How much dairy effluent is produced each day?

The amount of dairy effluent produced varies from farm to farm, depending on how the farm operates.

Dairy effluent is made up of excreta (cow urine and dung) and water used to wash down the dairy, any feeding or housing areas along with small amounts of things like leftover milk, cleaning products, feed or bedding. 

The amount produced each day varies from farm to farm. A dairy cow typically produces around 50–70 kg of excreta per day, but how much of this is collected as effluent depends on the farming system. On pasture-based farms, around 10–15% may be collected, while housed systems may collect up to 100%.  

The amount of water used to clean concreted areas also makes a difference. This can depend on factors such as the number of milking units, the size of the dairy yard and the wash-down system. How often cows are milked, how much they eat and how much milk they produce also makes a difference. 

Once collected, dairy effluent is stored and managed so it can be reused as nutrients on pastures or crops.