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Some of our competitors are sanitising by just using ozonators. Is this proper sanitisation? Ozone is a highly effective disinfectant – one of the best – but it isn't a cleaning agent. Its use must be preceded by physical cleaning of the surface. The definition of sanitisation is cleaning followed by disinfection. The objective of sanitisation is to remove the biofilm that forms on the water contact surfaces of coolers and render them fit for another period of use. After three months or more, biofilm levels can become significant. Biofilm is a layer of protective polysaccharides excreted by bacteria attached to a wetted surface, which can contain millions of bacteria within it. A disinfectant may only kill those bacteria at the surface, as most disinfectants react and combine with organic matter. This means that they quickly become neutralised when confronted by significant organic matter such as biofilm. Therefore, only the surface layers of biofilm are reached and many undesirable microorganisms may remain unaffected. In addition, the biofilm matrix remains even when bacteria within are killed. This acts as a food source and a refuge for further bacteria that will inevitably come along. This is why the biofilm must be physically removed before disinfection. Ozonation remains to be tested by the EBWA test protocols for cooler sanitisation methods. The only form of ozone that can be used on its own is in the cooler ozonators, which ozonate daily and wipe out the naked bacteria before they can lay down biofilm. These have been tested according to the EBWA protocols and work. What is the correct procedure for schools and offices that are closed over the Christmas break with regards to switching off POU coolers? Should they be sanitised before use is resumed? It's part of the BWCA and EPDWA schools codes that coolers should be sanitised at the beginning of each school term even if the coolers are left running. The trouble is that many schools and businesses now switch off coolers over long breaks to "save the planet". This will permit bacterial regrowth in a POU cooler and may lead to raised microbial counts and possibly unpleasant tastes developing in the cooler. There are, however, no health issues here as the heterotrophic plate count of water comprises harmless water bacteria that are able to grow in the low-nutrient conditions existing in clean coolers and bottled water. I also recommend that the mains feed be disconnected at the cooler before sanitisation, and that it's run until the water comes through cold before reconnection. Water sitting in warm feed pipes may have deteriorated. After shorter breaks, five litres should be run to waste by the school before drinks are taken. This should flush out the feed pipes, filter and cooler. A client who has just taken delivery of new POU coolers from us is complaining that the water from the hot tank is causing tea to “go frothy”. What can we do? I've heard of this before. I'm assuming, of course, that you have cleaned/sanitised the cooler and removed any manufacturing residues/chemicals from the hot tank before issue. A client of mine recently had this problem, which was caused by gas trapped in organic tea bags being released in the hot water, and had nothing to do with water quality. We've recently installed a cooler in a local community centre and are finding that it's being damaged and soiled by people washing their feet from it. What can we do? This does go to show the unexpected perils encountered by coolers in the field. The trouble is that a POU cooler doesn't obviously have a bottle on it and may be perceived as just a fitting on the tap water supply. I suggest the following, some of which may work:

1. Put a notice on the cooler in the appropriate language saying: ‘To be used for drinking purposes only’.

2. Speak to those who run the centre and suggest that they install foot washing facilities for those preparing to pay.i>Change the cooler for one with recessed taps.Point out that the cooler ought to be sanitised more often.We have a client on a large development site that regularly returns most bottles to us encrusted in dust, paint, cement or worse. What should we do? Such bottles must be discarded, as they're not fit for washing. If washed, they will probably affect your washer, with the result that most of your bottles will go out in a contaminated condition. Excessive bacterial and algae growth are likely consequences of a dirty washer. At present, you're losing significant money on every bottle you sell, as the economics of bottle use rely on many refills into each washed bottle. Ask yourself what does a new bottle cost? How much am I charging this customer for a filled bottle? The sums may prove alarming. You have a number of choices:

3. Stop supplying the customer. You're probably losing money on every delivery.

4. Charge a bottle deposit. The drawback is that this adds to administrative costs.

5. Include the full cost of a new bottle in your charge for filled bottles.

6. Suggest that POU may be more appropriate. The trouble is that sites like this often don't have running water in the right places. And then, of course, we could well have heavily soiled coolers instead of dirty bottles!