NU Transmission | Projects | Agawam-West Springfield

At WMECo, overhead transmission line construction typically, but not always, occurs in the following sequence:

Right-of-Way Clearing

Initially, the right-of-way is cleared of trees and brush to provide the necessary access for construction equipment and a safe work area for crews. Clearing the right-of-way ensures an environment that safely and reliably supports the construction and ongoing operation of the transmission lines. No herbicides are used for clearing during construction.

Although the right-of-way will appear very different after clearing, brush grows back quickly. To meet electric industry vegetation clearance standards, non-compatible species of trees must be permanently removed. These are trees that could become tall enough to grow or fall into the high-voltage transmission lines. You can read more about how WMECo manages vegetation on their rights-of-way.

Work Area Preparation

Construction vehicles must be able to access the location of each structure that will support the transmission lines. Gravel roads approximately 15-20 feet wide are needed for the large equipment used during construction. Large level work areas (generally 100 feet by 100 feet), called crane pads, are needed to stabilize equipment, such as drill rigs and cranes.

Timber mats may be used in or around wetlands to protect these environmentally sensitive areas. Silt fencing and other environmental controls are also used to stabilize the soil and protect wetlands during construction.

With the consent of property owners, gates are placed across new access roads where these intersect with town or state roads. These gates help deter unauthorized access to the right-of-way. By landowner request, gates are also installed where access roads cross agricultural land containing livestock. Access road/work area development averages two to three days on each property.

Distribution Line Relocation

Distribution lines are the lower-voltage power lines that bring electricity to customers� homes. Sometimes these lines are on transmission rights-of-way. During construction, WMECo carefully coordinates the removal of existing lines with the installation of new lines.

Where relocations are required, new distribution poles and wires are first installed in an alternate section of the right-of-way. Once complete, the existing distribution line is de-energized so that power can be transferred to the newly built line. The de-energized lines are then removed so that transmission line construction can continue. The old poles are taken to an off-site location and disposed of properly.

Existing Transmission Structure Removal

WMECo carefully plans the sequence of construction to allow workers to safely construct the new lines while customers continue to receive electrical power.

Existing structures that require removal are de-energized and the overhead wires removed. The wood poles or steel structures are taken off-site and disposed of properly. Concrete foundations are removed below grade and the area is filled.

Structure Foundation Installation

The next step in the construction process is drilling foundations for the new transmission structures. This involves drilling large holes, which are then typically filled with concrete for the steel structure foundation.

Drilling operations occur for a few days at each new structure location using rigs such as that pictured. Once drilling is complete, a steel rebar cage is placed in each hole and concrete is poured to create a secure foundation for the new steel structure. Concrete trucks are used to deliver the concrete mix for the foundations.

Some structures (such as wood pole or H-frames structures) can be placed on a direct-buried foundation where the hole is filled with processed rock, rather than concrete.

New Structure Installation

Once the foundation is cured, transmission structure installation can begin. The new steel poles often come in sections that are assembled on or near the foundation. Cranes and/or bucket trucks are used to lift the poles and set them into position on the foundations.

The structure components are delivered to the right-of-way well in advance of this installation process. Generally, it takes one to three days to assemble and erect each new structure. After installation, the structure is grounded.

Wire Stringing

With the new steel structures in place, the next step is to install the wire (�conductor�). The wire-stringing operation requires equipment at each end of the section being strung. Wire is pulled between these �pulling sites� through stringing blocks (pulleys) at each structure. These pulling sites are set up at various intervals along the right-of-way, typically one to three miles apart. Specific pulling sites are determined close to the time the stringing activity takes place. WMECo notifies property owners about the sites chosen at that time. Once the wire is strung, the stringing blocks are removed and the wire clipped into its final hardware attachment. Helicopters may be used during wire-stringing operations.

Restoration

When construction is complete, disturbed areas will be restored. Native shrubs and ground cover are allowed to regrow. Environmental controls are removed, though some may remain until the area is stabilized.

In areas that were previously landscaped, WMECo works with property owners to restore the area to its pre-construction condition. Before construction is complete, a project representative will visit affected property owners to develop property-specific restoration plans. These plans will require the final approval of both the property owner and WMECo.

Agawam-West Springfield Project - Construction Q&As

General

A: The Agawam-West Springfield project separated two high-voltage circuits that occupied the same towers. By placing each circuit on its own set of structures, the project improves the reliability of the electric system. It does this by reducing the likelihood of both high-voltage circuits being damaged or otherwise being forced out of service at the same time, and the potential impact such an event would have on electrical service in the area.

