Herndon — Dominion Power hosted a hurricane drill Wednesday, June 6, simulating the effects of fictional Hurricane Joseph and showing how they would manage such a storm. The Herndon headquarters serves about 900,000 customers.

The simulated Hurricane Joseph left 800,000 customers without power, a number similar to the real Hurricane Irene, which hit the area in 2011. Phillip Sandino, director of customer solutions, said that the customer number, which is used by Dominion, is a different measurement than numbers quoted by places like the governor’s office.

"The governor’s office uses a people without power number, which is a head count," he said. "We use a customer numbers, which is households without power, and we estimate about 2.5 people per home, which is why sometimes the numbers are different depending on where you look."

As power outages become wider, Dominion uses a list of priorities when they start repairs, based on a descending order of customers effected. First they look at the transmission lines, which affect more than 10,000 customers. From there, they work down to substations (which serve around 6,000 customers), main circuits (which serve 1,500), residential lines (which serve around 50 customers), individual transformers (which serve one to eight customers) down to individual households.

FACILITIES LIKE HOSPITALS, water treatment plants and public safety facilities are in the first wave of restorations.

"Our priority list is why at first it seems like the number of customers without power begins to get smaller very early, but takes a while to get everyone back online," Sandino said.

Sandino also said it was very important for customers to report outages, because depending on the damaged equipment and how many people it serves, they might not know about outages.

He also urged anyone to use extreme caution if they should see downed power lines.

"Never, ever approach a power line, even if it’s been down for 10 days," he said. "The smartest thing to do in that situation is to always assume that there’s power running through it."

Dominion does not start repairs until the storm or other event is over and the roads are clear, though trucks are often dispatched to gather information about outages.

Deborah Johnson, Dominion’s manager of Regional, State and Local affairs said that they went through all the precautions during the heavy storms on Friday, June 1.

"We didn’t know if it would be a multi-day event, so we sent notices of warning to our contacts, state and local officials who can get the information out via e-mail, Twitter and Facebook," she said.

Lynn Chaffin, director of New Media and Communications Planning, said that customers are increasingly looking at social media for information.

"Social media is mobile, so when the power is out and the laptop batteries are dead, people are using their phones to stay updated," he said. "We try to start posting information two days ahead of a storm and during it we’ll share pictures and other information about damages."

Chaffin added that while social media allows them to get information out, it isn’t particularly helpful to perform account-level services for customers, since most social media information is public, meaning account numbers cannot be used.

DOMINION’S CALL SYSTEM can handle up to 10,000 calls per hour, and Le-Ha Anderson, Media and Community Relations manager, says that the wait time for customers calling about outages comes when people want to report outages to a person, automated reporting works much faster.

More information on Dominion can be found at dom.com, and information is also published on their Facebook, Twitter and YouTube accounts.