INORGANIC IMPURITIES:
Dirt and Sediment or Turbidity -- Most waters contain some suspended particles which may consist of fine sand, clay, soil, and precipitated salts. Turbidity is unpleasant to look at, can be a source of food and lodging for bacteria, and can interfere with effective disinfection
Total Dissolved Solids -- These substances are dissolved rock and other compounds from the earth. The entire list of them could fill this page. The presence and amount of total dissolved solids in water represents a point of controversy among those who promote water treatment products. Here are some facts about the consequences of higher levels of TDS in water:
1. High TDS results in undesirable taste which could be salty, bitter, or metallic.
2. High TDS water is less thirst quenching.
3. Some of the individual mineral salts that make up TDS pose a variety of health hazards. The most problematic are Nitrates, Sodium, Sulfates, Barium, Copper, and Fluoride.
4. The EPA Secondary Regulations advise a maximum level of 500mg/liter (500 parts per million-ppm) for TDS. Numerous water supplies exceed this level. When TDS levels exceed 1000mg/L it is generally considered unfit for human consumption.
5. High TDS interferes with the taste of foods and beverages, and makes them less desirable to consume.
6. High TDS make ice cubes cloudy, softer, and faster melting.
7. Minerals exist in water mostly as INORGANIC salts. In contrast, minerals having passed through a living system are known as ORGANIC minerals. They are combined with proteins and sugars. According to many nutritionists minerals are much easier to assimilate when they come from foods. Can you imagine going out to your garden for a cup of dirt to eat rather than a nice carrot; or drinking a whole bathtub of water for LESS calcium than that in an 8 ounce glass of milk?
8. Water with higher TDS is considered by some health advocates to have a poorer cleansing effect in the body than water with a low level of TDS. This is because water with low dissolved solids has a greater capacity of absorption than water with higher solids.
Toxic Metals or Heavy Metals -- Among the greatest threats to health are the presence of high levels of toxic metals in drinking water - Arsenic, Cadmium, Lead, Mercury, and Silver. Maximum limits for each are established by the EPA Primary Drinking Water Regulations. Other metals such as Chromium and Selenium, while essential trace elements in our diets, have limits imposed upon them when in water because the form in which they exist may pose a health hazard. Toxic metals are associated with nerve damage, birth defects, mental retardation, certain cancers, and increased susceptibility to disease.
ORGANIC IMPURITIES:
Tastes and Odors -- If your water has a disagreeable taste or odor, chances are it is due to one or more of many organic substances ranging from decaying vegetation to algae; hydrocarbons to phenols. It could also be TDS and a host of other items.
Pesticides and Herbicides -- The increasing use of pesticides and herbicides in agriculture shows up in the water we drink. Rain and irrigation carry these deadly chemicals down into the groundwater as well as into surface waters -- There are more than 100,000,000 people in the US who depend upon groundwater for sources whole or in part of their drinking water. As our reliance upon groundwater is escalating, so is its contamination. Our own household use of herbicide and pesticide substances also contributes to actual contamination. These chemicals can cause circulatory, respiratory and nerve disorders.
Chlorine -- Trihalomethanes (THM's) are formed when chlorine, used to disinfect water supplies, interacts with natural organic materials (e.g. by-products of decayed vegetation, algae, etc.). This creates toxic organic chemicals such as chloroform, and Bromodichloromethane. A further word about chlorine: Scientists at Colombia University found that women who drank chlorinated water ran a 44% greater risk of dying of cancer of the gastrointestinal or urinary tract than did women who drank non-chlorinated water! Chlorinated water has also been linked to high blood pressure and anemia. Anemia is caused by the deleterious effect of chlorine on red blood cells.
Chloramine: Chloramine is another substance used now in many larger municipalities (i.e. Los Angeles). In systems where the level of chlorine is at the highest acceptable level but need still more disinfection, the utility will then add a chlorine/ammonia compound. Chloramine is represented as totally safe but with the disclaimer to not give chloramine-treated water to your animals or use it in your fish tanks (it kills fish)!
BIOLOGICAL IMPURITIES : Bacteria, Virus, and Parasites