-from sfgate.com-

By AP

Federal authorities say they have disrupted a major indoor marijuana-growing operation in northern San Diego County.

Assistant U.S. Attorney Stewart Young says agents arrested 13 men and seized marijuana plants that could have a street value as high as $27 million.

Raids Tuesday at four homes found 6,848 plants. The houses used a sophisticated irrigation system and stolen electricity to grow the plants under lamps. Court records show another home contained scales and processed marijuana for sale.

Authorities say two 48-year-old men owned or controlled the houses. Those men, Thomas Swift of San Marcos and Kevin Kennedy of Vista, pleaded not guilty Wednesday to charges of conspiracy to manufacture a controlled substance.

Each faces a minimum sentence of 10 years in prison if convicted.