ability to safely install facilities using a trenchless technology
allows for minimal impact on established properties.”
Construction is being done by five contractors assigned to
seven geographic areas throughout the Virginia service territory.
“Each contractor provides design, right-of-way and
construction services,” Bradshaw said. “So, while they are
installing new underground facilities, they are also securing easements and completing designs for future work. They
build their own backlog and in many ways are responsible
for their own success. We have been very pleased with our
According to postconstruction surveys, Dominion Energy customers are “very” satisfied with the underground program,
scoring more than 4. 5 out of 5.
“We make it a priority to communicate regularly with
customers impacted when securing easements for new underground facilities, to review construction schedules, safety,
and landscaping once a project is complete,” Bradshaw said.
“We use a variety of communication mediums including letters, postcards, telephone calls and door hangers. We have
also created a portfolio of reference pieces on topics such
as easements, meter base conversions and how directional
boring mitigates impact to tree roots. On larger projects, we
host community informational meetings to review proposed
layouts and discuss project schedules. We have had an overwhelmingly positive response to easement requests, which is
critical to the completion of any project.
“Because we rely so heavily on vendors to help us with the
program, we are very conscientious about sharing feedback
with our contractors and hold them to the same standards we
hold our own employees,” he said.
These results have been promising in other ways, as well.
“As expected, tap lines that have been converted have seen
significant improvement in their reliability going from an
annual SAIDI of 372 minutes prior to underground conversion to less than two minutes after conversion,” Bradshaw said.
As the conversions continue, Bradshaw believes there will
be a small reduction in the number of customers that actually
experience an outage during these events as a result of the Strategic Underground Program.
“We will have a slight decrease in the number of customers impacted and a significant reduction in the number of work
repair locations, and we expect our traditional restoration curve
will look a lot different as we complete the program,” he said.
Subject to continued annual regulatory approvals, it is anticipated the Strategic Underground Program will take 10–12 years
to complete 4,000 miles of underground conversions.
Undergrounding in Oklahoma
Public Service Company of Oklahoma (PSO) has been converting selected areas from overhead to underground since the
early 2000s. Following an ice storm in late 2007 that caused
widespread outages, a program was initiated that ultimately
converted service laterals in 30 neighborhoods—mostly in the
Tulsa area—from aerial to underground.
“Most laterals were in backlots with heavy tree growth,
and limited accessibility limitations were replaced with front-lot laterals,” said Stan Whiteford, corporate communications
The conversions left feeder lines on poles and replaced
back-lot aerial laterals and service lines with new underground
cable at the front of the property. Most underground cable was
buried primarily by HDD, which limits the amount of excavation required and reduces surface restoration needed after
cable is in the ground.
The program was successful in reducing weather-related
outages. PSO has since shifted focus from targeting neighborhoods to employ undergrounding when it is determined to be
necessary to address outages or where their are voltage and
“We’ve shifted focus now and employ undergrounding
determined to be necessary to address voltage or capacity
issues where underground is determined to be the best alter-
native,” Whiteford said. “A good example is a project started last
year for upgrading circuit capacity in a well-established neigh-
borhood from 4 [kilovolts] to 13 [kilovolts]. In this instance, it
made sense to abandon backyard services to replace with front
yard laterals underground.”
When backyard laterals are replaced, typically a 2-by-2-by-
3-foot, pad-mount transformer is placed every three or four
houses. Services to each house are directionally drilled. RF
meters previously were replaced with smart meters.
“Aesthetics are important, but the focus on undergrounding
today is improving service,” Whiteford said.
GRI FFI N, a construction and tools writer from Oklahoma City, can
be reached at email@example.com. P H
A Dominion Energy employee explains the conversion of power lines from
aerial to underground to property owners in affected areas.