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Voters in California will decide on a measure in November, which would legalize and tax marijuana. Amid the debate over the pros and cons of this is the environmental impact of pot cultivation. Illegal pesticide use and creek water diversion at large-scale outdoor operations are well-documented.
And as Lisa Morehouse reports, environmental concerns are also growing over indoor marijuana cultivation.
LISA MOREHOUSE: One day two years ago, Larry Lancaster was called to the scene to an environmental disaster outside of Garberville in southern Humboldt County. A thousand gallons of diesel fuel died a brilliant red had spilled into a tributary of Salmon Creek.
Mr. LARRY LANCASTER: In a day or so the whole creek was completely red and it was very dramatic to stand in a creek bed and see the effects of that.
MOREHOUSE: The spill's origin: an indoor pot-growing operation so far out in the woods it was powered by a diesel generator.
Lancaster works for the Humboldt County Division of Environmental Health. Since 2001, his office has responded to violations at 50 diesel-powered indoor grows. Spills are only part of the problem. Diesel growers often use crude storage for waste motor oil and antifreeze and unsophisticated transportation systems for diesel, such as pipes and fittings meant to carry water.
Lancaster says hundreds or thousands of gallons of fuel can leak into the soil and into the water table. The damage has prompted an unusual publicity campaign.
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Unidentified Man: Growing indoors off the grid? Well, listen up...
MOREHOUSE: Activists in southern Humboldt are appealing to their neighbors to grow green. This is new for the region, where folks generally take a live and let live attitude.
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Unidentified Man: Just grow in nature's natural way - outdoors in the sun.
MOREHOUSE: Grower Tim Blake remembers one reason people moved their operations indoors: when law enforcement started cracking down on outdoor growers in the region.
Mr. TIM BLAKE (Grower): About 20 years ago when they decided they were going to really try to suppress the growing up here in this region, they brought in military people and they really kind of wiped out the area at that time.
MOREHOUSE: Many growers responded by going indoors and they quickly realized they could cultivate marijuana year round. That's when the environmental damage started to add up. But diesel grow operations aren't the only ones that raise environmental questions.
Ms. MARIELLEN JURKOVICH (Director, Humboldt Patient Resource Center): So, these are the mother plants and they're at the beginning of the cycle.
MOREHOUSE: At the Humboldt Patient Resource Center, a medical marijuana dispensary in Arcata, director Mariellen Jurkovich points to a few of several hundred marijuana plants growing near a huge fan.
Ms. JURKOVICH: All of our medicine is grown here onsite and it's all organic. So, we don't use any toxic chemicals, for people or the environment.
MOREHOUSE: But grown indoors, this crop needs electricity and lots of it. Some lights here run 18 hours a day. With fans, dehumidifiers and security cameras, the electricity bill comes out to $4,500 a month - more than rent.
Mr. PETER LEHMANN (Director, Schatz Energy Research Center): Indoor grows use an enormous amount of electricity and put an enormous amount of carbon dioxide into the atmosphere.
MOREHOUSE: Peter Lehmann directs the Schatz Energy Research Center at Humboldt State University. He says 14 years ago, Humboldt County's energy demands were like anywhere else in the state, but then California voters passed Proposition 215 authorizing pot growing for medicinal uses.
Mr. LEHMANN: That's when our electricity use in Humboldt County started diverging from the state per capita average.
MOREHOUSE: He says some indoor grows use 20 times the electricity of an average household. Lehmann and a colleague found that Humboldt County residents use 25 percent more electricity per capita than the average Californian. That's like every person in the county having a personal full-sized refrigerator.
Mr. LEHMANN: It's disturbing. We build power plants. We burn fuel. We block rivers with dams.
MOREHOUSE: Why? To make electricity.
Mr. LEHMANN: To use it to grow a plant indoors is a little galling.
MOREHOUSE: What effect would legalization have on indoor growing? These scientists aren't speculating. But many growers believe that the price of pot would plummet. And with the high cost of electricity and diesel fuel, that may force some growers to revert to more natural methods.
For NPR News, I'm Lisa Morehouse.
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