This record provides an overview of the NESP Marine and Coastal Hub project "Ecological outcomes of wastewater discharges in contrasting receiving environments". For specific data outputs from this project, please see child records associated with this metadata.

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Coastal and marine environments are increasingly exposed to pollution from land-based sources, including wastewater. With the majority of Australians living near the coast, household chemicals, pharmaceuticals, and plastics can enter the ocean via wastewater treatment plant outfalls. National policies and action plans, including Australia’s Waste Policy Action Plan, the Threat Abatement Plan for the impacts of marine debris, and the One Health Master Action Plan, all emphasise the need to incorporate emerging pollutants into contaminant guidelines. However, current monitoring programs focus on a limited set of contaminants, leaving major gaps in our understanding of the presence, concentration, and ecological effects of emerging pollutants in the marine environment.

This project addressed this problem by: (1) identifying priority pollutants of concern; (2) determining concentrations of Chemicals of Emerging Concern (CEC) at a range of wastewater outfall sites with varying hydrodynamic settings; and (3) assessing where environmental impacts are likely to be greatest. It focused on five key pollutant groups: microplastics, nutrients, heavy metals, PFAS (per- and polyfluoroalkyl substances), and antimicrobials. Hydrodynamic modelling was used to evaluate residence times and pollutant dispersal in selected marine settings, and field sampling was conducted to assess contaminant levels and potential ecological impacts on the lower food web. The project built on the findings of NESP Marine and Coastal Hub Scoping Study 1.16, which identified the need for impact assessments for CECs.

The project generated new knowledge to inform risk assessments of emerging contaminants in the marine environment and provides recommendations for prioritising future monitoring and investment. It also enhances access to wastewater discharge data through continued development of the National Outfall Database.

Outputs

• Measures of CEC (contaminants of emerging concern) and microbial community composition in water and sediment samples taken from outfall sites [dataset]

• Final project report [written]