Answer:  Farms and Ranches: Bacteria free animal drinking water increases production by eliminating losses due to water-borne infection. Improved sanitation promotes healthier stock and higher yields.

• Water Wells: Eliminates bacteria which may build up from time to time from seepage of surface water or sewage.

• Private Homes, Trailer Parks, Recreation Vehicles, Schools, Hotels, Airplanes: Provides safe, germ-free drinking water. Destroying bacteria, a serious problem for rural water supplies, prevents disease.

• Swimming Pools: Helps control bacteria, algae and slime formation. Ultraviolet water purification allows the user to substantially reduce the chlorine usage.

• Aquariums and Hatcheries: Bacteria-free water prevents disease organisms from growing or spreading without producing by-products toxic to marine life.

• Laboratories: Provides ultrapure water required for accurate testing and research.

• Hospitals: Insures ultrapure water for pathology labs, kidney dialysis and post disinfection rinses where bacteria-free water is essential.

• Swimming Pools: Helps control bacteria, algae and slime formation. Ultraviolet water purification allows the user to substantially reduce the chlorine usage.

16.  What are Some Naturally Occurring Sources of Pollution?
Microorganisms: Bacteria, viruses, parasites and other microorganisms are sometimes found in water. Shallow wells — those with water close to ground level — are at most risk. Runoff, or water flowing over the land surface, may pick up these pollutants from wildlife and soils. This is often the case after flooding. Some of these organisms can cause a variety of illnesses. Symptoms include nausea and diarrhea. These can occur shortly after drinking contaminated water. The effects could be short-term yet severe (similar to food poisoning) or might recur frequently or develop slowly over a long time. Radionuclides: Radionuclides areradioactive elements such as uranium and radium. They may be present in underlying rock and ground water.

Radon — a gas that is a natural product of the breakdown of uranium in the soil — can also pose a threat. Radon is most dangerous when inhaled and contributes to lung cancer. Although soil is the primary source, using household water containing Radon contributes to elevated indoor Radon levels. Radon is less dangerous when consumed in water, but remains a risk to health.
Nitrates and Nitrites: Although high nitrate levels are usually due to human activities (see below), they may be found naturally in ground water. They come from the breakdown of nitrogen compounds in the soil. Flowing ground water picks them up from the soil. Drinking large amounts of nitrates and nitrites is particularly threatening to infants (for example, when mixed in formula). Heavy Metals: Underground rocks and soils may contain arsenic, cadmium, chromium, lead, and selenium. However, these contaminants are not often found in household wells at dangerous levels from natural sources.

Fluoride: Fluoride is helpful in dental health, so many water systems add small amounts to drinking water. However, excessive consumption of naturally occurring fluoride can damage bone tissue. High levels of fluoride occur naturally in some areas. It may discolor teeth, but this is not a health risk

17. What Human Activities Can Pollute Ground water?
Bacteria and Nitrates: These pollutants are found in human and animal wastes. Septic tanks can cause bacterial and nitrate pollution. So can large numbers of farm animals. Both septic systems and animal manures must be carefully managed to prevent pollution. Sanitary landfills and garbage dumps are also sources. Children and some adults are at extra risk when exposed to water-born bacteria. These include the elderly and people whose immune systems are weak due to AIDS or treatments for cancer.

Fertilizers can add to nitrate problems. Nitrates cause a health threat in very young infants called “blue baby” syndrome. This condition disrupts oxygen flow in the blood.
Concentrated Animal Feeding Operations (CAFOs):
The number of CAFOs, often called “factory farms,” is growing. On these farms thousands of animals are raised in a small space. The large amounts of animal wastes/manures from these farms can threaten water supplies. Strict and careful manure management is needed to prevent pathogen and nutrient problems. Salts from high levels of manures can also pollute groundwater. Heavy Metals: Activities such as mining and construction can release large amounts of heavy metals into nearby ground water sources. Some older fruit orchards may contain high levels of arsenic, once used as a pesticide. At high levels, these metals pose a health risk.

Fertilizers and Pesticides: Farmers use fertilizers and pesticides to promote growth and reduce insect damage. These products are also used on golf courses and suburban lawns and gardens. The chemicals in these products may end up in ground water. Such pollution depends on the types and amounts of chemicals used and how they are applied. Local environmental conditions (soil types, seasonal snow and rainfall) also affect this pollution. Many fertilizers contain forms of nitrogen that can break down into harmful nitrates. This could add to other sources of nitrates mentioned above. Some underground agricultural drainage systems collect fertilizers and pesticides. This polluted water can pose problems to ground water and local streams and rivers. In addition, chemicals used to treat buildings and homes for termites or other pests may also pose a threat. Again, the possibility of problems depends on the amount and kind of chemicals. The types of soil and the amount of water moving through the soil also play a role.

Industrial Products and Wastes:
Many harmful chemicals are used widely in local business and industry. These can become drinking water pollutants if not well managed. The most common sources of such problems are:
• Local Businesses: These include nearby factories, industrial plants, and even small businesses such as gas stations and dry cleaners. All handle a variety of hazardous chemicals that need careful management. Spills and improper disposal of these chemicals or of industrial wastes can threaten ground water supplies.
• Leaking Underground Tanks & Piping: Petroleum products, chemicals, and wastes stored in underground storage tanks and pipes may end up in the ground water. Tanks and piping leak if they are constructed or installed improperly. Steel tanks and piping corrode with age. Tanks are often found on farms. The possibility of leaking tanks is great on old, abandoned farm sites. Farm tanks are exempt from the EPA rules for petroleum and chemical tanks.
• Landfills and Waste Dumps: Modern landfills are designed to contain any leaking liquids. But floods can carry them over the barriers. Older dumpsites may have a wide variety of pollutants that can seep into ground water.
These and many other reasons are why water purification systems are essential for private wells and public utility sources

18. Why Use Water Filtration Systems At Home?
Just because you are on a municipal system, doesn't mean that you don't need a drinking water filtration system in your home. The Safe Drinking Water Act (SDWA) helps but it does not regulate all possible contaminants. The is even truer if you are on a private well.
There are many factors that impact the quality of water that comes out of your household tap. The water treatment plant adds chemicals to the water through the process of treating the water, which may become contaminants with potential health risks. Some of these water treatment chemicals may not be eliminated and can be transported in the water to your home. Municipal water treatment plants can not remove every possible contaminant in water. The (SDWA) sets legal limits for certain contaminants that consider human health and the ability of municipal water treatment systems to achieve these levels based on available technology. Considering the average person uses 100 gallons per day, there is a tremendous load on a municipal treatment system to meet the SDWA standards. 90% of people that get their water from a community source are serviced from a medium to very large system (serve 3,301 to 100,000 people). Your local water filtration systems may be responsible for delivering 330,100 to 10,000,000 gallons per day. With this kind of demand, it may not be economically feasible for a municipal treatment facility to remove certain contaminants to a level that will have no health risk to humans.
If you are bottling your own water in jugs at a local supply, you may be putting yourself at risk. Storage requires specific guidelines to prevent bacteria growth during storage. Containers should be sterilized prior to filling and contamination is easy during the filling process. Direct light has an impact on storage as well as the room temperature