A 51-year-old Fresno man has been convicted of a role in a marijuana-growing operation on agricultural land in Stanislaus County. Sam Kounhavong on Monday pleaded guilty to conspiring to manufacture, distribute and possess with intent to distribute the marijuana grown along the San Joaquin River near Newman. Federal prosecutors said Kounhavong admitted that he and four other men cultivated 907 marijuana plants under the guise of compliance with California medical marijuana law. Although federal law does not recognize a medical purpose for marijuana, Kounhavong said the marijuana was grown for profit without any medical purpose, according to the prosecutors. While serving a search warrant at the grow site, investigators discovered that river water had been diverted to irrigate the marijuana plants. Kounhavong faces a maximum sentence of 20 years in federal prison and a fine of up to $1 million. He is scheduled to be sentenced June 2. The case was investigated by U.S. Drug Enforcement Administration and the Stanislaus Drug Enforcement Agency, a federally funded, multi-agency drug task force in Modesto.