General

All large urban centres in Australia are located on or near the coast and have reticulated sewerage systems and sewage treatment plants (STPs) that treat domestic, commercial and industrial wastes to various levels prior to discharge. Discharge of effluent is mostly to the ocean or tidal estuaries. Developing peri-urban areas may rely on small package plants or have on-site wastewater systems that discharge to local waterways or to land. Smaller regional centres and rural towns dispose of waste to inland waterways or land. Until recently most sewage received only primary treatment (removal of large solids by screening and of sediment and organic matter by settlement) or secondary treatment (removal of biodegradable organic material and of some nitrate and phosphorous) and the effluent remained high in nutrients. Currently many more facilities incorporate some tertiary treatment (removal of nitrates, phosphates, chlorinated compounds, salts, acids, metals and toxic organics) and are reducing pollution loads in discharges. Reuse of treated effluent for non-potable purposes and use of biosolids in agriculture, horticulture, landscaping and land remediation is also occurring. Improvements to septic systems, other on-site wastewater systems and composting systems have also occurred and management of on-site systems is also being addressed through the Septic Safe Local Government Program.

Key Issues

Sewage treatment plants can discharge relatively high loads of nitrogen and phosphorous into receiving waters which can support excessive growth of algae. Also a range of chemicals including metals, chlorinated by-products (from the disinfection process), surfactants and pesticides are discharged. These are toxic and can impact adversely on human health, other biota and aquatic ecosystems. Pathogens are also of concern. Sewage overflows occur when the capacity of the system is exceeded during wet weather, or with treatment plant breakdowns; these are a major source of pollution as untreated or minimally treated sewage is discharged. STP discharges also alter river flow patterns by providing constant flows and these can affect ecological balances within aquatic ecosystems. Wastewater from on-site sewage systems carries nutrients, bacteria, and possibly viruses, parasites and other organisms and can contaminate surface and groundwater and impact adversely on soils and vegetation.

Protocols

National Water Quality Management Strategy's Guidelines available for Sewerage Systems relate to effluent management, sewerage system overflows, sludge (biosolids) management, and acceptance of trade waste (industrial waste). Guidelines for the use of recycled water from treated effluent (reclaimed water) are a recent addition to the strategy. They outline levels of treatment and associated uses and monitoring guidelines relating to the uses; general criteria underpinning these are the closeness of application to the human food-chain and the ability to restrict public access to areas where recycled water is used for irrigation.
For methods for the analysis of water pollutants consult the EPA (1998) reference: Approved methods for the sampling and analysis of water pollutants in New South Wales. The methods are based on the American Public Health Association, USEPA standard methods and the Standards Association of Australia.

Core protocols are those for the following indicators:

Bacteria monitoring
Physical and chemical
On-site sewage management

Supplementary protocols / information relate to:

Aquatic ecosystem health
Endocrine disruptors

Contacts - Core Agencies

The main organisations with formal responsibilities include the following.

• The EPA arm of the Department of Environment and Conservation issues under the Protection of the Environment Operations Act 1997 (POEO Act) 'Environment Protection Licences' for all government owned sewage treatment systems (including the treatment works, pumping stations, overflow structures and reticulation system) and all other systems that have a capacity of more than 750 kilolitres per day and involve discharge of wastes to land or water. EPA also implements load-based licensing for pollution point sources such as Sewage Treatment Plants These licences set operating (pollutant loads and discharge frequency), monitoring and reporting conditions and require the testing methods to be approved and carried out in accordance with relevant load calculation protocols. Pollution reduction programs may be negotiated also with associated requirements for environmental monitoring. The EPA also audits SWC and HWC water quality monitoring results.
• Department of Health develops standards and guidelines for the treatment of wastewater.
• Councils have responsibility for licensing and monitoring the performance of small package sewage treatment plants and on-site wastewater systems under the Local Government Act 1993 and its associated regulation, Local Government (Approvals) Regulation 1999. The POEO Act provides councils with stronger powers to investigate complaints and issue legally binding notices if compliance with performance standards is not met.

Other organisations involved

• The Department of Energy, Utilities and Sustainability is involved in managing sewerage schemes for country towns and reports annually on sewerage breakdowns and overflows.
• Department of Infrastructure, Planning and Natural Resources provides technical management and financial support to Councils through the Country Towns Water Supply and Sewerage program.
• Sydney Water Corporation manages wastewater systems in the Sydney Metropolitan Region. It undertakes a performance assessment monitoring program to meet the EPA licence requirements.
• Hunter Water Corporation manages the Inland Wastewater Environmental Program; it undertakes monitoring to meet the terms of its environment protection licence (DEC (EPA))
• The Water Services Association of Australia (WSAA) reports on the performance of the large water authorities around Australia.

Case Studies

Various Local Government Case Studies (Septic Safe Grant Funded)

Moreton Bay Waterways and Catchment Partnership (South East Queensland)