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Waste Management

How do you manage your waste? Waste water from hydro grows etc? Waste organic materials? Waste plastics, netting and materials? Do you have a waste management plan? Do you measure your waste footprint and offset it in any way? Have you found that you have different waste management requirements due to the local laws than others?


502 licensed grows require the treatment of salt based nutrients as a toxic waste. Seal them up and have them disposed of by a qualified disposal service.

Turns out that recycling nutrient delivery and concentration of the minimal waste can reduce, if not eliminate this burden. In addition, rock wool compresses really nicely in a trash compactor and, with all that biodegrable plant matter locked inside, would really turn a landfill into a lush property.


One grower I spoke to told me that they have problems with dumpster divers going through their trash. I guess they can smell the grow and are hoping to find discarded plants or trim in the trash. He says they often come outside to find trash bags torn open and trash strewn about. Anyone else have this issue?


We have had that issue at our grow. Locks on dumpsters are required where we are, which definitely helps. However, we now compost all of our plant waste and turn it back into valuable nutrients. After switching to a living soil system, we throw away very little. I hope everyone will start heading in this same direction (though difficult for hydroponic setups).

The importance of composting correctly becomes very real when you’re using debris from the same species you are growing in order to make sure plant-specific pathogens don’t survive the process. Go bokashi.

Minimizing waste in this industry will be an important industry preservation tactic in the long term, not only economically, but to stay in a positive light with the general public. It’s only so long before people start catching on to how detrimental this industry is (as a whole) to the environment. Go organic.


I have to wonder – has anybody tried mixed cropping to reduce the amount of waste product? The reason I ask is that mono-cropping has a tendency to produce undesirable ecosystems (for both humans and the ecosystem in general).


I have intercropped with tomato, basil and lettuce - the tomato and basil really like the extra nutrients and care they receive interspaced in the cannabis and the lettuce both does well in the shady understory and helps act as a living mulch. I think companion planting and polycultures are potentially much more efficient and productive. Maybe not for indoor but in an outdoor or open greenhouse situation it makes sense to incorporate the ecosystem into the mix. If nothing else it confuses the bugs.


Sorry, it’s in Dutch, but we recycle rockwool slabs. In 2012 - year of this video - 120.000 cubic meters per year.


For lamps, we have got the WEEE rules in Europe (you pay for lamp disposal when you buy a lamp), in the US there are initiatives for lamp recycling, also by the manufacturers.

Listed are local lamp recyclers.

In Holland people sometimes bring their old stuff to he grow shop, who has special containers for that type of waste. Shops do this as a service to customers, and to take responsibility of the waste problem (prevent it getting dumped). Large lighting companies, such as Gavita, take in the horticultural lamps they replace in large greenhouse projects, to be recycled. For retail in the US unfortunately there are no such programs.

I suppose there are local recycling intakes right? We have them in every council, it is where you already separate your large waste and dangerous waste.

First thing that needs to be forbidden nationwide however is drain to waste.


btw this is a common technique to get slabs or other substrates out of a greenhouse. Think labor when you get into industrial scale grow ops.


We have issues with homeless ppl going through our trash and spreading it all over the neighborhood, in which case we have had to have the entire crew come in before work an pick up trash -at one point it was over 50trash bags full. We have locked our dumpsters, in a couple different ways and still have issues with them breaking into the dumpsters. We have unfortunately resorted to storing our trash indoors until trash day. It is such a pain, as we are limited on space with an indoor grow, so trash gets stored in our locker room with all the employee’s belongings. We don’t throw any products in the trash and have to shred all plant material and mix it 50/50 with soil (old rootballs).

One side of the business that the public never hears about…


Yeah it wasn’t something I was aware of until I was told about it. I know that there are dumpster divers who go through dumpsters looking for tossed food or furniture, but somehow those folks don’t seem to be as destructive. Maybe it’s easier to find old donuts or a chair in a dumpster than having to tear apart the whole bag looking for a tiny missed piece of bud.

Your situation does sound difficult, with even locks getting broken into. Makes me wonder if planning for urban grow operations needs to incorporate a fully enclosed trash room as part of the floorplan.


[quote=“nicholas, post:11, topic:1901, full:true”]Makes me wonder if planning for urban grow operations needs to incorporate a fully enclosed trash room as part of the floorplan.

I think it might depend on the business. If your operation is hidden through obscurity, it wouldn’t be necessary. But if you’re a dispensary… it would probably be wise to build an enclosure of some sort.


Bumping this topic for the newer folks. How do you handle waste management at your grow?


Does anyone use an incinerator for plant waste?

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