Questions to Ask Before You Buy A Water Treatment System


First step: Test your water

The first step in choosing a water treatment device is to have your water tested. Tests should be done at an independent, state certified lab.

If the water test indicates that you have a problem, installation of a treatment system may be necessary to remedy it. Be aware that water treatment equipment has trade-offs. There is routine maintenance. Some systems may need to be periodically back-flushed, which will increase the wastewater load to your septic system. The treatment may remove one contaminant, yet add something else to your water. For example, an ion exchange system installed to remove iron and manganese, may add sodium to your drinking water, causing a potential problem for people with high blood pressure or on sodium-restricted diets. Be a good consumer and do your research when shopping for water treatment equipment. The following are questions you can ask a water treatment professional or the water well contractor who installed the well to determine the type of system needed. Background information follows many of the questions. The extent to which the manufacturer or distributor is willing to provide answers can assist you in making an informed choice.

Second step: Be a wise consumer

Were the water tests adequate?

Some water treatment companies include free in-home water testing in their services. Not all contaminants can be evaluated this way. For example, many man-made chemicals, which have been associated with serious health problems, must be analyzed in a laboratory with sophisticated equipment. The consumer must be wary of companies that claim that their home analyses determine more than basic water quality constituents such as hardness, pH, iron, and sulfur. Ideally, you should verify in-home tests with a water test conducted by a state certified laboratory. Once you’ve accurately determined what contaminants and characteristics your drinking water has, the level detected will dictate the type of treatment system. Factors to consider include whether the water presents a health hazard and how the levels detected compare to EPA Federal and/or State Drinking Water Quality Standards.

Other consumer protection concerns

Choose a reputable company

Make sure the company you choose to install your water system is reputable and established. How long has the company been in business, and is there a list of referrals you can contact? Ask the company for referrals and contact the referrals to find out if customers were satisfied.

Choose a certified product

Has the treatment system been tested by a third party organization, like the National Sanitation Foundation (NSF) International, to treat the specific contaminant in question? NSF International is a non-profit organization whose function is to set performance standards for water treatment equipment. It evaluates test results of the treatment device to determine if claims are realistic. Products that have been tested and certified by NSF and that meet their minimum requirements are entitled to display the NSF mark on the products or in advertising literature for products. Manufacturers and models that meet the applicable standard are included in a listing published twice a year.

Ask the sales representative which standards the product meets. Also, ask for test results showing that the specific contaminant(s) you need or want to remove will be addressed by the system you are considering. Tests by third party organizations (those neutral to and trusted by all interests served) should provide extra confidence.

Second opinions on treatment recommendations

Is a second opinion on treatment procedures and equipment necessary? Consider a second opinion on recommended water treatment equipment. Check with at least one additional dealer to see what treatment procedure and equipment is recommended, and ask questions. Compare at least two brands, and consult other references.

Other questions to consider

Is whole-house or just single-tap treatment needed?

Depending on the type of contaminant and its concentration, you may need to treat all the water entering the house or only the water used for drinking and cooking. If the contaminant is only a problem when you drink it, such as lead, you may only need single tap or point-of-use (POU) treatment. POU treatment devices are typically installed at the kitchen faucet to treat water for drinking and cooking. However, if the contaminant is also hazardous when you get it on your skin or inhale it, for example a volatile organic compound or radon, you will need to treat all the water entering the house at the point-of-entry (POE). POE treatment devices are typically installed in the basement after the water pressure tank. Many treatment units are available in both POU and POE models, including granular activated carbon filters, reverse osmosis, and microfiltration units.

Will the unit produce enough treated water daily to meet household needs?

The consumer must be certain that enough treated water will be produced for everyday use. For example, distillation units produce 3-12 gallons of treated water daily depending on the model. In addition, the maximum flow rate of the treatment device should be sufficient for the peak home use rate. Consider installing a flow water meter to help determine what the peak home water use is.

What are the total purchase price and expected maintenance costs of the device?

The consumer must watch for hidden costs such as separate installation fees, monthly maintenance fees, or equipment rental fees. Additionally, the disposal of waste materials, such as spent cartridges from activated carbon units and used filters, can add to the cost of water treatment and should be figured into the purchase price. You may be able to install some treatment devices on your own. Ask the dealer for all costs involved in the installation and maintenance of the treatment system.

What are the service intervals and the costs involved with this equipment?

Regardless of whether you or your dealer provides the service, there is a cost. Filter cartridges must be changed, materials added as needed, and the water tested regularly to be sure things are working properly. Unserviced equipment may contribute to increased levels of some contaminants. Find out what supplies and equipment are needed, and the expected costs. Determine how often a filter membrane, ultraviolet light, or media will need to be changed and who is responsible for doing this. Ask the dealer if there are any other water quality conditions, like pH or sediments that can affect the effectiveness of the treatment system.

Will the unit substantially increase electrical usage in the home?

The cost of treated water in the home will vary depending upon the cost of electricity and the amount of energy required to operate the treatment unit. Ask about average monthly electrical use for the system you are interested in purchasing.

Is there an alarm or indicator light on the device to alert the consumer of a malfunction?

Many units have backup systems or shutoff valve functions to prevent consumption of untreated water.

Does the purchase price include follow-up water testing to ensure the equipment is working properly after a month or two?

Testing the water a month after the equipment is installed will assure the homeowner that the unit is accomplishing the intended treatment. Have the water tested at a state certified lab.

Additionally, water used for outside purposes should not have to be treated. This will provide you with a raw water tap, which can be periodically tested to compare the effectiveness of your treatment system. Water test results from the raw water tap will also help you to assess changes in your water quality.

What is the expected lifetime of the product and warranty coverage?

How long is your new system expected to last? What is the length of the warranty period and what does the warranty cover? The warranty may cover only certain parts of a device. The consumer should be aware of the warranty conditions.

What potential secondary effects will the treatment unit have on your water quality?

The consumer should be aware that some water treatment equipment works by adding something to your drinking water to remedy the problem at hand. For example, water softeners installed to remove iron may replace the iron removed from the water with sodium.


The purchase of water treatment equipment is a decision that must be carefully considered. Whether the purchase is being made to improve the aesthetic characteristics of the water or to address health considerations, many factors must be determined. You may want to keep a log book to keep track of water test results, and maintenance and repairs on your treatment system. The following key steps can be used as a checklist when selecting equipment.

  • Have the water tested at a state certified lab before purchasing any treatment equipment. Results of these tests should be used to purchase a treatment system that will address your specific water quality concern.
  • Inquire about the history of the groundwater in your neighborhood to help determine if any water quality problems exists. If so, test your drinking water for these contaminants.
  • Identify options for correcting the problem. Decide whether whole house (point-of-entry) or single-tap (point-of-use) treatment is needed.
  • Determine if the system will treat enough water to meet your needs.
  • Select a reputable dealer.
  • Obtain second opinions.
  • Check to see if proposed equipment has been tested or validated by independent organizations such as NFS International or the Water Quality Association.
  • Talk with others who have the same equipment you may purchase.
  • Be sure to know all the costs of the equipment: purchase price, installation, operating, and routine required maintenance.
  • Understand what maintenance will be required and who will be responsible for doing it.
  • Understand how to determine if the equipment is operating satisfactorily.
  • Determine the expected life of the treatment system.
  • Understand any warranty provided with the treatment system.