A chemical leak kept rescue crews busy for a time yesterday. Crews were called to the scene at the CN Railroad property in Port Huron Township shortly before 1 p.m. Sunday. Authorities say the chemical Dipentene leaked from a container in a warehouse on CN Railroad property off Griswold Road. According to Port Huron Township Fire Chief Craig Miller a 55-gallon drum of the chemical was being moved when it was accidentally punctured….and the chemical leaked inside a container at the warehouse. Authorities say the chemical was contained with minimal threat to the environment. Dipentene is considered hazardous waste because it is a marine pollutant and an inhalation hazard. Responding crews included units from Port Huron Township Fire Department, St. Clair County Hazardous Materials Team, Tri-Hospital EMS, St. Clair County Sheriff Office, and U.S. Customs and Border Protection and Hazardous material specialists from CN Railroad.