For the second time in a year, Nova Scotia's Northern Pulp has been ordered to stop a high amount of air pollution being emitted from the paper mill, CBC News has learned.

Inspectors said sulphur emissions have exceeded allowable levels.

Over the fall and winter, Northern Pulp tested emissions coming from its plant. The findings were recently passed on to the Nova Scotia Department of Environment.

"Their levels for particulate and total reduced sulphur were in excess of the limits specified in their approval," said regional director Jay Brenton.

On March 8, the department ordered the company to fix the air pollution.

"The directive requires the company to take an engineering study of their recovery boiler system and to choose an option to address the exceedances," said Brenton.

In April 2011, the department ordered the mill to install air pollution equipment, six years after a scrubber ceased to function.

All of this comes after the federal government gave the mill $28 million to improve its environmental performance.

The company claims its reduced odour compounds by 70 per cent.

 Jane Thomson, a vocal critic, doesn’t buy it

"Local residents were being bombarded constantly by this incredible stench," she said.

The province said company consultants will begin work on April 1.

It has until the end of September to comply with the directive.

Northern Pulp did not respond to CBC’s request for an interview.