City officials in Blaine said Monday night that the city's water system is up and running, and the water is safe to drink.

Test results from the Minnesota Department of Health conclude that there are "no safety or contamination issues with the water," according to an update posted on the city's website just before 11 p.m.

"Residents and businesses may resume using water for normal day-to-day activities," according to the post.

The second disruption to Blaine's city water pressure in two months spurred school closings and a boil water advisory Monday, but city officials said it was unrelated to a similar incident in January.

In both cases, systems intended to monitor and react to low levels in the city's water towers did not properly communicate problems. City officials attributed the January disruption to a software error and this weekend's to a power supply failure. That failure occurred Saturday, but it became apparent as water use rose on Sunday night.

"The cause of the communication problem is different," City Administrator Clark Arneson said at a news conference Monday.

He added: "We are working by the minute to ensure that will never happen again."

Cities issue boil water advisories when water pressure drops below a certain level, which could allow bacteria or chemicals to backflow into the system.

Arneson said the city determined the cause of January's software error, but he repeatedly declined to elaborate — citing Minnesota's open records law. He began the news conference with a disclaimer that "the Minnesota Data Practices Act prohibits me from commenting on any personnel matters."

It wasn't an attack on the system, however.

"There was neither criminal intent, nor criminal action, to disrupt water service to the city of Blaine," Arneson said.

The city uses software from Blaine-based In Control Inc. for its monitoring system. It has replaced the power supply and Arneson said the city will add sensors on separate systems to avoid future problems.

"We are doing a complete scrub on our system," Arneson said. "It hasn't happened before. These are independent issues. We have a very safe water system."