In 2014, the NSW Land and Environment Court imposed penalties on Orica Australia for a number of polluting incidents that occurred in 2010–11 at their Kooragang and Botany facilities. The monetary penalty was directed to fund projects that aimed to restore and enhance the environment for the benefit of affected neighbouring communities. Part of this environmental service order was issued to the former Office of Environment and Heritage to fund the Lower Hunter River Health Monitoring Program.
The program included:
- a review of literature and environmental monitoring data to assess the impact of industrial pollution on the past and current condition of the Hunter River estuary – Lower Hunter River Health Monitoring Program: Legacies of a century of industrial pollution and its impact on the current condition of the lower Hunter River estuary
- a water quality monitoring program to assess current water quality in the estuary under a range of typical conditions – Lower Hunter River Health Monitoring Program: Water Quality Monitoring Program 2014–2015 report
- a stormwater quality monitoring program, during and after rain events, to identify sources of pollutants in stormwater delivered to the lower Hunter estuary – Lower Hunter River Health Monitoring Program: Stormwater Quality Monitoring Program 2015 report
- a Preliminary Ecological Assessment of the Lower-to-Mid-Hunter River Estuary 2015–16 to investigate a range of ecological processes in the lower and mid estuary
- development of the Health of the Hunter: Hunter River estuary report card 2016 to explain the river’s health in an easy-to-read format.
Main findings
Monitoring of the Hunter River estuary included the tidal sections and tributary rivers and creeks. Water quality in the Hunter River estuary had not been assessed on a broad scale for over a decade. Since 2000, land use and activities in the Port of Newcastle had changed considerably and the population in the region had also increased.
The 2014–16 monitoring program found:
- Water quality in the Hunter River estuary had improved significantly over the past decade, with concentrations of ammonium, nitrates and phosphates in the South Arm (Newcastle Harbour) 5–10 times lower than before 2000.
- Improved water quality had been achieved through rehabilitation of portside land formerly used for steelmaking, pollution reduction programs by industry to improve the treatment of wastewater discharges, and remediation of contaminated lands and sediments.
- Significant improvement of the ecological condition of the estuary had been achieved by restoration of natural tidal flows and rehabilitation of estuarine habitats and riverbank vegetation.
- Ecological condition in the South Arm (Newcastle Harbour) and Throsby Creek was poor. The lower reaches of the harbour and the Port of Newcastle have been modified extensively by human activity. Decades of land reclamation and dredging for port operations removed intertidal mudflats and sand shoals from the lower estuary, drastically reducing its ecological function. When functioning properly, these habitats improve water quality by removing excess nutrients and sediment from estuary waters, and by filtering nutrients and sediment from stormwater.
- Despite improved water quality since 2000, the Hunter River estuary receives excess sediment and nutrients, such as ammonium, nitrates and phosphates, from agriculture and urban–industrial runoff. It also receives high concentrations of nutrients and metals from industrial discharges and contaminated groundwater. Levels of dissolved nutrients in estuary waters usually exceeded water quality guidelines. Following rainfall, levels of dissolved copper and zinc in lower estuary waters exceeded the guidelines for the protection of marine ecosystems.
The water quality data collected during this program forms a baseline against which future developments in the lower catchment can be assessed. Water quality monitoring in the estuary should continue into the future to build a long-term dataset. This dataset can then be used by stakeholders to detect changes in condition as a result of management and regulatory actions in the heavily urbanised and industrialised catchment.
