Tap water can contain many impurities, both natural and artificial. Some are harmless or may only have an affect on how it looks, tastes or smells, whilst others can lead to immediate illness or slowly damage your health over a long period of exposure. Some chemicals (such as chlorine and fluoride) are added at the treatment plant, which there is some serious debate around. It is all of these things, and more, that water filters are designed to remove.

Micobiological Risks

Water filters are able to remove pathogenic micro-organisms (in other words, those that can make you sick) from your supply.

• Bacteria – Most pathogenic bacteria found in water is a result of contamination from human or animal faeces. It can also grow on the mains. This is why chlorine is added, so that the liquid is protected at the treatment plant until it comes out of your tap.
   
• Protozoa – This group includes cryptosporidium and giardia, which can cause severe illness. Their cysts have also been known to resist disinfection, so it’s best to prevent them from getting into our water supply in the first place.
   
• Viruses – Some viruses that can be found in water are potentially harmful. Whilst disinfection will kill most, some may survive and could potentially make you sick. The source of viral infection here in Australia is hard to trace, so we don’t know how big of a problem it is.

Chemical Risks

Water filters are also able to remove a number of chemicals that can find their way into your supply, either purposely or accidentally.

• Pesticides & Herbicides – These can leach into waterways in rural areas. Some are potentially carcinogenic and can live in the environment for a long time. Whilst small concentrations have been found, our drinking supply is usually free of them when tested.
   
• Nitrate/Nitrite – The main sources of these chemicals are sewage and fertiliser run off. Whilst nitrate itself is harmless, it can be converted into nitrite, which mostly poses a problem for babies and young children (it can reduce the amount of oxygen the blood can carry).
   
• Chlorine & Chlorination-By-Products – Chlorine or chloramine is usually added to kill bugs at the treatment plant and protect against recontamination in the distribution system. These chemicals can react with naturally occurring organic substances.
   
• Fluoride – This has been added to our drinking water since the 1960s and 70s to help reduce tooth decay. We don’t, however, know the potential health risks of ingesting lots of fluoride over a lifetime, so many people prefer to remove it all together.
   
• Aluminium – Chemicals containing aluminium are used in a process known as flocculation, which removes suspended particles from water to make it clearer. Whilst most aluminium can be filtered out, small amounts have been known to pass through.

We haven’t even touched on the contaminants that could get into your water as a result of damaged or faulty plumbing in your home. Whilst most of these contaminants are aesthetic rather than harmful (with the exception of micro-organisms and lead), if they occur in high concentrations they could be. If you’re dealing with discoloured water, an unusual taste or odour, corrosiveness or even slime, water filters can help to rectify these problems.