Livestock may be affected by poor quality water causing death, sickness or impaired growth. Variables of concern include nitrates, sulphates, total dissolved solids (salinity), a number of metals and organic micropollutants such as pesticides. In addition, bluegreen algae and pathogens in water can present problems.
Some substances, or their degradation products, present in water used for livestock may occasionally be transmitted to humans.
The purpose of quality criteria for water used for livestock watering is, therefore, to protect both the livestock and the consumer.