To find out what’s coming out of your tap, ask your local water department for a copy of the "Consumer Confidence Report," which must be provided annually to the public. It details what contaminants are present in water, past violations and health effects of detected pollutants. Water quality data for community systems are also available at www.awwa.org, or call the Environmental Protection Agency’s Safe Drinking Water Hotline 800/426-4791 for information.

For general questions on lead and drinking water, call 800/426-4791 or 800/424-LEAD. If your home has lead-soldered pipes, or if your water supply is contaminated with radiation, trihalomethanes, or other industrial and agricultural chemicals that you are unable to filter out, bottled water might be better.

You can use resources such as Consumer Reports, which has done some testing. You can also check with the National Sanitation Foundation (NSF) to see if the model you are considering is "NSF certified" at www.nsf.org or 1-877-8-NSF-HELP. You can also purchase their publication "Water Wise-The Consumers Guide to Safe Drinking Water," which lists all certified filtration systems and the contaminants they remove.

A note on reverse osmosis systems: Be aware that for every gallon of water purified 2-10 gallons are wasted. Further information is available at: http://en.wikipedia.org/wiki/Reverse_osmosis.

If you prefer a gravity flow system, consider a Micro-filtration system like the Berkey line (www.berkeywater.com). These filters will work even in times of emergencies without water pressure and do a fine job of removing most contaminants.

When you drink water from plastic bottles, which I recommend as an occasional strategy only, be careful about your internal environment as well as remembering to care for the natural environment. Polycarbonate plastic is generally marked with the #7 recycling symbol, but not all plastics marked #7 are polycarbonate since research suggests certain plastics contain materials that may have an estrogenic effect, although it has not shown conclusively. The safest #s to use are 1,2,4 and 5. Remember, when using any disposable water bottle that they are made with plastic designed and intended for one-time use. Water bottles that are sold in sporting good stores are usually made from a plastic that is more durable and are designed to be used over and over. Also, the opening of the bottle is wider making it easier to clean. I recommend to eliminate your risk of exposure altogether, glass bottled beverages are preferable. Alternately, carry a reusable stainless-steel bottle filled with filtered water from home. This alternative is environmentally respectful and safe. Many stores now sell these.

When you get a drink from a restaurant or other public place, think twice before you put ice in the drink, especially if you are suffering from immune system problems. Ice is often made from unfiltered tap water. There are growing concerns of bacterial contamination in commercially prepared/dispensed ice (i.e. ice machines) due to lack to cleaning and maintenance.