Community and Patients alike will be interested to see medical cannabis come to Missouri without harming the environment. Cannabis could have similar downsides as traditional agriculture unless producers are responsible with their cultivation practices.
Pesticide use and bad farming practices that induce erosion could apply to cannabis as well. Although most responsible producers will avoid the use of pesticides, it is still possible that some will attempt to use these product and that toxins may find their way into water supplies. Your local legitimate cannabis operation should be held to high standards in this regard.
Odor is a surprising problem for the cannabis business operator. Cannabis contains a host of volatile organic compounds (VOCs) that can be very odoriferous. You can literally smell the business from blocks away depending on the wind. A community should not have to deal with this issue, however. Odor controls should be put in place so that these businesses can do business without stinking up the neighborhood.
A real issue with indoor cultivation is the potential to impact electricity consumption. While there is good reason for the preference to cultivate in a controlled environment, the high-intensity lighting that is used for indoor cultivation along with the air conditioning required to cool it puts forward a huge demand for electricity. Cultivation operations will need to adopt newer technology to lessen these costs if they expect to meet community expectations.
Further reading:
ScienceDirect.com (1)
ScienceDirect.com (2)
ScienceDirect.com (3)
TheGuardian.com