Please note that this is only a very brief overview of what is a very complex issue. We will be adding updating this information between now and June 2009.
The Issue: The management of stormwater and wastewater (effluent) being discharged into the marine environment is a big issue in South Australia. Pollutants, including sewage, stormwater, industrial effluent, anti-foulants, ballast water and catchment discharges that contain nutrients, organic sediments, heavy metals, and agricultural chemicals, impact on coastal, estuarine and marine habitats and species (1). These impacts are both direct and indirect, primarily resulting from a decline of water quality through discharges from industries, waste water treatment plants and major stormwater outlets.
The State of the Environment Report 2008 by the EPA (2) for South Australia notes that while there have been improvements it summarizes trends as follows:
What is happening:
Stormwater
Stormwater management in South Australia is now being addressed jointly by State and Local Government. The Stormwater Management Authority (SMA) was established on 1 July 2007 under the Local Government (Stormwater Management) Amendment Act 2007. The South Australian Government lead is Minister for Water Security. The SMA was established following an agreement between the Local Government Association and the State government. For more information: http://www.lga.sa.gov.au/site/page.cfm?u=575
The SMAs role is to implement and operate the Stormwater Management Agreement as the planning, prioritising and funding body in accordance with the Agreement. Local councils play a major role in stormwater management. They must prepare stormwater management plans under guidelines from the SMA. While this is a positive step the CCSA thinks (5) there is a need for a more co-ordinated, state and/or Adelaide-wide stormwater strategy. Currently the Stormwater Management Authority examines individual projects but does not manage a bigger picture with a co-ordinated approach.
There also needs to be co-ordinated and timely implementation of the Adelaide Coastal Waters Quality Improvement Plan, with adequate resources, when the plan is finalised.
In total, the State has 23 wastewater treatment plants -three major plants in metropolitan Adelaide and 20 in country South Australia. Each year across the State approximately 90 billion litres of wastewater is collected and treated.
The infrastructure required to manage the South Australias wastewater is vast and expensive. All but one of the 23 plants are managed by SA Water
Wastewater Projects (6).
Most wastewater treatment plants use a three stage process to make wastewater suitable for reuse or discharge: