Sewage spills

A sewage spill can be caused when wastewater treatment plants or pump-stations experience a mechanical fault such as loss of electrical power.

Broken or blocked sewer mains can also cause sewage spills.

Sewage may enter the waterway directly from the point of rupture or overflow, or through stormwater drains.

This can make the water unsafe for swimming and other forms of recreation such as water-skiing, jet-skiing and diving. Secondary contact activities such as boating, fishing and wading may also be affected.

Yes. If you have contact with or swallow water that is polluted with sewage it can make you very sick. Some illnesses may include:

• gastroenteritis (diarrhoea, vomiting)
• viral infections such as hepatitis
• infections of the skin or eyes.

There are many different organisations involved when a sewage spill occurs.

The roles and responsibilities of various government agencies is outlined in the Wastewater Overflow Notification and Response Procedures (PDF 911KB).

One of the primary responsibilities is making sure the public is aware when a sewage spill occurs.

When a sewage spill occurs the community will be informed as a top priority.

Warning signs and media releases will be issued to let you know the spill has happened.

If you ever see a health warning sign along the river or beach make sure you follow the advice and do not go swimming.

After a sewage spill, it usually takes from 48 to 72 hours for a water body to return to a safe condition. Sometimes it can take a week or more.

A number of factors will determine when a contaminated water body will return back to a safe condition. These include:

• salinity (the more salt the better)
• sunlight (the more sun the better)
• tidal movement
• weather conditions
• the volume of the spill.

The Department of Health will not give the water body the all clear until it has been determined to be safe for recreational purposes.

Evidence suggests that eating fish or crabs taken from water contaminated with sewage will not result in any known health effects as long as standard hygiene measures are followed.

This includes:

• washing your hands with warm water and soap after handling fish or crabs
• thoroughly washing fish with clean water before cooking
• cooking using correct times and temperatures.

You should not eat any filter feeding shellfish such as oysters or mussels taken from water contaminated by sewage because:

• They feed by drawing water through a membrane and trapping food for digestion. Therefore, they draw contaminated water through the flesh that you'll end up eating – this is particularly dangerous if consumed raw because of the disease causing bacteria associated with sewage.
• Organisms like viruses (especially Hepatitis A and Norovirus) are trapped in the flesh of the shellfish and are not killed by the normal cooking process of shellfish.

The Department of Health does not support the collection of wild shellfish from recreational waters surrounded by urban, industrial and commercial areas because the safety of eating wild shellfish cannot be guaranteed.

Further health information about the collection of shellfish from the wild can be found in the Wild shellfish collection (PDF 68KB) pamphlet.

If you notice sewage draining into a natural water body, you should immediately contact:

• Water Corporation
  
  • (Faults, emergencies and security)
  • T: 13 13 75 (24 hours)

• Department of Environment Regulation
  
  • (Emergency Pollution Response)
  • T: 1300 784 782 (24 hours)

You may also advise:

• Department of Health
  
  • Environmental Health Directorate
  • (Monday to Friday, 8.30am to 5.00pm)
  • T: (08) 9222 2000
  • Health Duty Officer
  • T: (08) 9328 0553 (24 hours)

• Swan River Trust 9278 0900 (If sewage spill is in the Swan or Canning Rivers)
• Your local council (external site)