Transmission

A transmission right-of-way is made up of one or many contiguous parcels of land with the actual corridor dimensions described within an easement document. Easement(s) allow a right-of-way to be established for the purpose of construction, operation, and maintenance of transmission electrical facilities and contain information regarding how each of these activities may be completed.

Transmission facilities transmit power from generating stations to substations, often covering many miles before the electricity is distributed to customers. A transmission power line can carry voltages of 34 thousand volts (kV), 69kV, 115kV, 230 kV, or greater. A single transmission line can travel 1 to 50 miles and provide power to thousands of customers. These lines occupy right-of-way corridors that ordinarily range in width from 50 feet to 100 feet and up to 350 feet when paralleling adjacent rights-of-way.

Transmission poles can be identified by their unique numbering system. Typically, each pole will have a black, 6-digit number with a yellow background called a TEFIS number that is aligned vertically on the face of the pole. This number is used to reference information such as pole location, line name, and pole type within the TEFIS (Transmission Electrical Facility Information System) software application. Since no two poles will have the same number, it is important when providing this number that it is communicated as it appears on the pole so the correct information can be obtained. Landowners that have transmission lines traversing their property are asked to have this number available when questions arise about our normal operations & maintenance as well as any emergency situations.

Distribution

A distribution right-of-way is a corridor of land that is dedicated to the construction, operation, and maintenance of distribution electrical facilities. Distribution facilities distribute power from substations to industrial, commercial, and residential customers. A distribution power line can carry voltages of 7.5 thousand volts (kV), 12 kV, or 34kV. Distribution lines often travel for miles across rural stretches of land, but they typically follow urban and suburban streets. A distribution feeder might serve several to several thousand customers. These lines occupy right-of-way corridors that range in width from 10 to 40 feet, with 20 feet being most common.

Secondary and service lines are the lines that carry your power from the primary distribution system to your home or business. The power that you use is reduced in voltage by a transformer that converts the higher voltage to a level that is appropriate, usually 110 volts or 220 volts. Santee Cooper distribution poles can be identified by an oval plate that is positioned about 5 feet above ground on the pole. The plate bears the name of the SC Public Service Authority (Santee Cooper), and has a 4-6 digit number embossed on the plate.

IVM is an approach to vegetation maintenance that employs a variety of management tools to control troublesome vegetation in a way that is safe, efficient, and environmentally responsible. Large trees that conflict with the power lines are controlled by directional pruning and/or removal, which is performed by qualified line clearance tree trimmers. Closer to the ground, troublesome brush is controlled by manual or mechanical cutting, as well as the selective application of herbicides in low, regulated volumes. Tree growth regulators (TGR's) are sometimes used to reduce the growth rates of fast-growing trees. Santee Cooper's vegetation managers integrate these management tools to achieve the desired results, while maintaining a strong commitment to environmental stewardship. Whether the lines belong to distribution or transmission power systems, our goals are the same.

When trees and vines grow into the power lines, or when tree limbs fall onto the lines, they create the potential for power outages. Also, when a tree is too close to an energized conductor, a potentially hazardous situation exists for people who work or play near the trees. Santee Cooper regularly trims trees in order to provide adequate clearance to help prevent power outages and to protect public safety. Our commitment is to provide reliable electric service at the lowest possible cost. Controlling trees that will interfere with the power lines is one of the many things Santee Cooper does to meet these goals.

The most prominent written pruning standard in the entire arboriculture industry is published by the American National Safety Institute (ANSI). The standard is commonly referred to as A-300, but is entitled, American National Standard for Tree Care Operations - Tree, Shrub and Other Woody Plant Maintenance - Standard Practices. ANSI A-300 is not only relevant to the utility industry, but is widely used and supported by organizations such as, The International Society of Arboriculture, National Arbor Day Foundation, and American Forests. Santee Cooper relies on the ANSI A-300 standard as a tree pruning guideline for its line clearance contractors. Variation from the standard is only applied when special conditions require alternate methods.

