Frequently Asked Questions

  1. What did I hear about new electric transmission lines being built from southwestern West Virginia to Maryland?

  2. What is PJM and what is its role in planning new transmission lines?

  3. Where will the new proposed transmission line be located?

  4. Why is the PATH project needed?

  5. What are the benefits of the project?

  6. How does the transmission grid help to deliver electricity to my home or business?

  7. I’ve heard that PATH is only being constructed to transport power to New Jersey and none of the electricity will supply our region. Is that true?

  8. I’m also hearing that you’re only building this line so you can sell more power from coal-fired power plants in the Midwest to electric users in the Northeast. Is that true?

  9. How will Allegheny and AEP build PATH?

  10. How much does PATH cost, and who will pay for it?

  11. Isn’t Allegheny already building a transmission line? If TrAIL goes into service, why do we need PATH?

  12. What regulatory approvals will be required?

  13. Is the vicinity of the proposed PATH line within a National Interest Electric Transmission Corridor (NIETC)?

  14. Can you provide more details on the routing process for the project?

  15. How was the proposed route selected?

  16. Why can't you expand the capacity of current lines?

  17. Does a 765-kV line require a wider right-of-way than a 500-kV line? Will the towers need to be taller?

  18. Isn’t it true that exposure to electric and magnetic fields (EMF) cause health problems?

  19. What about the noise level of EMF coming from transmission lines?

  20. How will you acquire the property for this project?

  21. Will new transmission lines increase our reliance on coal-fired generation and further contribute to global warming?

  22. Stringing new transmission lines is not the solution. Can we avoid the need for the line via energy conservation measures capable of reducing demand?

  23. Can a 765-kV line such as PATH be placed underground?

  24. Why don’t you just re-conductor some of the existing transmission lines using this technology?

 

1. What did I hear about new electric transmission lines being built from southwestern West Virginia to Maryland?
In 2007, PJM Interconnection, Inc. (PJM) approved upgrades to the region’s electric transmission system, including the construction of a new high-voltage transmission line from southwestern West Virginia to central Maryland, the American Electric Power (AEP) and Allegheny Power transmission zones, designed to maintain reliability of the regional transmission system. Thereafter, Allegheny Energy and AEP announced a joint venture to build the line named "Potomac-Appalachian Transmission Highline," or PATH, for short.

The PATH project consists of a 765-kilovolt (kV) transmission line extending approximately 275 miles from the Amos Substation in Putnam County, W.Va., to the proposed Kemptown Substation, southeast of New Market, Md. The project also includes the new Welton Spring Substation along the proposed route in northwest Hardy County, W.Va.

As part of the project, AEP and Allegheny have worked with local communities to actively solicit the public’s input. Through this open process, the PATH companies held 24 public open houses in the communities within the study area in West Virginia, Maryland and Virginia. Over 2,500 individuals attended, received information about various aspects of the project and offered information about their interests in the project. In addition, the PATH companies are:

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2. What is PJM and what is its role in planning new transmission lines?
PJM is the regional grid operator that coordinates the movement of electricity, ensures reliability of the transmission system and plans transmission expansion in 13 states and the District of Columbia.

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3. Where will the new proposed transmission line be located?
The PATH project will connect the Amos Substation in Putnam County, W.Va., to the proposed Kemptown Substation southeast of New Market, Md. The project will also include the new Welton Spring Substation along the proposed route in northwest Hardy County, W.Va. Check the maps page of this web site to view the proposed route.

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4. Why is the PATH project needed?
The U.S. Department of Energy, the North American Electric Reliability Corporation and PJM all agree new transmission lines must be built to prevent documented reliability concerns. The need for the PATH project has been established by conclusions noted in the past three annual Regional Transmission Expansion Plan (RTEP) reports, citing reliability violations in the PJM region, including the Mid-Atlantic area. PJM is in the process of preparing the 2010 RTEP analysis, which will re-evaluate the date PATH is needed, in addition to other major transmission system improvement projects within the PJM region.

