Utility workers in eastern Maine worked throughout the day on Monday to repair downed power lines following weekend storms spawned by tropical storm Arthur.

But it could be as late as Wednesday night before some customers in Washington and Hancock counties have their electrical power restored.

Susan Faloon, a spokeswoman for Emera Maine – formerly Bangor Hydro Electric Co. – said late Monday that about 1,500 customers were still without power.

Faloon said the final outages from a storm are the most challenging because they are typically those homes with only a few customers on a circuit. That means that power restoration effort can be extremely slow, with only a few customers’ power being restored at a time.

Emera Maine reported that 2,970 customers were without power at 11 a.m. Monday in Washington County, the hardest-hit region in its service area. That number had dropped to just over 1,400 late Monday.

Faloon said helicopters were in the air throughout the day Monday surveying the damage. Pilots relayed that information to ground repair crews.

“With the storm tracking farther west and hitting harder and in more counties than expected, damage has been widespread and severe,” Faloon said in a statement.

Faloon said Monday night that power has been restored to 33,000 customers since Arthur hit Maine late Friday night.

Repair work has been slowed in areas where roads were impassable and because of the extent of damage, which included snapped utility poles and trees that had fallen on power lines.

The Emera Maine outages were concentrated in Washington, Hancock and central Aroostook counties. Only 71 customers in Aroostook County were without power Monday night.

Maine’s neighbor to the north was also suffering from the powerful storm.

Central Maine Power Co. crews were headed to Canada, where electricity customers have been experiencing “the largest blackout in New Brunswick history,” according to officials with New Brunswick Power.

CMP spokeswoman Gail Rice said that 19 two-person CMP crews along with support equipment have been dispatched to the Frederickton, New Brunswick, area to help restore power there.

Rice said the crews could be in Canada for up to five days.