Residential water filters are primarily designed to back up the water treatment facility in your community. They're good for reducing unpleasant odors and tastes, discoloration and other annoying features that the water utility doesn't remove. You can also use them to reduce potential health risks, like lead, that your water utility can't always control. However, if you have your own well, don't depend solely on the devices we show here. Follow the water testing and purification procedures established by your state and county.
The key to choosing a filtration device is knowing which contaminants you want to remove. Your first step should always be a call to your local water utility. A water engineer can almost always tell you what's in your water and what's causing the problem you're dealing with. If you have health concerns, follow up with a call to your local department of public health. You'll get more information about the issues involved and how to test for and solve problems. Although some filter systems go a long way toward purifying water, don't rely on them alone to solve potential health problems.
The water filters we show here solve many aesthetic problems, such as bad taste, smell and appearance. For water that leaves crud rings around your sink, scale on the faucets or stains on fixtures, don't hesitate to call in water-softening or water-conditioning experts for evaluation and testing—often free if you sit through a sales pitch! (Search “Water Softening” or “Water Conditioning” online.)
Water experts classify “bad” water two ways: contaminated water that affects your health, and water that offends your senses. The first group includes contaminants such as lead, nitrates, harmful bacteria and viruses, and solvents. Your local water utility spends a lot of time and money controlling these types of contaminants. The second includes substances like chlorine, sulfur, iron, calcium and sediments. It may smell or taste bad, but it won't make you sick or lead to chronic health problems. So public controls are more lax here. Of course, if you have your own private well, the responsibility for safe, clean water falls entirely on your shoulders.
For more information on contaminants that water utilities monitor and control see “Common Water Contaminants That Affect Your Health” in Additional Information, below.
Despite visions of fresh, clean water in some pristine wilderness setting, water has rarely been pure—that is, free from contamination. Naturally occurring chemicals from leaves and animal feces as well as substances from rocks and soil, like iron and calcium, typically contaminated it. So did “biologicals,” like disease-causing bacteria, viruses, parasites, algae and insects. And water usually had some unique taste, odor, color and cloudiness.
Ensuring safe, clean drinking water has always been difficult, and during the past 100 years, delivering clean water has become vastly more complex. Thousands of new chemicals, developed for industrial, agricultural and home use, have been released into the environment. Many of these have seeped into the water supplies. And some are toxic. Even deep groundwater has been affected.
It's difficult and costly to remove all foreign substances from water. (Water wouldn't necessarily taste good if you did.) Rather, the goal of water treatment is to reduce contaminants to acceptable (safe) levels and make water palatable.
How to Detect Bad Health Effects
Short of actually getting sick, the best tools you have for detecting bad water are your senses of taste, smell and sight. If your water tastes or smells odd, or it changes color or appears cloudier than normal, call your local water utility to find out what's causing the problem.
Municipal water systems are generally safe and reliable. Municipalities are required by law to test their water frequently for excessive levels of potentially harmful contaminants listed by the Environmental Protection Agency (EPA) and make those results available to the public. If you're concerned or simply curious, ask your water utility for a copy of its latest Water Contaminant Analysis Report and compare contaminant levels with the EPA guidelines. The water utility will have copies of the EPA guidelines, or you can get them from your state health department or from the EPA web site water.epa.gov.
What's more, any engineer at the water utility can tell you what you're tasting, smelling or seeing in your water. Seasonal changes in the sources (rivers, lakes or groundwater), heavy rainfall, high temperatures or altered treatment methods can all cause detectable differences. The effects are rarely harmful, but at least you'll know what's going on.
Three conditions could merit further investigation:
- The water delivery system itself sometimes introduces health risks. Lead and asbestos, two potentially hazardous materials once used in supply pipes, are two common examples. Your water utility can outline the general risks in your area, but in the case of lead, the effect in each household can vary. Although dust from old lead-based paint is the primary cause of lead poisoning, lead can leach into the water from old brass valves, soldered joints or lead pipes. If you have reason to believe the risk is significant, have your water tested by an EPA or state-certified laboratory.
- Family members with impaired or weakened immune systems from a medical condition or simply old age may be more vulnerable to certain biological organisms or other substances. Discuss health risks with your physician to determine whether water purification is advisable.
- You simply want to set higher standards than your water utility delivers, especially if you have reason to suspect the safety of your water.
If you're concerned about your water supply, study the issues first. Your public health department and the EPA have fact sheets covering most common contaminants that pose a health threat. The sheets include strategies on how to control them. Much of this information is intended for private well owners, who have to ensure the safety of their water systems themselves, but you can use similar strategies and equipment in your home.
The potential for health problems is higher in a small municipal system or private system where testing may be less frequent and the system may have fewer skilled personnel to operate it. The risk is also higher if you have your own well. Test your well annually and even more often if you're aware of potential contamination sources nearby. Contact your state health department for testing guidelines. And keep in touch with local health officials who monitor local water conditions and potential contaminants. For example, nitrates from fertilizers and pesticides can be a problem in agricultural areas, and solvents (volatile organic compounds, or VOCs) and other chemicals can seep into groundwater in industrial or landfill zones.
Once you know which contaminants are causing the trouble, pick a filtration device that solves that particular problem. Labels on the packaging advertise what each filter does. Usually they list more contaminants than you need removed. That's because the filtration method— for example, activated carbon to remove chlorine—also removes many other tastes and odors.Look for an NSF (www.nsf.org) or other listing mark that indicates that the unit has been tested to meet a certain NSF standard, typically Standards 42 and 53 for activated carbon and mechanical (particle) filters.
