SAN DIEGO — Authorities raided an illegal marijuana farm in northern San Diego County on Friday, seizing 15,000 plants and 9 1/2 pounds of pot products with an estimated street value of more than $7.5 million, authorities said.

Detectives also detained seven people during the operation in unincorporated Valley Center, a rural and agricultural community northeast of San Diego, according to a statement from the Sheriff’s Department.

Photos showed thousands of plants in a greenhouse along with trays of processed marijuana.

San Diego Gas & Electric, the county’s code compliance team, the California Water Board and the state Department of Fish and Wildlife helped in the operation and found fire dangers and health and safety risks at the farm, according to the Sheriff’s Department.

“It is not uncommon for investigators to find dangerous chemicals, illegal pesticides and other hazardous materials used at unlicensed marijuana grow sites,” the department’s statement said. “These dangerous materials may enter the local ground water supply and streams, creating extreme environmental hazards.”

The marijuana may have been intended for sale at illegal dispensaries, authorities said.

The grow site is about 18 miles (28 kilometers) from where seven people were shot to death last September at an illegal marijuana growing operation in a rural area of neighboring Riverside County. [Read More @ Tribtown]