Mt. Storm - Doubs 500kV Rebuild Project

Mount Storm - Doubs ProjectDominion's Mt. Storm to Doubs 500 kilovolt (kV) transmission line is a critical component of the electric grid that serves West Virginia, Virginia, and Maryland. This line was built in 1966 and after more than four decades of operation the structures and equipment are approaching the end of their expected service life and require replacement to maintain reliability. Dominion has been addressing maintenance issues on this line for more than 15 years and must now completely rebuild it.

Dominion's Mt. Storm-Doubs (MSD) rebuild project will replace the aging lattice steel structures you see today with new ones located entirely within the existing right-of-way. In other words, Dominion does not need to acquire additional land from property owners in order to rebuild the existing line. The rebuild project has been approved by the Virginia State Corporation Commission and West Virginia Public Utility Commission.

PLEASE NOTE: Dominion is NOT involved in the former PATH project in West Virginia, Virginia and Maryland. Dominion's rebuild of its Mt. Storm to Doubs line is entirely separate from PATH.

Project Details

Construction Update

As of mid-February, construction is still proceeding ahead of schedule, despite challenging weather conditions. All structure foundations are complete. Approximately 91% of the structures have been erected and more than 77% of the line is complete at this time. Rehab work is 69% complete and will be done by the end of the year.
Active construction is currently underway in Jefferson County, West Virginia. Construction activities including tower erection, new wire installation/pulling, removal of old structures and occasional implosive splicing. Restoration of the corridor will continue through 2014. There also is some remedial rehab work going on in Loudoun County. Final rehab will happen when the weather warms up.


Crews are working in Loudoun County, VA and will move westward through Jefferson Co., WV, Clark Co., VA, and Frederick Co., VA. Construction activities, including tower erection, new wire installation/pulling, removal of old structures, occasional implosive splicing, and restoration of the corridor will continue through 2014.

Implosive splicing is a safe and reliable technique utilizing a sleeve containing a small, engineered implosive charge that is wrapped around another specifically-designed metallic sleeve. Upon detonation, the charge creates an implosive compression, seamlessly joining the two conductor (wire) ends. The split-second detonation creates a loud "boom" that may be heard in the vicinity of the work.

The sound can travel further depending on atmospheric conditions. Dominion and our contractors will contact property owners in the immediate vicinity of implosive splicing work and contact local law enforcement and 911 call centers prior to causing noise disturbances.

West Virginia -- On December 16, 2010, Dominion received an order from the WV Public Service Commission confirming that its approval is not required for Dominion to proceed with rebuilding 66 miles of the 100 mile line that are located in WV.

Virginia -- Dominion received a final order from the Virginia SCC on September 1, 2011. Construction activities began in 2012.

The 96-mile project involves the replacement of over 450 existing electric transmission structures between Mt. Storm Substation in West Virginia and the Potomac River/Maryland border.

The existing transmission structures are numbered 1-458, and the structure spans for each of the six counties crossed by the rebuild project are shown below.


Construction Update – January 2014

The line is being rebuilt in three phases; please refer to our construction phases map. Details of the work completed and the counties crossed by each phase are summarized below. Please note, some work continues at a few structure locations within "completed" spans. All dates are estimates and could change based on weather and other factors.


Thank you for your patience as we continue to enhance reliable electric service in the region. Please maintain your distance from construction sites and transmission easements for your protection and to allow crews to work safely.

Project Overview

Remove existing structures and rebuild 96.4 miles of new 500kV line between Mt. Storm Substation and the Potomac River/Maryland border. Rebuilding this line now will:

  • NOT require new right-of-way 
  • Replace aging infrastructure prior to equipment failure
  • Take advantage of a window of opportunity to allow the Mt. Storm to Doubs line to be rebuilt during off-peak periods without disrupting power service to customers
  • Replace structures at, or very near, the current locations with slightly taller structures (See structure diagram)
Route Maps

West Virginia County Maps

Virginia County Maps

General MapClick to enlarge this map.
Route Details

The Mt. Storm to Doubs line is 99.26 miles long. Dominion's portion totals 96.4 miles; 65.7 miles in West Virginia and 30.7 miles in Virginia. Allegheny Energy owns and operates 2.86 miles in Maryland. (See the Route Maps tab for further details.)

