Thursday, 6 May 2021 | The Latest Buzz for the Appraisal Industry

Illegal Indoor Marijuana Grow Operations – Part Three

Michael Cleveland
Michael S. Cleveland, President and Principal Scientist at Cleveland Environmental, Inc. and Mold Diagnostic Services.

Part One and Part Two of this article can be found by following their links.

Part one of this article presented a real-life case study involving the landlord of an apartment complex who was sued for negligence and personal injury by a former tenant who claimed that water damage and mold in his apartment had exposed the tenant to toxic mold.

It was only after the vacant apartment was inspected by his defense attorney’s expert, a Certified Industrial Hygienist with a Master of Science in Public Health, who was an exposure scientist with expertise in moisture intrusion and mold issues in buildings, that the landlord learned that all of the extensive water damage, mold and insect infestation in the apartment had been caused by a clandestine indoor marijuana grow operation. The expert had run into this type of situation many times before and knew how to recognize the telltale signs of a clandestine indoor marijuana grow operation, even when the operators tried to cover them up.

After the plaintiff’s attorney was told what the defense expert was going to say on the witness stand, the plaintiff attorney immediately dropped the case.

Part two of this article discussed why clandestine indoor marijuana grow operations are proliferating and, when they are discovered, how the extensive water damage, mold and other safety/health hazards they can cause in a property should be remediated.

Clandestine indoor marijuana grow operations are an epidemic and they cause extensive damage to the buildings they are carried out in. In the words of the U.S. Drug Enforcement Administration in their report entitled Residential Grows in Colorado, the New Meth Houses?, “Marijuana grows often cause extensive damage to the houses where they are maintained and are increasingly the causes of house fires, blown electrical transformers and environmental damage. Much like the ‘meth houses’ of the 1990s, many of these homes may ultimately be rendered uninhabitable.”

Part three of this article will discuss how to recognize the many possible telltale signs of a clandestine indoor marijuana grow operation. This is important for property managers to know because clandestine indoor marijuana grow operations are most often carried out in leased properties, including commercial spaces, residential homes and apartments. Who would want to cause that kind of damage to their own property? The sooner property managers recognize that a tenant is growing marijuana inside of one of their properties, the sooner they can put a stop to it so no more damage occurs.

Being able to recognize the many possible telltale signs of a clandestine indoor marijuana grow operation is also important for property insurance claims professionals, because, as discussed above, once the water damage, mold and many other possible safety/health hazards render a property uninhabitable, operators may try to conceal the fact that they were growing marijuana indoors and sue their landlords for negligence and personal injury (what I call a Type 2 clandestine indoor marijuana grow operation as discussed in part two of this article). With Type 2s, it’s like solving a mystery. There will be an “ah-ha” moment when you diagnose one. The more telltale signs you find, the more likely you are dealing with a Type 2. Clandestine indoor marijuana grow operations have become so common, I recommend that property insurance claims professionals always consider the possibility when they receive claims involving water damage and mold, especially if there is no obvious source of the moisture intrusion.

I have found telltale signs of Type 2s in all of the various parts of lawsuit discovery. The inspection of the property by the defense expert is, of course, critical. What the inspection should include is described in part one of this article. At the site, the telltale signs of equipment and supplies used for growing marijuana may be found on the back patio or put away in closets, the garage or the attic, so be sure to check all spaces in the building and all areas of the yard as well. I have also found telltale signs in discovery casefile documents, photos and depositions.

The many possible telltale signs of a clandestine indoor marijuana grow operation are listed and described below. As you go through this list, I encourage you to Google the telltale signs and look at the images that come up. Seeing the many possible telltale signs of a clandestine indoor marijuana grow operation with your own eyes will make you better at recognizing them.

I have put the many possible telltale signs of a clandestine indoor marijuana grow operation into a checklist format, so when you think you have run into one, you can print out this checklist and start checking the boxes. Again, the more telltale signs you find, the more likely you are dealing with a clandestine indoor marijuana grow operation.

If you are fairly certain that you are dealing with a Type 2, but want more evidence to prove your case, you can also have your Certified Industrial Hygienist perform environmental sampling at the property. The Certified Industrial Hygienist can use collection media to wipe residue off smooth floors or vacuum dust from carpeted floors. Both types of samples can be analyzed in the laboratory for the presence of THC. The dust samples can be also analyzed in the laboratory by light microscopy. Under the microscope, marijuana plant particles found in the dust have a distinct appearance that can be definitively identified by the analyst.

  • Mysterious source of moisture intrusion/history of toilet/sink backups

There is water damage and mold, but no obvious source of where the moisture came from, e.g., no roof leaks, no window leaks, no plumbing leaks, etc. The property may have a history of toilet/sink backups. This is because operators of clandestine indoor marijuana grow operations put a lot of debris, such as soil and plant parts, down the drain.