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5. What are the benefits of the project?
Due to the interconnected nature of the grid, each transmission zone is interdependent on its neighboring zones. The PATH project will benefit the entire PJM region by:

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6. How does the transmission grid help to deliver electricity to my home or business?
The electric delivery system is basically divided into two parts: transmission and distribution. The transmission and distribution systems work together like a network of roadways. Transmission lines — like PATH — can be described as multi-lane highways, transporting power at higher voltages across the region. Distribution lines are considered the two-lane roads and streets of the electric network. Substations along the highway serve as exit ramps, stepping down voltage from the transmission lines to the distribution lines so electricity can be delivered to homes and businesses in our towns and neighborhoods.

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7. I’ve heard that PATH is only being constructed to transport power to New Jersey and none of the electricity will supply our region. Is that true?
No, that is not true. In addition to maintaining the reliability of the transmission grid, PATH will supply electricity to regional homes and business through its interconnection with the 500-kV system. The 765-kV PATH line will tie in to the 500-kV system at two new substations — Welton Spring Substation in northwest Hardy County, W.Va., and Kemptown Substation southeast of New Market, Md. Here’s a closer look at how PATH’s connections with Welton Spring and Kemptown will help to provide power to our region:

Welton Spring

View illustrated map

Kemptown
At Kemptown, PATH will interconnect with existing 500-kV lines linking to major substations of Allegheny Power, Baltimore Gas & Electric and Potomac Electric Power. As a result, PATH will provide power and reinforce the transmission system to the north, south, east and west, including:
View illustrated map

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8. I’m also hearing that you’re only building this line so you can sell more power from coal-fired power plants in the Midwest to electric users in the Northeast. Is that true?
The objective of the PATH project is to strengthen the reliability of our region’s power grid. According to PJM, the need for PATH is driven primarily by the threat of voltage violations and line overloads. In either case, these reliability problems could have a direct impact on service to Allegheny Power customers in the eastern panhandle of West Virginia, northern Virginia, central and western Maryland, and south central Pennsylvania. PJM selected PATH as the best alternative to resolve these reliability violations. Transmission owners within PJM — such as Allegheny Power and AEP — are charged with the legal obligation of maintaining a transmission grid that will provide reliable service to residential, commercial and industrial customers. The PJM region includes the Mid-Atlantic area, where growth in consumer demand for electricity, the lack of adequate new generating capacity being constructed, and the actual and anticipated retirement of older generating units are causing the need for PATH to assure continued reliability of the transmission system.

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9. How will Allegheny and AEP build PATH?
Effective September 1, 2007, Allegheny and AEP finalized a joint venture to build the project. The companies began working on routing and environmental studies for the line in early 2008. The PATH companies are committed to obtaining authorization to build the project from the respective state utility commissions in order to meet the in-service date as determined by PJM.

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10. How much does PATH cost, and who will pay for it?
Based on current plans, the total project is estimated to cost approximately $1.8 billion. Allegheny currently estimates that its total investment in the project will be approximately $1.2 billion. AEP’s investment will be approximately $600 million. The cost of the project will be shared by all customers in the PJM’s region. PJM serves about 51 million people in 13 states and the District of Columbia. The typical rate increase that AEP and Allegheny expect for their residential customers is listed below.

Allegheny Typical Residential Customer Rate Increase

AEP Typical Residential Customer Rate Increase

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11. Isn’t Allegheny already building a transmission line? If TrAIL goes into service, why do we need PATH?
TrAIL is a separate, 210-mile project scheduled for completion in 2011 and is not part of the Allegheny/AEP joint venture. TrAIL and PATH are both needed to strengthen our underlying transmission grid, and that’s why PJM has directed us to build both projects.

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12. What regulatory approvals will be required?
The PATH companies must receive authorization to build the project from the state utility commissions in West Virginia, Maryland and Virginia. Approvals from other federal, state and appropriate agencies also will be required.

