Area fire and police departments have implemented backup plans in the event that 911 emergency phone centers lose service during Hurricane Sandy, officials said.

No problems had been reported by Monday afternoon, but law enforcement authorities — eager to avoid a repeat of the system’s failure recently during the violent thunderstorm complex known as the derecho — warned that could change as wind and rain worsen.

Throughout Virginia, 25 emergency 911 call centers lost critical services during the June 29 storm, according to state regulators. Outages in Northern Virginia alone affected 2.3 million people.

If D.C. residents face any problems reaching 911 in an emergency, they can call 202-265-9100, according to the Office of Unified Communications. City officials said residents may also contact their nearest police and fire units; many will be on the street to assist in emergency situations.

On-call staff members are available for walk-in emergencies at each firehouse in Arlington County, Fire Department spokesman Lt. Gregg Karl said.

Alexandria County residents are advised to call the non-
emergency number at 703-746-4444, and those in the city of Alexandria can call 703-746-HELP. Communications director Ray Allen said residents can also go to fire and police stations in an emergency.

Prince William County police can be reached at their non-
emergency number, 703-792-6500, Officer D.L. Harris said. And Loudoun County residents can reach the Leesburg Police Department by calling 703-771-4500, 571-238-4864 or 571-439-4506.

Prince George’s County police spokesman Edward Martin said residents can call 301-279-8000 or the 311 non-emergency phone system if 911 is not available. People can also contact police via Twitter at @pgpdnews.

Montgomery County fire officials said they have a Verizon technician on site if communication problems arise. Montgomery County 311 can be reached at 240-777-0311 and will be open throughout the storm.