How to Track Down Bad ‘Aesthetics'
Most strange tastes, smells and colors, characteristics that water experts call bad aesthetics, aren't a health risk; they just bug you. These include water that corrodes or clogs pipes, stains sinks and drains or leaves rings of crud around the toilet bowl. There are few mysteries in a local water supply. The engineers at your water utility have seen it all before and can usually identify the problem if you describe the symptoms. They'll often tell you possible solutions, too. Common problems include:
Chlorine smell or taste. If your water smells or tastes a bit like a swimming pool, you're probably dealing with the disinfectant that the water utility uses to kill bacteria and other biological contaminants. If you let drinking water sit or pour it back and forth a few times, enough chlorine will dissipate into the air to improve the taste of the water. Or you can remove chlorine with simple filtration devices.
Hard water. You probably have hard water if minerals both build up around faucets and clog them; persistent soap scum shows up on shower tiles, tubs and wash basins; and soaps and detergents leave residues or don't clean well. Hard water contains excessive dissolved calcium and magnesium, which form scale and inhibit the cleaning power of soaps and detergents. Although it won't harm your health, hard water makes cleaning more difficult and requires more plumbing maintenance. Hardness is readily removed with a water softener that you connect to the main water line. Many companies (check “Water Softeners” online) will test the hardness level and sell you a softening system for $500 to $1,000 if you need one.
Stains. Brown or black stains on sinks, or a rusty or metallic taste usually signals excessive iron and/or manganese in the water. In this case, the water might even be reddish when run into a glass. Stains and bad odors can also be caused by dead leaves and other organic material. Many stains, colors and odors are easily removed by inexpensive whole-house filtration. But some, dissolved iron, for example, require more specialized equipment.
Cloudy. Hazy water is usually caused by fine sediments in suspension. Sometimes they can clog up appliances, like an ice maker. These are easily removed by inexpensive, whole-house filtration.
Fishy or musty smell or taste. These are usually caused by the naturally occurring algae and bacteria that grow in most surface water sources. It's also easily handled by inexpensive filtration.
Rotten egg smell. The sulfur smell is hydrogen sulfide produced by bacteria that live in deep wells. If you closed your eyes, you could imagine you were in Yellowstone! This water is generally acidic and will corrode your plumbing system. The solution requires professional analysis and special equipment.
Most aesthetic contaminants can be eliminated at little expense. But before you spend a dime on solutions, contact your local water utility or public health department to get firsthand information about the contaminants and suitable control methods. If these experts are baffled or unsure, you might have to take a water sample to an environmental testing lab to identify the exact type and volume of contaminants. Your public health department can provide a list of certified testing labs.
Or you can hire a water-quality contractor to evaluate your water. (Search “Water Purification and Filter Equipment” or “Water Softening and Conditioning” online.) Testing for simple conditions like water hardness or acidity is inexpensive and sometimes free if the contractor hopes to sell you a conditioning system.
The key is to identify the scope and type of problem before focusing on a solution. With the confusing array of water treatment devices on the market, it's easy to buy high-powered solutions to problems you don't have!
Most filters for aesthetic water problems, such as this under-counter cartridge type, run the water through a fine screen to catch particles or through activated carbon, which eliminates impurities that affect taste and odor. Many “all-purpose” filters include both.
1. First buy a carafe or faucet filter to see if it improves the taste and appearance of your water. They're inexpensive and easy to install and use, and they contain filter elements that are similar to more expensive types. However, they're usually low volume, require more frequent cartridge changes, cost more per gallon in the long run and clutter the sink area.
If you like the filtration result, consider a countertop or under-sink filter for lower-cost, long-term use. Cartridges last longer, need less frequent changing and have a lower long-term cost per gallon. They can deliver a higher volume of water and have more specialized types of filters available. Some types can even serve several points of use, like nearby refrigerators and ice makers Drawbacks are the higher initial cost and more difficult installation. The below-sink model also requires a separate fixture hole in which to mount the faucet (usually the spray/rinse attachment hole)
If you want extra assurance that your water system is safe, consider a reverse osmosis (RO) system, which can filter out virtually all biological contaminants such as bacteria, viruses and cysts, as well as most other contaminants, including lead. RO systems also filter out most tastes and odors, and are more economical than bottled water in the long run. The downsides are that several gallons of water are wasted for every purified gallon (ROs require a drain connection for waste water), and they don't work as well and require more frequent filter changes if you have hard water. RO systems are also not designed to be the primary water treatment system. For installation instructions, see How to Install a Reverse Osmosis Water Filter.
Taste is highly subjective. What tastes good to you might taste bad to your neighbor, and water that contains some minerals often tastes better than purer water. Water also affects the taste of soup, coffee, tea, ice cubes and Kool-Aid. So we suggest you keep your initial investment small until you know if you like “cleaned-up” water and how often you'd use it.
No filtration device is maintenance free. Look for units that signal when the cartridge is worn out. Otherwise you have to rely on a change in taste or clarity or on reduced water pressure to know when to replace the cartridge. RO units should be tested annually for bacteria buildup. Make sure you can get replacement parts for the unit you buy, as well as replacement filter cartridges.