HALIFAX -- The Nova Scotia government says recent tests at a pulp mill near Pictou show pollution emissions above acceptable limits.

The Environment Department has issued a statement saying it has handed a directive to Northern Pulp.

The directive says the company must complete an independent engineering assessment of its power boiler system by Nov. 30.

The department says the evaluation must include recommendations for modifications needed to lower emissions.

According to stack test results conducted in September by Stantec Consulting Ltd., the boiler's emissions remain above acceptable limits.

Northern Pulp Nova Scotia Corporation (NPNS) says it has already completed the commissioning of the company's new $35 million electrostatic precipitator.

The company also says in an email that it is committed to "resolving the issue of power boiler emissions."

It says preliminary findings show there's too much combustion air within the power boiler furnace, causing increased particulates.

The email from spokeswoman Kathy Cloutier says as the excess air is removed, particulate levels are expected to fall below the regulated limits.

Cloutier also says that bark size can increase particulate size, and the company is planning to study the issue.