06.The bigger environmental picture
Water utilities are doing more to recycle wastewater for use in industry, agriculture and urban irrigation, and are experiencing higher concentrations of detergent ingredients in wastewater. This limits the potential use of recycled water as higher levels of detergent can be detrimental to plant growth and soil structure.
In addition to our usual performance and greywater reuse tests, we’ve teamed up with the Water Services Association of Australia and City West Water (a government-owned Melbourne water retailer) to analyse the chemical load the detergents add to wastewater treatment plants, so you can find products that wash well, and by keeping chemical loads low, maximise opportunities to use recycled water and limit impacts on inland ecosystems.
The main concern is the high levels of total dissolved solids (TDS) – mostly salts such as phosphates, nitrates, sulphates and sodium – in laundry detergents. Removing tonnes of salt from wastewater is a very energy-hungry and expensive process – a reverse osmosis (or desalination plant) is required. And then there’s the problem of how best to dispose of the salts once they’re removed, particularly for inland cities and towns.
A more sustainable and economical solution is to use a detergent with low TDS, (see waste water recycling in compare detergents). Liquids generally have lower TDS per wash but there are some good powder options also. Secondly, try using half of the recommended dose, as tests show you can still get good performance. For more information, see Detergent overdose.