About 2,000 of the utility’s customers were without power early Monday, down from more than 5,000 on Sunday night.
Dominion will get assistance from 2,000 crews that are arriving in Virginia to help with the anticipated outages.
Spokeswoman Alison Kaufmann tells WWBT-TV that the three-day window of the storm will make it difficult for crews to restore power until the winds have passed.
If the outages reach 1 million, Kaufmann says Sandy would likely be one of the worst storms on record as far as leaving people in the dark. About the same number of customers were without power after Hurricane Irene last year.