St. Paul Regional Water Services officials lifted their boil water advisory for affected areas in Maplewood and St. Paul on Tuesday after test results showed that the water is safe.

Racquel Vaske, assistant general manager of the utility, said the boil order had involved about 1,900 water service lines. She said she doesn't know how many people were affected.

"Anybody who did drink the water the last few days has nothing to worry about," she said.

The advisory was issued at 8:40 p.m. Sunday after a loss of pressure at the St. Paul Regional Water Service's Ferndale tank in Maplewood. When pressure is lost and water sits in a tank, there is a chance bacteria could enter the system, Vaske said.

The pressure issue was caused by faulty communication between the tank and the water service's monitors, Vaske said. The communication system mistakenly showed the tank was full when it wasn't, preventing fresh water from entering the tank. The faulty communication system has been replaced, she said.

"We're doing a thorough analysis of all these assets to determine how this communication error happened," Vaske said.

The lifting of the advisory was done in consultation and with the approval of the Minnesota Department of Health, officials said in a news release Tuesday morning.

The advisory, which asked residents of Maplewood and several St. Paul neighborhoods to boil water for at least three minutes before consuming, was a precautionary step after the tank lost pressure briefly Sunday.

The notice is posted at stpaul.gov/water. Anyone with additional questions can call the Water Service's customer service department at 651-266-6350.