This was a Hamilton home inspection, the house was over 60 years old and the back flow valve was installed connected to a cast iron drain pipe. Due to the age of the house the sanitary and storm sewer discharges were connected to one drain line. My client ask me if there was any indication of water seeping into the basement, I said no visual evidence. However, when we inspected the area around the valve the soil was quite damp, indicating the basement could have moisture/water issues originating from the exterior due to poor drainage issues, clogged or broken weeping tiles. This is not an uncommon problem when inspecting homes of this vintage or older.