Pollution and sewage regulations

As the number of large recreational boats and commercial vessels in Western Australian waters increases, it is becoming more and more important to control the discharge of sewage into the marine environment.

Marine pollution due to sewage and sullage is regulated at the international, national and state levels.

How does it enter the marine environment?

Treated and untreated sewage can be discharged from vessels under normal operating conditions. Accidental discharges could also come from vessels and land-based sources.

Sewage treatment plants may also make controlled discharges into the water.

What impact does it have?

Sewage can have varying effects on the marine environment, depending on habitat types and locations. Some may be able to absorb more sewage, but others could be significantly impacted.

Large quantities of nutrient-rich sewage may encourage algal blooms, which deplete the oxygen supply, killing larger marine life.

Sewage could also introduce bacteria that cause disease for humans who come into contact with it, or who eat seafood from an affected area.

What you can do

You can reduce the amount of sewage being released into the water by:

• Using shore facilities when in harbour, rather than your vessel's toilet.
• Installing an approved sewage treatment system in your boat if possible (please contact the Department of Health for more information).

Department of Transport sewage strategy

The Department of Transport's sewage strategy provides guidelines for sewage discharge in Western Australian waters. It established 3 zones based on the degree of risk to public health and the environment:

• Zone 1 - No discharge.
• Zone 2 - No discharge except for vessels with approved treatment systems.
• Zone 3 - Open zone.

Please download our sewage strategy below.

Rottnest Island

Release of untreated sewage is prohibited in the bays and designated sanctuary zones (see Zone 1 above). Waste from a Department of Health approved treatment units may be discharged into other parts of the marine reserve (see Zone 2 above).

For more information, please go to the Rottnest Island Authority.

Swan and Canning rivers

Sewage discharge is totally prohibited (see Zone 1 above).

For more information on the Swan and Canning Riverpark, please go to the Swan River trust.

Murray and Serpentine rivers

Sewage discharge is totally prohibited (see Zone 1 above).

Peel and Harvey Inlet

Sewage discharge is totally prohibited (see Zone 1 above).