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13. Is the vicinity of the proposed PATH line within a National Interest Electric Transmission Corridor (NIETC)?
The entire vicinity where PATH will be sited is within a designated National Interest Electric Transmission Corridor (NIETC). This designation is a clear recognition from federal officials and policymakers of the importance of the electric transmission system to the nation's economy and security. However, we fully intend to work with state regulators to gain authorization for the PATH project.

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14. Can you provide more details on the routing process for the project?
The goal of the routing process was to evaluate potential impacts, develop alternative routes and select the most suitable route for a 765-kV transmission line between the Amos Substation in Putnam County, W. Va., and the proposed Kemptown Substation near New Market, Md. The most suitable route was defined as one that minimizes the effect on the natural and human environment while avoiding unreasonable and circuitous routes, extreme costs and non-standard design requirements.

Many sources of information were employed to develop alternative routes for PATH. Valuable sources of information included:

After three months of planning, PATH project staff launched a public outreach effort that included 24 public open houses held in communities within the study area. Maps of the alternate routes were displayed at the meetings, as well as on the project web site, for public comment. As of May 1, 2009, nearly 3,000 public comments were received and evaluated by project staff.

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15. How was the proposed route selected?
The PATH companies determined the proposed route after careful study, including consideration of feedback received at public open houses. In West Virginia, much of the Amos-Welton Spring segment follows an extremely rural route and avoids populated communities and sensitive environmental habitat. Between the proposed Welton Spring and Kemptown substations, the majority of the route closely parallels the existing Mount Storm-Doubs 500-kV line, including overbuilding of an adjacent 138-kV line that has been in service for many years. Detailed maps and aerial photos depicting the proposed route can be viewed on the Maps page of this site.

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16. Why can’t you expand the capacity of current lines?

A number of practical and economic issues make that alternative unworkable:

Right of Way Constraints — In some cases, the rights-of-way for existing 138-kV transmission lines will not accommodate the Extra High Voltage (EHV) transmission lines that are required for this project. While efforts can be made to parallel existing rights-of-way, the lower voltage lines are often built in close proximity to customers, making it more difficult to construct new EHV facilities along the same path.

Existing Extra-High Voltage Lines Are Needed — Sometimes a new line can be built over an existing line. However, the existing line must be de-energized while the new line is being constructed. But because our transmission system is already constrained, reliability would be at risk if we de-energized any of the area’s extra-high voltage transmission lines for the duration necessary to complete this work.

Overall Cost — Additional construction costs are incurred due to the increased amount of time and additional steps required to maintain the existing circuit during construction.

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17. Does a 765—kV line require a wider right-of-way than a 500-kV line? Will the towers need to be taller?
For 765-kV and 500-kV lines, the right-of-way width typically is the same — 200 feet. As for the height of a transmission tower, it depends on the topography of the land and other factors. On average, the towers for 765-kV lines are only about 15 feet taller than the towers for 500-kV lines.

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18. Isn’t it true that exposure to electric and magnetic fields (EMF) cause health problems?
It’s important to understand that EMF occur wherever electricity flows. For example, a lamp that is turned on produces both an electric and magnetic field. Because our society relies heavily on electricity, people are almost constantly exposed to EMF throughout their daily environments at home, work and school. Many common household appliances, such as electric shavers or hair dryers, generate magnetic fields that can be tens of times higher than transmission line fields.

Questions about EMF and health first arose in the 1960s and 1970s with the use of higher transmission voltages in the U.S. Over the past several decades, numerous scientific studies have been conducted on EMF and health. The epidemiology studies taken as a whole, along with the laboratory studies on animals and cells, do not provide a reliable scientific basis to conclude that exposure to EMF from power lines increases the risk of cancer, including leukemia, or of other adverse health effects, in children or adults. Furthermore, there is no reliable scientific basis to conclude that exposure to power frequency EMF from PATH will cause or contribute to adverse health effects in children or adults along the proposed route.

