It is common sense, and a mandatory part of the outcomes based requirements, that farm dairies supplying raw milk intended for milk factories and milk processing plants must ensure that the water used in the dairy shed cannot adversely affect the milk quality.
Suppliers should ensure that all water which may come into contact with milk during milking, or as a result of cleaning the milking plant, is of suitable quality to ensure that the raw milk is safe from microbiological and physical contamination. While the requirements in Australia are results based, in New Zealand these are mandated by legislation. This is also laid down in EU legislation and therefore, dairy farmers serving export factories need to comply anyway.
While it is generally accepted that the water in the shed should meet drinking water quality requirements proving and maintaining complete compliance is expensive. Farmers do have to develop a water management plan and test the water for physical and microbiological safety.
In this respect two parameters should be measured:
Turbidity, which is fine suspended sediment and a measure of the clarity of water, must be no greater than 5 NTU.
Faecal coliforms, the indicator of faecal pollution of the water source must be no more than three per 100mL.
Water not complying with these parameters should not be used. Under the current extreme drought conditions, for many farmers alternative supplies may not exist so treatment of the water to achieve compliance is the ideal option. With many spring or surface sources the water quality is weather and environmentally dependent, so treatment is also recommended as insurance against bad results even if quality is usually good enough.
For many farm dairies the appropriate methods to ensure good quality water are to use cartridge filtration to reduce turbidity and UV light to inactivate bacteria, including E-Coli. In several circumstances both treatments are used as they are complementary, filtration removes turbidity that can shield micro-organisms from the UV light. It would be rare that water containing significant turbidity would be free of E-Coli.
UV systems and filters are available in a range of sizes, the Davey Steriflo series being the extremely comprehensive with a model for every flow rate from 10 litres per minute and upwards to whole of town systems. While a new technology to many Australian dairy farmers, UV light is used World-wide to treat water on a large scale for town and food industry water supplies to eliminate microbiological contamination.
Filtration with cartridges is simple and economical if chosen correctly. In several installations a pre-filter rated at 20 microns is the first stage of treatment. The cartridge in this filter can be cleaned several times. The second stage filter is fine with a 1 micron rating. This is fine enough to remove turbidity particles and the unpleasant protozoa Giardia and Cryptosporidium, which cause severe tummy upsets and worse.
The UV unit is the final stage and it consists of a stainless steel cylinder through which the water passes and is exposed to the UV light, which inactivates harmful organisms including coliforms and pseudomonas.
In many cases fitting suitable cartridge filters and an appropriate UV unit into an existing water system is quite simple. Filter and UV system connections are standard BSP pipe threads and power consumption is only 45 watts in the majority of installations. In the case of severe suspended matter contamination or high iron loadings other treatment may be needed.
As additional protection for dairy water supplies, a safe chemical option like the Davey Acquasafe can be added to storage tanks. Acquasafe is completely non-toxic, and breaks down to simply water and oxygen. It can last as long as two months between dosing.
The installation of a suitable water treatment system will not only reduce the possibility of adverse milk grades it may have benefits for the farm family. It is frequently the case that the treated water is used in the dairy and the farmhouse, so water not meeting the quality needed for the dairy shed is also unsuitable for drinking by people.
Acquasafe available from Davey Water Products dealers provides cost effective protection of tank water against e.coli and streptococci or similar bacteria load.
Acquasafe is available in one litre, five litre or 25 litre containers and is non-toxic and environmentally safe as it breaks down into oxygen and water.
Ensuring a safe water supply is becoming an increasingly important issue as rainfall deficits persist. The wide variety of potential contaminants that can provide personal health issues as well as the risk of litigation.
Davey Water Products offers a range of water treatment solutions like this Steriflo UV and filtration system for household and commercial water supplies.