The power grid mostly garners attention in times of disruption. The Northeast blackout of 2003 and power outages during major storms — these are the times when the grid is put to the ultimate test, when the system’s reliability is pushed to the limits of its aging power infrastructure. What the country takes for granted, however, is the day-to-day work behind the scenes that enables reliable electricity in times of calm.
ITC Holdings owns and operates 15,700 miles of high-voltage transmission lines across the Midwest and Great Plains of the U.S., so the job of keeping those lines operating safely is a 24/7 endeavor. ITC’s vegetation management strategy factors environmental sustainability into its overall operations to provide reliable power. The utility’s vegetation management measures and partnerships with national wildlife organizations help to protect local species and preserve the environment while still maintaining system reliability and operational excellence across seven states.
Environmental Management System
ITC’s environmental stewardship activities are heavily influenced by an ISO 14001-based environmental management system that the utility has applied across its operations. Regulatory standards provide a framework for setting goals for environmental improvement; developing policies, procedures and work practices to meet those goals; evaluating performance; developing corrective and preventive actions; and performing management reviews.
Vegetation management contributes to a utility’s environmental goals, and as a result, ITC places a heavy emphasis on achieving operational excellence in this area. ITC’s right-of-way (ROW) integrated vegetation management (IVM) program effectively and efficiently supports electrical safety and reliability as well as multiple land-use objectives.
For instance, ITC’s collaboration with Stony Creek Metropark (a 4,500-acre multiuse park north of Detroit, Michigan) to reestablish natural prairie land in a transmission corridor, providing not only natural habitats for native animals but also opportunities for education about proper care of the environment, is but one successful story of merging environmentalism with operational excellence.
Challenged to maintain systems within the natural environment, utilities must deliver safe and reliable power in a way that helps to protect land, water and diverse species. The approach and results of ITC’s vegetation management program add to the body of evidence that sustainable operational excellence is possible and is being done.
For example, ITC maintains threatened and endangered species location data in its vegetation work planning software. With this digital aid, contractors select proper IVM methods and the ideal timing for the work, and they are prepared to document relevant presence or absence data. Work is prescribed for times when threatened and endangered species or host species are hibernating or dormant, or manual or specialized equipment is called for on a site-specific basis for line clearance or land stewardship.
When grasses, wildflowers and low-growing shrubs thrive under and around wires that deliver reliable power to communities, everyone wins. A multidisciplinary team at ITC — including contracted International Society of Arboriculture certified arborists — makes this happen, mile by transmission corridor mile. Detecting and preventing tall-growing vegetation from interfering with power lines is a vital part of ITC’s preventive maintenance program to ensure ongoing system dependability. ITC conducts aerial and ground patrols of the transmission system to determine which vegetation needs to be removed and how frequently maintenance will be prescribed on a location-by-location basis.
Applying their knowledge of utility arboriculture, electric system equipment and hazards, and defined scope of work, contracted arborists visually inspect each span, tailoring vegetation management to fulfill individual objectives, protect each community and sustain the natural environment. This long-term approach, backed up by science and economics, is better for the community, less costly for the utility and safer for people and the environment.
Disturbance is a fundamental principle in anthropocentric ecosystem management and natural plant community dynamics. ITC uses targeted disturbance to address both line clearance and corridor ecosystem conditions simultaneously. A key component of ITC’s vegetation management approach is to limit and balance the inputs — the people, equipment and management tools needed to inspect corridors and perform tree clearance work — into the natural environment.
IVM principles of managing in favor of sustainable, low-growing plant communities are applied throughout the utility’s 90,000-sq-mile footprint. The targeted removal and long-term eradication of tall, incompatible species — while fostering conditions favoring the establishment of short-statured plant communities — minimizes the frequency of ROW management activity and increases the presence of native and rare species. The result of intentional disturbance to control incompatible woody species is the development of suitable habitat for many species declining with the disappearance of fire-based ecosystems: Karner blue butterfly, Eastern box turtle, prairie smoke and goat’s rue are all found in ITC’s ROW.
The Utility Arborist Association (UAA) advocates for this process and trains ITC arborists to execute it. UAA guidelines and training tenets prepare arborists to practice responsible IVM. IVM combines three components:
• The American National Standards Institute tree care operations and tree worker safety industry standards
• The International Society of Arboriculture’s interpretations of these same standards
• Recommended work practices based on the latest science and information.
ITC benchmarks itself against UAA’s guidelines to ensure it is applying best management practices and against ROW stewardship principles to chart the course for the future. The utility works continually to balance not only its effects on the natural environment but also its effects on the people with whom it shares space and boundaries. This includes working with residents to help them understand what kinds of plants and shrubs can be established safely near transmission lines, and the right places for trees. Tree removal can be a sensitive issue for property owners. However, the safety of residents and reliability of the electricity system must take top priority.
