The U.S. Environmental Protection Agency (EPA), actually only tests for less than a dozen contaminants in our water supplies. There are actually thousands of different contaminants, but they are listed as low risk and/or emergent threats that may be periodically reclassified. Many of these contaminants are dissolved in water, and they cannot be detected by our own senses. There is no way to taste, spot or smell these contaminants in our water and they can cause health problems. Let’s take a closer look at this issue so that you have a better understanding of water contaminants. 
Total Dissolved Solids:
Many people, don’t know that water is actually an incredible solvent that is capable of dissolving most materials given enough time. All kinds of materials, such as salts, metals, organic matter and minerals can be dissolved in our water. When dissolved these materials are undetectable without a chemical test, and the only clue is a strong metallic taste when the water is drunk. These materials are known as Total Dissolved Solids or TDS, and they are not considered to be a primary pollutant. Drinking water containing TDS can be unpalatable and may cause stomach upsets in certain people. There are non health related issues, such as corrosion in plumbing and damage to appliances.
Metal Contamination:
The water that is delivered into our homes contains natural levels of metals, such as copper, manganese, iron, mercury, lead and even arsenic. This may seem frightening, but usually, these metals are present in extremely low levels that are not a threat to our health. The main problems that are encountered are when the levels of metals are elevated because of corroded pipes or other circumstances. An easy way to spot elevated metal level is the presence of orange stains in your sinks and a strong metallic taste to your water. Ingesting metals in high concentrations is extremely detrimental to your health, and it should be addressed immediately.
Chemical Contamination:
The municipal water supplied to our homes is treated with chemicals to disinfect our water and remove bacteria. These processes have the side effect of adding small residual amounts of chloramine and chlorine to the water we use and drink. These chemical byproducts can cause a number of health issues, and they should be avoided. Another consideration is chemicals from industrial processes and pharmaceuticals that are flushed into our waterways and end up in our water supply. Some of these chemicals have been shown to affect the reproductive capacity of fish, so common sense would suggest that avoiding them would be a good idea.
Bacterial Contamination:
When water from private wells, streams, and runoff from rain is not treated, it can be an ideal environment for bacteria. When water is laden with bacteria, it will smell dirty or even fishy and sulfurous. There are many harmful microbes that reproduce at an astounding rate in untreated water, drinking it and using it for recreational purposes is very harmful to human health.
If you have concerns, about TDS or other contaminants in your water supply, contact a local water treatment professional. There are many different water softeners/water conditioners and filtration systems available to treat all kinds of water quality issues. Always ensure your chosen water treatment professional is fully WQA certified to ensure that they meet and even exceed water industry standards.
About The Author, Terry Reeh, EcoWater Systems of Nebraska:
With more than 25 years experience in the residential and commercial water treatment space, Terry is a WQA (Water Quality Association) certified water specialist, LEVEL 3, as well as a WQA certified sales representative. Terry currently sits on EcoWater Systems (a Berkshire Hathaway Company) national Peers committee, as a water treatment expert advising other water professionals with less experience on best trade and technology practices. EcoWater Systems of Nebraska is one of the biggest water treatment and water delivery businesses in the state.