Vegetation Management Along High-Voltage Transmission Lines

Updated January 2013
Vegetation Management Along High-Voltage Transmission Lines
Reasons for Doing this Work:
It is critical that we maintain the reliability of our electric transmission system.
Transmission vegetation management work is required so we can keep the lights on for
homes and businesses throughout the region.
We understand this work can cause concern for some individual landowners, and we are
sensitive to that. Our first priority has to be reliable electric service for millions of people
in this region.
We also have an obligation to keep costs reasonable, since vegetation management costs
are paid by all customers in their electric bills.
Our increased vegetation management activity is already paying dividends for customers
in terms of maintaining a reliable electric system.
PPL Electric Utilities is required to meet federal reliability standards on certain highvoltage
lines.
We take very seriously our obligation to keep our part of the nation’s power grid reliable.
We are always willing to meet with property owners to hear their concerns and discuss
the work we need to do to keep our lines safe and reliable.
Federal Regulators Oversee Electric Grid Reliability
After the Northeast Blackout of 2003 – in which a tree contact led to power loss in a very wide
region – the federal government adopted strict new mandatory reliability standards for certain
high-voltage power lines.
And in May 2012, the Federal Energy Regulatory Commission and the North American Electric
Reliability Corporation recommended that utilities increase their efforts to remove trees from
around transmission lines to help prevent future storm-related outages.
Overview of Electric Grid Vegetation Work
PPL Electric Utilities operates 4,400 miles of high-voltage electricity transmission lines in its 29-
county service territory in central and eastern Pennsylvania. These lines fall into three main
voltage classes:
230-kilovolt and 500-kilovolt lines — 1,351 miles
115-kilovolt and 138-kilovolt lines — 299 miles
69-kilovolt lines — 2,750 miles
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230-Kilovolt and 500-Kilovolt Transmission Lines
These highest-voltage power lines are the most critical for grid reliability and are subject to strict
federal reliability standards. Over the past three years, we completed vegetation work along these
lines called Wire Zone-Border Zone, recognized as an industry best practice. Power lines
maintained in this way have grasses under the wires in the Wire Zone area, and low-growing
compatible trees and shrubs along the sides of the wires in the Border Zone area. This work is
now complete.
115-Kilovolt and 138-Kilovolt Transmission Lines
In 2012, PPL Electric Utilities completed work on these lines. We removed trees and other tall
vegetation from the PPL right of way. In residential areas, wherever feasible, we did not remove
lower-growing trees and shrubs that are compatible in areas of the right of way bordering the
wires. Almost all of the lines in this voltage class are in the company’s Lehigh, Lancaster and
Northeast regions.
69-Kilovolt Transmission Lines
These are the lines that supply power to neighborhood substations. Many of them are closer to
residences than our higher-voltage lines. Trees and other incompatible vegetation in the rights of
way will be removed because they are a safety concern and a threat to reliability. This work will
be ongoing for the next three years.
PPL Electric Utilities’ Rights to Manage Vegetation
In all cases, PPL Electric Utilities has the right to do vegetation management work because of
specific written agreements the company has with property owners. The company only does the
work permitted by these written agreements.
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Questions and Answers about Transmission Line Vegetation Maintenance
How do property owners know you are coming to do work on the right of way
For planned vegetation management activities, we have a multi-step communications process.
First, we mail initial notices to property owners along the transmission line about 4-6
weeks before work is to be done. This letter includes a phone number to call if residents
have questions, and a link to our website that contains more information.
We will schedule a personal meeting to discuss the work in advance with any property
owner who wishes to ask questions or get more information.
Next, our contractor for the job follows up with another notice and also attempts to
personally contact the property owner.
In addition, we will provide another notice just before the work takes place. This notice
is provided when specific concerns exist, when the property owner has requested it, or
when we have been unable to reach the property owner on previous attempts.
Why remove trees Can’t you just trim the branches instead
We recognize that some property owners may not want the trees removed under or near
transmission lines. But we know that all customers want reliable electric service. We have to
think of the millions of people served by the electric grid, and do the right thing to keep their
lights on.
We try very hard to strike a careful balance – improving reliability for customers by keeping
trees away from power lines while at the same time being sensitive to landowner concerns about
vegetation management.
When I look at power lines, they don’t look like they are even close to touching nearby
trees.
That may be true at most times. But when electric use is high, power lines significantly sag
because of the large amount of current flowing through them. Also, windy conditions can cause
wires to swing out and touch trees that are too close to the sides of the lines. We have to take the
maximum sag and the swinging of lines in the wind into account when determining whether
there is adequate clearance between the wires and the vegetation. We also have to consider the
fact that trees can grow closer to lines every year. Finally, we have to consider the fact that tall
trees – even those just outside our rights of way – may fall into lines and cause a problem.
