HALIFAX -- Nova Scotia's auditor general says the province hasn't sufficiently investigated potential contamination at many old and abandoned mine sites, meaning there could be unknown future hits to the government's finances.

Michael Pickup released a report Tuesday saying the province can't effectively assess its financial exposure related to future remediation projects.

"The cost to clean up contaminated sites could significantly change in the future as the province collects more information on these sites," Pickup told reporters.

He said a weakness in the assessment of abandoned mines by the Department of Lands and Forestry has led his office to conduct a performance audit that is to be released next spring.

Pickup noted that the province's liability for contaminated sites had grown from $107 million in 2014 to $372 million in 2018.

In July, the government announced it was spending $48 million to clean up the former Montague Gold Mines near Dartmouth and Goldenville in Guysborough County; overall, it said it was looking at a list of 69 sites on Crown land in order to determine which ones need to be reclaimed.

In addition to the money for the two mines in 2018, $230 million was allocated for the cleanup of the Northern Pulp holding ponds at Boat Harbour and another $94 million went to other projects.

Pickup said while the province had recorded the costs of those projects properly, the looming problem is the dozens of other sites.

"What about all these other sites that you have that you haven't done an assessment on yet to figure out whether there's contamination?" Pickup said.

Minister of Lands and Forestry Iain Rankin didn't quarrel with the auditor general's assessment, saying the province "can always move faster."

"There are a lot of contaminated sites and there's a lot of remediation that has to take place," said Rankin.

Given that, Rankin said it would likely take "a number of years" before all sites are addressed.

He said currently an additional four abandoned mines -- two gold and two coal -- are identified as priorities for further testing and evaluation, while work continues on an overall assessment strategy with the Department of Energy and Mines.

"We are taking more concrete actions than previous governments," said Rankin. "We need a sophisticated plan."

Another area of concern singled out in Pickup's report is the government's response to dealing with potential fraud risks.

The auditor general said government departments aren't assessing fraud risks fast enough, and the training of staff to detect those risks is lagging.

Pickup said nearly half -- 47 per cent -- of provincial departments hadn't completed fraud risk assessments as of March 31.

The report also found that less than 35 per cent of staff in three government departments and four public service units have completed mandatory fraud training, while the government still hasn't implemented a fraud tip hotline.

"These things are important to do because they help create an atmosphere and environment where you are less likely to have fraud to start with -- and if you do have fraud, you are more likely to detect it," Pickup said.

This report by The Canadian Press was first published Oct. 29, 2019.