Washing wisely includes considering what happens to your laundry wastewater, which contains dissolved detergent ingredients, suspended solids, and microorganisms from your laundry activities.
In Australia, most wastewater is treated to produce biosolids and effluent. The destination of these products dictates what level of treatment is required. Treatment minimises any negative impacts on public health and on the environment, and increases the opportunities to recycle these products.
If you live in a large urban community, it is likely that
your household is serviced by a sewage treatment plant. Many coastal
plants discharge to the ocean, but many also discharge to inland waterways
within the urban areas.
Wastewater from smaller inland communities is usually treated at local sewage treatment plants and the effluent is discharged to inland waters or reused on land.
If you live in a small or isolated community, you are
likely to have a septic tank. These rely on anaerobic microorganisms
breaking down some of the suspended solids in the wastewater. The liquid
effluent then drains to absorption trenches or seepage pits where the
surrounding soil bacteria break down organic matter. Further treatment
such as disinfection can be performed if the water is to be recycled.
In 2007-8, Australian capital city water utilities recycled 11.3% of their total effluent, and rural water utilities recycled 19.3% of their total effluent. (National Water Commission) Some households recycle greywater for use on their garden. Click here for more information.