Disston Transmission Line Upgrade

Duke Energy is planning several projects in Pinellas County to upgrade the transmission system to help ensure continued reliability and meet the growing demand for electricity used by homes, businesses and community facilities. One of the projects involves upgrading a 3.5-mile existing underground transmission corridor.

The existing 3.5-mile underground transmission line is in Pinellas County, starting at the Disston Substation at 5192 62nd Ave. N in Pinellas Park and ending at the 40th Street Substation at 4055 13th Ave. N in the Disston Heights community. The line follows a railroad corridor for approximately 1 mile and then turns south along 40th Street for the remaining 2.5 miles. The route for the new transmission line can be viewed at duke-energy.com/Disston.

Pinellas County is experiencing rapid growth and increased energy use. Between 2016 and 2021, the county grew approximately 8% and is the sixth-largest in Florida. Upgrades to the transmission system are needed to help ensure continued reliability throughout the county as it continues to grow.

This project is one of several in the region that are needed to help support the growth in the area and modernize the transmission infrastructure. It will bring the necessary additional capacity and help prevent system overloads.

The Disston Line Upgrade Project is being constructed as an underground line because the underground facilities already exist. Using this existing location for the line upgrade results in the least overall impact on the community. The project avoids the development of a new corridor and the acquisition of new easements. Using the existing underground facility also reduces the impact caused by electrical pole construction and maintains the current visual aesthetics of the neighborhood.

In 2022, crews began several activities related to preconstruction. This will include land and environmental surveying, soil sampling and other related on-site activities. Beginning in early 2024, trees and vegetation, along with other obstructions, will need to be removed to prepare for safe access and construction. The installation of the underground transmission facilities will also begin in 2024. The work will be done in phases over the 3.5-mile route to shorten the duration of the disruption to any specific area. Duke Energy will communicate schedule details to property owners throughout the project.

The installation of underground facilities is challenging and complex. A large portion of the corridor is located within the road right of way along 40th Street North.

During construction, there will be excavation of the corridor/road to allow for the installation of the new line. In busy intersection crossings and other areas where trenches aren’t feasible, an underground boring method (trenchless) will be used. Approximately every half-mile, a maintenance vault measuring approximately 24 feet by 8 feet will be installed in the ground to allow for equipment and the maintenance of the new line.

Following construction, the properties and roadway will be restored as closely as possible to their original conditions.

The Disston Line Upgrade Project is being constructed as an underground line because the underground facilities already exist. Underground transmission lines represent only about 2% of all transmission lines nationwide. Unlike lower-voltage local distribution lines – which are often installed underground – the construction of higher-voltage transmission lines is complex and invasive, requiring significant trenching and the likely removal of much more vegetation compared to overhead line construction. For this reason, along with the significant costs associated with undergrounding, this type of installation is limited to areas where overhead facilities are not possible: city settings with tall buildings, near airports or where the underground infrastructure already exists.

Excavation and installation activities will cause temporary lane and road closures. If there are access issues or other coordination needed, a representative will discuss this with the property owner in advance of conducting the work. We will make every effort to minimize impacts to property owners, businesses and occupants. No power outages are anticipated during the work.

Duke Energy will conduct all activities in a manner that is safe for the public and our crews. Appropriate safety protocols will be followed, and work zones will be clearly marked. It will be important for the public to avoid these work zones and drive slowly in the areas where crews are working.

We do not anticipate the need to acquire any additional easements or land rights and will utilize the existing transmission corridor where the necessary rights already exist.

Yes. Duke Energy uses a number of methods to keep the public up to date on project developments and to allow people to contact us with questions and concerns.