Water Quality Guidelines

The following tables match water type for intended use. The main methods of determining the salt content of water are by measuring Total Dissolved Salts (or Solids) and Electrical Conductivity.

Total Dissolved Salts (TDS) is measured by evaporating a known volume of water to dryness, then weighing the solid residue remaining. Electrical conductivity (EC) is measured by passing an electric current between two metal plates (electrodes) in the water sample and measuring how readily current flows (i.e. conducted) between the plates. The more dissolved salt in the water, the stronger the current flow and the higher the EC. Measurements of EC can be used to give an estimate of TDS.

TDS is recorded in milligrams of dissolved solid in one litre of water (mg/L). Parts per million (ppm) is equivalent to mg/L but it is not a favoured unit. EC measures the charge carrying ability (i.e. conductance) of liquid in a measuring cell of specific dimensions. It is necessary to clearly define the units of both conductance and length when talking ECs.

The standard EC unit used by the Victorian Salinity Program and the Murray Darling Basin Commission is microSiemens per centimetre (µS/cm) at 25oC.

Measurement Key:

1dd/Sm = 1mS/cm = 1,000mS/cm = 600 mg/l = 600 ppm

Table 1:Water uses according to EC Range

EC Range (mS/cm)	Usefulness of water
0-800	Good drinking water for humans (provided there is no organic pollution and not too much suspended clay material) Generally good for irrigation, though about 300mS/cm, some care must be taken, particularly with overhead sprinklers which may cause leaf scorch on some salt sensitive plants Suitable for all livestock
800 – 2,500	Can be consumed by humans although most would prefer water in the lower half of this range if possible When used for irrigation, requires special management including suitable soils, good drainage and consideration of salt tolerance of plants Suitable for all livestock
2,500 – 10,000	Not recommended for human consumption, although water up to 3,000mS/cm could be drunk if nothing else was available Not normally suitable for irrigation, though water up to 6,000mS/cm can be used on very salt tolerant crops with special management techniques. Over 6,000mS/cm, occasional emergency irrigation may be possible with care When used for drinking by poultry and pigs, the salinity should be limited to about 6,000mS/cm High magnesium may be present in water of this salinity level and above causing stock health problems. Water analysis is recommended
10,000 and above	Not suitable for human consumption or irrigation Not suitable for pigs, poultry or any lactating animals. Beef cattle can use water up to 17,000mS/cm and adult dry sheep can tolerate 23,000mS/cm. However it is possible that waters below these EC levels could contain unacceptable concentrations of particular ions. Detailed chemical analysis is recommended before using high salinity water for stock Water up to 50,000mS/cm can be used to flush toilets provided corrosion on the cistern can be controlled

0 – 800 EC (mS/cm) 0 – 500 mg/L(ppm)	800 – 2,300 EC (mS/cm) 500 – 1,500 mg/L(ppm)	2,300 – 5,500 EC (mS/cm) 1,500 – 3,500 mg/L (ppm)
Avoid wetting leaves on hot, dry days	Avoid light, frequent watering and wetting leaves during daytime	Avoid wetting leaves Adequate leaching necessary
Fruits
Passionfruit Strawberry Apricot Peach Plum Grape Grapefruit Orange Lemon	Mulberry Apple Pear Raspberry Quince	Olive Fig Cantaloupe
Vegetables
Lettuce Green beans/peas Carrot Celery Onion Radish Sweet corn Potatoes	Cabbage Cauliflower Broccoli Broad beans Tomato Sweet potato	Spinach Asparagus
Flowers
Violet Primula Dahlia Begonia Azalea Camellia Magnolia Fuchsia	Rose Gladiolus Aster Geranium Zinnia	Stock Chrysanthemum Carnation Hibiscus Oleander Bamboo

Livestock	Levels	EC (mS/cm)	Mg/L (ppm)
Poultry	Production decline begins	3,100	2,000
Poultry	Maximum	6,250	4,000
Pigs	Production decline begins	3,100	2,000
Pigs	Maximum	6,250	4,000
Horses	Health/growth affected	6,250	4,000
Horses	Maximum	10,900	7,000
Dairy Cattle	Production decline begins	4,700	3,000
Dairy Cattle	Maximum	9,300	6,000
Beef Cattle	Production decline begins	6,250	4,000
Beef Cattle	Maximum	15,600	10,000
Lactating ewes, weaners	Production decline begins	6,000	3,800
Lactating ewes, weaners	Maximum	10,000	6,400
Sheep, dry feed	Production decline begins	9,300	6,000
Sheep, dry feed	Maximum	21,800	14,000

Water Quality Guidelines

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