Hundreds of licensed practical nurses who work in the Halifax area are set to get payments that could be as much as $36,000 each in a retroactive pay boost.

The LPNs have received an award ordered by an independent arbitrator after their union, the Nova Scotia Government and General Employees Union (NSGEU), argued they were doing work above their pay grade and their work deserved to be reclassified.

"They're elated," said union president Jason MacLean.

"They're very happy, very pleased, they feel vindicated that they thought there was an issue there and obviously we've all agreed there was an issue."

The award was mutually arrived at by the employer and employees. It's expected to cost the Nova Scotia Health Authority about $17 million this year.

The pay increase is 12 per cent for all LPNs who were members of the NSGEU and worked for the former Capital District Health Authority, which was one of nine health authorities that merged into the Nova Scotia Health Authority in 2015.

The increase is retroactive from March 17, 2014, which was the date when the NSGEU first formalized the complaint. It applies to 386 full-time equivalent positions at the health authority.

The Nova Scotia Health Authority says since some workers are part-time, retired, or have moved on from nursing, the total number of people who will be eligible is more than 500.

Payment amounts will vary.

"It all depends on how long they were in the position and if they were there all six years," said Joanne Stone, the NSHA's senior director of human resources.

MacLean said some examples of LPN responsibilities that have evolved over time include supervisory authority over care team assistants, running immunization clinics, transferring health information between services, administering medication by IV, and transfusing blood and blood products.

"They didn't do that prior to 2012 or 2009, but they were doing all this stuff and that's what triggered us to approach the employer about the change in their duties," he said.

The retroactive payment is expected to work out to a pay increase of roughly $3 per hour.

The increase does not apply to LPNs who are members of different unions or worked for health authorities other than the Capital District Health Authority.

Stone said the NSHA made the announcement on Monday and has not had an opportunity to discuss it with the Nova Scotia Nurses' Union, CUPE and Unifor, which also have LPNs as members. There are about 2,000 LPNs working for the Nova Scotia Health Authority.

Stone said the NSHA would follow processes laid out in the collective agreement for nurses, which expires on Oct. 31, and the pay plans will be reviewed as part of the upcoming bargaining process.