In utility arboriculture, the most common method of pruning is called directional pruning. Directional pruning seeks to eliminate branches that will grow toward the power lines, while leaving behind select branches that will grow away from the lines. This is done to reduce the need for future pruning. Pruning cuts are made in a way that is best for the long-term health of the tree. Branch collars are left intact, and flush cuts and stubs are avoided.

For a more detailed description on the proper pruning, please refer to the web site for the International Society of Arboriculture.

Transmission and Distribution share the same goal, which is to provide reliable electrical service as well as a safe environment for property owners and line personnel within the right-of-way. Both use accepted arboriculture tree maintenance standards such as directional pruning and/or removal when dealing with trees in urban and rural areas. The exception to this is when a species of tree does not have the necessary structure that allows directional pruning and when the goal is to reduce the threat of tree related outages from felled trees. In these cases, the tree(s) will be topped appropriately to conserve the remaining portion of the tree and ensure that upon falling it does not make contact with electrical conductors. Tree species, age, and site quality are taken into consideration before a tree is topped. Only those species that have shown a positive response in the past to this type of maintenance practice are topped. All other species are removed if directional pruning is not an option.

Because an outage to a transmission line can literally impact thousands of customers, it is important to remove or decrease the heights of trees growing along the edge of a transmission right-of-way as a normal maintenance practice. The byproduct of such a practice is good electrical reliability for customers who rely on electrical service for their home and businesses.

Trees on private property are the responsibilities of the property owner. Santee Cooper inspects service wires periodically to identify situations where limbs or vines are in contact with the wires. Trees needing attention are lightly trimmed to alleviate tree/wire contacts. Santee Cooper does not remove trees that are near service wires.

Santee Cooper inspects the primary distribution system periodically to identify situations where trees, limbs, or vines constitute a threat to the power system. Trees that are growing into the wires, or will grow into the wires before the next maintenance cycle, are trimmed to obtain adequate clearance. Santee Cooper will remove some trees that are close to the primary lines, if they are deemed to be an unacceptable risk or a perennial maintenance problem. All such tree removals are discussed with property owners in advance.

In general, Santee Cooper uses three methods to maintain low-growing vegetation within the rights-of-way. They are: manual cutting, mechanical control, and herbicide applications.

• Manual cutting - In areas where vehicular access is restricted, or in other special situations, manual cutting crews may be used. These crews may use machetes, bush axes, and/or chain saws to clear vegetation. Often, the cut vegetation is treated at the stump with a herbicide to control resprouting.
  
  

• Mechanical control - Although it is being used less and less, mowing with heavy-duty machinery is still a common form of brush control on transmission and some distribution rights-of-way. Bush hogs, kershaws, and other mechanical brush cutters can dramatically reduce vegetation density, temporarily. However, over time, mowing is very expensive since it must be repeated frequently as vegetation rapidly re-grows. Mowing also does little to promote wildlife habitat diversity because it encourages the growth of woody vegetation that can dominate a site at the expense of grasses, forbs, and shrubs that provide food, cover, and breeding habitat.
  

• Herbicide applications - Increasingly, herbicide applications are being used to provide a more long-term control of troublesome vegetation, while also creating habitats that are conducive to wildlife. Herbicide applications are typically done with low-volume foliar sprays that are delivered by backpack crews or by personnel on all terrain vehicles when poor ground conditions exist. Just the right amount of solution is selectively delivered to each plant that is targeted for control. This way, no excess chemical is put into the environment, and other wildlife-supporting plants are spared. This method demonstrates how objectives can be met, while not sacrificing the integrity of the environment.

The herbicides that are most commonly used in IVM programs contain active ingredients called glyphosate and imazapyr. These chemicals are formulated to interfere with specific plant processes and are low in mammalian toxicity. Properly handled and applied, these chemicals have a low potential for leaching into ground water supplies. The EPA has placed these chemicals in Category IV for oral toxicity, which is the least toxic of the four categories that they use. Typically, it takes seven to ten years to complete extensive safety and toxicology tests before the EPA will approve a herbicide for use.

