Wastewater and sewage
All forms of household wastewater are infectious, pollutant and a risk to human health and the environment. When managed properly and carefully through sewage treatment processes wastewater can be managed in a relatively safe and environmentally sustainable way. Wastewater can also be treated for utilisation by recycling and reuse. There are three types of household wastewater:
- Blackwater is wastewater generated from a toilet, bidette or bidet which is heavily and directly contaminated with human faeces and/or urine and may contain contaminated solid material, such as toilet paper. This wastewater is highly infectious.
- Greywater is wastewater which does not arise from a toilet and includes wastewater from a hand basin, shower, laundry and kitchen. Greywater is often contaminated with human faeces, dirt and other materials but to a lesser extent than blackwater and is therefore less infectious than blackwater.
- Sewage is a combination of both blackwater and greywater, and again is very infectious.
Stormwater refers to the water resulting from rain draining into the stormwater system from roofs (rainwater), roads, footpaths and other ground surfaces. Stormwater can include sewage from sewer overflows.
Wastewater may be disposed of in three ways:
- Centralised through pipes called sewers into a sewerage system and treated in a single large sewage treatment plant where it can be converted into a resource for selective reuse for car washing, outdoor household garden watering, toilet flushing, golf course watering and irrigation of crops. The treated effluent may also be discharged to rivers and oceans.
- De-centralised through pipes into a local community small sewage treatment plant for local community reuse. A number of these local systems make up de-centralised sewage management.
- On-site singe domestic wastewater management where the sewage or components such as greywater must be partially or fully treated for utilisation or reuse within the property boundaries. On-site single domestic wastewater management is regulated jointly by local councils and NSW Health. On-site systems may not be installed unless approved by the local council. NSW Health accredits on-site sewage management facilities under the provisions of the Local Government (Approvals) Regulation, as a pre-requisite to local council approval.
What is water recycling?
Water recycling refers to the treatment and reuse of sewage, greywater and/or stormwater, for non-potable purposes. NSW Health supports the reuse of treated wastewater provided the health risks are adequately managed.
Regulation and application process
The regulatory path depends on the source water to be recycled and the proponent of the scheme as shown in the tables below. NSW Health recommends the use of the Australian Guidelines for Water Recycling 2006 which advocates a preventive risk management approach. The risk management framework is used to develop a management plan that describes the recycled water system and how it should be operated and managed.
Wastewater recycling stakeholders and roles in NSW
Sydney Water and Hunter Water
Sydney Water and Hunter Water are regulated through operating licences administered by the Independent Pricing and Regulatory Tribunal (IPART). Sydney Water and Hunter Water are required to implement a Recycled Water Quality Management System consistent with the Australian Guidelines for Water Recycling 2006 and ensure that all relevant activities are carried out to the satisfaction of NSW Health.
Local water utilities
In regional NSW, local water utilities undertaking construction or modification of a water recycling scheme are required, under Section 60 of the Local Government Act 1993 or section 292 of the Water Management Act 2000, to seek approval from Department of Industry (DoI) Water, formerly Department of Primary Industries (DPI) Water. Local water utilities are encouraged to consult with their local Public Health Unit when considering the development of a recycled water scheme.
Private schemes – on-site use (residential or commercial)
Local councils are responsible for issuing approvals to both install and operate systems of sewage management (including recycled water) as defined under section 68 of the Local Government Act 1993. This includes on-site single household recycling. Councils are encouraged to consult with their local Public Health Unit and DoI Water when considering applications for private recycled water schemes.
Private schemes – corporations providing water utility services
A corporation (other than a public water utility) must obtain a licence to construct, maintain or operate any water industry infrastructure or to supply recycled water. IPART administers these licences under the Water Industry Competition Act 2006. The Minister for Health is invited to make a submission on these licence applications. NSW Health supports IPART’s assessment and approval process.
Other schemes- including metropolitan councils
For other recycled water schemes, NSW Health does not have a formal regulatory role but works closely with regulators, recycled water scheme proponents and other relevant stakeholders to ensure public health risks are considered and managed.
At present, metropolitan councils (in the Sydney Water and Hunter Water areas of operations) are not required to seek approval under Section 60 of the Local Government Act 1993
or section 292 of the Water Management Act 2000
. Metropolitan councils are encouraged to consult with their local Public Health Unit when considering the development of a recycled water scheme to ensure that public health risks are managed.
There are specific plumbing requirements for recycled water schemes. NSW Fair Trading is the regulator for plumbing and drainage in NSW.
NSW Health recommends the use of the Australian Guidelines for Water Recycling: Managing Health and Environmental Risks for wastewater and stormwater.
DPI Water (now DoI Water) developed guidance and information sheets for local council water utilities that are seeking approval for new or existing recycled water schemes. DPI Water's NSW Guidelines for Recycled Water Management Systems and a series of information sheets on the provision of safe recycled water support the implementation of the preventive risk management approach in the Australian Guidelines for Water Recycling 2006 .
NSW Fair Trading
provides information on the plumbing code and standards for recycled water schemes.
An incident notification and response protocol should be developed in consultation with NSW Health. The protocol should define potential incidents that are specific to the recycled water system and include sufficient detail to determine an incident. This may include treatment information such as the critical control point critical limits, health related water quality objectives such as microbiological criteria and end use information. The roles, responsibilities and contact details of all involved parties need to be clearly defined and kept up to date.
Incident notification to NSW Health should occur immediately and be followed up in writing as agreed with the appropriate regulatory agency. NSW Health has general powers under the Public Health Act 2010 to issue orders and direct suppliers of water (including recycled water) to prevent public health risks.
NSW Health recommends that stormwater harvesting schemes are developed and managed in line with the Australian Guidelines for Water Recycling: Stormwater Harvesting and Reuse 2009
for stormwater to ensure health risks are managed. The guidelines advocate a preventive risk management approach. This approach includes a scheme specific risk assessment involving all relevant stakeholders including NSW Health. Councils/organisations conducting stormwater harvesting are encouraged to contact their local Public Health Unit for advice.
Stormwater recycling stakeholders and roles in NSW
NSW Chief Health Officer, Dr Kerry Chant convened an expert advisory panel to consider community concerns of health risks from the use of biosolids sourced from Sydney Water in response to reports that these products were causing gastrointestinal disease in Sydney residents.
Members of the expert advisory group considered the risk to human health from Grade A and Grade B biosolids was negligible if the recommended treatment and use followed the Environment Protection Authority (EPA) guidelines.
The panel’s findings are available. Also see the NSW Health fact sheet on biosolids.