Burson CA…On October 19, 2022, at approximately 1315hrs, the Calaveras County Sheriff’s Office began receiving multiple reports of an explosion which was heard and felt throughout the Burson area of Calaveras County. After the initial reports of the explosion were received, secondary reports of a structure fire that had extended to surrounding vegetation were received. No reports of injury from the affected structure or surrounding residences were reported.

Numerous fire agencies and Cal Fire aircraft responded to the scene and extinguished the vegetation fire; however, it was observed that materials within the outbuilding continued to burn despite fire suppression efforts.

The Calaveras County Sheriff’s Office Marijuana Enforcement Team (MET) had responded to the area at the initial report of the explosion and conducted a preliminary investigation of the scene. Sheriff’s MET investigators observed objects and material within the burning structures consistent with equipment and material used for an illegal butane honey oil lab (BHO). BHO labs use flammable gasses as solvents in a process used to extract and concentrate tetrahydrocannabinol (THC) from marijuana. This chemical extraction process is illegal in the State of California and carries an extremely high risk of explosion or fire.

MET investigators acquired a search warrant for the residence; however, due to the ongoing fire and smoke, Calaveras County Environmental Health and Air Pollution Control District representatives were requested to respond to the scene. In the interest of the protection of public health and safety houses within the footprint of the settling smoke were notified to evacuate or shelter in place. In total, 21 residences were potentially affected by the smoke and placed on the automated notification list.

The Calaveras County Office of Emergency Services was contacted and responded to the scene. After an assessment conducted by Environmental Health, Air Pollution Control District, Calaveras Consolidated Fire, and The Sheriff’s Office, a request was made for a hazardous materials team to respond and assess substances that were continuing to burn.

On October 20, 2022, the substances which had continued to burn within the structure were tested and determined to be oils consistent with homemade “biodiesel” production. These oils are believed to have ignited as a result of the explosion which had occurred at the BHO lab. In addition, the presence of THC was found within the equipment associated with BHO extraction.

Calaveras County Code Compliance responded to the residence and determined it to be unsafe for occupancy. The investigation is ongoing, and a criminal case will be sent to the District Attorney’s Office for prosecution.