Over 240 million people in the United States get their water from public water systems. Before water makes its way to your faucet, it goes through a complex treatment process including filtration and disinfection to ensure that the water you drink is safe.

The downside to these water treatments is that they can increase levels of unwanted chemicals in public water sources. The geology of the area where you live can also effect the amount of minerals or contaminants that have a sneaky way of making their way into drinking water.

According to Paul Pestano, a research analyst for the Environmental Working Group,  “No matter where you live, the tap water is sure to contain some chemicals you don’t want to drink.” This does not necessarily mean you need to worry about the quality of your water, but it is a good idea to keep a look out for certain chemicals that could really be harming your health.

Next time you receive a water quality report, be sure to look out for the following contaminants as they pose a serious risk to your health:

1. Trihalomethanes

These nasty chemicals are referred to as “disinfection byproducts” by the EPA, the Environmental Working Group (EWG) more aptly names them ‘toxic trash.’ This group of chemicals are an unintended consequence of chlorinating water. Many water companies add chlorine to drinking water to kill bacteria and other disease-causing microorganisms. However, when chlorine reacts with rotting organic matter such as sewage, manure from livestock, or dead leaves, it produces chemicals in the trihalomethane family.

Trihalomethanes have been strongly linked to bladder cancer.  Research shows that concentrations over 21 part per million heightens the risk of bladder cancer. The EWG found concentrations greater than 35 ppms in over 53 percent of the 201 water systems they tested.

2. Nitrate

Nitrogen from commercial fertilizers and manure is converted by bacteria into nitrate. Nitrate is very water soluble and finds its way into groundwater, streams, and rivers, especially rural farming areas. Nitrate poses a fatal risk to infants under six months old and is associated with respiratory and reproductive conditions, kidney damage, and various forms of cancer.

According to Clean Water Action, over 254,000 people are at risk from nitrate contamination in Calif. alone.  It is estimated that current best management practices could reduce the use of nitrogen Pollution from agriculture up to 50 percent. The California Water Board suggests a “fertilizer fee” to reduce the overuse of fertilizers that cause ground water contamination, measures like this could help reduce nitrate Pollution across the country!

3. Arsenic

Arsenic is a heavy metal that occurs naturally in soil and rock formations across the United States. But just because arsenic is natural does NOT mean it is safe. Arsenic builds up in the body over long periods of time and has been shown to cause cancer and damage to the circulatory system.

The Environmental Working Group found arsenic in the drinking water of 43 states across the country, 37 of which had levels high enough to exceed to the EPA’s legal limit. Private wells are at a higher risk for arsenic contamination than public water supplies so make sure to have your well tested to protect your health.

4. Lead

Lead leaches its way into drinking water through contact with corroding plumbing in your house or street pipes. Water with a high acidity (soft water) and water that stands in pipes for long periods of time is more likely to leach lead into the water supply. New homes that are legally marketed as “lead free” may contain up to eight percent lead in their plumbing.

Lead is a persistent bioaccumulative, meaning it builds up in your body over time causing serious damage to your health. Long-term exposure to lead has been linked to learning and behavioral disabilities in children, it also can damage the reproductive and nervous system in adults.

5. Fluoride

You probably already knew that fluoride was in your water because 70 percent of water facilities in the U.S. add this mineral to public water supplies. Fluoride is added to water to prevent tooth decay but, in an ironic twist, too much fluoride can increase likelihood of bone fractures in adults and mottled teeth in children.

According to the CDC, sources of fluoride have increased since the 1960s. Fluoride is now added to toothpastes, mouthwash, as well as foods and beverages, making the fluoridation of water obsolete. Click here to check the fluoride levels in your local water supply.

How to minimize your exposure to these chemicals

First, put down the bottled water! Even bottled water is not as “pure” as it claims to be, not to mention the other health and environmental impacts plastic bottles can have.

Check out Food & Water Watch’s guide to learn how to read your water quality report. This will help you identify which chemicals and minerals are in your water.

Once you know what is in your water, you can install a home water filter to remove unwanted chemicals and minerals. To find the perfect filter for your home, click here for the Environmental Working Group’s guide to affordable and effective filters.

You can also advocate for stricter regulations on water quality by joining the efforts of groups like Clean Water Action. Get in touch with your local Waterkeeper branch and help clean up your watershed.

You have a right to know what is in your water — don’t wait another minute to voice your opinion!