FACTOR IN MORE THAN 2 MILLION TREES OF MANY SPECIES GROWN in a favorable climate with good soil conditions with 1.1 million electric customers served through 9400 line-mile overhead and 13,800 miles of underground distribution system, and you have the basis for a potential collision among reliability, trees and customers. Additionally, bulk power is transported through almost 600 wooded miles of transmission rights of way.

Baltimore Gas & Electric Co. (BGE) is a largely urban-suburban gas and electric utility situated in the central Maryland region that stretches from the Pennsylvania border into the outer reaches of the Washington, D.C., suburbs and borders the environmentally sensitive Chesapeake Bay. In addition to its home base, Baltimore City, it serves all or part of eight counties within its 2300-sq-mile service territory.

It is important to note that virtually all of the trees on the distribution system are customer-owned and under some type of regulatory authority. It is also important to note that the regulatory environment governing utility tree work in Maryland is one of the most challenging in the nation.

Like most major metropolitan areas that have been transformed into the service economy, BGE's customers are increasingly more educated and more articulate about issues that affect their quality of life. They have high expectations of their service providers and an elevated environmental awareness. Since vegetation management practices span both the customer service and environmental arenas, program visibility and performance receive heightened attention from both internal and external stakeholders.


In the late 1980s, BGE was in the steady-state environment of providing utility services. In the same time frame, BGE's vegetation management program was in the process of changing its pruning practices in response to the exciting research findings about tree-wound response. In the early 1990s, BGE continued its interest in innovation by investigating how trees caused outages in the distribution environment. This work began a minor revolution that helped to reveal the true nature of tree-wire contacts — that natural tree growth has a limited ability to cause tree-related outages — and led to a greater emphasis on mitigating problematic overhanging branches above the wires as well as hazardous trees adjacent to the wires. At the same time, this work helped illustrate the impacts of overhead construction configurations in the reliability equation that helped lead to a comprehensive in-house approach to improving reliability.

The stage was set for program improvements, but some pieces of the puzzle were still missing. Adequate funding was required to fuel the improvement engine, and a contracting methodology had to be developed to get the most program value. BGE's vegetation management program operated under a long-standing sole-source T&E contract. And, up into the early 1990s, program funding was relatively static. A basis was needed to project funding, so a consultant was hired to survey the system to determine workload. Additionally, BGE began to benchmark contracting processes nationwide.


BGE determined that a unit-based, multicontractor alliance was most effective for reducing costs, projecting workload and using contractor expertise to manage how the work was accomplished. In 1995, the move into the unit arena began on the distribution side of the vegetation business. Also, based on the system survey, distribution program funding began to increase at about the same time. One of the challenges of unit price contracting is developing a set of standards that are reliability- and safety-based that at the same time can be effectively followed by contract crews and enforced by the utility personnel. BGE successfully managed this transition with standards that varied by voltage and construction configuration based on the knowledge gleaned from the earlier outage studies.

As the distribution vegetation program was about to expand, it was apparent that an aggressive program that was performed systematically and comprehensively might not be viewed positively by many of our customers, especially customers who had been able to limit or completely stop work on their trees in years past. So the customer notification process was born. The process began small and has grown in scope to include more levels of customer contacts, along with an expanded list of stakeholders who may be advised of the planned work activities.

As this process has continued to mature, we have incorporated an ever-expanding public information campaign that includes bill-stuffers, newspapers, radio and television. We have also increased the use of tree replacements as an enticement to allow the removal of tall-growing trees. It cannot be stressed enough, however, that if all else fails, it is critical to have the desire and the fortitude to enforce your ability to do the work to the full legal limit allowed under the law. This is an unpleasant task, but one that has helped BGE consistently address tree-related reliability and safety issues.

A program manager was added as the program expanded in size and complexity to track performance and budgets. The program manager is matrixed to the forestry supervisor to ensure program continuity and coordination and to allow the forestry supervisor to focus more on technical issues and process improvements. This separation of duties has continued to pay dividends as the program has become more reliability-driven with increasing budgets tied to corporate objectives to improve reliability.


