EPA reviewed the previous standards with the Department of Health (DoH), Melbourne Water and Monash University. The review found the previous standards are out-of-date.
The previous standards:
- no longer represent best practice
- don’t reflect national guidelines used in other states.
The new standards will help EPA and councils give better advice about water pollution.
Causes of beach and river pollution
Pollution often reaches beaches and rivers after storms, but it can also happen during dry weather.
The biggest risk of illness comes from faecal pollution (poop). It can come from a range of sources, including:
- faulty septic tanks
- sewerage system leaks
- poor waste management at homes and businesses
- cross connections between sewers and stormwater
- boat discharges
- animals, including pets, wildlife, birds and farm animals.
This pollution can increase the risk of illness for people using the water for recreation.
Risks to human health when swimming in Port Phillip Bay
EPA commissioned a quantitative microbial risk assessment at three popular Melbourne beaches to better understand the risk on swimming in the bay. Monash University undertook the study that shows that risks are much lower than expected, and this may be due to the origin of the faecal contamination. More information is available in Assessing risks to recreational water users in Port Phillip Bay using quantitative microbial risk assessment (publication 1935).
The new standards reflect the latest advice from the National Health and Medical Research Council (NHMRC). The NHMRC is a national body that does medical research and recommends health guidelines.
The new standards are based on scientific studies to better protect public health. These studies link microbial levels in water with the risk of illness. Microbes are tiny living things in water, soil and air. Some are harmless and others may make us sick. We are now reporting on these more accurately with the new standards.
Being aware of the link between microbial levels in water and illness, means being able to make more informed decisions about safely enjoying water activities.
How the new standards will change water quality reporting
The new standards include ‘microbial objectives’ that are linked to health outcomes. This means that we have thresholds (levels) which we will use to warn the public of immediate health risks.
When we apply the new standards to Beach Report and Yarra Watch, we may find more sites with poor microbial water quality, posing increased risk of illness. Microbial water quality means the amount of microbes in the water.
This means you may see more ‘Poor’ water quality forecasts, alerts or swim advisories. A swim advisory is a notice or alert that gives advice, for example, to avoid the water for swimming. This doesn’t necessarily mean that the water is now poorer, it just means the new standards are more accurate.
EPA has started using the new standards
We are already applying the new standards when we issue forecasts and swim advisories. A forecast tells you what the expected water quality is likely to be. A swim advisory tells you if water quality is unsuitable for swimming.
During the summer, EPA will continue to provide twice daily forecasts for Beach Report and Yarra Watch. Weekly monitoring will also continue and we will issue swim advisories in line with the new standards.
EPA will work with Bay and Yarra River councils to communicate with the public and investigate water quality when it is not suitable for swimming.
How to access forecasts that use the new standards
Check Beach Report and Yarra Watch. There have forecasts twice a day. They are the main information source on water quality for recreation during summer. These forecasts advise of likely water quality so that you can make informed decisions about swimming.
Continue to follow the advice in swim advisories when the water quality is not suitable for swimming.
Actions to improve water quality in the Yarra
EPA and Melbourne Water will continue to monitor water quality in the Yarra. This is to:
- better understand the health risks
- identify the pollution sources
- inform future management actions.
Reviewed 26 November 2021