News21: America’s Weed Rush

Growing marijuana industry raises environmental concerns

Chuck Lyon lives in a house he built "one concrete slab at a time" in the hills of Mendocino County, California.

Lyon, 62, only uses about 5 gallons of well water each day, including the 1.5 gallons it takes for him to take what he called "navy showers." The average American uses more than 16 times that amount each day, according to the U.S. Geological Survey.

And when it comes to irrigating his garden, which includes six marijuana plants just a few steps off the front porch of his home, he takes it a step further. Lyon captures about 60,000 gallons of rainwater in massive silos each year and uses that to water his cannabis.

"Without water, I'm nothing. Without water, this planet's nothing," said Lyon, who can legally grow medical marijuana under California's system. "I don't waste water. I don't plunder water. To plunder water, that's a crime against nature."

Lyon grows his pot in the "Emerald Triangle," one of the largest cannabis-producing regions in the country. Although Lyon tries to leave little impact, the area around him highlights some of marijuana's negative effects on the environment. Marijuana can require massive amounts of water, and growers have often left behind toxic chemicals, trash and scars on the land. Growing indoors can use excessive amounts of energy, which costs large sums of money and eats up resources.

Twenty-three states and Washington, D.C., have approved marijuana for medical use, with Alaska, Colorado, Oregon, Washington and the District, legalizing recreational pot as well. At least a dozen other states may vote on legalization initiatives in the 2016 election, including Arizona.

Jesse Peters, owner of Eco Firma Farms near West Linn, Oregon, said the fears concerning the impact of the marijuana industry as it expands are fears any industry should address.

"Call centers need to be more sustainable. Mills need to be more sustainable. Cannabis farms needs to be more sustainable," he said. "There's more and more people being added to this planet. We're putting more and more stress on the planet as a whole. We shouldn't create any new industries to add to that stress."


Marijuana is a thirsty plant. A single plant needs up to 6 gallons of water every day.

That's double the amount of water consumed by grape vines.

California is an ideal location to grow both crops—its mild seasons make for lush outdoor grows. Because of these conditions, growers have flocked to the state, and the land has felt the effects.

A recent study by researchers from the California Department of Fish and Wildlife found each of four watersheds in northern California—an area within the Emerald Triangle—supplies water to between 23,000 and 32,000 marijuana plants. These grows deplete each watershed by anywhere from 138,000 to 192,000 gallons per day. Researchers collected this data by accompanying law enforcement on search warrants and site inspections.

Chris Van Hook spent more than two decades diving and farming abalone off the coast of Crescent City, California. He raised his children near the rivers that flow beneath the redwood canopy and has seen their flows diminish over the years.

All it takes is a drive along U.S. Route 101 to see that some areas of the rivers that run along it have pooled up and do not connect—there's simply not enough water.

Lyon said he sees the destruction around him as well. Large-scale grows, the legality of which is unknown, surround his property.

"These million-dollar growers up here are using millions of gallons of water," Lyon said. "They're pumping directly out of the river. They're pumping directly out of the springs."

"Everybody thinks it's somebody else. They think that their grow is conservative on water, and it's somebody else that's doing all the plundering of the water. We can't look at it like that anymore. We're all responsible whether we grow or not."


Marijuana grow sites may harm surrounding habitats in other ways, too.

Use of excessive pesticide, herbicide and rodenticide—poison used to keep rodents away from plants—may have potentially lethal effects on wildlife.

Researchers have studied the impact of pesticides and rodenticides on wildlife, in particular the weasel-like fisher, in the Sierra National Forest along California's eastern border.

The researchers found traces of rodenticides as well as pesticides in the soil and vegetation surrounding cultivation sites. They observed a correlation between these chemicals and the dwindling population of fishers, according to Mourad Gabriel, executive director and senior ecologist at the Integral Ecology Research Center.

The researchers also discovered some owl species in the area were exposed to rodenticides, likely because of a diet heavily dependent on small mammals.

They found three out of four northern spotted owls and between 40 and 70 percent of barred owls had been exposed—and those estimates may be conservative, according to Gabriel.

Illegal grow sites use multiple toxicants in large quantities to kill anything that might harm the crop, according to the study. Many illegal growers blatantly disregard regulations intended to protect sensitive habitats and lands.

These grow sites also have been associated with large amounts of trash and non-biodegradable waste.

According to the U.S. Forest Service, illegal growers "frequently damage soils, cut timber and clear vegetation to create room for their grows, creating resource damage and erosion problems." The service estimated that in fiscal year 2014, 72 national forests across 21 states were home to illegal marijuana cultivation sites.

Chris Boehm, the assistant director of the service's law enforcement and investigations, said more than 6,000 illegal cultivation sites have been raided in national forests since 2005. Ninety percent of those sites were in California.

In 2011, the Forest Service cleared out and restored 335 illegal cultivation sites in California alone, according to David Ferrell, the director of law enforcement. During the clean-up, workers removed more than 130 tons of trash, as well as 300 pounds of pesticides and 5 tons of fertilizer.

Because of such waste, Ferrell deemed the illegal cultivation of marijuana "a clear and present danger to the public and the environment."


Indoor grows have different needs from those outside, and those needs come with costs of their own. They may use less water, but indoor grows use a tremendous amount of energy.

Indoor cultivators typically use LED or HPS — high-pressure sodium — lights to provide the energy plants would naturally obtain from the sun.

One study comparing these high-efficiency lights found that both types were equally efficient.

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