The Environment Protection Authority (EPA) has concluded its assessment of a proposal by the Tasmanian Water and Sewerage Corporation Pty Ltd (TasWater) for relocation of Cygnet Wastewater Treatment Plant (WWTP) outfall (discharge) in Port Cygnet in the Huon Valley.
The proposal is to move the existing outfall of the Cygnet WWTP from its current location on the foreshore above the high-water mark in the Port Cygnet Marine Conservation Area. It will be relocated to deeper water off Crooked Tree Point, still within Port Cygnet, but outside the conservation area. The proposal includes construction and operation of a new treated effluent pumping station within the boundary of the Cygnet WWTP, a new 1.7 km pipeline and an outfall pipe with diffuser to a water depth of 6m.
Deputy Director EPA Tasmania, Cindy Ong, who made the determination under delegation from the EPA Board, concluded the proposed development can be managed in an environmentally sustainable and acceptable manner, with certain conditions. The Board requires these conditions to be included in any permit subsequently granted by Huon Valley Council.
“Various environmental issues were considered by the Board in its assessment, particularly the impact of the relocated discharge on water quality in Port Cygnet. The proposed location at Crooked Tree Point is into deeper water than the current discharge and the outfall pipe will be fitted with a diffuser to assist with dilution and dispersion of the effluent. This will offer immediate benefits in terms of reducing eutrophication impacts at the current discharge location. Environmental conditions imposed require a program of receiving environment studies following commissioning of the new outfall to validate modelling conducted for the discharge, understand the impact of the new discharge regime, and inform any further improvements that may be required” Ms Ong said.
No representations were received in relation to the permit application. Public consultation was open for 28 days from 18 August 2021.
The proposal was considered by the Deputy Director in the context of the sustainable development objectives of the Resource Management and Planning System of Tasmania (RMPS), and in the context of the objectives of the Environmental Management and Pollution Control System (EMPCS) established by the EMPC Act.
The functions of the EPA are to administer and enforce the provisions of the EMPC Act, to further the RMPS and EMPCS objectives and, in particular, to use its best endeavours to protect the environment of Tasmania.
The Deputy Director undertook the assessment of the proposal in accordance with the Environmental Impact Assessment Principles defined in Section 74 of the Act.
The Deputy Director’s environmental assessment report, including the environmental conditions, has been issued to TasWater and Huon Valley Council for their information.
The decision in relation to TasWater’s proposed relocation of the Cygnet Wastewater Treatment Plant outfall can be viewed on this website.