West Virginia: Owned and operated by Dominion  
Grant County, WV 15 miles
Hardy County, WV 15 miles
Hampshire County, WV 20 miles
Jefferson County, WV 15 miles
  65.7 miles total
Virginia: Owned and operated by Dominion  
Frederick County, VA 20 miles
Clarke County, VA Less than 1 mile
Loudoun County, VA  10 miles
  30.7 miles total
Maryland: Owned and operated by Allegheny Energy  
Frederick County, MD 2.86 miles total
Project Need

The structures, wires, insulators, and other equipment on this 44-year-old line are nearing the end of their useful life, and must be replaced. Inherent corrosion problems have led to continuous deterioration of all components of the Corten steel structures, raising the risk of premature failure. Conductor splices and porcelain insulators are also at the end of their service lives.

Taking proactive steps now to replace the aging equipment before it fails will ensure greater reliability for our customers and the regional system.

Project Benefits
  • Reduces the risk of a major failure of the high-voltage network
  • Improves local and regional electric reliability
  • Increases capacity of the line by approximately 66% (from approx. 2,600 MVA to 4,325 MVA; see below for explanation)
Proposed Timeline
  • Fall 2010 -- Outreach to stakeholders and regulatory entities for necessary approvals
  • Spring 2011 -- Initiate construction activities in West Virginia
  • Fall 2011 -- Initiate construction activities in Virginia
  • December 2014 -- Energize rebuilt line
Regulatory Approval Process

On December 1, 2010, the PJM Board authorized the rebuild of the Mt. Storm to Doubs line as part of PJM's 15-year Regional Transmission Expansion Plan. The line crosses three states, see below for further information.

  • VIRGINIA: The State Corporation Commission (SCC) is responsible for determining the need, route and environmental impact of transmission lines at 138 kV and above in Virginia. Dominion submitted an application with the SCC on January 18, 2011 for authority to construct the rebuild. The application and further information will be made available to the public on the SCC Docket Search section of the SCC web site, in the "Search Cases", case number PUE-2011-00003. In addition, interested parties may also comment directly to the SCC by sending an email to

    Update: May 17, 2011 - Staff Report - "Based on the Staff's field inspection and review of the information submitted by the Company, including the Quanta Technology report, the Staff concludes that the Company has sufficiently demonstrated the deteriorated condition of and resulting need for the proposed rebuild of the Mt. Storm-Doubs 500 kV transmission line. Accordingly, the Staff recommends that the Commission issue the necessary certificates of public convenience and necessity for the Project."

    Update: July 19, 2011 – Hearing Examiner’s Report Recommends Mt. Storm – Doubs Transmission Line Approval: SCC Hearing Examiner Ann Berkebile on July 19 stated in her Report that DVP’s application to rebuild the Mt. Storm – Doubs transmission line is justified by the public convenience and necessity, and the SCC should issue a Certificate of Public Convenience and Necessity (CPCN) authorizing the construction and operation of the proposed project. She noted the evidence in the proceeding demonstrates that the condition of the existing line has deteriorated significantly, and the respondents in the proceeding did not contest the need for the project. Moreover, because the project will be constructed along the same route as the existing line, Berkebile found that the route of the project will minimize adverse impact.

    Update: September 1, 2011 - SCC Approves Mt. Storm- Doubs Transmission Rebuild Project: SCC issued Final Order. The SCC found Dominion’s application to construct and operate the proposed 500 kV Mt. Storm – Doubs transmission line is justified and a certificate of public convenience and necessity (CPCN) should be issued authorizing the construction and operation of the proposed project. The SCC ordered the transmission line shall be constructed and in service by July 1, 2015.
  • WEST VIRGINIA: Dominion consulted with the Staff of the Public Service Commission of West Virginia regarding the requirements of their regulatory laws. On December 16, 2010 the Public Service Commission of West Virginia concluded that Dominion's planned replacement of the existing facilities does not require a Certificate of Convenience and Necessity because it is an ordinary extension of an existing system in the usual course of business. Accordingly, Dominion is moving forward with pre-construction activities in West Virginia.
  • MARYLAND: Allegheny Energy owns the short section of this line located in Maryland and would need to work with the Maryland Public Service Commission to secure the needed approval in that state.
Contact Us

Contact us if you have questions or concerns about the Mt. Storm - Doubs 500kV Rebuild Project.

Questions and Answers

Will Dominion require additional right-of-way?

No, the proposed transmission line will be constructed within the existing right-of-way.