In 1998, transmission vegetation management migrated to multicontractor alliances and unit-price contracting. All of the key elements from the distribution program were incorporated into the transmission arena. As the transmission program was being evaluated for improvement potential, we realized that much work was required to reduce exposure from tall-growing trees both on and off of the rights of way. A gradual phase-in of this tall tree remediation began in 1999 and hit full stride in 2002. Presently, BGE pursues a zero transmission tree-related outage policy for transmission lines where good property rights exist (approximately 490 miles). In addition to managing for low-growing trees on the rights of way, BGE also works to ensure that off-rights-of-way trees will not be able to fall within flash distance of the conductors. This is a particularly challenging effort where the rights of way are less than 70 ft wide. Any trees that remain on the rights of way because of regulatory requirements, and all off-rights-of-way trees, are presently managed on a five-year cycle. Mowing is performed yearly, and herbicides are applied as warranted.

The BGE forestry program has continued to mature. In addition to the ongoing vegetation management on the transmission system, we are investigating the development of an encroachment mitigation strategy and a strategy to ensure adequate access onto and through the transmission rights of way. Left unchecked, rapidly expanding development that occupies the former farmland adjacent to our rights of way presents ever-increasing challenges to be able to maintain the integrity of the rights of way to ensure easy access for inspection, maintenance and repair in the present and future.


Today, the BGE vegetation program continues to evolve ahead of customer demand for reliable and safe service, performed in a way to promote customer satisfaction. Given the sensitive nature of managing trees on the property of others, minimizing customer dissatisfaction is a measure of success in some cases. Nonetheless, we keep working to refine customer notification efforts along with general education and outreach. These efforts are critical when a program works to push the envelope to maximize system reliability associated with trees. Our most recent efforts involve removing problematic overhanging branches from the substation out to the first protective device for the 2% worst-performing system feeders. Additionally, we perform “walk-around” hazard tree inspections out to 40 ft from either side of the pole line (for all system feeders from the substation), out to the first protective device and for the entirety of the 34.5-kV subtransmission lines.

In 2004, as part of a comprehensive Forestry Six Sigma initiative, we completed an outage follow-up study to better understand the failure factors associated with tree outages. This effort, ultimately, may be performed on a routine basis. In addition to managing for trees, BGE continues to look for opportunities to improve system design.

While there has been a general trend in reduced tree outages, recent SAIFI measurements have provided strong evidence of program success. The nonstorm tree SAIFI 12-month rolling average has declined by 39% from June 2004 through June 2005. Additionally, the 12-month rolling average for tree SAIFI as a percentage of overhead SAIFI (exclusive of major and severe impact storms) went from 33% to 28% in the same time frame.

These positive performance trends reflect the synergies achieved from the combination of improvements associated with tree management and other reliability improvement initiatives.


BGE recognized it could no longer do business the way that it always had. Customer expectations were increasing and a competitive environment for utilities was looming on the horizon. Combining technical advances, solid program management, teamwork and management support, BGE has traveled a long road in a relatively short period of time. The trip has not been easy, nor is it over by any means, but it has been rewarding.

Key elements to the success achieved to date have been a knowledgeable forestry staff that has been innovative and flexible; highly competent program management personnel who have been willing to learn and provide across-the-grain suggestions for improvement; reliability engineers who have worked closely with forestry personnel to collectively and constructively develop reliability solutions; and management that has been steadfastly supportive in the effort with ideas and funding. To say the least, all personnel involved have had broad shoulders to carry the burden of criticism of those opposed to the many changes that have been implemented.

The most important attributes of all have been the patience and trust that have been practiced at all levels of the company to allow time for the “trees of success to bear fruit.” The challenges continue, and we must continue to rise up to meet them if we plan to stay ahead of the change curve and to continue to provide the services that our customers need and expect.

It really all gets down to BGE's vision and mission statements, which are respectively: to “Be a recognized leader in energy delivery by enhancing our customers' quality of life, our shareholders' value and our team's well-being;” and to “Safely, economically, reliably, and profitably deliver gas and electricity to our customers.”

William T. Rees, Jr. is supervisor of Forestry and Right-of-Way Management at Baltimore Gas and Electric Co. in Baltimore, Maryland. William.T.Rees@bge.com