Dominion'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.
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.
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:
West Virginia County Maps
Virginia County Maps
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|
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.
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.
Contact us if you have questions or concerns about the Mt. Storm - Doubs 500kV Rebuild Project.
No, the proposed transmission line will be constructed within the existing right-of-way.
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.
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.
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.
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 NPR.org, 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.
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.
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.
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.
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.
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.
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.
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.
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."
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.