Washwater

A 2002 study on the quality of waste wash water used on Australian vegetable farms revealed some treatment would be needed before it could be safely recycled.

Some persistent herbicides were found in high enough concentrations to cause damage to future crops and organic matter levels were usually too high to effectively use disinfectants for the control of water and soil-borne diseases.

Water treatment depends on a range of factors such as intended use, quality of source water and quality after existing treatment or storage operations. There is no single answer and decisions should be based on careful consideration and advice for each situation.

Benefits:

• Remove objectionable odours
  
  
• Improve water quality so current water disinfection treatments are effective against human and plant pathogens
  
  
• Efficiently use a scarce resource and lower overall water consumption on farm

Washwater recycling cuts the water cost of washing to around $5/tonne of produce. However, low cost water treatment may be necessary to ensure the use of recycled water does not lower the food safety standards of the product..Water impurities vary in size and character from plant material, sand and soil to fungi, bacteria, viruses and chemicals.