Marijuana Matters: Environmental effects of growing pot

BURLINGTON, Vt. (WCAX) As Vermont gears up for legalized pot, some are considering the possible environmental impacts.

Several state departments will have new responsibilities once recreational marijuana is legalized in July.

The Vermont Agency of Agriculture is taking a look at pesticides. Since marijuana is illegal at the federal level, the Environmental Protection Agency does not have a recommended pesticide for growers. Cary Giguere, a program manager for the Agency of Agriculture, says product recommendations would be left up to his department.

He says if growers tell them they’re being pressured by pests, they’ll come up with a list. He’ll be looking for help from other states that have already passed legalized pot.

"We’re going to rely heavily on a lot of the work California is doing with regard to on the risk assessments and health effects of the pesticides used on cannabis," Giguere said.

Giguere says it's important to use pesticides that don't leave a residue so the pot doesn't become toxic when used and so runoff doesn't contaminate our water. But, since only a few plants will be legal, he says he's not worried about pesticide runoff.

Taylor Readyhough, a University of Vermont graduate student studying plant and soil science, says he isn’t too concerned. However, Readyhough says even a small amount of pesticides and synthetic fertilizer would add pollution to an already dirty Lake Champlain.

"I would encourage growers to use local products," Readyhough said. "Vermont Compost Company and Black Deer Farm makes a very good compost product, as well, and to use those products you don't need the leachate that will contaminate the water supply."

Readyhough says his concerns about waterways and drinking water would increase if Vermont lawmakers were to pass a regulated market with the ability to grow more pot. He says greenhouses are the most environmentally friendly way to grow pot.

"To be able to be in a greenhouse where you can protect yourself from the elements of rain and high humidity, as well as frost, would be ideal," said Readyhough. "Where you can utilize natural sunlight and reduce your need for high-pressured electricity lamps, as well as utilize the local soil, the local composts."

Readyhough says pesticides aren't even necessary if people are growing in a healthy ecosystem and using the right soil. The UVM graduate student is working on creating classes with local stores to teach people how to grow without synthetic fertilizers and pesticides.

It's not all negative though. Readyhough says pot takes contaminates out of the soil and carbon out of the atmosphere.

Officials at the Department of Environmental Conservation declined to comment on the environmental effects of legalized pot.