How will the completion of this project benefit me as a resident?

Due to the interconnected nature of the electric transmission grid, all power users in the area rely on Dominion's transmission infrastructure to deliver reliable power. When the Mt. Storm to Doubs 500kV line is rebuilt it will provide greater reliability of service and increase operational flexibility. As an area resident, the project decreases the likelihood of outages, and potentially shortens durations should an outage occur.

Please explain the projected 66% increase in capacity of the Mt. Storm-Doubs rebuild project.

Once rebuilt, the Mt. Storm to Doubs line voltage will remain 500 kilovolt (kV) as it is today. Rebuilding the Mt. Storm - Doubs line with modern equipment will increase the capacity of the line by approximately 66%, from 2,600 MVA to 4,325 MVA.

Here's an analogy to explain this. Consider voltage like a pump that pushes water through a pipe. The diameter of the pipe determines the amount of water, or the capacity, that can be pushed through. For this line, we are keeping the "pump" (meaning the voltage) the same but increasing the diameter of the "pipe" (capacity) with modern construction materials to allow more power to flow.

Explain what "MVA" means.

Almost all bulk electric power in the United States is generated, transported and consumed in an alternating current (AC) network. Elements of AC systems produce and consume two kinds of power: real power (measured in watts or MW) and reactive power (measured in volt-amperes reactive, or MVAR). Real power accomplishes useful work (e.g., running motors and lighting lamps). Reactive power supports the voltages that must be controlled for system reliability. Total or apparent power is a combination of both MW and MVAR (measured in MVA). When talking about transmission capacity, it is referred to as MVA or total line capability for transporting the total power.

What is the electric transmission grid and how does it serve local customers and electric cooperatives?

The electric grid is the network of power lines that carry electricity from power plants to residential, industrial and commercial customers. To work effectively, electricity must at all times flow safely and reliably throughout the grid so the power is available when needed. Aging infrastructure, combined with a rise in electricity consumption, has forced experts to critically examine the status and health of the nation's electrical systems.

A ten-part series of stories from National Public Radio has been published on, examining the costs, the politics and other challenges of upgrading the country's electricity grid. Learn how the electric grid operates and how power gets to your house.

What is the cost of the Mt. Storm-Doubs rebuild project?

Preliminary estimates are $300 million to $350 million for Dominion's portion of the rebuild. The Allegheny Energy portion in Maryland is estimated at $20 million.

When did Dominion first consider rebuilding this line?

Dominion planners identified the need to rebuild the Mt. Storm to Doubs line several years ago, and discussed the deteriorated condition of the facilities during 2008 hearings on the Meadow Brook to Loudoun line (aka TrAIL). During the 2010 PJM Regional Transmission Expansion Plan (RTEP) process, this project to rebuild the Mt. Storm to Doubs line was presented based on the need to replace aging infrastructure. The project was approved by the PJM planning team and will be submitted to the PJM Board in December 2010 for final approval as an operational performance upgrade.

PJM has noted the critical importance of this line to the transmission system. It has said that the heavy electrical load carried by this line make it a challenge to take out of service long enough to complete a rebuild. However, in 2011, new lines will be energized in the region, providing a window of opportunity for Dominion to temporarily take the Mt. Storm to Doubs line out of service and upgrade the wires and equipment.

Why do the new structures have to be taller?

Currently, this line is composed of 458 lattice towers -- 202 are self-supporting and 256 are anchored with angled wires that are secured into the ground (guyed). The average height of existing towers is 100 feet. The line can be rebuilt within the existing 150 - 160 feet wide right-of-way with new towers that will average 122' in height. 

PLEASE NOTE: Previously, Dominion estimated the rebuilt Mt. Storm to Doubs line structures would average 130 feet in height. Now that engineering for the new line is complete, we have determined the average overall height of the new structures will be 122 feet. The average height of the structures in Virginia is 114 feet and the average in West Virginia 126 feet.

Dominion's Transmission Engineering Group determines structure locations and structure types for high-voltage transmission lines based on a wide variety of data and factors including, but not limited to, National Electrical Safety Code (NESC) clearance requirements, terrain, line sag between towers, voltage levels, equipment needs, route design, land use, and natural or manmade obstacles. The new structures will be self-supporting galvanized lattice steel towers. Use of modern materials, compliance with NESC clearance requirements, and application of good utility engineering practices require the new towers to be taller structures with wider bases; see structure diagram.

