Distilled Water and the Impurities that can be found in ordinary tap water

What are the impurities found in tap water?

Tap water in the UK is treated to meet safety standards. However, despite rigorous treatment protocols (coagulation, filtration, chlorination), trace levels of contaminants can still be present. These impurities may come from:

• Natural sources (rocks, soil, wildlife)
• Agricultural runoff (pesticides, fertilisers)
• Industrial processes (heavy metals, chemical waste)
• Aging or corroded plumbing (lead, copper)
• Distribution systems (bacterial growth in pipes)

These chemicals can be drawn into the water by minerals and gases in the air, or eroded from the soil or rock. The integration of these dissolved materials are regarded as the ingredients that give water its title of 'pure water', which is actually a contradiction in terms, as water containing any form of foreign bodies, no matter how molecular can never be described as totally 'pure'.

The impurities that are found in water to give it its particular taste as well as causing such effects as hardness, caused by the presence of calcium or magnesium, colour, which is caused by the presence of iron in the water, going as far as possible poisoning caused by high concentrations of arsenic in the water or even radioactivity caused by the presence of radium.

Apart from these natural impurities that can gradually dissolve into water from its natural surroundings. There are also a number of forms of man-made contamination that can find their way into water. The most common are fertilisers and pesticides that can flow into water through overuse by the agricultural industry as well as toxic wastes and heavy metals from heavy industry.

On certain occasions, human effluent can leak into water systems through a fault in a sewage disposal system, However, and very thankfully, these occasions are few and far between.

The most common mineral impurities found in tap water are:

• Aluminum - Leached from the soil

• Arsenic - Leached from the soil

• Calcium - Leached from the soil

• Chlorine - Added as a disinfectant

• Copper - Leached from pipes

• Fluoride - Sometimes added for dental health

• Lead - Leached from underground pipes,

• Nitrates - Leached from the soil

• Phosphates - Leached from the soil/Agriculture

• Radium - From the breakdown of Radium-containing rocks

• Sodium - Leached from the soil/seawater

These are just a few of the more than 330* impurities that can be found in tap water. In most developed regions of the world water undergoes fairly high levels of filtration, and after which chlorine is introduced into the water in very low concentrations, making it suitable to use for most domestic applications. Water that has undergone a regular filtration process is known as potable water and can be drunk from the tap without excessive danger to health.

Tap water is inexpensive, but can still contain up to 800ppm of dissolved minerals and heavy metals as these are not removed during the filtration process. It is easy to see how over time, these minerals can build up and destroy heating elements in kettles and washing machines.

1. Nearly All Impurities Are Removed

   • Distillation Process: Distilled water is made by boiling water until it becomes steam, then condensing the steam back into liquid form. This process effectively separates out the majority of contaminants—including minerals, heavy metals, and microorganisms—because they do not vaporise as easily as water.
   • Resulting Purity: The end product is water with greatly reduced levels of dissolved solids, metals, and other potential impurities like nitrates or volatile chemicals.

2. Free of Chemical Additives

   • No Residual Chlorine or Fluoride: Unlike UK tap water supplies that add chlorine, chloramine, or fluoride during treatment, distilled water does not contain these additives because they are left behind in the boiling chamber.
   • Reduced Risk of Disinfection By-Products: Without chlorine or natural organics in the final product, the risk of trihalomethanes (THMs) or haloacetic acids (HAAs) is virtually eliminated.

3. Consistent Quality and Taste

   • Neutral Flavour: Because salts and minerals are removed, distilled water has a very neutral taste—free from the metallic or chemical flavors sometimes associated with tap water.
   • Reliable Quality Control: Our distilled water undergoes strict quality checks, ensuring each batch meets set purity standards.

4. Suitable for Sensitive Uses

   • Medical and Laboratory Applications: Distilled water is often required in labs and hospitals because it does not interfere with tests or treatments that could be affected by extra minerals or impurities.
   • Baby Formula and Special Dietary Needs: Many parents prefer distilled water for mixing infant formula, and some individuals with kidney or immune system concerns may find distilled water gentler on the body.
   • Appliances and Electronics: Because of its low mineral content, distilled water reduces scale buildup in humidifiers, steam irons, and other devices that heat water.

*source: https://www.opencollege.info/do-you-know-whats-in-your-tap-water/