Drinking Water:

The United States has one of the safest water supplies in the world. However, national

           statistics don’t tell you specifically about the quality and safety of the water coming out

           of your tap. That’s because drinking water quality varies from place to place, depending

           on the condition of the source water from which it is drawn and the treatment it receives.

           Now you have a new way to find information about your drinking water, if it comes from a

           public water supplier (EPA doesn’t regulate private wells, but recommends that well owners

           have their water tested annually). Starting in 1999, every community water supplier must

           provide an annual report (sometimes called a consumer confidence report) to its customers.

           The report provides information on your local drinking water quality, including the water’s

           source, the contaminants found in the water, and how consumers can get involved in

           protecting drinking water. You may want more information, or have more questions. One

           place you can go is to your water supplier, who is best equipped to answer questions about

           your specific water supply.

There is no such thing as naturally pure water. In nature, all water contains some impurities.

           As water flows in streams, sits in lakes, and filters through layers of soil and rock in the

           ground, it dissolves or absorbs the substances that it touches. Some of these substances

           are harmless. In fact, some people prefer mineral water precisely because minerals give it an

           appealing taste. However, at certain levels, minerals, just like man-made chemicals, are

           considered contaminants that can make water unpalatable or even unsafe. Some

           contaminants come from erosion of natural rock formations. Other contaminants are

           substances discharged from factories, applied to farmlands, or used by consumers in their homes and yards. Sources of contaminants

           might be in your neighborhood or might be many miles away. Your local water quality report tells which contaminants are in your drinking

           water, the levels at which they were found, and the actual or likely source of each contaminant. Some ground water systems have

           established wellhead protection programs to prevent substances from contaminating their wells. Similarly, some surface water systems

           protect the watershed around their reservoir to prevent contamination. Right now, states and water suppliers are working systematically to

           assess every source of drinking water and to identify potential sources of contaminants. This process will help communities to protect

           their drinking water supplies from contamination.

When a water supplier takes untreated water from a lake, river or reservoir, the water often

          contains dirt and tiny pieces of leaves and other organic matter, as well as trace amounts

          of certain contaminants. When it gets to the treatment plant, water suppliers often add

          chemicals called coagulants to the water. These act on the water as it flows very slowly

          through tanks so that the dirt and other contaminants form clumps that settle to the

          bottom. Usually, this water then flows through a filter for removal of the smallest

          contaminants like viruses and Giardia. Most ground water is naturally filtered as it passes

          through layers of the earth into underground reservoirs known as aquifers. Water that

          suppliers pump from wells generally contains less organic material than surface water and

          may not need to go through any or all of the treatments  described in the previous

          paragraph. The quality of the water will depend on local conditions. The most common

          drinking water treatment, considered by many to be one of the most important scientific

          advances of the 20th century, is disinfection. Most water suppliers add chlorine or another

          disinfectant to kill bacteria and other germs. Water suppliers use other treatments as

          needed, according to the quality of their source water. For example, systems whose

          water is contaminated with organic chemicals can treat their water with activated carbon,

          which adsorbs or attracts the chemicals dissolved in the water.

People who have HIV/AIDS, are undergoing chemotherapy, take steroids, or for another

          reason have a weakened immune system may be more susceptible to microbial

          contaminants, including Cryptosporidium, in drinking water. If you or someone you know

          fall into one of these categories, talk to your health care provider to find out if you need to

          take special precautions, such as boiling your water. Young children are particularly

          susceptible to the effects of high levels of certain contaminants, including nitrate and lead. To avoid exposure to lead, use water from the

          cold tap for making baby formula, drinking, and cooking, and let the water run for a minute or more if the water hasn’t been turned on

          for six or more hours. If your water supplier alerts you that your water does not meet EPA’s standard for nitrates and you have children

          less than six months old, consult your health care provider. You may want to find an alternate source of water that contains lower levels

          of nitrates for your child.