ABERCROMBIE POINT, N.S. -- A Nova Scotia paper mill shut down operations Tuesday after it discovered wastewater was leaking from a pipe into surrounding wetlands and a river, said the province's environment minister.

Randy Delorey said Northern Pulp in Abercrombie Point contacted his department Tuesday to notify it about the leak.

He said it's not clear how much effluent, some of which went into the East River, leaked from the pipe.

"It appears there was ... a break or a leak in the pipe that transfers the effluent from the mill to the treatment facility," Delorey said in an interview.

He said a third party is conducting tests to evaluate the effect, if any, on the environment. Any remediation plans would be determined after those results are known.

The effluent contains some naturally occurring substances, he added.

Delorey said his department was not taking the leak lightly, regardless of its effect on the environment.

"It's serious in terms of the fact that it occurred at all," he said.

Northern Pulp could not be reached for comment.

The mill shut down operations for about two weeks in 2008 and laid off about 180 workers after a leak was discovered in a pipe leading to Boat Harbour. A more serious break was discovered while the pipe was being examined.

Delorey could not say how long the latest shutdown would last.