If you live within a few hundred kilometres of the Great Lakes and have strewn rock salt over an ice-encrusted driveway, that salt on your shovel likely came from the Goderich salt mine.

Located deep beneath the blue waters of Lake Huron and five kilometres from its shore, it's the world's largest underground salt mine.

By even the most conservative estimates, there's enough salt in the mine operated by Compass Minerals to break up ice for the next 100 winters. With about 500 workers, it's the largest employer in a town that has seen its share of good-paying manufacturing jobs melt away in recent years.

And while the salt lies under the lake, about 350 unionized workers can't help but wonder about the future of their jobs as an increasingly nasty strike enters its ninth week today.

Workers and management walked away from the bargaining table on April 27.

There are no new talks planned as the mine continues to operate using a mix of replacement workers and managers.

David Kelly is a 33-year-old heavy mechanic and father of three. He's worked at the mine for five years.

But since the strike started, he's been splitting his time between walking the picket line and working at other mines a plane ride away.

"We're all frustrated," Kelly told CBC News, moments after stepping off a plane in Montreal. He'd just flown back from a job in Nunavut and planned to make the eight-hour drive back to Goderich later that day. "A lot of young families, a lot of single-income families, rely on these jobs. We're just anxious to go back to work. It's hard going to a job that you're good at and like doing, to being put out."

Compass Minerals did not respond to CBC's request for comment on Wednesday. But the company has posted on its website what it calls a framework for a settlement with the workers who are represented by Unifor Local 16-0.

It's hard going to a job that you're good at and like doing, to being put out, - David Kelly

It outlines a company offer that includes a $10,000 signing bonus for all regular employees along with wage increases that start at 63 cents an hour in 2018 and rise to $1.08 an hour by 2020. Kelly said the main sticking point isn't money but a push from management to get workers to try 12-hour shifts. In information posted on its website, the company says the moves are needed to keep the mine competitive and move toward a safer work model, one that uses fewer explosives to wrest the salt from the ground.

The company also wants to eliminate certain benefits — including medical, dental and life insurance — for employees who retire after March 2021.

Kelly says the company's demands for longer shifts and mandatory overtime pose dangerous risks to the health of employees who work in a challenging underground environment.

He says the $10,000 signing bonus, while tempting, pales in comparison to the benefits they're being asked to give up.

He also says the use of replacement workers galling.

"It's frustrating for me to have to leave and watch somebody from somewhere else come in and do my job," he said. "And to sit at the lunchroom in Nunavut and have a guy across the table show me an email that says 'Hey, do you want to have a job in Goderich, Ontario? We're looking for workers at a salt mine.'"

Mine workers have posted videos on social media of people they call replacement workers boarding a bus at a hotel in St. Jacobs, Ont., to be transported to the Goderich mine more than 100 kilometres away.

Unifor president Jerry Dias has also tweeted about the use of replacement workers.

Dias plans to attend a barbecue today at a park in downtown Goderich, not far from the mine entrance. He said the gathering is intended to "show support for the strikers."

What's not clear is whether the visit from Unifor brass will help kick-start talks in a dispute that has seen no movement for weeks.

For Kelly, the lack of news about talks is unsettling.

"Nothing can happen unless they're at the table," he said. "As soon as that happens, a contract can be negotiated and settled. We have to be at the table to talk."