Trestrail C, Reis Santos P, Gwyther D, Rohmana, Qurratu A’Yunin, Gemmill J, Gillanders B, Roughan M, Bishop D, Seymour J* and Doblin M* (2023). Ecological outcomes of wastewater discharges in contrasting receiving environments: Report to the National Environmental Science Program. University of Technology Sydney. *project leaders
Overview
This project determined the ecological effect of coastal wastewater treatment plant (WWTP) outfalls in two different coastal settings. Treated effluent, seawater, and marine sediments were collected from the Glenelg and St Kilda outfalls located in the St Vincent Gulf, South Australia. This is a shallow and retentive receiving environment and may accumulate effluent contaminants. Additionally, sediments were collected from the Malabar outfall in New South Wales. This deep-water outfall discharges into a highly dispersive environment and offers a point of comparison for contaminant retention with the St Vincent Gulf. Work focused on five contaminants that water quality managers had identified in the NESP 1.16 project as being highly important: nutrients and metals as traditional effluent pollutants, and antibiotics, per- and poly-fluoroalkyl substances (PFAS) and microplastics as contaminants of emerging concern. Ecological effects of effluent were assessed by measuring changes to the diversity and composition of microbial assemblages in the water and sediment.
