Any water source can become contaminated by biological or chemical contaminants naturally occurring in the environment or introduced through human activity. Water that will be used for drinking or cooking must be free of contaminants that can damage our short- or long-term health.
The best way to understand the quality of your water is through a comprehensive water analysis which will identify the levels of any contaminants present. Once the specific contaminants have been identified, you can determine the appropriate water treatment technology required.
Each regional municipality typically has its own regulations that limit the permissible quantities of contaminants or elements present in potable water. It is advisable to be aware of the maximum contaminant level covered by local regulations. In the absence of local regulations, guidelines are published by international organizations such as the World Health Organization (WHO) Standards.
Most people take for granted the availability and the safety of their water supply. Thankfully, in large public systems, the standards are high for testing and treatment, and they are closely regulated by authorities like the EPA. However, for those who are on a private water source, such as a well or a lake, they are responsible for the quality of their own water.
Water contaminants can generally be grouped into three groups: suspended solids, dissolved solids, and microbiological concerns. These may not be the only classifications, but they cover many of the contaminants encountered in water supplies worldwide.
This describes material that exists in a suspended (insoluble) form in water, which will typically settle on the bottom of a glass or bottle as visible sediment. This type of contamination is very common in surface waters, such as rivers, where water movement generates high turbidity. To remove this type of contamination, the physical method of filtration is employed. Different filter pore sizes allow for removal of particles to specific “micron” (millionth of a meter) ratings.
The solids are chemically dissolved as part of the water, and their concentrations are measured overall as total dissolved solids (TDS). The maximum concentration allowed in drinking water is usually around 1000 ppm.
TDS is a general measure of all solids dissolved, while more detailed analysis will report the levels of individual dissolved species (for example, calcium, magnesium, bicarbonates, and nitrates). Dissolved solids are generally in the form of ions, cations carrying a positive charge and anions carrying a negative charge.
In any situation involving microbiological contamination, the primary concern is to eliminate illness-causing microorganisms that may be present in the water.
The microorganism most often identified as a cause for concern in drinking water is E.coli, a type of Coliform bacteria. Coliform bacteria are naturally present in the environment and also live in the intestinal tracts of animals. The presence of coliforms in water indicates a general water quality issue. However, if E.coli is found in the water, it indicates the presence of fecal contamination and signals an elevated risk of other pathogenic contaminants also being in the water. Some other waterborne bacteria of concern are Salmonella, Shigella, and Campylobacter.
Giardia and Cryptosporidium are both organisms that live in the intestinal tracts of animals. As part of their lifecycle, these organisms are flushed out with feces and form an extremely difficult-to-penetrate cyst to protect them, even in harsh environments. These organisms can live in the environment, even in cold water, for months until they are ingested and start the cycle over again.
These cysts typically originate from surface water intrusion de to flooding events, poor well construction, or the deterioration of well components. Both Giardia and Cryptosporidium can cause illness, and in children, the elderly, or immune-compromised people, they can be serious illnesses. Because of their protective cyst coatings these organisms are resistant to chlorine.
Water Contamination