Wastewater is used water and waste from our homes and workplaces, and is also known as “sewage”. It is 99.9 per cent water. The other 0.1 per cent consists of:

• Organic matter such as human waste and food scraps
• Oil and grease
• Traces of heavy metals such as silver, lead, zinc and copper
• Debris such as sand, grit, wood and plastic
• Bacteria and viruses that can make people ill
• Nutrients such as nitrogen and phosphorus that sound healthy but in reality harm our harbours and waterways. Nutrients can deplete oxygen and cause fish to die, create excessive plant growth, and result in toxic algal blooms.

Wastewater also comes from your toilet,bath, shower, kitchen (including your insinkerator) and laundry, and contains soaps, detergents, food scraps and whatever else we dispose of. Wastewater also comes from all types of shops and industries such as fish shops and butchers, factories, breweries, schools, hospitals and offices.

Added to our wastewater mix is stormwater that can enter the system either by infiltration (leaking into the sewer) or illegal connections. The purpose of a wastewater system is to take all the wastes away and make them harmless to our community and environment.