Multiple law enforcement agencies are investigating a series of recent wildfires in Passaic County, authorities said Wednesday. Investigators with the Wanaque Fire Department, the New Jersey Forest Fire Service and the Passaic County Prosecutor’s Office are investigating. “At this time, there is nothing concrete to report,” Chief Assistant Prosecutor Julie Serfess, of the county’s vehicular homicide and arson units, said in an email. Serfess did not say where the fires occurred or release details about the investigation. The state’s Forest Fire Service said on Sunday wildfires “have occurred a…