Marijuana seedlings found on Copperopolis siteCOPPEROPOLIS — Authorities in Calaveras County eradicated 10,800 marijuana plant seedlings Thursday after uncovering a cultivation site on a rural private property in Copperopolis.Investigators from the Calaveras County Sheriff’s Office checked the property at the owner’s request after learning that a clandestine waterline was found running into a pond on the property.