What will the new structures be made from and how does it differ from the materials used in the old structures?

The lattice towers on the existing line were made of a high strength low alloy material introduced in the 1960s called weathering steel (Corten). Weathering steel is designed to create an iron oxide patina that is supposed to protect the steel such that no other surface coating is required, thus reducing maintenance costs. Patinas have a dark brown uniform appearance that blends into the natural background. Corten was advertised as a superior product designed for longevity requiring less maintenance (no painting) over its projected 60-year life. Over the years however, Corten steel has proven to be anything but maintenance free. It has been found to have inherent corrosion problems that continuously deteriorate the steel members in lattice type towers. The new towers proposed are made of galvanized steel to better withstand the weather and conditions of the terrain and to ensure longevity with decreased need for costly maintenance.

Will the rebuild of Mt. Storm to Doubs result in an increase in its capacity?

Yes, modern conductors with higher transfer capacity will be utilized, and the rebuild will maximize line capacity by assuring adequate ground clearances. The potential capacity of the rebuilt line will be increased by 66%, which would be a major benefit to the reliability and efficiency of the electric grid.

What will be the environmental impact of construction of the line?

This project replaces existing infrastructure within an existing transmission corridor. As part of our regulatory applications, Dominion completes an evaluation of potential environmental, cultural, and historical impacts of the project. Dominion works with many local and state agencies to complete these evaluations and mitigate any impacts. The company also submits annual Erosion and Sedimentation (E&S) Control Specifications for the construction and maintenance of transmission lines to the Virginia Department of Conservation and Recreation for review and approval. For each project, our contractors receive copies of the E&S plans and specifications and any additional permit conditions prior to construction and are directed to meet any requirements. The right-of-way will be rehabilitated when construction is complete.

Should I be concerned about Electric and Magnetic Fields?

Dominion is sensitive to public concern about possible health effects from exposure to electric and magnetic fields (EMF). Dominion includes data on the levels of both electric and magnetic fields produced by proposed facilities in all applications submitted with the SCC. We continually monitor EMF research and speak to our customers and employees regularly to share the latest information available.

The Virginia SCC, which regulates the construction and operation of electric transmission lines of 138kV and above, considers EMF in every application. Hearing Examiner’s remarks from recent proceedings are below.

  • March 23, 2009 Beaumeade-NIVO (Case Number PUE-2008-00063) Report of Michael D. Thomas, Hearing Examiner concludes that "… electric transmission line electromagnetic fields do not represent a human health hazard."
  • May 4, 2010 Hayes-Yorktown (Case Number PUE-2009-00049) Report of Deborah V. Ellenberg, Chief Hearing Examiner, states, "I find that EMF has not been identified as a carcinogen for human beings despite extensive study over many years, and there is, therefore, no basis on which to prohibit the Company from authorizing appropriate uses of its right-of-way."
  • August 23, 2011 Hollymead (Case Number PUE-2011-00015) Report of Michael D. Thomas, Hearing Examiner, states, "The proposed facilities do not represent a hazard to human health, which finding is consistent with the Virginia Department of Health’s report entitled Monitoring of Ongoing Research on the Health Effects of High Voltage Transmission Lines (Final Report) dated October 31, 2000."

The Virginia Department of Health in its final report evaluating EMF research concluded:

"Based on the review and analysis of the exhaustive literature review and other research projects completed under the EMF-RAPID program, the Virginia Department of Health is of the opinion that there is no conclusive and convincing evidence that exposure to extremely low frequency EMF emanated from nearby high voltage transmission lines is causally associated with an increased incidence of cancer or other detrimental health effects in humans. Even if it is assumed that there is an increased risk of cancer as implied in some epidemiologic studies, the empirical relative risk appears to be fairly small in magnitude and the observed association appears to be tenuous. The studies published in the literature lack clear demonstration of a cause and effect relationship as well as a definitive dose-response gradient."

Additional information:

Will Dominion repair damage due to construction?

Yes. Our easement agreements allow us access to private roads of property owners crossed by the right-of-way. The company, at its expense, will repair any private roads damaged by Dominion or its contractors during construction of the line or during future maintenance. In addition, we will reimburse property owners for crop damage, and repair or replace fences or gates if we damage them.

NYSE : (April 24, 2014) D 71.55 0.49