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19. What about the noise level of EMF coming from transmission lines?
It is typical for 765 kV lines to produce some corona – which can include some audible noise. PATH will use a six-conductor bundle configuration, which significantly reduces corona effects. In fair weather, sound levels 100 feet from centerline for PATH are in the range of the sound levels inside a library or typical suburbs at night. In foul weather, the sound levels will be comparable to or lower than the sound of falling rain.

Also, 765 kV lines may produce some induction effects, such as small spark discharges from metal objects that may be in or near the right-of-way. To address possible induction effects, the PATH project will follow the requirements of the National Electrical Safety Code.

In summary, the extensive research conducted on EMF for many years has not shown a reliable scientific basis to conclude that EMF from power lines cause or contribute to any adverse health effects.

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20. How will you acquire the property for this project?
We will negotiate agreements with property owners to acquire rights-of-way, also known as “easements.” We will negotiate with each property owner individually in an effort to reach a fair and equitable agreement. Although all owners will be treated fairly, there is no fixed amount that each property owner will be paid or formula for determining the amount to be paid. Each property is unique and the price paid for each easement will reflect the differences from one parcel to the next. For example, the area covered by the easement may be greater or smaller on one parcel than another; some parcels may have road frontage where others do not; and some parcels may have a higher or lower value than others due to land use, topography, size, location or characteristics of the property.

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21. Will new transmission lines increase our reliance on coal-fired generation and further contribute to global warming?
We can’t fully benefit from any electric power generation, whether from existing sources or from new renewable sources, if we can’t transport this energy from where it is generated to where it is needed. In its Long-Term Reliability Assessment, the North American Electric Reliability Corporation (NERC) stated that new transmission lines are needed to deliver renewable power from remotely-located wind and solar generation projects into population centers. New transmission is also vital to connect proposed nuclear power plants.

Specifically, PATH will utilize advanced transmission technology that is capable of reducing system losses significantly, resulting in greenhouse gas reductions. Studies show that peak line losses on PATH will drop by 200 megawatts or more, which will reduce carbon dioxide consumption by an estimated 280,000 tons per year. That’s the equivalent of removing 55,000 cars from the road for one year, or 1,291 railcars of coal that would be otherwise consumed for electricity.* In addition, replacing traditional conductor wire with a new advanced design could save an additional 28,000 metric tons of carbon dioxide annually.

*Source: U.S. Climate Technology Cooperation

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22. Stringing new transmission lines is not the solution. Can we avoid the need for the line via energy conservation measures capable of reducing demand?
We support energy conservation. We’re working hard on new programs that will help customers use energy more efficiently. But these measures are largely voluntary, and more importantly, they take time to implement and even more time to produce results. A 2006 study by the Edison Foundation states that despite conservation efforts, "the reality is that our nation’s appetite for electricity continues to grow, and electric utilities must be able to make the necessary investments to meet this growing demand." Experts agree — new transmission lines are needed to keep the lights on for years to come.

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23. Can a 765-kV line such as PATH be placed underground?
No transmission line of this length, voltage or capacity has ever been placed underground, nor has the technology been commercially developed at this voltage level. Even if the technology was available, the project cost would increase dramatically — as much as 10 to 20 times or more — and the time to complete the project would increase substantially.

Prolonged outages are required to repair underground cable failures, and this could jeopardize the reliability of our power system. The environmental impact of undergrounding is significant — underground cables require massive excavation that could severely impact streams, wetlands and other sensitive areas. Multiple above-ground stations would be required along the line route, with permanent access required along the full length of the line for maintenance and repairs.

Transmission is typically placed underground for relatively short distances, and only when an overhead option is not feasible. AEP and Allegheny have and will continue to put transmission lines underground when appropriate.

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24. Why don’t you just re-conductor some of the existing transmission lines using this technology?
Due to ongoing contraints on the grid, the lengthy outages required to re-conductor existing lines in the PJM region cannot be undertaken. Building PATH will help to relieve these constraints and permit future upgrades, such as the re-conductoring of existing lines.

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