ERA was engaged by TasWater to assist with the outfall relocation projects for the Cygnet and Geeveston sewage treatment plants. Both projects in southern Tasmania involved relocating discharge outfalls into deeper, faster flowing locations to significantly improve the dilution and dispersion of treated effluent and thereby reduce any impacts to the aquatic environment. ERA developed the environmental impact statements, development applications and planning reports.

Both projects were considered class 2B assessments by the Tasmanian EPA and were subject to a combined EPA and council approval process.

The main environmental assessment aspect of the projects involved integrating ambient environmental monitoring results with hydrodynamic modelling and qualitative risk assessments to assess potential impacts to the receiving environments. The impact assessments identified that the outfall relocations would result in a net environmental benefit at both sites.

Approval for both projects was secured in early 2022.