Two Hamilton medical marijuana producers say the city's urban air is too polluted for them to successfully grow their product in industrial areas.

We are growing a very sophisticated plant for medicine here. - Ian Wilms, Green Organic Dutchman

Hamilton city councillors want medical marijuana producers to locate their operations on old industrial brownfields instead of farmland and are pondering whether to limit how much marijuana is grown in greenbelt land.

On Tuesday, Beleave and Green Organic Dutchman said that would be "catastrophic" since the air would pollute the product.

If the crop gets even a little polluted, the company has to destroy it, said Ian Wilms, vice chair of Ancaster's Green Organic Dutchman. This is according to the company's Health Canada license.

"We are growing a very sophisticated plant for medicine here," he told city council's planning committee. "Any contaminants or pollutants could cause devastating crop failure, and we could not give this to our patients whatsoever.

"That's why everyone is going out to the rural area, where obviously the air is much fresher."

Not all councillors bought into that argument.

Pot versus cucumbers

Earlier this month, Coun. Lloyd Ferguson of Ancaster complained of marijuana producers building "concrete bunkers" on farmland. Marijuana, he said, is different from cucumbers. Food should take priority.

You're not talking about the family farm anymore. - Matthew Green, councillor

Matthew Green, councillor for Ward 3 in the central lower city, was skeptical of the air quality claim too.

The companies grow indoors, and can create conditions that keep out air pollution, he said.

There are only four medicinal marijuana corporations in Hamilton right now. But once the plant is legalized in June, Green said, more will come.

"If we planned properly, we could create an industry here — a green economy" on industrial land, he said.

Both Beleave and Green Organic Dutchman plan major expansions that dwarf their initial plant sizes.

Green Organic Dutchman wants to add 150,000 square feet to its existing 7,000 square foot facility. Beleave wants to grow its initial 14,000 square foot operation by an additional 80,000 square feet, and that's just to start.

On that scale, "you're not talking about the family farm anymore," Green said. "You're talking about multinational corporations."

'It's disappointing'

Companies, he said, could "create high tech agricultural factories, or factory productions of cannabis, in a way that accounts for contamination."

​Wilms said Green Organic Dutchman is already on land deemed to be impractical for growing food. Both also said their licences require setbacks from other buildings, which they couldn't meet in the lower city.

Both said if they can't expand in Hamilton, they will probably locate elsewhere.

"We've been working on this for three years," Wilms said.

"It's disappointing."

CBC is trying to get comment from Health Canada about the licencing conditions regarding air quality.