Bacteria
Bacteria cells generally range in size from less than 1 to 10 microns long, and from 0.2 to 1 micron wide. While small, there is a huge quantity and variety of them the world over, and they greatly outnumber humans.
The lower forms of bacteria can be categorized as either helpful or harmful to humans. The harmful bacteria we know as those that cause disease. The helpful bacteria speed up the process of decomposing organic waste, and thus aid in purifying water.
Protozoa
Protozoa are single-celled organisms that live mainly in water. Many protozoa we know as parasites, but like bacteria, they can be classified as helpful or harmful. Drinking water can become infested with certain protozoa which are not disease causing, but will give the water a fishy taste and odor.
Not all available home water filters on the market remove protozoa. The good news is that these cysts are usually 2 to 50 microns in diameter, much larger than bacteria, and can be removed from water by Culligan reverse osmosis filtration, the best protection in home filtration.
Viruses
Viruses are the smallest of the infectious microorganisms. They cannot be seen under a microscope, as they are only 0.004 to 0.1 micron in diameter, and thus can pass through porcelain filters capable of screening out bacteria. Viruses are a unique kind of parasite that are incapable of growth unless they are in the presence of living cells. They can survive both freezing and drying.
While viruses are more difficult to directly detect in a water source, they can be carried in feces of both animals and humans. This is why fecal coliform bacteria is a good indicator of sewage contamination. The presence of coliform bacteria in sewage may mean that the water source itself is contaminated with other parasites. It is important to note, however, that the absence of coliform bacteria in a water source does not necessarily indicate the absence of parasites in that water source.
Lead
Lead, a metal found in natural deposits, is commonly used in household plumbing materials and water service lines. The greatest exposure to lead is swallowing or breathing in lead paint chips and dust. But lead in drinking water can also cause a variety of adverse health effects. In babies and children, exposure to lead in drinking water above the action level can result in delays in physical and mental development, along with slight deficits in attention span and learning abilities. In adults, it can cause increases in blood pressure. Adults who drink this water over many years could develop kidney problems or high blood pressure.
A number of cartridge type filtering devices are available. These devices use various types of filtering media, including carbon, ion exchange resins, activated alumina and other privately marketed products.
Nitrate
The presence of nitrate in a water analysis is a danger signal. Nitrate is an indication that your water supply may be contaminated with bacteria. Even small amounts of nitrate make the water supply suspect. In farming areas like Illinois, nitrates are a real problem.
Large amounts of nitrate are dangerous to infants. Babies drinking high nitrate water develop a blue color of skin because the blood has a decreased ability to carry oxygen. Continued drinking of the water will cause the baby to become ill, or may even result in death.
Partial removal of nitrate can be accomplished by reverse osmosis. Complete removal of nitrate may be accomplished by deionization treatment. If the water supply is found to be contaminated, chlorination may be needed to kill the bacteria. If nitrate water cannot be reduced to an acceptable level through water treatment, we suggest that bottled water be used for drinking.
Iron
Iron can be present in water in several forms: colloidal iron, oxidized iron, soluble iron and iron bacteria. Colloidal iron is a special case of extremely small particles of oxidized iron that do not settle out. Oxidized iron is insoluble in non-acid water. Water containing oxidized iron is filled with some red rust when first drawn from the tap. Soluble iron is called "clear water iron" because the water is not red unless it stands.
Iron oxide deposits can plug up plumbing and other equipment that uses water, like farm equipment, home washing machines, hot water heaters and dishwashers. The other objection to iron in water is that it can cause reddish-brown stains on laundry, plumbing fixtures and cooking utensils. Iron causes a disagreeable metallic taste and, in some cases, can have a sewer type of odor.
The presence and amount of iron in your water can be determined with testing. Iron is normally removed from water through mechanical filters, water softeners and reverse osmosis.
Salt
Every natural water supply contains some sodium, with concentration depending upon the exposure of the water to soluble compounds which are present in the earth or in the atmosphere.
The natural contamination of fresh ground water by saltwater is an important water-quality issue in many areas of Illinois. This saltwater comes from naturally occurring salt minerals in the subsurface. Proper management of ground water reduces, and frequently avoids, intrusion of saltwater into freshwater supplies.