A: The project spans approximately 2.5 miles through the towns of Agawam and West Springfield, Massachusetts. Construction occurred within the existing overhead right-of-way.

A: The existing transmission structures were removed and replaced with single-circuit, 115-kilovolt (kV) steel structures. The new structures average 110 feet in height, replacing existing structures averaging 90 feet.

On March 13, 2009, WMECo filed petitions with the Massachusetts siting authority. The project received approval from the Massachusetts Department of Public Utilities, with some conditions, on March 19, 2010. These documents are accessible via this Web site.

A: The construction of the 115-kV transmission lines took about a year to complete, from preparation through construction and site restoration. Construction began in summer 2010. The lines were in service by late April 2011. Restoration work is now taking place.

Q: How will we know if workers on or near the right-of-way are associated with your project?

A: All contractors associated with the Agawam-West Springfield Circuit Separation Project are required to carry proper identification. If you have concerns with contractors on the right-of-way during restoration efforts, feel free to contact the project hotline at 1-800-793-2202 or e-mail AWSproject@nu.com.

Stages of construction

A: Click here to learn more about how WMECo constructs overhead transmission lines.

About Vegetation Clearing and Planting

A: The first step in the construction process is clearing rights-of-way of vegetation where needed to provide safe access for construction equipment. This vegetation clearing is limited to areas where construction work and, ultimately, clearances for safe line operation are required. Clearing methods involve cutting trees close to the ground; allowing roots to remain in the ground; and removing lower-growing vegetation. No herbicides are used during the clearing process. You can read more about how WMECo manages vegetation on its rights-of-way at www.NURightsOfWay.com.

Q: Will manicured lawns and landscaped property be restored at the completion of construction?

A: Yes; WMECo will restore previously grassed areas using topsoil and seed. In some areas where visual impacts are greatest, WMECo will replant trees and shrubs with vegetation that is compatible with the future operation and maintenance of its transmission line and in accordance with applicable state law and/or regulatory directive. However, species of trees that threaten the safe operation of the lines will not be re-planted in the right-of-way in order to meet mandatory national electric system reliability standards. You can learn more about planting vegetation on or near rights-of-way at www.NURightsOfWay.com.

A: Power line rights-of-way provide a natural habitat for animals and vegetation, and will quickly revert to a natural, shrubland state following construction.

Once power lines are built and energized, managing the vegetation within transmission rights-of-way becomes an ongoing maintenance activity critical to the safe and reliable operation of our electric system.

Q: What if I want to plant my own trees or shrubs to help screen the transmission structures?

A: You can find a helpful guide to planting in and around transmission rights-of-way at www.NURightsOfWay.com. In particular, we suggest you review the Tree and Shrub Planting Guide, which provides height guidelines and other considerations for planting in this area.

Other Construction-Related Activities

Q: Is my septic system, sprinkler system or invisible dog fence in danger of being damaged by construction?

A: WMECo works with property owners to identify undocumented subsurface items, such as septic systems, sprinkler systems and dog fences, in the right-of-way that could inadvertently be damaged during construction. We are available to meet with property owners to review the locations of any underground facilities and work with them to identify and mark underground facilities within or near the rights-of-way. We encourage property owners to contact us with information on any subsurface items that may be affected during construction. In the event that damages do occur, please call the project hotline at 1-800-793-2202 or e-mail AWSproject@nu.com.

A: With prior approval from the landowner, WMECo will install gates to deter unauthorized access to the right-of-way, particularly where the affected locations are readily accessible to the public, such as public road crossings. Prior to any gate installation, the property owner will need to sign a gate agreement that outlines the policies and maintenance associated with that gate. You can read more about this at NURightsOfWay.com under "Managing Access to Transmission Rights-of-Way."

The files provided below represent the DPU petitions on the Agawam-West Springfield project. The DPU petitions have docket numbers of DPU 09-24 (Zoning Petition) and DPU 09-25 (Section 72 Petition).

The Agawam to West Springfield Circuit Separation Project proposes the separation of two high-voltage circuits that currently occupy the same towers. The project would improve system reliability by placing each circuit on its own set of structures between the Agawam and West Springfield Substations.

Please note that volumes containing photographs are quite large and may take a considerable amount of time to download if you are using a 28K or 56K modem. Hard copies of the petitions are available in the Agawam and West Springfield town halls.