Vegetation Management

Presented by

Joel Smith / PG&EForesterArea 1Vegetation Management

Pacific Gas and Electric CompanySystem and

San Francisco County Overview

Basic Electric System

Power PlantPower Generated at

13 - 25 kV

Transmission Substation

Transmission Line 60, 115, 230 or 500 kV

Possible NERC regulation

Distribution Substation

Distribution Line 4, 12, 17 or 21 kV

Home or Business 120 - 480 Volts

Home

Business

• Nuclear• Hydroelectric• Geothermal• Natural Gas

• Nuclear• Hydroelectric• Geothermal• Natural Gas

Compliance Requirements

PRC 4293 – Utility Vegetation Management - Tree Pruning/Removal• Maintain 4 feet of clearance between trees and primary distribution power lines

and 60/70 KV transmission lines• Maintain 10 feet of clearance between trees and all transmission lines 115 KV and

above• Remove dead, diseased, defective and dying trees that could fall into the lines

(facility protection trees)

PRC 4292 – Utility Vegetation Management – Pole Clearing • Clear 10’ x 8’ cylinder around the base of subject poles and transmission

structures• Remove dead vegetation up through the primary conductor level

CPUC G.O. 95 Rule 35 – Utility Vegetation Management – Tree Pruning/Removal• Maintain 18 inches of clearance between trees and primary distribution power lines

and 60/70 KV, greater clearances for higher voltages• Remove facility protection trees (as defined above)• Address situations where trees cause strain or abrasion on secondary conductors

NERC Standard FAC-003-1 – Vegetation Management Requirements for Transmission

• Minimum Clearance Standard based on voltage class• Zero tolerance for vegetation caused outages

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18 in.

California Regulations for Distribution Lines

HIGH VOLTAGE

10 ft.

8 ft

.

18 in.

4 ft.

4 ft.

PRC 4293 PRC 4292GO-95 Rule 35

Routine T&D Vegetation ManagementProgram Scope

• Address through trim or removal, any tree that will encroach within minimum clearance distances and any hazard tree to maintain regulatory compliance.

– 113,00 miles of distribution line– 19,500 miles of transmission line– 70,000 square mile service territory– Trim or remove over 1.2M trees per year

• 5M trees in inventory with potential to “grow into” conductors

• 50M trees with potential to “fall into” conductors

• Maintain fire breaks on 120,000 subject poles

• Maintain transmission right of way

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• The Routine Patrol Standard – Defined Scope of Work

– The Annual Patrol: Inspect 100% of overhead line, identify and clear only trees that will encroach before next cycle.

– Aggressively target trees up to 12” DBH, palms, and fast growers for removal

– Pruning for 2 to 3 years clearance – Hazard trees– Strain or abrasion on secondary lines– Pruning Standards – Utility Pruning BMP– 600+ contract tree crews– 350+ utility arborists/foresters– Approx 60 PG&E office and field personnel

PG&E Distribution Tree Trimming

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Territories

Tools1) Right Tree Right Place 2) Work Practice

• Inspection, pruning and removal • ROW and NERC Standards

3) Emergency Operations

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Tell me what’s missing…

Customer InterfaceConsistent graphics and language to comprise our educational presence across all communication channels to both internal and external audiences.

City challenges…230 Magellan

19 Maywood

217 Tocoloma

240 Casitas

“If a tree falls in the City, and there is no one there to hear it, will it still…hit a car?”

Contact Information

Joel Smith, Forester (local project manager)

San Francisco and San Mateo Counties

• Office 650.985.5710• Cell 650.477.8874• jpsr@pge.com