Pouring a bit of out-of-date milk down a kitchen sink might seem harmless, but the interconnected nature of drainage systems means it is not.
Redland City Council and City Water are reminding residents that Fats (including those in milk), Oils, Greases (FOGs) poured down the kitchen sink pose a significant threat to Redlands Coast’s wastewater network.
Many people don’t think twice about what they put down their kitchen sink, but things such as cooking oil, food scraps, milk, coffee grinds, chemicals and paint, all eventually end up in the same wastewater pipeline as sewage.
All indoor wastewater – from toilets, sinks, laundries, bathtubs and showers – connects within the property and is then directed into public sewer pipes where it travels to a sewage treatment plant.
When matter not designed to be flushed down toilets (anything other than the three Ps – poo, pee and paper) combines with FOGs they can clump together in large deposits known as fatbergs which can block drains.

Fatbergs can weigh in the tonnes and are difficult to pull apart and dislodge.
One way of disposing of old milk is to add water (four parts water, one part milk) and pour it on the garden or pot plants as a natural fertiliser.