  • Disconnected flues/exhausts of natural gas/propane gas appliances, such as hot water heaters, ranges, HVAC system furnaces and dryers so they vent indoors

Operators of clandestine indoor marijuana grow operations might do this to increase carbon dioxide levels indoors, which promotes photosynthesis and the growth of marijuana plants. Natural gas and propane gas combustion products consist mainly of carbon dioxide gas and water vapor. But they also contain carbon monoxide gas, a deadly asphyxiant. So, if you find this telltale sign, fix it right away because this condition can be immediately dangerous to life and health (IDLH).

  • Electrical hazards

Operators may bypass power company electric meters in a “jury rigged” and possibly hazardous fashion to avoid paying for electricity, which is rapidly consumed by grow lights, axial fans used to promote marijuana plant stem health and ventilation systems used to exhaust heat from grow lights. This is another condition that you will want to fix right away because it can be IDLH

  • Electrical company distribution transformer explosions

“Jury rigged” electrical systems and/or the large amount of electricity consumed by clandestine indoor marijuana grow operations can overwhelm power company distribution transformers (the big cylindrical- or box-shaped objects you see at the top of power line poles) and cause them to explode.

  • Structure fires

The grow lights used in clandestine indoor marijuana grow operations can explode, either due to energy surges from “jury-rigged” electrical systems or from the high humidity caused by indoor marijuana growing, which in turn can cause water condensed on surfaces to drip onto grow light bulbs (colder water meets hot light bulb glass).

  • Windows always covered

The grow lights used for indoor marijuana growing put off a lot of light, which can be noticed from the exterior of the building. Operators of clandestine indoor marijuana grow operations also do not want anyone looking in the windows. I have seen instances where the operators simply cover their windows with cardboard or aluminum foil, which is kind of obvious. The savvier approach I have seen is the closing of drapes, curtain, blinds, etc. backed up on the inside with cardboard. You can see the letter approach in the photo accompanying part one of this article.

  • Limited access

Landlords have the right to inspect their properties but have to give tenants notice of inspection. This gives operators of clandestine indoor marijuana grow operations a chance to conceal what they are doing by, perhaps by moving things to a certain room. A maneuver I have seen more than once is for operators to limit access to a certain room because “someone is sleeping in there.” I recommend that landlords do whatever it takes to inspect all areas of the property.

  • Airing the place out

Marijuana gives off a distinct skunky odor. I have seen operators of clandestine indoor marijuana grow operations open up all of the doors and windows, run the HVAC system fan and run axial fans before a noticed inspection takes place. In one instance, the operator had all of the above going on and also had a window-mounted air conditioner running full blast when the outdoor temperature was 60 degrees. Brrr!

  • Carpeting/floors with black splotches

Operators of clandestine indoor marijuana grow operations use rich, black soil (technically called “chernozem”) to promote the growth of their plants. The kind you get from the nursery. And it gets everywhere, especially on floors, leaving very distinct black splotches.

  • Water damaged building materials/mold near water utilities

Tubs, showers and kitchen/bathroom sinks are the watering stations for indoor marijuana growing. Water gets splashed everywhere, especially near these water utilities. Adjacent drywall, flooring and sink cabinets get soaked. The wet building materials, in turn, promote mold growth.

  • High relative humidity, condensation on windows and musty odor; water damage/mold on drywall beneath exterior windows and on bathroom ceilings

Everybody has been in a greenhouse. It feels like a sauna because of the high relative humidity. Exterior windows drip with condensation because water vapor condenses on cold surfaces. There is a musty odor because the high relative humidity and wet soils promote mold growth. The same holds true for indoor marijuana growing. Water vapor condenses on cold surfaces, especially exterior windows. The high relative humidity, along with wet soils and splashed water, promotes mold growth, which gives off a musty odor. Condensation drips from exterior windows and down underlying sills and walls, soaking the drywall and promoting mold growth. Bathrooms ceilings in clandestine indoor marijuana grow operations are especially vulnerable to the high relative humidity because bathrooms are usually the main watering station. Water vapor rises because it is lighter than air (counter-intuitive, but has to do with the water molecule having a smaller molecular weight than the N2 Nitrogen molecule, which makes up the majority [80 percent] of the air we breathe). Drywall absorbs water vapor like a sponge. I have seen bathroom drywall ceilings near exterior walls (which makes the ceilings colder) in clandestine indoor marijuana grow operations collapse from being soaked with water and digested by mold growth.

  • History of water damage/mold growth

I had one case where the operator of a clandestine indoor marijuana grow operation had gone through four different apartments at the same complex. Each time, the landlord, not realizing he was dealing with Type 2s, would move the tenant to another apartment in the complex, repair the extensive damage in the vacated apartments and turn over those apartments to new tenants. Ironically, this tenant had volunteered photos of one of the collapsed bathrooms ceilings for the lawsuit discovery (see “calling cards” below). Yes, the tenant had sued his landlord for negligence and personal injury.

