The legal cannabis market is growing from nothing to a potential $25 billion industry by 2021. There are now 21 states that have legalized cannabis for medical use and another 8 that have legalized for adult-use, creating one of the fastest growing industries in the country.
With all this rapid growth, water consumption and conservation have become important issues. In places that already struggle with access to enough water, like California, this new market has led to concerns about how the state will handle such a large increase in water needs.
On top of all the obstacles the industry has faced over the last few years, cultivators now must consider water usage as well because cannabis cultivation is incredibly water-intensive. The specific amount of water that a facility will consume depends on Vapor Pressure Deficit which is largely impacted by the type and amount of lighting in the space. This is because plants use water solely as a vehicle for nutrients, consuming it and then transpiring it back into the air through their leaves. In order to get as much yield from the plant as possible, cultivators inevitably drive transpiration rates through lighting and temperature, encouraging the plants to take up more nutrients through greater consumption of water.
This can be an expensive and potentially a venture-ending challenge. Fortunately, there are solutions to this issue in a controlled environment, which is becoming more common in cannabis cultivation. Not only do controlled environments reduce waste, like runoff associated with outdoor crop production, but they also offer the option to reclaim transpired water. Any space that is dehumidified produces condensate which can be reclaimed, filtered and used again. In a Surna system, both the dehumidifiers and fan coils are designed with a condensate drain line. This can easily be routed into a reservoir, offering a constant stream of “free” water, time and time again. For the small cost of an additional reservoir and a filtration system, cultivators can re-use water and reap the many benefits.
The benefits of reclaiming condensate are wide reaching. Water is currently not very expensive, especially compared to energy. However, reclaiming water does lead to some cost savings, which is important for achieving a high ROI. There may also be consumption requirements or limitations depending on where the cultivation takes place. In these instances, reclaiming condensate could mean the difference between an open and closed business.
Reclaiming condensate also produces distilled water, a nice alternative to reverse osmosis (RO) so many cultivators use. RO water is beneficial because the process removes any minerals or nutrients than may be in the municipal water supply, giving cultivators a baseline from which to add nutrients. Distilled water, on the other hand, offers the same benefits of a baseline supply. The RO process produces at least 1 gallon of dirty water for every gallon of clean water (and can waste up to 4 gallons of dirty water for each gallon of clean water, depending on the quality of the water supply) Instead, using reclaimed condensate saves facilities at least 2 gallons of water per gallon they would have used in an RO system.
Perhaps the greatest benefit is understanding that we can do good AND do well. Being more conscious of how we consume in this new market will be key to how it develops. Because the industry is young, we have the ability to build consciously and this is just one more way for us to do whatever we can do to reduce the resource intensive nature of cultivation.