Microbiological Contaminants

  • Ecoli / Bacteria
  • Protozoa - Giardia & Cryptosporidium
  • Viruses

Chemical / Mineral Contaminants

  • Chlorine 
  • Iron
  • Maganese
  • Calcium & Magnessium (Hardness)
  • Fluoride
  • pH 
  • Copper
  • Sodium & Chloride
  • Silica
  • Nitrates
  • Hydrogen Sulphide (Rotten Egg Smell)
  • Tannins
  • Arsenic
  • Boron
  • Lead
  • Aluminium
  • Zinc

2 Approximately 1% of water treated is used for drinking and cooking purposes. The mains that carry water to our homes often leach harmful pollutants into the water supply, which increases as the pipes age. A significant percentage of existing pipes are made of asbestos fibre cement.

The increase in population is placing a greater demand on water supplies and industrial waste, tips leaching, chemical spills, excessive herbicide, pesticide sprays, chemical dumps and sewerage have all contributed to our underground aquifer being seriously affected by pollution, harmful bacteria and cysts.

Treated water supplies use the deadly poison CHLORINE to kill cysts, bacteria and viruses. Research has proved that chlorine forms carcinogenic compounds such as trihalomethanes and chloroforms and when mixed with organic matter can cause different forms of cancer.

The most sophisticated water treatment plants in the world are unable to stop a number of unwanted diseases and chemicals from entering our water. Parasites and cysts such as GIARDIA and CHRYPTOSPORIDIUM are resistant to chlorine. This is why the amount of chlorine used is increased. When washing concrete with chlorine, care must be taken not to erode the concrete. Chlorine also kills Vitamin E and other vitamins. Animals prefer chlorine free water.

What about boiling/bottled or rain water?

Boiled water

To ensure water is free from disease it should be boiled for at least 15 minutes. With the increase in chlorine and spray chemicals in everyday water, just bringing the water to boil can double the amount of contaminants.

Bottled water

Some bottled water has been shown to contain excessive bacteria. This occurs when the chlorine has been removed from the water which is then stored, allowing bacteria to multiply.

Rain water

Nature uses rain water to cleanse the atmosphere free of contaminants. Rainwater picks up 25% of its impurities before it reaches the ground. The significant increase in giardia, chryptosporidium and spray chemicals are major contributors to pollution in rain water tanks.


You can find contaminants, their sources and the problems they may cause listed in table below





Geothermal areas

Health problems


Septic tanks, bird and animal faecesback flushing from incorrectly connected W.C. bowls, sewage discharges

Diarrhoea, Gastroenteritis 
Other waterborne disease


Geothermal areas

Health problems.

Carbon dioxide

Atmosphere and decaying vegetation



Backflow (suck-back) from incorrectly connected dosing equipment, cattle feeding systems, garden hoses dangling in container etc

Health problems depending on the nature of chemical contaminants.


Decaying vegetation



Dissolved from pipes or taps by aggressive water

Staining, taste

Faecal material

Backflow (suck-back) from incorrectly connected waste disposal equipment animal washdowns, etc

Diarrhoea, Gastrointestinal infection


Dissolved rocks

Soap demand 
Scale formation in kettles and Hot water tanks


 Dissolved rocks, especially in bore water

Taste, Staining, Clogging of pipes and valves


 Dissolved rocks

Taste, Staining


Fertilisers, clover, Septic tank soakage

Can cause health problems for bottle fed babies


Atmosphere, decaying vegetation, dissolved rocks

Corrosion if too low, Scale forming if too high

Protozoan cysts, eg Giardia 

Septic tanks: bird and animal faeces on roofs, in streams; sewage discharges

Diarrhoea, Protozoan infection

Taste and odour


Unpleasant to drink, Can be toxic



Appearance (usually biologically Contaminated 
as well)


Sewage, bird and animal faeces

Other waterborne diseases