When Hershey's had a plant in Smiths Falls, Ontario, you could smell chocolate from miles away. But not a single chocolate bar has rolled off the line since the plant closed in 2008, one of six employers to leave the town at the same time.

Now, Smiths Falls, a working class town of about 10,000 in Eastern Ontario, has a new industry: medical marijuana. Health Canada is changing its medical marijuana rules, and Tweed, a licensed marijuana production company, has just received its license to grow medical cannabis there. Some are hoping the new plant will bring much-needed jobs to an area that's had it tough for the last few years.

Tweed's grow room is kind of like Willy Wonka gone 21st century. Except, instead of chocolate, it's pot.

Row after row of small marijuana plants nestle in plastic nursery trays. It's moist and bright – huge lights hang from the ceiling while standing fans whir quietly. Growers in lab coats, hair nets, and gloves glide through the aisles.

Master grower Ryan Douglas has me put on a lab coat, hair net and booties, an outfit I associate more with lunch ladies than with marijuana growers.

We walk along the rows of plants, and he tells me there are about 3,000 growing here.

"This is called L.A. confidential," Douglas explains. "And that has a reputation for being good for things like chronic pain or insomnia. So if you're having trouble falling asleep due to pain this is a strain we'd recommend for you."

The old Hershey's plant is transforming fast. This just the first of 28 rooms where Tweed will grow marijuana for national sale. Construction workers are building walls and hanging up lights, in preparation for the day that Tweed can officially start business: April 1, when Health Canada's new medical marijuana regulations go into effect.

Philippe Lucas researches medical cannabis access in Canada. He's also a medical marijuana patient. He says industry is poised for a big role in the country's medical marijuana future: "What's happening in Canada is unprecedented anywhere in the world. We have a federal government that's allowing theoretically an unlimited number of licensed cannabis to establish themselves and test the market."

Canada first permitted medical marijuana in 2001. The government authorized patients to either grow their own or have someone else grow it for them.

But that will all change staring on April 1. Patients won't have to get Health's Canada's approval to access medical marijuana. And they also won't be able to grow their own anymore. Instead, if their doctor prescribes medical marijuana, patients will go directly to authorized suppliers, like Tweed.

The new program does make medical marijuana accessible. But Tweed and the seven other companies that have been licensed so far have a lot of rules to follow.

"In the Canadian system, I cannot advertise, because you can't create demand," explains Tweed chairman Bruce Linton. "We don't take cash, we only use credit cards. We don't have any retail, we only use couriers."

Tweed can only sell the dried marijuana bud, and has to destroy the rest of the plant.

CEO Chuck Rifici says the company has had to get its name out there – fast: "Being part of the first cohort of producers has an advantage because there's an existing market that's losing their current license that'll be looking for a supplier. There's a little bit of a land grab component, or a green rush."

Smiths Falls isn't exactly the place you'd imagine Canada's medical marijuana story to be playing out. But Tweed has found a supporter in Smiths Falls mayor, Dennis Staples. Staples is a slender, clean cut guy in his late sixties with tidy grey hair. He says it's been hard finding work in Smiths Falls since 2008, when Hershey, along with five other employers, left town.

"In the past we've had factories come and go, usually one at a time, and it gives you a chance to recover, but this time, all six left around the same time and it was a huge, huge challenge."

Of course you got the people, 'uh oh, drugs are growing in Smiths Falls?' Come on, it's 2014, it's not 1950 anymore.

So when Tweed expressed interest, Staples – and the town – welcomed the company and the approximately 100 jobs they've said they'll create.

And it turns out, medical marijuana has touched the mayor too. Staples took care of his younger brother as he was dying of pancreatic cancer – and was able to obtain medical marijuana.

"My brother never shared with me where he got it, I can say that," Staples remembers. "Less nausea, less pain, it helped him in terms of his last five or six weeks on this earth."

James White is a construction worker who's lived in Smiths Falls his entire life. He says Tweed is the talk of the town.

"What you hear in the news here is, oh, new marijuana factory open here in Smiths Falls, and of course you got the people, 'uh oh, drugs are growing in Smiths Falls?' Come on, it's 2014, it's not 1950 anymore."

As for the jobs, White says he'll believe it when he sees it: "Well they're bringing some jobs but I don't know about a hundred. I can't see it taking 100 people to grow some pot."

And White wonders why, of all places, Tweed chose his home town: "What kills me is, why Smiths Falls? You know, like, this is just a little wee hick town."

But for mayor Dennis Staples, the question is, why not? If it's going to happen somewhere in Canada, why shouldn't Smiths Falls do it?

But not everyone is happy with the new Canadian system. A class action lawsuit has been filed against Health Canada in federal court. The plaintiffs claim that they have a constitutional right to produce their own marijuana or have somebody do it for them.

Tweed's new production facility doesn't look totally industrial yet, but companies across Canada are scaling up. Health Canada says the market is there, and that the number of people using medical marijuana could top 450,000 in the next ten years.

Tweed CEO Rafici says that perceptions of marijuana are changing: "It's becoming less taboo and as that happens we're going to help move that along and make it a more acceptable medicine for people to consider."

In Canada, it's industry that's shepherding marijuana into the mainstream.