Electric utilities are particularly sensitive to public opinion not only about what the electric services cost, but also about routine company operations that include day-to-day activities involving maintenance of lines and equipment. An important area of maintenance is right-of-way (R/W) cleanup, which ensures easy access to lines and prevents excessive tree growth that can affect system reliability if line-to-ground clearances are impaired.

With its 10-county territory across the Florida Panhandle, Gulf Power Co. serves more than 373,000 retail customers, as well as more than 13,000 customers through wholesale delivery of electricity to an investor-owned utility and a single municipality. These electricity consumers are the ultimate beneficiaries of vegetation control on the system.

Organizing a Program

Gulf Power's forestry services department directs R/W cleanup. This department is responsible for a vegetation-management program encompassing 139 substations, 6673 miles (10,739 km) of distribution R/Ws and 1562 miles (2514 km) of transmission R/Ws.

In 1987, Gulf Power originally hired a forester to provide technical oversight for its vegetation-management programs and to identify practices to increase cost efficiencies. In 1994, by centralizing all vegetation-management programs under a new forestry services department, the company reemphasized the importance of these programs.

Prior to 1987, Gulf Power's transmission program used mechanical clearing of vegetation with virtually no herbicide use. The program was typical for most utilities at that time, which involved mowing the R/W floor every three to four years and side trimming trees along the R/W edges. To increase the effectiveness of the clearing process, Gulf Power implemented Integrated Vegetation-Management (IVM) techniques that combined mechanical and herbicide control methods. A particular challenge arose in implementing IVM since the coarse, sandy soil, which is common in Florida, makes groundwater contamination a more significant concern than in other states.

Before integrating herbicides into the program, the forestry services department considered several factors with respect to the potential effectiveness of the proposed practice — the short- and long-term costs, the impact on Florida's unique topography and soil composition, company employees' acceptance and adaptability to the program, and the reaction of customers and landowners adjacent to the R/Ws.

The forestry services department, believing the success of the transition to an IVM program would depend on hiring a reputable and dependable applicator, selected Applied Solutions of Natchez, Mississippi, U.S.

Applied Solutions provides low- and high-volume applications and can apply herbicides aerially or from the ground using backpacks or a fleet of sprayers mounted on skidders, tractors and four-wheel-drive, all-terrain vehicles. Applied representatives have been involved in every phase of the program, which includes writing herbicide prescriptions; recommending improvements to the program; and meeting with customers and pre-planning applications to ensure that application techniques and herbicide formulations are specifically suited to vegetation types, soil, topography and other characteristics of the R/W.

On small portions of the transmission R/Ws, the forestry services department evaluated different herbicide combinations:

• Garlon as a stand-alone application
• Arsenal herbicide mixed with Krenite in upland areas
• Accord in wetlands.

Arsenal EUP (Experimental Use Permit) herbicide was added to Accord when the company received an EUP, allowing for its application in wetlands. The success of tests with these herbicides resulted in decreased mowing schedules, which reduced the cost of the mowing program.

Although Gulf Power observed that, even with limited use, IVM could result in overall savings for the company, customer reaction to the new spraying program was a key factor in its decision to commit to a long-term IVM initiative. Initially, the company was concerned about the public's reaction to large-scale use of herbicides along R/Ws when one of the early herbicide applications drew some adverse reaction. However, public support for the program was strengthened when environmental profiles regarding the products were publicized. Benefits were demonstrated for using herbicides instead of mechanical clearing since there would be less noise and less disturbance of the soil and to desirable vegetation.

The current program targets one- to two-year-old brush that already has been mowed at the start of the management cycle. By the end of the first year, the mowed vegetation had begun to resprout, a condition where spraying is ideal. The preferred tank mix was Arsenal herbicide with Krenite, used at the labeled rate, except in wetlands where Arsenal EUP was used with Accord.

Specifying the Application Process

For the initial application, a low-volume broadcast application used Radiarc nozzles to cover the area. Three to five years later, backpack-laden crews spray only undesirable vegetation that is incompatible with the R/W. Three main reasons for targeting one- to two-year-old brush with the herbicide program were aesthetics, ease of application and cost. Spraying larger, older vegetation leaves behind tall trees and brush, which can be unsightly when the herbicide has taken effect. Crews can target younger brush most easily from the ground and spraying smaller brush requires less herbicide, which reduces the cost of the application.

