Although states have legalized marijuana, the growing of pot has caused environmental problems. Since marijuana is illegal according to the federal government, laws regulating the growing of an illegal substance cannot be created and enforced.
The main environmental issues with growing marijuana are:
- native vegetation and wildlife is killed
- fish populations are killed when water is dammed, drained or diverted for the plants
- one marijuana plant can consume up to 15 gallons of water daily
- toxic pesticides are spread and leach into water supplies
- chemical run-off flowing into storm drains and sewers cannot be controlled with permits from the Environmental Protection Agency since marijuana is illegal under federal law
- rat poison capable of killing humans in small doses is being put out to protect marijuana seedlings and is killing wildlife including threatened owl species who eat the poisoned rodents
- pesticides that can kill humans in small doses or just when breathed, like aluminum phosphide that turns into phosphine gas when it hits the air, are being used
- greenhouse gas emissions from diesel generators used to light bunkers pollute the air
- muddy, deforested slopes erode during rainy seasons and choke salmon streams
- medical marijuana growers are not subject to federal laws as are conventional farmers regarding fertilizer and water use
- rangers who used to be able to care for the forests and parks are now spending 100 percent of their time working on the environmental impacts of marijuana
- illegal growers leave behind many garbage bags worth of trash like clothes, sleeping bags, tents, beer cans, backpack sprayers and plastic waste that pollute streams and wildlife dies trying to eat. Helicopters have to be used to carry the trash out of the remote areas at taxpayers' expense.
An exception to a couple of these issues are the states of Colorado and Washington which have laws dictating how, where and by whom marijuana may be grown. In Colorado, where the state has a seed to sale tracking system, pot vendors' packages must list all farm chemicals used to produce their products. Most of the crop there is grown indoors, reducing pesticide use but being highly energy intensive.
United States law enforcement officials and attorneys are saying that Mexican drug cartels plant marijuana across the border on the United States side because it is easier than smuggling it across. In remote areas of national parks and forest, secret gardens are planted using streams for irrigation and toxic pesticides which have been banned in the States.
Scott Bauer, a biologist with the California Department of Fish and Wildlife, says cannabis farm irrigation has used up all the water that normally keeps salmon streams going through the dry season with at least 24 salmon and steelhead streams dried up in summer 2013. He considers it the number one threat to salmon in his area and says the spending of millions to restore streams, contain sediment and fix fish path barriers is a waste without water for the fish.
The U.S. Justice Department has proposed treating prosecution of these growers similar to methamphetamine producers since toxic chemicals are involved. They suggest heavily increased prison sentences in contradiction to the Obama administration's move to cut bulging prison populations with shorter times for federal drug defendants.
The main source of the problem in the U.S. is in northern California's Emerald Triangle of Mendocino, Humboldt and Trinity counties known for massive U.S. marijuana cultivation. California has allowed growth of marijuana for health reasons since 1996. Just in the years from 2009 to 20012, cultivating marijuana on private land doubled.
Where the U.S. Forest Service rangers used to find occasional areas of a few hundred plants, they are now regularly seeing as many as 40,000 plants. And as especially during prohibition when it was dangerous to walk in the woods where moonshiners had their stills, it is now dangerous to be in the woods near marijuana patches where guns are protecting the crops. Watch the heartbreaking Forest Service video for pictures of the environmental damage they are seeing.