Services

Why Vegetation Management is Important

Electric Utilities and Vegetation Management

In 2003 the Northeast United States suffered a power outage that was the second most widespread electrical power outage in US history. More than 10 million people in Canada and 45 million people in the United States were affected. The blackout was caused when high-voltage power lines came in contact with "overgrown trees". The cascading effect that resulted forced the shutdown of more than 100 power plants. It took nine seconds for the grid to collapse.

In January 2009 a major ice storm produced widespread power outages for more than 2 million people in the Midwest. Ice-laden trees and branches contributed to outages as they crashed down onto power lines throughout the eight state areas impacted.

2003 Blackout - Area Affected	Ice Accumulation on Power Lines and Trees

These are but two examples of why vegetation management is important. The maintenance of power line right-of-ways for both transmission and distribution lines are essential to assuring system reliability.

Pipelines and Vegetation Management

Vegetation Management is important in maintaining the pipeline industry infrastructure as well. Gas, chemical and oil pipelines snake through every region of the country, often unseen except for marker posts indicating a pipeline right-of-way (ROW). The pipeline right-of-way is strip of land usually about 25 to 150 feet wide containing the pipeline.

Pipeline right-of-ways are often recognizable as corridors that are clear of trees, buildings or other structures except for the pipeline markers. Sometimes ROWs may not have markers clearly present and may only be indicated by cleared corridors of land.

Keeping right-of-ways clear is essential to assure the safe operation of electrical lines and pipelines, as well as to enable the proper access to the ROW for maintenance, inspections and upgrades.

Utility Distribution Line	Pipeline Right-of-Way	Utility Transmission Line

Tree Trimming – What you need to know

• If a tree or limb falls onto a power line it can create a path for electricity to flow causing several people to lose power.
• Trees or limbs can potentially tear down entire power lines by falling on the lines.
• Even though there may not have been problems in the past, tree trimming is a preventative measure and an important safety issue.
• Tree trimming is performed carefully to not harm the tree; only the necessary limbs are removed.
• Mowing is used for dense growth and is a short term answer to overgrown vegetation.
• If a tree is removed and a new tree planted in its place, the new tree selected should be shorter than the power lines at full maturity to prevent future interference
• All work is completed in accordance with governmental standards, including but not limited to OSHA regulations and ANSI standards.

What your trees may look like after trimming:

We trim trees in a method endorsed by the International Society of Arboriculture. Instead of trimming limbs back to unnatural stubs, branches are pruned back to the center of the trunk where trees normally shed them. Future tree growth is directed away from the power lines. We do not “round” trees over because it is not good for the health of your trees.

Trees pruned in this manner are less susceptible to disease and insects, and the overall structure of the tree is stronger and more resistant to high winds and ice. Although the shape has been altered, it is recommended over topping or rounding of trees, which tends to promote quick re-growth of small, weakly attached branches.

Herbicide Treatment

Vegetation Management methods include tree trimming, as described above, and herbicide spraying and treatments as well. Herbicides can be used to either eliminate undesirable plant species or to inhibit the growth of existing vegetation.

Quite simply, mowing or cutting vegetation usually results in that same vegetation growing back, usually with a higher stem count and in a more robust manner. The use of herbicides in coordination with mowing or tree trimming helps eliminate invasive species and weeds, thereby enabling the untreated vegetation to grow back in its place.

A coordinated approach referred to as Integrated Vegetation Management is used by many companies to not only manage their right-of-ways but to even enhance the environment and aesthetic beauty of the ROW be eliminating unwanted vegetation and returning the environment to natural grasses and wildflowers. The result can often be a well-maintained right-of-way that becomes a robust habitat for natural wildlife.

Herbicide products work into the stems and leaves of targeted plants and stop the growth and any re-sprouting that may occur. These highly specialized herbicides block the chemicals found in plants that are required by the plant to grow, and when applied properly are safe for use near fish, birds, animals and humans.

• Herbicide application is a tested, approved, and environmentally safe way to control unwanted growth around power lines and other critical infrastructures.
• Application crews are licensed and carefully trained to only target the desired part of the brush that needs to be treated.
• Herbicide is used for its reliability and efficiency; after a well-coordinated herbicide application program some treated areas may not need any additional control for years to come.
• Herbicides are approved and regulated by the EPA. Many herbicides are selective, meaning that they control certain species while not harming others. Non-selective herbicides may be used to clear large tracts of land from all vegetation, such as areas around substations or power plants.