It's safe to drink your tap water again.

The city of Ann Arbor's "boil water" advisory for the northeast side of town has been lifted, city officials announced shortly after 3 p.m. Friday.

Test results have confirmed there is no bacteriological contamination and the water is safe to drink, city officials said in a news release.

The city issued a boil water advisory Thursday morning after the water system was depressurized unexpectedly by a city contractor conducting scheduled valve maintenance.

Any time there is a loss of water system pressure, a boil water advisory is issued as a precautionary measure.

Ann Arbor uses its Code Red emergency telephone calling system to notify residents and businesses of an emergency or potential hazard.

The system will call each registered phone number and will leave a voicemail message for residents if the call is not answered. Citizens are encouraged to register for free online.

• Register here

Ryan J. Stanton covers government and politics for AnnArbor.com. Reach him at ryanstanton@annarbor.com or 734-623-2529. You also can follow him on Twitter or subscribe to AnnArbor.com's email newsletters.