With an increasing array of environmental concerns facing the United States and the public highly scrutinizing large corporations, utilities can help national anxiety by making environmentally sound decisions.

American Electric Power (AEP; Columbus, Ohio, U.S.) is keenly aware of this and has taken steps to maintain its rights-of-way (R/W) in a manner that focuses on environmental concerns, while at the same time protects its workers and the bottom line.

One such step is a move by AEP vegetation managers toward contract-mixing services to receive herbicides and premixed solutions in returnable, refillable containers. These services decrease the number of used containers taking up landfill space, while increasing worker safety, saving time and cutting R/W maintenance costs.

While this technology has been available in the agricultural sector for many years, it has only recently emerged as a trend among utilities.

Before the advent of contract mixing, AEP had no system in place to detour herbicide drums from landfills. To put it in perspective, AEP manages 210,000 distribution and 39,000 transmission line miles. Since adopting the returnable, refillable program, the utility has prevented the disposal of enough herbicide containers to fill more than two football fields.

Aside from the environmental aspects, disposing of empty drums is costly. In five years, it is estimated that just one returnable, refillable container saves US$365 in container disposal fees compared to a normal drum.

With that said, it is no surprise that AEP, stretching across parts of 11 states, now orders 90% of its herbicides via contract mixing services such as the Continuum Prescription Control & Container Management System from Dow AgroSciences.

However, reducing the impact on the ecosystem and saving on disposal costs are only two of the benefits that contract-mixing services offer.

A Texas Timesaver

AEP operates in some geographically diverse areas. From rough terrain in West Virginia and Kentucky, to wide-open countryside in Oklahoma, company employees face unique vegetation management challenges in each region. But a similarity shared by every vegetation manager is the desire to increase efficiency and save time. This is another area where contract mixing has proven its value to AEP.

One employee with a particularly unique role is Jim Cruser. On any given day, Cruser can be found visiting a rancher or landowner to discuss AEP Texas' herbicide program. This utility forester faces the unconventional challenge of having 90% of his R/W run through ranches, some of which are owned by high-profile individuals or companies with ranches as big as 800,000 acres.

With several absentee property owners living in San Antonio, Houston or Dallas, Texas, Cruser can spend anywhere from three hours to a full day locating these owners so he can gain access to their ranches. That hurdle has him constantly seeking ways to increase efficiency and save time when it comes to his main responsibility: managing vegetation.

“We can spend anywhere from two to four hours each day just driving to a location,” Cruser says. “If we can eliminate any steps in our preparation, we'll be much more productive when we finally get to work. That's why one of the biggest selling points of herbicide contract mixing is the amount of time it saves my crews.”

The U.S. Environmental Protection Agency requires used herbicide containers to be triple rinsed, cut into pieces and specially bagged before disposal. By the time they finish, workers have handled each container at least three times. Acquiring herbicides in returnable, refillable containers eliminates these steps.

Prescribing Success

AEP's power lines in Texas are surrounded by an array of vegetation. There's the brush and smaller trees, such as catclaw, black brush, acacia and mesquite, as well as oak, pecan, willow and hackberry, which are taller.

“Our rights-of-way are very diverse with vegetation, which makes it difficult to describe what typical AEP Texas rights-of-way looks like,” Cruser says. “One area south of Houston has lots of hardwoods and taller trees with thick vegetation all around, while the Rio Grande Valley has more exotics, such as palm trees and Australian pines. And, of course, both of these areas look completely different from the arid southwest Texas, where you have a lot of mesquite, prickly pear and huisache.”

Depending on which types of vegetation he's targeting, Cruser prescribes one of two herbicide mixes with which he has had enormous success. For areas with access and potential reliability problems because of large stem densities and tall trees, he uses a high-volume foliar application of 2 quarts (1.9 liters) brand-name triclopyr product, 2 quarts brand-name picloram product and surfactant in 100 gal (378 liters) of water per acre. This is applied through an automated system, either a Radiarc or Boom Buster.

If a R/W has been sprayed within five years and has had some regrowth, Cruser opts to conduct basal applications. The chosen rate is 20% brand-name triclopyr product and basal oil. This rate is also used for AEP Texas' cut-stump applications. Typically, both applications take place along row fences adjacent to the R/W.

By acquiring these mixtures from a Continuum system provider, which uses computerized systems to create the mixes, AEP is guaranteed a precise mixture just in time for application. This eliminates the hassle and time associated with crews mixing herbicides on site, which increases worker safety by reducing the potential for exposure to product, and helps the utility better-manage inventory.

The returnable, refillable containers require no cleanup measures, and their closed-loop application systems decrease the chance for worker exposure. AEP uses Aqumix Inc. to perform utility contract mixing. This relieves AEP of the need to store empty containers on its property, because Aqumix immediately retrieves drums and refills them accordingly.

The method also gives AEP vegetation management crews increased credibility. With returnable, refillable containers and closed-loop application, onlookers never see crews pouring herbicides into tanks or disposing of empty jugs. Because workers throughout the utility's service areas are constantly in the public eye, portraying this positive land stewardship image reduces the chance for complaints.

Total Integration

Because contract mixing has aligned so well with AEP's main goals of safety, reliability and cost control, he stopped purchasing herbicides in 2.5-gal (9.4-liter) containers and implemented contract mixing on all of his lines in 2004.

This system redefines the way vegetation managers purchase and handle herbicides because, in the long run, it will save AEP a lot of money. When herbicides are acquired through a contract-mixing provider, you purchase the same products you've always used, but eliminate many of the prep and post steps required for applying herbicides. And that leaves more time for spraying brush.

There are additional benefits of herbicide contract mixing, as well.

Before AEP receives its shipments, permanent bar codes are affixed to drums for tracking. The bar code numbers, container contents and destinations are logged into an electronic database.

Aqumix identifies the specific batch number of registered products used from manufacturers, type of mix and amount of product, as well as many other variables, from the time the container leaves the facility to when it returns. This tracking system gives AEP higher product accountability standards and decreases leftover and wasted herbicides, thus saving the utility money.

Integrating contract mixing into his vegetation management program complements Cruser's efforts to share with his customers that he's out to increase grasses, forbs, food and shelter for cattle and wildlife. After all is said and done, the ranchers typically thank AEP staff for turning their once-infested-with-brush R/W into lush grazing areas for cattle. In fact, AEP's success has led to many ranchers requesting herbicide applications on R/W crossing their land.

When woody stem vegetation is eliminated, the path is cleared for good grasses and other forbs that are attractive to cattle. This result, of course, is an excellent benefit for ranchers, but it is an even better stewardship point for AEP when it involves the Continuum system.

From a public image standpoint, acquiring herbicides through a contract mixing service may be one of AEP's wiser investments. While the technology may not dismiss all challenges facing utilities, it is certainly a step toward economical, environmentally sound R/W maintenance.

Terry K. Smith is the forestry system coordinator with American Electric Power Forestry under the Asset Management Department. He has more than 35 years experience as a utility forester, working in vegetation management. Smith holds a bachelor of science forestry degree and a teaching certificate in environmental education from the University of Michigan (1969, 1972). His duties include contract administration for the forestry right-of-way maintenance program, program development and related environmental issues. He is a member of the International Society of Arboriculture and the Utility Arborist Association.
tksmith@aep.com