Guidelines for the use of non-potable water in food businesses Introduction Potable water in When the water supply is These guidelines provide information to food businesses not guaranteed to be safe assist food businesses to ensure that Food laws require food businesses to use a. The reticulated drinking water supply their water supply is safe for food “potable water” for all activities that use to a food business has had a preparation and human consumption. water on the premises unless the use of temporary interruption to the safety of The reasons why the water supply to a “non-potable water” will not affect the that supply maybe because of water food business may not be safe may be safety of the food. treatment plant breakdown, fire, due to either a temporary interruption to Potable water simply means water that is flooding etc. the safety of the reticulated drinking acceptable and safe for human b. A reticulated water supply does not water supply or the source of water is not consumption and must be used in a food meet drinking water standards. from an adequately treated drinking business for: c. A private supply such as: water supply. •Washing food and/or food ingredients; • Rainwater tanks; or These guidelines will assist businesses •Cooking: where there is the possibility that the •Ground water such as Bores; or water supply is microbiologically unsafe. • Adding to food and drinks; • Surface water sources such as a Concerns and issues regarding the •Making ice; river or lake. chemical safety of the water supply •Cleaning of food contact surfaces; should be raised with the local council Food laws and potable water health department. •Cleaning of food containers and utensils; and Paragraph 4 of Food Safety Standard •Personal hygiene. 3.2.3 requires a food business to use potable water for all activities that use Non-potable water can be used only water on the food premises, unless the when it will not affect food safety. For business demonstrates that the use of example the flushing of toilets or cleaning non-potable water for a purpose will not non-food contact surfaces such as floors, adversely affect the safety of the food or if it is treated to be safe for human handled by the food business. consumption. If in doubt please consult your local council health department. Paragraph 14(2)(b) of Food Safety Standard 3.2.3 requires hand washing facilities to be connected to, or otherwise provided with, a supply of warm running potable water. Department of Human Services Guidelines for the use of non-potable water in food businesses 2 Figure 1: When water is safe to use in a food business Water from reticulated supply that Reticulated water meeting does not meet Drinking Water Standards Drinking Water Standards or a private water supply Temporary interruption unsafe unsafe Possible chemical to safety of supply contamination unsafe unsafe safe Temporary treatment Permanent treatment Contact local • Use commercially bottled water council health • Boiling department •Disinfection by chlorine Disinfection by Ultraviolet chlorine in water sterilisation or storage vessels Ozone treatment safe safe safe Safe water for use by food business Possible health risks Chemical Contamination Harmful smoky residues from solid wood heaters can also condense near flues on from non-potable water Chemical contaminants are usually less roofs. These chemicals may leach from common than microbiological Microbiological Contamination the roof surface over time and may be contaminants, but they can still be washed into rainwater tanks. Contaminated water may contain harmful present in the rural environment. micro-organisms, such as viruses and Aerial application of fertilisers and Soil from old industrial, mining or bacteria such as Salmonella or pesticides such as ‘crop dusting’ can agricultural areas may contain arsenic, Campylobacter and gastro-intestinal sometimes result in these agricultural heavy metals, pesticide residues or other parasites such as Giardia or chemicals entering rainwater tanks. chemicals. If dust is blown onto roofs and Cryptosporidium. These harmful micro- Agricultural chemicals may also drift or is washed into rainwater tanks, chemical organisms, known as pathogens, are not be washed into drains, irrigation residues may build up in the water. visible to the naked eye and may even be channels, local streams and dams. Runoff from roofs in urban or industrial present in clear water. areas may also contain chemical Whatever the water source is it is the Drinking water containing these micro- pollutants from the air. responsibility of the food business to organisms can cause severe gastro- check what possible chemical Lead-based paints or flashing used on enteritis, possibly lasting for several contaminants can get into the water some older roofs may also flake off weeks. Infants, the elderly and people supply. and be washed into rainwater tanks. with suppressed immune systems are Tar-based coatings can bind other These guidelines