Alternatives to tap water exist, but consumers face a confusing array of choices. Water-quality experts recommend that people arm themselves with information before making a decision.

The primary choice consumers have is between bottled water and a point-of-use water filter. Each has its advantages and disadvantages.

Bottled water is available in gallon jugs at stores, through vending machines and from companies that deliver to your door. The important thing to know is what type of water is actually in the bottle. In some cases, bottled water may be nothing more than municipal tap water. Although label requirements have improved over the years, some bottlers still use marketing jargon. Names like "Crystal-Pure Drinking Water," "Infant Water" and "Artesian Drinking Water" adorn the rows of jugs at local markets. In all probability, bottled water is one of three types of water: ground water from a natural spring (also called mineral water), filtered water or distilled water.

Delivered bottled water is convenient, but it can get costly. In addition, the typical 5-gallon jug and accompanying dispenser can be a bulky addition to a space-conscious kitchen.

People who don't use much water for drinking and cooking might find buying water at the grocery store or through vending machines in gallon jugs more economical than having it delivered. Vending machines usually use municipal tap water and run it through several filters before reaching the bottle. For some vending machines, people must bring their own jugs. While more economical than delivered bottled water, hauling gallon jugs to and from the market may be very inconvenient for some.

Point-of-use water filters come in many configurations; some attach to your tap, some sit on the counter top, and others are installed under the sink. Costs vary from less than $50 to more than $800. However, the most important factor in determining which filter is right for you is knowing exactly what you want filtered out of your water.

To accomplish this, have your water tested by a laboratory and review the results with a water specialist. Water tests cost from $25 to $100, depending on the type of tests ordered. Your local health department or EPA office should be able identify reputable water-testing labs in your area. Water specialists usually are listed in the Yellow Pages under "Water Purification and Filtration" or "Water Softening and Conditioning." Look for products and service technicians certified by the Water Quality Association, the leading trade association.

Water filters are not a one-size-fits-all product. Certain filters take out specific contaminants. There are three popular types of water filters - carbon, reverse osmosis and distillation.

Carbon filters are very common and are sometimes called taste-and-odor filters. Tap water passes through activated carbon granules, which reduce organic materials, chlorine, dissolved gases and some minerals. Carbon filters are typically available as carafes, tap-mounted filters and counter-top appliances that connect to the tap.

Reverse Osmosis use a semi-porous membrane that reduces bacteria, lead, mercury, iron and most other contaminants. These systems are usually installed under the kitchen sink.

Distillers produce the closest thing to pure water. Water is boiled, condensed and then filtered through a carbon filter. Distillers are available in counter-top models and as large, installed appliances.

Other filters exist, but are not yet very common. For example, ozone and UV (ultraviolet light) filters kill bacteria, and chemical filters treat problems like extreme concentrations of iron.

Water filters are considered by some to be the most convenient of all options. However, some models, especially installed products, can come with a high initial cost and all require some form of maintenance or periodic filter replacement. Still, one filter manufacturer estimates the average cost of a gallon of filtered water, over time, can be as little as 33 cents.