Under its Right Tree, Right Place program, ITC holds site-selection education events in communities to complement property-owner landscape management and to help prevent tree interference with transmission lines. It has been a Tree Line USA utility for nine years, helping the organization to employ the dual goals of safe, reliable electric service and abundant, healthy-tree canopies across the utility’s service areas.
Supplementing the framework of safety and reliability UAA and ITC vegetation management line clearance protocols provide, the utility’s internal teams creatively partner with other land stewards on initiatives and projects to help conserve and protect native species and the environment.
ITC’s work with native prairie restoration in both Michigan and Iowa in the following case examples exemplifies the utility’s proactive approach to understand, identify and improve ecologically significant features of the landscape, all while managing its transmission system operation:
•Recycling power poles for wildlife. ITC partners with national wildlife organizations to help conserve local species and the environment while still maintaining system reliability and operational excellence across its operating regions in seven states. When a utility needs to rebuild an old, dated section of power line, the wood poles can be reused as wildlife habitat. ITC donated cedar poles from decommissioned power structures to the Iowa Department of Transportation (IDOT) in 2015 for appropriation as bat poles, serving the habitat of the Indiana long-eared bat, a federally endangered species. The poles are planned for installation in two locations where the IDOT has woodland and wetland mitigation projects.
In Michigan, ITC is working with the Huron River Watershed Council, Osprey Watch, Audubon Society and City of Ann Arbor in an effort to increase the number of osprey in southeast Michigan. Two 16-ft-high osprey nesting platforms made from recycled ITC power structures were placed in the watershed within the Ann Arbor parks system in 2015.
• Reinvigorating transmission corridors and the Stony Creek Metropark. Responsible management of plants and trees under and around transmission corridors can accomplish more than the primary objective of maintaining safe and reliable electric service. This work can result in diverse, stable, natural greenways with less environmental disturbance. For example, in 2010, ITC began partnering with Stony Creek Metropark to manage wildlife habitat in ITC’s transmission corridor passing through the park. The work included removing invasive plant species as well as re-establishing and seeding native prairie grasses and wildflowers. Involving the community was an essential piece of the IVM program. ITC worked with local agencies to develop a field-based training curriculum to create a sense of pride and ownership for residents in the area.
•Restoring native prairie vegetation under and around transmission lines. Michigan as a whole is dealing with a declining natural feature: lake plain prairie lands. ITC began working with The Nature Conservancy in 2013 in a multiyear effort to restore these lands in southeast Michigan, including some found along ITC transmission line corridors. Restoration involves eliminating invasive plant species that crowd out the original prairie. This effort helps to restore ecosystem functions; improve and increase habitat for rare insects, plants and animals that characterize lake plain prairie; and increase flora and fauna diversity.
To help Iowa address its own decline in native prairie lands, ITC overseeded three electric transmission line corridors in the Cedar Rapids area in 2014, covering about 42 acres. The plantings feature native grasses, wildflowers and broadleaf native plants. Well-established prairie grasses will help to prevent various types of invasive trees from taking root and potentially growing into the power lines.
• Planning sensitivity. When planning transmission projects, ITC includes environmental assessments for wetlands, threatened and endangered species, and other sensitive habitats. By including these factors at the front end in a transmission line route analysis, ITC can adjust the placement of the line and structures to avoid or limit the environmental impact.
Line rebuild projects in rural wetlands can pose particular environmental challenges. In west Michigan, ITC needed to replace five 138-kV lines running through 4.5 miles of wetlands on deteriorated wood H-frames. Before line work could begin, crews had to reconstruct an old access road and install three temporary bridges over waterways. The five lines were consolidated onto three sets of double-circuit steel monopoles, leaving room for a future sixth circuit. Because wetland regulations restrict the digging and installation of foundations, caissons for the towers had to be sunk directly into the ground using a hydraulic vibration process. The five lines were returned to service in 2011.
The nation’s power lines, particularly the high-voltage lines transmitting bulk power thousands of miles across the country, coexist with the natural environment. ITC takes its responsibility for the environment seriously, from responsible corridor vegetation management to complementary projects beyond vegetation management impacts. Environmental considerations figure into all stages of a transmission line’s life cycle — from planning and siting to construction, maintenance and adaptive management through time.
Environmental responsibility is a core value reflected by ITC employees and throughout its operations. ITC is committed to the safe and reliable delivery of power in an environmentally responsible way to help protect land, water and species. The ITC vegetation management team of resource specialists, and public outreach and environmental project leaders is proud to be front and center in this core value.
Amy Murray administers the vegetation management program for ITC Holdings Corp., the nation’s largest independent electricity transmission utility. She and her colleagues are responsible for keeping the utility’s 15,700 miles of high-voltage lines across seven states free of vegetation interference. She also supports ITC’s community relations activities for vegetation management, including vegetation management field work clarifications and customer interaction. Murray is an ISA certified utility arborist.