address how to make more likely to be affected. harmful organic chemicals such as the water supply safe if there is the pesticides to the roof surface and also possibility that the water supply is make it difficult to clean. microbiologically unsafe. If you suspect that your water supply could be chemically unsafe, consult with your local council health department. Guidelines for the use of non-potable water in food businesses 3 Water treatment methods Table 1: Temporary treatment Temporary treatment Water used for Action or treatment There can be times when a water supplier Drinking Use either commercially bottled water or water that has been brought to a rolling boil, that is the water is boiling vigorously for at least one (1) minute. may notify that its normally potable water supply will either be shut off for Ice making If you need to make ice during this time, only make it from water that is maintenance or has suffered from suitable for drinking (see above). temporary contamination, which is Washing of hands Use a water container with a tap that contains either bottled water or usually microbiological but may be water brought to a rolling boil for at least one (1) minute, or that has been accompanied by dirty water. They may disinfected with chlorine (see Chlorination guide on page 4). advise to boil the water for a short time, to Cleaning of Equipment For the cleaning of equipment, such as pots, pans, cutting boards, treat any possible contamination in the dishes and cutlery the following options can be considered: water supply. • Sanitising by immersing the utensils in hot water at or hotter than 77°C foratleast 30 seconds. As it is unlikely that a hot water system will There are number of things a food deliver water at a minimum of 77°C at the sink, it may be necessary to business can do to ensure the safety of use a water heater in the sink to maintain the temperature to at their water supply during a short-term least 77°C or an urn to feed water to the sink. A rinsing basket to interruption. submerge the utensils in the water is desirable for safety reasons. • Using a commercial dishwasher capable of sanitising. • Using disposable cups, plates and other utensils. • Using a chemical sanitiser for cleaning eating and drinking utensils and for other utensils that require sanitising such as large mixing bowls, chopping boards, etc. that will not fit in the commercial dishwasher. Cleaning of floors and If you want to sanitise these surfaces washing in water with a non food contact concentration of chlorine 100–200 mg/L is more than adequate. surfaces Note: In sewered areas the responsible authority should be consulted as to whether discharge of effluent containing these concentrations of chlorine are permitted. Also care should be taken if you have a septic tank as this may compromise the septic system. Please consult your local council health department. Guidelines for the use of non-potable water in food businesses 4 Permanent treatment Chlorination guide Food businesses can either follow the • The initial dose should give a free chlorine residual of 5.0 mg/L. advice in the previous section ‘Temporary • There should be enough chlorine to give a free chlorine residual of 1.0 mg/L after 30 minutes treatment’ on a more permanent basis, or contact time. seek a longer-term solution to managing • Check after 30 minutes using a colour comparator, like the ones used for swimming pools. the safety of their water supply. •Ifnecessary add more chlorine to ensure that the required minimum of 1.0 mg/L maintained for Treating water in a water storage 30 minutes, is achieved. vessel––such as a watertank •Each time the storage vessel is running low, refill it and retreat with chlorine. •Chlorinate each time the storage vessel is filled with water from a non-potable source. If the water source is from a non-potable water supply, groundwater, or surface •Tables 2, 3, and 4 outline how much available chlorine is required to achieve free chlorine residuals. water, a practical way to ensure the water • Some household bleach contains alkalis and other chemicals such as perfumes. The alkalis in these products will increase the pH of the water, often above pH 9, making other sources of chlorine for supply is safe is to periodically fill a water disinfection of drinking water preferred. storage vessel from the water supply and treat the water in the vessel with chlorine. Table 2: Volume of 4% available chlorine (household bleach) required to achieve free chlorine residuals Storage vessels for treated water should: • be clean; Water volume Concentration required to be treated 5 mg/L 100 mg/L 200 mg/L •have covers; 5 litres 0.63 ml 12.5 ml 25 ml •be above ground level; 1000 litres 125 ml N\A N\A • be in a cool position; 5000 litres 625 ml N\A N\A • be cleaned periodically; • be mosquito proof; and Table 3: Volume of 12.5% available chlorine required to achieve free • be unlikely to taint the water (seek advice chlorine residuals from manufacturer).