But it wasn't always that way. Ship ballast was once regarded as a potential health hazard. For many decades, from the 1850s, our harbour authorities forbade ship captains from disposing of ballast "from infected ports" into the harbour. That expensive policy finally changed, and so by 1907, the bulk of about two million tons of ballast coming in ships to NSW came to Newcastle. That's why Stockton's entire western foreshore (now parkland) is made from ballast.