31

Pre-storm communication checks

0.0

1.5

16.7

45.5

36.4

4.17

Important (4)

Unimportant (2)

n=65 to 68

Very Unimportant (1)

Storm practice drills 4.5 4.5 28.4 46.3 16.4 3.66

Pre-mobilization 1.5 1.5 30.8 41.5 24.6 3.86

Coordination with local government

1.5

7.6

30.3

37.9

22.7

3.73

Other: (1 response: Prep cranes, storm alerts)

-

-

-

-

-

-

65

7. Who declares a storm emergency? n=65 (CHECK ALL THAT APPLY)

38.5% Operations director

40.0% Operations manager

20.0% President

20.0% Vice-president

26.2% Storm response committee

15.4% Other (9 responses) City manager (2); Distribution system operator; Duty supervisor; General manager; Grid control center; Incident commander (2); Shift supervisor

8. Do you cap hours worked during storms? n=66

(CHECK ONE) 63.6% Yes

36.4% No → (PLEASE GO TO QUESTION 10)

9. What strategy do you use to cap hours during for the following time periods? n=5 to 26

Time Period

Total # of Hours

Consecutive # of Hours

Example Answer 16 8

First 24 hours

18.5 (0.73 SE)

15.9 (1.42 SE)

Daily 15.9 (0.21 SE) 13.2 (0.86 SE)

Weekly 14.9 (0.73 SE) 10.7 (1.33 SE)

Monthly 15.4 (0.57 SE) 10.4 (1.60 SE)

Other: (4 responses: 16 in 24 no more continuous clock; After 24 hrs 16 hours on, 8 hours off; Must rest 8 hrs after working 16 consecutive hours; Storm duration).

10. How is your media department involved in storm response? n=62

(CHECK ALL THAT APPLY)

71.0% Communicating estimated time of restoration

59.7% Media relations control 100% of the messaging for storms

30.6% Pre-approved message for tree crews (e.g., “We are working hard to get things back to normal.”)

77.4% Press releases on the extent of outages

37.1% Restrictions on front line employee communications

6.5% Other (4 responses):

Public Information Officer (1)

Social Media (3)

11. Do you document production data during storms? n=67

(CHECK ONE) 50.7% Yes

49.3% No → (PLEASE GO TO QUESTION 13)

66

12. What production data do you collect during storms? n=35

(CHECK ALL THAT APPLY)

11.4% Ft2 / m2 worked

94.3% Hours worked

71.4% Locations worked

8.6% Loads or ft3 / m3 collected

25.7% Numbers of trees worked

13. How important is a pre-approved message for tree crews to provide to media (e.g., “We are working hard to get

things back to normal.)”? n=65

18.5% Very unimportant

15.4% Somewhat unimportant

36.9% Neither unimportant or important

20.0% Somewhat important

9.2% Very important

2.86 (Mean, 0.15 SE)

Section VIII – Communications 1. How do you communicate with customers before work? n=70 (CHECK ALL THAT APPLY)

55.7% Contract utility foresters/arborists

57.1% In-house utility foresters/arborists

12.9% UVM managers

50.0% Tree crews

35.7% Other Direct mail (10 responses, 14.3%) Phone message (10 responses, 14.3%) Door hanger (6 responses, 8.6%)

2. Do you conduct customer satisfaction surveys? n=70

(CHECK ONE)

54.3% Yes

45.7% No

3. How do you conduct customer satisfaction surveys? n=37 (CHECK ALL THAT APPLY)

27.0% Door hanger

8.1% Follow-up personal visit

43.2% Phone call

40.5% Website directed survey

16.2% Other

Survey (2 responses, 5.4%)

Focus group (1 responses, 2.7%)

Mail/web (1 responses, 2.7%)

Outside firm (1 responses, 2.7%)

Select group (1 responses, 2.7%)

67

4. Rate the importance of the following groups for UVM-related communications of utility operations (outside of

Mean Index Score

Very Important (5)

Important (4)

Neither Important or Unimportant (3)

Groups (% of total & mean)

Unimportant (2)

Very Unimportant (1)

