Mactaquac's new system to stop oil spills isn't working, report says

A new system meant to contain oil spills within the Mactaquac Generating Station and out of the St. John River has not been as effective as NB Power expected, according to an environmental contingency report from the utility.

The report was filed after the most recent spill at hydroelectric plant on July 21, which released up to 38 litres of lubricant oil for the turbines into the river upstream from Fredericton.

The document, which was obtained by CBC News through the Right to Information Act, states the new system was installed after a larger spill in 2015.

• NB Power malfunction causes oil spill at Mactaquac dam
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• Mactaquac spills 3,000 litres of non-hazardous oil into river

The incident released about 2,650 litres of Teresso 46 lubricating oil into the St. John River.

NB Power says the oil is non-hazardous and biodegradable, but LizHendriks, vice president of fresh water at the World Wildlife fund, emphasizes that spills of relatively innocuousmaterialscan have a harmful impact on the water system overall.

"Maybe alone that [material] is fine, but cumulatively what's happening ... we're not telling the story on."

Henricks points out the pollutionlevel for the St. John level is rated as very high, according to the WWF'swatershed report.

4 spills, 2 suspected releases

Oil used as a lubricant for Mactaquac'sturbineshas been released into the St. John River four times since 2014, while it's suspected two other incidents also released oil into the river, according to NB Power contingency reports obtained by CBC News.

There were two other spills that were contained in the plant over the past two years.

"It shouldn't be a surprise that these leaks happen. I think they happen far more frequently than Canadians recognize," said Hendriks.

The largest spill happened in April 2014 when nearly 3,000 litres of oilTeresso 32 lubricating oil was released into the river.

NB Power makes changes

In the July report, NB Power saidit's workingon changes at the Mactaquac generating station to reduce oil spills into the river, including steps to "better seal oil containment dykes within the station."

Deborah Nobes, a NB Powerspokesperson, said in an email statementthe Crown corporationis "currently working with an engineering firm to install a more permanent solution to protect the turbines from future leaks and the river from accidental spills."

"This will involve reinforcing the existing systems to reduce the risk of spills, installing an oil/water separator to reduce the risk of oil seeping into the river and installing improved data monitoring and alarms to ensure rapid response to incidents when and if they occur in the future," she said.

The generating station is expected to reach the end of its service life prematurely in 2030 because of the expansion of its concrete structures.

NB Powerhas been exploring three end-of-life options, which includebuildinga new generating station on the opposite site of the St. John River, leaving the dam in place without power generation, orremoving the dam and generation station and allowing the river to return to its natural state.