As the water rushes out of the tap and into your glass, you will be comforted to learn the water systems across the metro area have met the minimum federal Environmental Protection Agency water standards.

Those companies that bring you the water you drink and cook with test that water for bacteria, chemicals, pesticides, herbicides, metals and disinfectants, as well as to many other contaminants.

The water gets tested to make sure it hasn't exceeded the EPA's acceptable amounts of each contaminant. The EPA requires water services check for about 90 contaminants. But the presence of small amounts of contaminants doesn't mean there is a health risk.

WHAT GETS TESTED?

• Turbidity -- The cloudier the water is the higher the turbidity, which comes from soil runoff and is created by suspended particles. The EPA says higher levels are "often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches."

• Microbes -- Naturally occurring coliform bacteria, in general, isn't harmful, but the EPA says fecal coliform and E-coli can cause stomach illnesses and headaches.

• Metals -- Once the water gets to your home, lead and copper are tested. Both can cause serious health problems. The main reason lead and copper would end up in your water is that your home's plumbing system is corroded. Copper also can come from the erosion of natural deposits.

• Inorganic contaminants -- These can occur naturally or can be from runoff, wastewater discharges and farming. Fluoride, nitrates from fertilizer use and cancer-causing arsenic fall into this category.

• Disinfectants and disinfectant byproducts -- Water additives, such as chlorine and chloromines are tested, as well as Total Trihalomethanes, byproducts of drinking water disinfection.

• Pesticides and synthetic organic chemicals -- These include agricultural and home pesticides. Chemicals discharged from factories would fall under this category.

• Volatile Organic Contaminants -- These are byproducts of industrial processes or from petroleum production. They can come from gas stations, storm water runoff and septic systems.

• Radioactive contaminants -- These occur naturally, and may result from mining or oil and gas production.

The EPA also requires treatment facilities to monitor for cryptosporidium. It occurs when water is water contaminated with sewage and animal wastes. It can cause abdominal infections with symptoms of nausea, diarrhea and stomach cramps.  Each year by July 1 you should receive in the mail a short report (consumer confidence report, or drinking water quality report) from your water supplier that tells where your water comes from and what's in it.  If you have not received yours, you can see the quality of your drinking water on-line.

Once you know the status of your water and what concerns you may have, then you may address improving the quality by boiling it, or using a filter system in your home. 

Here are some common classes of Water Filters:

• Home Water Treatment Systems can provide you with safe and healthy drinking water and shower water. Few people realize that water filtration can even improve your indoor air quality by removing chlorine from your water so it does not vaporize into the air in your home.
  
  
• Under the sink water filters are typically used where cabinet space is available under the kitchen sink and a permanent installation is desired. These are also referred to as under counter water filters and they provide filtered water through a special faucet for the ultimate convenience.
  
  
• Countertop water filters are typically used when a temporary installation is desired, such as in apartments, in a vacation cabin, or where a faucet hole is not available for an under sink installation, or where under the counter space is not available.

• Shower filters give you soft skin and silky hair by removing chlorine from your shower water. Shower filtration also protects your health by eliminating chlorine from your shower steam, which is easily absorbed by your lungs.
  
  
• The best shower filters use KDF-55 as the first media to reduce chlorine. Aquasana shower filters add carbon filtration, Sprite shower filters add Chlorgon, and Rainshow'r shower filters add crystallized quartz.
  
  
• You can also filter chlorine from your bath. It is especially helpful to remove chlorine from children's bath, as they are more susceptible to the effects of chlorine.
  
  
• Water filter cartridges should be replaced at the recommended intervals. In many cases, you can upgrade your water filter by replacing the cartridge.
  
  
• Filtered water coolers provide hot and cold water that is fresh and clean, with no need for those heavy water bottles. These are also referred to as water dispensers.
  
  
• Portable water filters are used when camping, hiking or other outdoor activities where carrying a large quantity of water is difficult. A portable water filter provides a measure of safety when drinking water from natural sources.

• Refrigerator water filters should use use better water filtration than the low cost Granulated Active Carbon (GAC) filters sold elsewhere or provided with new refrigerators. These are also referred to as ice maker filters.
  
  
• Reverse osmosis (RO) systems are recommended for salty water or water that has high levels of fine clay. In many cases, reverse osmosis is overly complicated and difficult to maintain, because many water problems can be solved by simpler means.
  
  
• The terms Water Purification System and water purifier are used as other names for water filters. Truth is that purification specifically means removal of bacteria, which is often accomplished by adding chlorine to the water supply.

Unless you already have a specific goal for your water filter system, you should look at water testing kits. A complete water testing kit will insure that the filter you buy removes all the contaminants in your water.

The best water filters include multiple stages of filtration. In addition, each stage of filtration works together with the other stages. In the ideal case, the multiple stages of filtration also provide a measure of backup or redundancy to increase the safety margin of your water filter system.  

Water Filter Chart  -  Important Features

Here are some points experts say to consider when buying a water filter:

• If you're concerned about more than taste and odor, get a water contaminant report from your local water utility. Ask for the Municipal Drinking Water Contaminant Analysis Report. This will tell you what's in your drinking water and guide your filter choice. The EPA website makes these reports available. .

• Estimate your water usage. Families will quickly grow tired of filling and refilling pitchers. You might be better off with a faucet-mount or undersink carbon-filtration system.

• Make sure replacement filters are readily available. One reason to go with a well-known brand is that it is easy access to replacement filters, since you'll need lots of them. Pitcher and faucet-mount filters must be changed every one to three months.

• Start small. Try using a pitcher or faucet mount before considering an undersink or whole-house unit. They're usually just as effective at improving taste and odor, the most common reasons for buying a water filter.

• Water filters don't make great gifts unless you also provide extra filters. While the initial investment is small for pitchers and faucet mounts, a year's worth of replacement filters can outpace the initial cost of the unit.