Supply chain disruptions brought on by this week's railway work stoppages could give rise to new boil water advisories across Canada, a chemicals industry spokesperson says.

Following the breakdown of union negotiations this week, more than 9,000 Canadian train engineers, conductors and yard workers have been locked out of their jobs as of Thursday morning by the country's two largest rail companies.

And as the day's roughly one-billion dollars' worth of commercial freight grinds to a halt and thousands of workers in Toronto, Montreal and Vancouver find their morning commute cancelled, even more serious impacts could be on the horizon -- including safety of local tap water.

"The impacts on municipalities' ability to provide clean drinking water [to] Canadians started last week," said Greg Moffatt, executive vice-president of the Chemistry Industry Association of Canada (CIAC), in a Thursday interview with CTV Your Morning. "Ninety-six per cent of Canadians get clean drinking water provided by municipalities, and that's dependent on a functioning chlorine value chain."

Treatment troubles

Local governments rely on chlorine and its derivatives to treat their water, and while Moffatt says a typical water authority keeps between 10 and 14 days' worth of those chemicals on hand, the only way they can transport and replenish those supplies legally is via rail -- supplementing by truck is not an option.

To make matters worse, that two-week timer didn't start Thursday morning, he notes. Because potentially hazardous chemicals like chlorine aren't allowed to sit on the tracks halfway to their destination, those supply chains began drawing down early in anticipation of the lockout, meaning there may only be days left for some before stores begin to run low.

"The clock's ticking before municipalities will have to start issuing boil water advisories," Moffatt said. "It's not 10 to 14 days from this morning, it's 10 to 14 days from a week ago."

Cities braced for shortage

In some parts of the country, municipal officials have taken steps to shore up their chlorine supplies in hopes of waiting out the stoppage.

In an emailed statement, a Metro Vancouver official told CTV News that they had been working in recent days to secure additional sodium hypochlorite, a chlorine treatment product, in case the flow of shipments ground to a halt.

"[Our] supplier is confident that it will be able to source sodium hypochlorite from its plants outside the region,” wrote Goran Oljaca, director of engineering and construction, in an email.

“Metro Vancouver is also working with an alternate sodium hypochlorite supplier to provide smaller loads to maximize chemical storage throughout Metro Vancouver’s drinking water treatment and distribution network,” he added.

As of Monday, CTV News reports that Oljaca said he did not "foresee any disruptions" to the water treatment process as a result of a lockout or strike.

But while impacts mount across aspects of Canadian life, CIAC's Moffatt says it's incumbent on the government to help ensure a resolution. 

"The Teamsters' Union has the responsibility to look after their member interests, the railroads have have to look after their shareholder interests, the only stakeholder in all of this that has the responsibility to look after the public interest is the federal government," he said.

"We and others have urged that they refer this to binding arbitration … The federal government needs to act." 

With files from CTV News Vancouver's St. John Alexander