UVM). n=66 to 67

Commercial customers 0.0 9.0 22.4 29.9 38.8 3.99

County government 1.5 4.5 28.8 39.4 25.8 3.83

Environmental organizations 3.0 10.6 42.4 30.3 13.6 3.41

Federal land management agencies

4.5

10.6

27.3

30.3

27.3

3.65

Media 4.5 1.5 30.3 39.4 24.2 3.77

Municipal government 1.5 3.0 15.2 45.5 34.8 4.09

Neighborhood associations 1.5 9.1 37.9 40.9 10.6 3.50

Non-utility arborists 3.0 9.1 50.0 24.2 13.6 3.36

(municipal, commercial and researchers)

Owners and investors 4.8 7.9 34.9 31.7 20.6 3.56

Property owners 1.5 1.5 4.5 38.8 53.7 4.42

Regulatory agencies 3.0 6.1 19.7 31.8 39.4 3.98

State department of natural resources

3.0

4.5

34.8

40.9

16.7

3.64

Residential customers 0.0 3.0 4.5 34.3 58.2 4.48

Suppliers 6.2 9.2 44.6 30.8 9.2 3.28

UVM contractors 0.0 0.0 12.1 34.8 53.0 4.41 Other: 1 response

0.0 0.0 0.0 0.0 100.0 5.00

(internal specific operational groups)

5. Rate the importance of the following types of communication you use for UVM (1 = least to 5 = most important). n=63 to 68

3.57 (0.18 SE) Brochures

2.51 (0.17 SE) E-mail messages (blasts)

2.86 (0.16 SE) Press releases

3.45 (0.17 SE) Social media

2.30 (0.18 SE) Town hall meetings

68

Responding Utilities · Alabama Power

· Manitoba Hydro

· American Electric Power – Ohio

· Menasha Utilities

· Ameren Illinois

· MidAmerican Energy Co

· Appalachian Electric Cooperative

· Milan Public Utilities National Grid

· Appalachian Power

· National Grid

· ATCO Electric

· New Brunswick Power

· Avista Utilities

· Oklahoma Electric Cooperative

· Black Hills Energy

· Orange Rockland

· Blue Grass Energy

· Pierce Pepin Cooperative Service

· Boone Electric Cooperative Central Hudson Gas and Electric

· Pioneer Electric Cooperative

· Central Hudson Gas and Electric

· Provo City Power

· Chelan County PUD Consumer’s Energy

· Public Service of New Mexico

· City of Naperville Electric Utility

· Public Service of Oklahoma

· City of Tallahassee

· Puget Sound Energy

· City of Westerville Electric

· Rappahannock Electric Cooperative

· City Utilities of Springfield

· Richland Electric Cooperative

· Cleveland Utilities

· Sacramento Utility District

· Consolidated Electric Cooperative

· Salt River Project

· Consumer’s Energy

· SaskPower

· Cuivre River Electric Cooperative

· Sevier County Electric System

· Dairy Power

· Tacoma Power

· Dayton Power and Light

· Tipmont REMC

· Duquesne Light Company

· Tullahoma Utilities Authority

· Duke Energy Corporation

· Union Power Cooperative

· East Central Energy

· Velco

· Edmond Electric

· Waverly Utilities

· Electric Power Board

· Xcel Energy: Public Service of Colorado

· Entergy Corporation

· Xcel Energy: Northern States Power -Minnesota

· Evergy

· Xcel Energy: Northern States Power -Wisconsin

· First Energy

· Xcel Energy: Southwestern Public Service

· Fortis Alberta · Golden Valley Electric Association · Huntsville Utilities · Hutchinson Utilities · Hydro One Networks · Independence Power and Light · JEA · Kirkwood Electric · Lansing Power Board · Liberty Utilities New Hampshire · Madison Gas and Electric

69

Any Questions? Please Contact Richard J. Hauer | PhD | Professor of Urban Forestry UWSP | p: 715.346.3642 | e: rhauer@uwsp.edu

Randall H. Miller | Director of Research and Development CNUC | p: 385.499.4094 | e: rmiller@cnutility.com