Chemicals That Can Contaminate Tap Water
Find out if your tap water is contaminated
If you suspect your tap water has harmful germs or chemicals in it, contact your drinking water utility. If you have a private well, contact your local health department for help with water testing. Consider using bottled water for drinking and cooking until the problem is resolved.
Some chemicals can make you sick if they are in your tap water at unsafe levels. Find information below about the chemicals that most often contaminate tap water and cause disease, and how to remove them.
Arsenic
- Common sources: Natural deposits in the earth or industrial and agricultural pollution
- Removing it from drinking water: Treat water using reverse osmosis, ultra-filtration, distillation, or ion exchange. Find treatment systems certified to remove arsenic.
- Illness: Symptoms can include nausea and vomiting, decreased production of red and white blood cells, abnormal heart rhythm, damage to blood vessels, and a sensation of “pins and needles” in hands and feet. Learn more.
Copper
- Common sources: Copper pipes or mining, farming, or industrial pollution
- Removing it from drinking water:
- Treat water using reverse osmosis, ultra-filtration, distillation, or ion exchange. Find treatment systems certified to remove copper.
- If copper pipes are contaminating your water, another option is to flush faucets that have not been used for 6 or more hours. Flush faucets by running the water for at least 15 seconds before drinking or using it. Avoid cooking with or drinking water from hot water taps because hot water dissolves copper more easily than cold water does.
- Illness: Symptoms can include nausea, vomiting, and diarrhea. Learn more.
Lead
- Common sources: Lead pipes are the most common source. Other sources include brass fixtures, “packer” elements in private wells that are 20 years old or older, or leaded-brass parts in older submersible pumps used in private wells.
- Removing it from drinking water:
- Remove the lead source, if possible. If you have a private well, check both the well and the pump for potential lead sources. A licensed well-water contractor can help you determine if any of the well’s parts are a source of lead.
- Use a filter certified to remove lead from water.
- Flush your water before using it.
Nitrate
- Common sources: Fertilizers, septic systems, animal feedlots, industrial waste, or food processing waste
- Removing it from drinking water: Treat water using ion exchange, distillation, or reverse osmosis. Find treatment systems certified to remove nitrate.
- Illness: High levels of nitrate or nitrite can decrease the ability of your blood to carry oxygen to your tissues. Infants younger than 6 months may be particularly at risk. Related symptoms can include decreases in blood pressure, increased heart rate, headaches, stomach cramps, and vomiting. Learn more.
Radon
- Common sources: Radon forms naturally in ground water when naturally occurring uranium, radium, and thorium break down. Showering, washing dishes, and doing laundry can disturb the water and release radon gas into the air you breathe.
- Removing it from drinking water: Treat water using aeration or GAC treatment where the water enters your home (point-of-entry device) so that it will all be treated. Point-of-use devices, such as those installed on a tap or under the sink, will only treat a small portion of your water and will not reduce radon in your water.
- Aeration treatment—spraying water or mixing it with air and then venting the air from the water before use
- GAC treatment—filtering water through granular activated carbon. Radon attaches to the carbon and leaves the water free of radon. Disposing of the carbon may require special handling if it is used at a high radon level or if it has been used for a long time.
- Illness: Radon is the second leading cause of lung cancer after cigarette smoking. Learn more.
Report Waterborne Illnesses
If you think you or someone you know got sick from water, please report it to your local health department. Report it even if you don’t know what made you sick. Reporting an illness can help public health officials identify a waterborne disease outbreak and keep others from getting sick.
Page last reviewed: August 23, 2022