When a tree grows too close to a power line it is difficult, if not impossible, to trim the tree for adequate clearance and maintain a healthy, natural-looking tree. In most of these difficult situations, clearance and tree health are achievable, but it is at the expense of beauty. If beauty is the main objective, then tree health will follow, but clearance and the reliability of the electric service will be compromised. However, when a tree is positioned a comfortable distance from the power lines, given the tree's ultimate height and spread, the result is a win, win, win situation! Planting the right tree in the right place means that clearance is less of an issue and the result is a healthy, beautiful community tree peacefully coexisting with the electric facilities.

Before planting a tree, remember this simple rhyme: "Look up; look down; look all around - before the tree goes in the ground." Never plant a tree that will grow more than 10 feet tall, directly beneath the wires. Plant small, medium, and large trees outside of the right-of-way and far enough away so that when they grow to their mature size they will not have to be severely pruned or have the potential of hitting the line if felled by inclement weather. Also, do not plant any type of tree(s) or plants closer than 25 feet to a structure or group a number of trees or plants in the center of the right-of-way that can impede maintenance and/or restoration efforts.

As a courtesy, before Santee Cooper vegetation management crews enter a residential area for maintenance, they will place a door hanger on those residences/businesses that may be impacted. This door hanger only serves to alert the owners that crews will be in the area within a few days. If a customer wants to discuss the tree trimming, a contact name and phone number is provided on the door hanger. While most door hangers announce routine maintenance, occasionally we will identify a tree that should be removed. All significant removals are coordinated with property owners in advance.

Free wood chips are often available after crews have completed tree maintenance and fed the limbs through a chipper. Santee Cooper offers free mulch and delivery, provided the location is convenient to the crew's work location. It should be noted that the quality of the mulch may vary and may not be appropriate for home landscaping. Pine needles, twigs, and pinecones may be in the mix, depending on what tree species have been chipped and how sharp the chipper blades were that day. The wood chips are generally suitable for composting, trail maintenance, or erosion control. To request wood chips, contact Jeff Lane at 843.347.9194 x. 7389 or speak directly to the crew foreman if you need faster service.

Santee Cooper is committed to wildlife habitat enhancement along rights-of-way and participates in habitat restoration programs and research projects to better understand our environment. Some of these programs and research projects are:

• Research Projects
  
  • Venus' Flytrap Study - Along with Coastal Carolina University and the South Carolina Department of Natural Resources (SCDNR), Santee Cooper is participating in a three-year Venus' fly trap project in Lewis Ocean Bay (South Carolina Heritage Trust Preserve). The project will include the identification and tagging of existing populations found mainly in Carolina Bays that are located within Santee Cooper transmission line corridors and the Preserve. Long term demographic monitoring will allow a better understanding of population trends that will aid in future restoration efforts. Also, Santee Cooper's vegetation management practices will be studied to determine which one is the most conducive for long term population growth.
    
    
    
    Santee Cooper and the SCDNR will provide logistical support to the primary research members from Coastal Carolina University. Also, college students who are accepted into Santee Cooper's Summer Environmental Intern Program will help locate fly trap populations, tag individual plants, and collect seeds that will be used to propagate new plants and later introduce them into new areas within Carolina Bays.

To report power outages, contact Santee Cooper by calling 1.888.769.7688.

To report less urgent tree problems or to discuss Santee Cooper's Vegetation Management Programs, contact:

Transmission Rights-of-Way
Kenneth R. Sott, Superintendent Right-of-Way Management
One Riverwood Drive
PO Box 2946101 (OC07)
Moncks Corner, SC 29461
843.761.8000 x. 5591
843.761.4105 (fax)
krsott@santeecooper.com

Distribution Rights-of-Way
Jeffrey L. Lane, Supervisor Right-of-Way Management
197 Dobros Road
Conway, SC 29526
843.347.9194 x. 7389
843.347.9199 (fax)
jllane@santeecooper.com