  • Insect and rodent infestation

Insect and rodent infestation problems occur inside of properties with moisture intrusion issues because these pests are attracted by readily available water. In fact, a problem with indoor marijuana growing that adversely affects the yield of the “crop” is infestation of the marijuana plants by a variety of insects. Spider mites are especially problematic. To combat spider mites, among other things, operators of clandestine indoor marijuana grow operations will employ predatory mites or insecticide foggers with the main ingredient Pyrethrum. Pyrethrum is preferred because it is of low toxicity to humans. Most indoor marijuana crops are intended, after all, for human consumption by smoking. Termites and cockroaches are also attracted by the water and one of the telltale signs recognized in the Type 2 case study discussed in part one of this article.

  • Equipment and supplies used for indoor marijuana growing

If you are using this checklist to assess a suspect clandestine indoor marijuana grow operation, I encourage you to print out all three parts of this article and underline the various equipment and supplies used for marijuana growing that are discussed to refresh your memory.

Part two of this article described how one reason that clandestine indoor marijuana grow operations are proliferating is that the information on how to efficiently grow marijuana indoors, and commercially-available equipment and supplies for doing so, have flourished on the Internet (Google “grow marijuana indoors” and see what comes up!). The photo accompanying part three of this article shows a commercially-available marijuana “grow box,” which are used as nurseries for young marijuana plants. Marijuana plants can grow to very large sizes, as high as 15 feet tall, so the young plants are moved to other rooms for further growth when they get too big for a grow box. Grow boxes may include the use of hydroponics, where the roots of the young plants are placed in a nutrient solution and an aquarium pump is used to bubble air through the solution. “Grow tents” are another version of the grow box, some of which are larger and can accommodate more and larger plants.

I had one case where a Type 2 plaintiff had placed his own photo of his home-made grow box in lawsuit discovery (see “calling cards” below). The plaintiff claimed that the box was a recording studio, although it was obviously too small for an adult to get into, much less record anything professionally. There was a trove of telltale signs in the photo – the grow box, itself, and on top of it, an aquarium pump, a box of LED Christmas tree lights (which can be used as grow lights) and a tabletop infrared heater (this was an older apartment with walls that were not well insulated in a cold region of the county – marijuana plants grow best at 70 – 90 degrees F).

  • Black soil dust trails around penetrations in walls

This is a subtle telltale sign. My first Type 1, a large clandestine indoor marijuana grow operation that I described in part two of this article, had black dust trails in many places on drywall surfaces where there were penetrations between rooms, e.g., ceiling fixtures, the thermostat and doorways. What caused these dust trails was the combination of a lot of airborne soil particles combined with pressure differentials between the rooms. The pressure differentials between the rooms was caused by extensive ducted ventilation systems used to exhaust heat from the grow lights to the outdoors. Some rooms had more air exhausted to the outdoors than others, which put those rooms at a negative static pressure relative to adjacent rooms. As air flowed into rooms with a lower static pressure, airborne black soil particles were deposited at surfaces adjacent to the penetrations because of impaction and electrostatic attraction. Remember, if the operator of a clandestine indoor marijuana grow operation knows the landlord is coming to inspect, they will probably try to hide their equipment and supplies, including any flex ducting and centrifugal fans for their ventilation systems. They might miss, however, cleaning up the black soil dust trails at penetrations between rooms, so be sure to look for those.

  • Round holes cut in walls and ceilings

Operators of clandestine indoor marijuana grow operation will cut round holes through walls and ceilings to accommodate the flex ducting used for their ventilation systems. Another method of exhausting air to the outdoors is the placement of drywall over the front of a fireplace with a round hole cut in the drywall to accommodate the ventilation system flex ducting.

  • Calling cards

Not unlike a good crime story where the perpetrator leaves behind clues or “calling cards” to frustrate investigators, I have seen calling cards a number of times in Type 2s. The photos of the collapsed bathroom ceiling placed in the lawsuit discovery by the tenant-plaintiff noted above is one example. That same tenement, who was airing out his latest apartment before and during our inspection, had left a baseball cap front and center on a bedroom dresser that was embroidered on the front with a big green marijuana leaf and the word “Budhead.” Operators of clandestine indoor marijuana grow operations are, by definition, risk-takers and seem to enjoy pushing the envelope.

  • In the business

Last but not least, especially in states where medical and recreational marijuana have been legalized, operators of clandestine indoor marijuana grow operations may advertise their business on the Internet. I had one case where the tenant-plaintiff operating a Type 2 grew marijuana clones (young plants started from the leaves of mature marijuana plants with desirable strain qualities, such as high tetrahydrocannabinol [THC] concentration) and advertised them for sale on the Internet. Free delivery included. This operator had a number of websites advertising his business. If you think you have a clandestine indoor marijuana grow operation on your hands, Google the name of the suspect operator and the words “marijuana” and “cannabis” and see what comes up.

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