The impact of a century of industrial pollution on the current condition of the lower Hunter River estuary

Newcastle has been a large industrial centre since early last century with BHP Steelworks operating from 1915 – 1999, and the region supporting a wide range of primary, secondary and tertiary industries involved with... [ view full abstract ]

Newcastle has been a large industrial centre since early last century with BHP Steelworks operating from 1915 – 1999, and the region supporting a wide range of primary, secondary and tertiary industries involved with agriculture, mining, manufacture and transport. Regulation of industrial waste was non-existent for most of last century and it was common practise to discharge untreated industrial waste laden with acids, phenols, ammonia, cyanide and metals directly to the Hunter River. The Port of Newcastle is now the world’s largest coal export port, exporting 159 million tonnes of coal in 2014. NSW Office of Environment (OEH) have completed a technical assessment of historical and current environmental and monitoring data collected in the Hunter estuary to inform on the current ecological health, and to address community concerns regarding the cluster of heavy industries having a significant cumulative impact on the estuary. Historical data revealed the extent of contamination of the estuary and riverbed sediments. Levels of ammonia, nitrates and phosphates in the estuary were up to 50 times above ANZECC guidelines in data collected during the 1970s to 1990s. Estuaries are efficient sinks for industrial contaminants such as heavy metals and hydrocarbon compounds which bind to sediment particles. Sediments in un-dredged areas of the harbour and port can be enriched with heavy metals at levels 3 times above background along with alarming levels of organic contaminants like chlordane, polyaromatic hydrocarbons and total petroleum hydrocarbons. Today, industrial waste discharges to the estuary are tightly regulated by the NSW Environment Protection Authority who also has powers under the Contaminated Land Management Act 1997 to enforce polluters to clean-up contaminated sites. BHP-B carried out the Hunter River Remediation Project to clean-up heavily contaminated sediments adjacent to the former Steelworks site. Recent water quality data collected by OEH suggests that the health of the Hunter River estuary has improved considerably since 2000 although nutrient levels are often above ANZECC guidelines. The data provide a baseline against which environmental impacts of future developments can be assessed which will be critical for the effective management of the health of the Hunter River.