Water quality on the farm

When buying a property it is easy to make the mistake of assuming that any water is good water. Unfortunately dam and bore water can have hidden quality problems including salinity, hard water and high or low pH, which make it unsuitable for some applications, and its impossible to know this just by looking at the water.
The two basic tests that can give you an indication of water quality are total dissolved solids (TDS) and pH. Total dissolved solids can be estimated using an electrical conductivity (EC) meter, which then gives you an indication of the concentration of dissolved solids, or the salinity, of the water in ppm (a full analysis involves evaporating all the water and weighing the residue). Approximately, 1 microS/cm of EC is equivalent to 640 ppm of total dissolved solids. This just tells you that you have dissolved minerals in the water, but you don’t know exactly what they are and what problems they could create.  

For example, dissolved calcium and magnesium tend to cause “hard water”, which will create deposits in pipework and react with soap to form a scum, rather than suds. Iron in the water feeds bacteria that produce a sludge which can block pipework. Nitrate concentrations can affect some crops and makes the water unsuitable for irrigation and some stock. Sodium is also toxic to plants at certain concentrations. Manganese can precipitate and block pipework. Even if the minerals are relatively benign, high levels of salinity will reduce the ability of plants to access water, and can make the water unpalatable for stock and humans.

The pH of water can be measured using a pH meter or pH strips, the meter will give you a more accurate result compared to interpreting the colour of a pH strip. Plants and animals need water close to pH 7.
pH metre
Higher than pH 7 is alkaline and suggests that minerals such as calcium and magnesium are dissolved in the water, which is common in bore water. A pH lower than 7 is acidic, and is common in rainwater due to dissolved pollutants including oxides of nitrogen and sulphur, which form nitric and sulphuric acid respectively when dissolved in water.
You may find that your local council or state agriculture department laboratories are able to test your water free of charge. Otherwise you can send your water for analysis at various commercial laboratories. The other option is to buy EC and pH meters yourself, as they are relatively cheap now, and you will be able to use these to regularly monitor your water sources. If you send a water sample to a laboratory you will receive a more detailed analysis than just TDS and pH, they will be able to tell you which minerals are present in the water as well, but this may not be necessary if you TDS is low anyway.

Before you use water for irrigation or stock water, you should first test it for TDS and pH. If the TDS is below 500 ppm it will be suitable for most applications, including potable water. Above this level, the water is not ideal for irrigation of crops.  Water can be used for livestock water up to around 5,000 ppm (depending on the animal), however it also depends which minerals are present. If your water is higher than 500 ppm and you want to use it for irrigation or stock water, I recommend that you send the water to a laboratory for a full mineral analysis and an assessment of whether the water is suitable for your proposed application.
Unfortunately, it is very costly to remove minerals from water. If bore water is to be used for potable water in the house, it is possible to use a water softener to remove the calcium and magnesium from hard water. However, for stock water or irrigation purposes this would be impractical.  
EC metre
Water quality is an important consideration before you buy a property, so that you understand how the water could be used.

Other articles written by Liz
About Liz
Liz lives on eight acres in south east Queensland, Australia, with her husband Peter and two dogs. They have a passion for small-scale organic farming and producing and eating real food.  They keep chickens, beef steers, two jersey cows and a big vegetable garden. Liz writes a blog about their farm to both inspire and help others who are interested in self-sufficiency, sustainability and permaculture. http://eight-acres.blogspot.com.au/  Liz has also published an ebook about keeping a house cow, for more information see http://housecowebook.blogspot.com.au/ 

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