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Do I need to treat my well water, and what type of treatment should I use?

Follows these steps to decide if you need treatment for your well water. Includes lists of common contaminants and popular treatment options.

Well water treatment may be necessary if testing reveals the presence of contaminants or water quality concerns. While treatment is not always required, when it is, the choice of system should be determined based on the specific contaminants detected, the type of well and plumbing systems, and the people it will be serving. No single treatment system can address all potential issues, and in many cases, a combination of treatment methods is needed.

Step 1: Test your water.

A well water test will determine exactly what is in your water. This will help you make informed decisions about whether treatment is required and what options are best. Check out these articles to learn more:

Table 1: Common contaminants found in private water wells.

Contaminant

Source

Potential Impact

Bacteria* (e.g., E. coli)

Septic systems, runoff

Illness, gastrointestinal issues

Nitrates*

Fertilizers, animal waste

Dangerous for infants

Arsenic*

Natural deposits

Increased cancer risk

Iron & Manganese*

Natural minerals

Staining, metallic taste, black slime

Hardness (Calcium/ Magnesium)

Natural minerals

Scale buildup, soap inefficiency

Hydrogen Sulfide

Natural bacteria

Rotten egg odor

Low pH

Acidic geology

Pipe corrosion

VOCs*/Pesticides*

Industrial/agricultural runoff

Health concerns, poor taste/smell

*These contaminants may pose a health risk.

Step 2: Learn about the different systems.

Once you’ve tested your water and identified if there are any contaminants or water quality concerns, the next step is to learn what options are available. Familiarize yourself with the different techniques, styles, and maintanence requirements before deciding on a system to install.

Below is a breakdown of the most common well water treatment systems. Click on each arrow to learn more. (This is not a complete list of options available.)

Sediment Filters

Activated Carbon Filters

  • Treats: VOCs, pesticides, chlorine, bad taste/odor

  • Use When: Water smells off or contains organic chemicals

  • Easy to install; improves taste

  • Con: Not effective against microbes or metals

  • Want to learn more: What is activated carbon filtration?

Reverse Osmosis (RO)

  • Treats: Nitrates, arsenic, fluoride, sodium, and dissolved solids

  • Use When: Targeting multiple contaminants in drinking water

  • Provides high-purity water

  • Con: Wastes some water; requires regular maintenance

  • Want to learn more: How does reverse osmosis work?

UV Disinfection

  • Treats: Bacteria, viruses, parasites (with clear water)

  • Use When: A water test indicates microbial contamination

  • Chemical-free and effective

  • Con: Requires electricity; doesn’t remove chemicals or sediment

  • Want to learn more: What is an ultra-violet (UV) filter system?

Continuous Chlorination

  • Treats: Bacteria, viruses, nuisance microbes; also oxidizes iron, manganese, and hydrogen sulfide (for later filtration)

  • Use When: You’ve had repeated positive tests for coliform bacteria or can’t eliminate the contamination source; also used for springs or surface-influenced wells

  • Provides ongoing disinfection and oxidation

  • Con: Requires careful monitoring, chemical handling, and follow-up filtration

  • Want to learn more: What is continuous chlorination, and when do I need to continuous chlorinate my well water?

Water Softeners

  • Treats: Hard water (calcium/magnesium), low levels of iron and manganese

  • Use When: You notice scale, soap scum, or appliance wear

  • Avoid When: You have microbial contamination, high iron levels, or are on a low-sodium diet

  • Protects plumbing and appliances; softens water

  • Con: Doesn’t remove microbes, chemicals, or many metals

  • Want to learn more: How does my water softener work?

Oxidizing Filters

Neutralizing Filters

  • Treats: Low pH (acidic water)

  • Use When: Plumbing shows corrosion or staining

  • Raises pH to safe levels

  • Con: May increase hardness, requiring the addition of a softener

Point Of Use (POU) versus Point Of Entry (POE)

Consideration needs to be given on if the whole home needs treatment or if treatment will only occur at the source (e.g. kitchen faucet). For instance, we recommend only using point of use treatment options for Reverse Osmosis (RO). RO can cause the water to become corrosive causing heavy metals such as lead to leach into your well water. On the other hand, a sediment filter is typically installed as a whole home unit because it takes out contaminants such as iron which can cause a build up in your pipes. To learn more, read these articles:

Step 3: Decide on a treatment system.

To learn more on how to decide on a treatment system, visit our article: "How do I know what kind of treatment option I should install on my well?"

Additional Resources

Want to learn more about your private well and how to care for it?

Sign up for the free 10-week email course from PrivateWellClass.org. The class is a project of RCAP and the University of Illinois, with funding from USEPA.

Not finding the answer you need?

Send us a message in the chat or call us at 1-866-945-0699.

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