Aesthetics played an important role in herbicide choice, because some products achieve a rapid brownout of vegetation, resulting in unsightly withered leaves. The slow-acting properties of Arsenal with Krenite were desirable, because they resulted in a gradual transition from a R/W dominated by tall-growing brush to one occupied by lower-growing forbs (broad-leaved herbaceous plants), grasses, flowers and brush species compatible with a R/W. For example, a few months after a summer application of Arsenal with Krenite, little difference in vegetation was observed. However, a year later, the control was much better than anticipated. Two years later, the effectiveness of the herbicides was even more dramatic.

The combination of Arsenal with Krenite took care of the most problematic tree species of oak, persimmon, pine, cherry and sycamore. In addition, the use of Garlon proved effective on waxy species such as bay trees. With respect to stem density, significant changes occurred as a result of the spray program. The density decreased from several thousand stems per acre to less than 400 stems per acre after the initial application. Follow-up herbicide treatments have further reduced stem density to less than 100 stems per acre.

Realizing Additional Benefits

IVM has proved to be valuable to wildlife in the area. Mechanical clearing destroyed wildlife nesting sites and desirable food sources such as forbs and legumes. Where herbicides were used, many species of lower-growing vegetation that do not interfere with power lines and that are beneficial to wildlife remain. Also, wildflowers and other vegetation that remain in the area attract deer, turkey, quail and butterflies. In one of the R/Ws, an endangered flower species, the Fringed Campion, was found when the tall-growing brush was controlled. Once the sunlight was able to penetrate to the R/W, the flower began to flourish, encouraging Gulf Power to work with the Nature Conservancy to manage this endangered species through the use of herbicides.

The cost savings of the program were an unexpected benefit, because it was originally expected that the application of herbicides would cost more than mowing. However, by using low-volume application techniques, not only was the cost of the initial application comparable to the cost of mowing, but follow-up treatments lowered the cost even more, to about 50% of the cost of mowing. Above and beyond the savings realized with vegetation management activities is the improved access to R/Ws by crews who can patrol a line faster and can enter a R/W, unimpeded, for line repair and maintenance. In addition, the use of herbicides has proved to be safer than mechanical clearing, since even when crews use care with mowers and chain-saws, occasional accidents occur. In this respect, herbicide applicators are exposed to less danger because they are not working around heavy equipment with sharp blades.

The real surprise was public reaction to the IVM program, with fewer customer complaints about damage caused by mowers throwing debris against fences and other neighboring property.

Promoting Project Habitat

An important part of the IVM program is training employees who have contact with the public to answer questions honestly and confidently. When customers ask about herbicide effects on wildlife, an opportunity opens to talk about Gulf Power's membership in the Project Habitat wildlife-enhancement program, which is the utility industry's premier program for promoting environmental stewardship in R/W management. Utility members partner with BASF Corp. and leading wildlife organizations such as Quail Unlimited, the National Wild Turkey Federation, Buckmasters, Butterfly Lovers International and the Quality Deer Management Association. When customers near R/Ws learn of Gulf Power's work with these organizations, they have greater confidence that the company is concerned with the natural environment.

Gulf Power's IVM program, incorporating the use of herbicides and mechanical control methods, has met all the important corporate criteria for success. As a result, more than half of the transmission line acreage is on the herbicide program. Ultimately, herbicides will be used on 75% of the transmission R/Ws, representing a big change from just a few years ago and which will benefit the company's bottom line.

Steve Burns served as a state forest manager with the Florida Division of Forestry for nine years before joining Gulf Power Co. in 1987 as forestry services supervisor. He earned the bachelor's degree in forest management from Auburn University and the master's degree in business management from Troy State University. He is a licensed herbicide applicator.

Registered Trademarks

Arsenal and Project Habitat are registered trademarks of BASF; Garlon is registered to Dow AgroSciences LLC; Accord to Mo.; Krenite to E.I. du Pont de Nemours and Co., and Radiarc to Waldrum Specialties Products.