AUBURN – Water district crews were putting a temporary pump in place Thursday after a ruptured line supplying New Auburn dropped pressure to about 600 customers.

Water district officials noticed a sudden drop in water pressure in New Auburn just after midnight Thursday. The leak was traced to a 12-inch water main installed under water across the Little Androscoggin River.

New Auburn water customers are also served by an eight-inch water main and by the water tower off Ipswich Street, so those customers did have water service, according to Norm Lamie, Water District superintendent.

“But pressure was the big concern, because it was very low,” Lamie said. Crews were putting an emergency water pump in place Thursday afternoon to boost pressure.

“By supper time, the water pressure should be back to normal,” Lamie said.

The broken line is underwater, and Lamie said crews were trying to isolate it with inflatable dams to make repairs. Crews have been working to install a new 24-inch main nearby, but Lamie didn’t know if that work was to blame for the rupture.

“What we know is that crews were working adjacent to the line break, about 100 feet away,” he said. Work on the 24-inch main has stopped, however, while crews repair the 12-inch main.

When it’s finished, the 24-inch main will replace the eight-inch main, which is 100 years old.

“What’s interesting is that the oldest pipe there is supplying most of the water to New Auburn right now,” Lamie said.

Final repairs to the 12-inch main should be finished by Friday, and it should be back in service on Saturday. They’ll continue working on the new 24-inch water line next week.