Does PPL Electric Utilities use herbicides
Yes. The judicious use of herbicides is an important part of our vegetation management program.
We use herbicides to manage undesirable growth in the right of way. These herbicides are all
EPA-approved and are applied by hand, or from trucks or using small ATVs. Herbicides are used
on all transmission rights of way unless the easement agreement specifically prohibits it.
We take necessary environmental precautions when using herbicides, some of which are the
same as those commonly used by homeowners. Herbicides are applied as part of the initial
treatment of the right of way and typically in a three-year cycle thereafter. Our goal for the area
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under the wires is to promote the growth of low-growing vegetation such as grasses and
eliminate taller growing vegetation. We achieve this goal by using herbicides that target woody
and broad-leafed vegetation but do not harm grasses and similar desirable plants.
You cut down trees in the right of way, but did not remove them. Why
In all cases we will do our best to work with property owners to meet their needs regarding cut
vegetation. Except in dense residential areas, we generally don’t remove or dispose of any
vegetation from cutting on transmission line rights of way. Many property owners want the wood
for lumber or firewood. In some areas, like hillsides, leaving cut vegetation protects against
erosion. It also can serve as valuable wildlife habitat. In addition, our actions in the right of way
are governed by the terms of the written easement agreement with the property owner.
What repercussions are there if trees get too close to high-voltage transmission lines
If vegetation gets too close to a high-voltage power line, it can cause outages of electric service
for our customers and potentially others in adjacent utility service areas. Tree contacts also can
cause serious safety issues for customers and our employees. In some cases, our company faces
penalties of up to $1 million per day for allowing even a single tree to get within a specified
distance of certain high-voltage transmission lines.
Does this approach mean a farmer can’t grow crops under your lines What about
Christmas tree farms or orchards
Seasonal crops may be permitted near our transmission lines in certain circumstances. PPL
Electric Utilities will work with commercial tree farms or orchards on a case-by-case basis to set
a maximum height for permissible vegetation that does not pose a threat to the line.
Does PPL Electric Utilities compensate people for trees they cut down
When appropriate and based on our contractual obligations in the right of way agreement, we
may compensate farmers for crop damage caused by power line construction and management
operations.
When appropriate and based on our contractual obligations, we also may compensate
commercial tree or orchard operations for trees that need to be removed because of power line
work, including Wire Zone-Border Zone work.
Beyond that, we generally are not obligated to reimburse for vegetation lost to clearing
operations because our easements typically provide that we have the right to perform such work.
In all cases, we are governed by the terms of our written easement or other agreement with the
property owner.
What about a private homeowner who has fruit trees or other valuable plantings in the
right of way Why are they different than a business
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We’re sensitive to that concern. But keep in mind that our written right of way agreements with
these property owners specifically permit us to cut incompatible trees and vegetation in the right
of way to maintain the safe operation of our lines. Property owners get notified well in advance
and can choose to transplant vegetation.
What exactly are the federal requirements for transmission line management
The Northeast Blackout in August 2003 affected more than 50 million electric customers in the
northeastern United States and portions of Canada. Investigations of the causes of the blackout
revealed that it was initiated by a contact between a tree and a transmission line in Ohio.
The U.S. Congress responded to the blackout by enacting the Energy Policy Act of 2005, which,
among other things, required the Federal Energy Regulatory Commission (FERC) to implement
mandatory reliability standards for transmission lines.
These reliability standards were developed by and are enforced by the North American Electric
Reliability Corporation (NERC), subject to FERC’s regulatory supervision.
NERC Standard FAC-003-1, Transmission Vegetation Management Program, was adopted in
February 2006. Its purpose is:
“To improve the reliability of the electric transmission systems by preventing outages
from vegetation located on transmission rights-of-way (ROW) and minimizing outages from
vegetation located adjacent to ROW, maintaining clearances between transmission lines and
vegetation on and along transmission ROW, and reporting vegetation-related outages of the
transmission systems to the respective Regional Reliability Organizations (RRO) and the North
American Electric Reliability [Corporation] (NERC).”
Standard FAC-003-1 requires transmission facility owners, such as PPL Electric Utilities, to
adopt and keep current a formal transmission line vegetation management plan for its higher
voltage (230 and 500 kV) transmission lines. The plan is required to include the transmission
facility owner’s objectives, practices, procedures and work specifications. Further, the
transmission vegetation management plan is required to specify clearances, or safety zones,
between vegetation and transmission supply conductors within which no vegetation is permitted
to grow. Transmission facility owners may be subject to fines of up to $1 million per day for
violations of the Reliability Standards.
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