LIVERMORE (CBS SF) – A total of ten suspects were arrested on Thursday in the culmination of a long-term investigation into an illegal 200-acre outdoor marijuana cultivation operation in rural Livermore, Alameda County sheriff’s officials said.

Sheriff’s officials said the arrests occurred when they served search warrants for the cultivation operation near mile marker 18.6 on Mines Road in rural Livermore and the primary suspect’s residence in Antioch.

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The Alameda County Narcotics Task served the search warrant in Antioch, where they found a small illegal marijuana grow, about two pounds of dried and processed marijuana and $10,000 in cash. Two suspects were arrested there, authorities said.

The search warrant at the cultivation operation in Livermore was served by Alameda County sheriff’s deputies with the assistance of Hayward, Fremont and East Bay Regional Park District police. The California Highway Patrol and the sheriff’s drone team provided aerial support.

Sheriff’s officials said the Mines Road location consisted of three separate parcels spread out over the 200 acres of land and more than 4,600 marijuana plants were eradicated.

Some of the plants were more than 9 feet tall and 6 feet wide, they said.

Investigators recovered 100 pounds of processed marijuana, two firearms and more than $15,000 in cash.

Eight people were detained and ultimately arrested for cultivation and distribution of illegal marijuana at the site, sheriff’s officials said.

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In addition, a marijuana oil extraction lab was also located, according to authorities.

California Fish and Game, Zone 7 Water District and Alameda County Code Enforcement officials inspected the land, gardens and dozens of outbuildings and game wardens discovered more than 20 violations of environmental crimes, sheriff’s officials said.

Some of the major violations were diverting natural water runoff, drilling illegal wells and pollution crimes, which all severely impacted the environment in a negative way, according to sheriff’s officials.

Fish and Game officials said the damage caused by the marijuana grow probably totals more than $1 million.

Sheriff’s officials said the California Department of Forestry and Fire Protection also evaluated the area and discovered several violations of fire safety regulations and endangerment to the environment, sheriff’s officials said.

They said the Alameda County District Attorney’s Office is expected to prosecute the people who were involved in the illegal marijuana grow operation.

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