A Port Huron man and woman were arrested Wednesday evening for the second time in the past three weeks for possession of heroin with intent to deliver.  The St. Clair County Drug Task Force arrested the 57-year-old Port Huron woman and the 56-year-old Port Huron man in a residence in the 800 block of Court Street in Port Huron, at about 7 pm Wednesday.  According to the news release from the police, they seized 35 doses of heroin that had been individually packaged.  The two may also face charges of operating a drug house. The suspects remain in police custody pending their arraignment.