Water Quality Guidelines
The guidelines below were obtained from: Australian and New Zealand Environment and Conservation Council 1998 Australian Water Quality Guidelines For Fresh And Marine Waters, National Water Quality Management Strategy, "Draft Version".
Salinity
Domestic use - 500 mg/litre:
Salinity is the sum of all the salts present and it provides a convenient guide to water suitability. Above this limits taste may be unacceptable but it does not pose a health problem. Total salinity and the concentrations of individual salts can be reduced by reverse osmosis, ion exchange or distillation. If most of the salinity is due to hardness it can be reduced by softening the water.
Stock use - 10,000 mg/L:
There may also be a need to assess concentrations of specific salts causing purgative or toxic effects, especially if the salinity is greater than 2500 mg/L. If salinity is in the range 4000 to 5000 mg/L stock may have an initial reluctance to drink or there may be some scouring, but they should adapt without loss of production. From 5000 to 10,000 mg/L loss of production and a decline in animal condition and health would be expected. Stock may tolerate these levels for short periods if introduced gradually.
Nitrate
Domestic use - 50 mg/litre:
Based on health considerations a limit of 50mg/litre is recommended for babies less than three months old and 100mg/litre for older children and adults. Nitrate levels can be reduced if necessary with the ion exchange process.
Stock use - 400 mg/L:
Excess nitrate can cause toxic symptoms and even death by reducing the oxygen carrying capacity of the blood. Stock may tolerate higher nitrate concentrations in drinking water provided nitrate concentrations in feed are not high. Levels above 1500 mg/L are likely to be toxic and should be avoided.
Fluoride
Domestic use - 1.5 mg/litre:
This limit is based on health considerations. Excess fluoride can be removed by treating water with aluminum sulphate or bone char.
Stock use - 2.0 mg/L:
Excess fluoride can cause tooth damage to growing animals and bone lesions and embrittlement in older animals. If livestock feeds or salt licks contain fluoride, the drinking water limit should be reduced to 1.0 mg/L.
Iron
Domestic use - 0.3 mg/litre:
Above this limit taste may be unacceptable but it does not pose a health problem. High iron concentrations give water a rust brown appearance resulting in staining of laundry, pipe encrustation and odour problems. A common way to remove iron is to aerate the water by cascading it into a tank and allowing the iron floc to settle.
Hardness
Domestic use - 200 mg/litre:
Hardness is a measure of the amount of calcium and magnesium in the water. Hard waters can cause the build up of scale in hot water pipes and fittings. They also require more soap to obtain a lather. It can be reduced by softening the water.
pH
Domestic and stock use - 6.5-8.5:
This is a measure of the acidity or alkalinity. Values less than 6.5 indicate acidic water and can result in corrosion of pipes and fittings. When pH is more than 7.5 the water is alkaline and encrustation of pipes with calcium carbonate can occur. pH can be adjusted to a more desirable level by the addition of either an appropriate acid or alkali.
Chloride
Domestic use - 250 mg/litre:
Above this limit taste may be unacceptable but it does not pose a health problem.
Sulphate
Domestic use - 250 mg/litre:
Above this limits taste may be unacceptable but it does not pose a health problem.
Stock use - 2000 mg/L:
No adverse effects should be expected below 1000 mg/L. Between 1000 and 2000 mg/L sulphate can cause diarrhoea, particularly in young cattle. Concentration above 2000 mg/l can cause chronic or acute health problems.
Sodium
Domestic use - 180 mg/litre:
Above this limits taste may be unacceptable but it does not pose a health problem.People with severe hypertension or heart disease should seek medical advice if sodium exceeds 20mg/litre in drinking water.
Calcium
Stock use - 1000 mg/L:
Levels above 1000 mg/L may cause phosphorus deficency by interfering with phosphorus absorption in the gastrointestinal tract.
Magnesium
Stock use:
In high doses magnesium can cause scouring and diarrhoea in cattle. Levels up to 2000 mg/L have been observed to have no adverse effects. There is insufficent information available at present to set a guideline value.
